Welcome to OLGA 6 User ManualThis is the OLGA 6 User Manual. The
User Manual includes both information about the OLGA 6 engine and
the graphical user interface (GUI). The complete program
documentation includes - Release Document for OLGA 6.2 - OLGA 6
User Manual (this document) - OLGA 6 GUI User Manual - OLGA 6
Conversion Guide - Well GUI User Manual - Tutorial - Installation
Guide All documents listed above are available from the Start Menu
(Start - All Programs - SPT Group - OLGA 6.2 - Documentation). The
OLGA 6 User Manual, OLGA 6 GUI User Manual, OLGA 6 Conversion
Guide, Wells GUI User Manual and the Tutorial are also available
from the Help menu in the GUI). User Manuals for other tools
included with the OLGA 6 installation are available from the Help
menus in the tools.
Release InformationPlease refer to the Release Document for
detailed release information for OLGA 6.2. The Release Document
describes changes in OLGA 6.2 relative to OLGA 5 and OLGA 6.1, and
should be read by all users of the program. The complete program
documentation consists of the OLGA User Manual, OLGA 6 GUI User
Manual, OLGA 6 Conversion Guide, Wells GUI User Manual, Tutorial,
Installation Guide, and the Release Document. The program is
available on PCs with Microsoft Windows operating systems (Windows
XP, Windows Vista and Windows 7). Several versions of OLGA may be
installed in parallel. Note that you may also run several versions
of the engine from one version of the GUI - please refer to the
Installation Guide to learn how to configure the GUI for several
engines. The support center provides useful information about
frequently asked questions and known issues. The support center is
available from the SPT Group Support Center Please contact SPT
Group if problems or missing functionality are encountered when
using OLGA or any of the related tools included in the OLGA
software package. E-mail: [email protected] Telephone: +47
6484 4550 Fax: +47 6484 4500 Address: SPT Group AS, P.O. Box 113,
N-2027 Kjeller
IntroductionOLGA is the industry standard tool for transient
simulation of multiphase petroleum production. The purpose of this
manual is to assist the user in the preparation of the input data
for an OLGA simulation. In this manual you can find a general
introduction to OLGA an overview of the required and the optional
input to OLGA. It also describes in some detail different
simulation options such as wax deposition, corrosion etc. a
detailed description of all input data and the required fluid
property tables a description of the output The sample cases
presented with the installation of OLGA are intended to illustrate
important program options and typical simulation output. A
description of the sample cases are also included in this manual.
OLGA comes in a basic version with a number of optional
modules;FEMTherm, Multiphase Pumps, Corrosion, Wells, Slug
Tracking, Wax Deposition, Inhibitor Tracking, Compositional
Tracking, Single Component Tuning, Hydrate Kinetics and Complex
Fluid. In addition there is a number of additional programs like
the OLGA GUI and the FEMThermViewer for preparation of input data
and visualisation of results. These optional modules and additional
programs are available to the user according to the user's
licensing agreement with SPT Group. See also: Background OLGA as a
strategic tool OLGA Model Basics How to use in general Graphical
User Interface Simulation model Input files Applications Threaded
Execution
BackgroundOLGA 6 is the latest version in a continuous
development which was started by the Institute for Energy Research
(IFE) in 1980. The oil industry started using OLGA in 1984 when
Statoil had supported its development for 3 years. Data from the
large scale flow loop at SINTEF, and later from the medium scale
loop at IFE, were essential for the development of the multiphase
flow correlations and also for the validation of OLGA. Oil
companies have since then supported the development and provided
field data to help manage uncertainty, predominantly within the
OLGA Verification and Improvement Project (OVIP). OLGA has been
commercially available since the SPT Group started marketing it in
1990. OLGA is used for networks of wells, flowlines and pipelines
and process equipment, covering the production system from bottom
hole into the production system. OLGA
comes with a steady state pre-processor included which is
intended for calculating initial values to the transient
simulations, but which also is useful for traditional steady state
parameter variations. However, the transient capabilities of OLGA
dramatically increase the range of applicability compared with
steady state simulators.
OLGA as a strategic tool
OLGA is applied for engineering throughout field life from
conceptual studies to support of operations. However the
application has been extended to be an integral part of operator
training simulators, used for making operating procedures, training
of operators and check out of control systems. Further, OLGA is
frequently embedded in online systems for monitoring of pipeline
conditions and forecasting and planning of operations. OLGA can
dynamically interface with all major dynamic process simulators,
such as Hysys, DynSim, UniSim, D-SPICE, INDISS and ASSETT. This
allows for making integrated engineering simulators and operator
training simulators studying the process from bottom hole all the
way through the process facility in a single high fidelity model.
Note that the OLGA flow correlation has been implemented in all
major steady state simulators providing consistent results moving
between different simulators.
OLGA Model BasicsOLGA 6 is a three-fluid model, i.e. separate
continuity equations are applied for the gas, for the oil (or
condensate) and water liquids and also for oil (or condensate) and
water droplets. These may be coupled through interfacial mass
transfer. Three momentum equations are used; one for each of the
continuous liquid phases (oil/condensate and water) and one for the
combination of gas with liquid droplets. The velocity of any liquid
droplets entrained in the gas phase is given by a slip relation.
One mixture energy equation is applied; assuming that all phases
are at the same temperature. This yields seven conservation
equations to be solved: three for mass, three for momentum, and one
for energy. Two basic flow regime classes are recognised ;
distributed and separated flow. The former comprises bubble and
slug flow [1], the latter stratified and annular mist flow.
Figure A Flow patterns in horizontal flow Transition between the
regime classes is determined by the program on the basis of a
minimum slip concept combined with additional criteria. To close
the system of equations, fluid properties, boundary and initial
conditions are required. The equations are linearised and a
sequential solution scheme is applied. The pressure and temperature
calculations are de-coupled i.e. current pressure is based on
previous temperature. The semi-implicit time integration
implemented allows for relatively long time steps, orders of
magnitudes longer than those of an explicit method (which would be
limited by the Courant Friedrich Levy criterion based on the speed
of sound). The numerical error is corrected for over a period of
time. The error manifests as an error in local fluid volume (as
compared to the relevant pipe volume). [1] In standard OLGA a slug
unit model is applied which calculates average liquid hold-up and
pressure, but which does not give any details about individual
slugs. To follow individual slugs through the system the slug
tracking module must be applied.
How to use in generalNumericsOLGA applies one global time-step
for the time integration and there is an automatic time-step
control based on the limitation that a fluid particle should not
spend less than one time-step on passing through any numerical
section length of a pipe (the Courant Friedrich Levy (CFL)
criterion based on the fluid velocity). The user controls the time
integration by specifying simulation period in time, time-step
parameters such as initial time-step and maximum and minimum
time-step values. The latter overrules the automatic control. There
is also an option for using the second-derivative of pressure as a
time step controlling criterion. Some functions in OLGA, e.g.
slug-tracking, take control of the time-stepping in order to ensure
a successful simulation. The spatial integration is performed on a
user-defined grid. There are tools available to facilitate the
gridding. There are no formal limitations on the numerical section
lengths, but it is considered good practice to keep all neighbour
section length ratios between 0.5 and 2:
0.5 Dxi/Dxi+1 2 for all iAdditionally it is recommended that
each pipe should have at least two sections. Due to the numerical
solution scheme, OLGA is particularly well suited for simulating
rather slow mass flow transients. This is important for the
simulation of long transport lines and thermal calculations, where
typical simulation times in the range of hours to several days, and
sometimes years, will require long time steps, to obtain efficient
use of the computer. OLGA is also being used successfully for fast
transients such as water hammer and pressure surges in general.
Certain precautions w.r.t. spatial grid and time-stepping may be
needed in order to keep the numerical error within acceptable
limits. Since OLGA not accounts for pipe elasticity the calculated
pressure peaks should be conservative. The de-coupling of
temperature from pressure would normally give a pressure wave
propagation velocity in gas which would be about 15% too low.
However, in OLGA 6 a quasi implicit correction of temperature
reduces this error considerably. Critical flow calculations are
performed in the OLGA valve model, only. A valve with cross section
equal to the pipe should then be positioned on e.g. a pipe outlet
if choked flow is expected.
TemperatureOLGA is particularly well suited for sophisticated
thermal simulations. Since OLGA is one-dimensional (calculates
along the pipe axis) any 2 and 3-dimensional effects must be
modelled explicitly. The basic OLGA thermal model calculates the
inner wall heat transfer coefficient. The built-in correlations are
valid for natural- and forced convection and also for the
transition between them. Flow pattern is accounted for. The user
may specify pipe walls with material properties, including
emissivity to account for radiation, and must give the ambient
properties, i.e. temperature and heat transfer coefficient. Based
on this the fluid temperature is calculated. Special features like
Annulus, Solid- and Fluid bundles make it possible to simulate very
complex structures of pipe-in-pipe and parallel pipes within
structures of various solid materials. Taking into account that
temperature is calculated along the pipes one obtains a combination
of two-dimensional convective heat transfer within 3dimensional
heat conducting structures. Solid bundle cross section of 4
vertical tubes within rock neighbour tubes are 2.5 m apart. The
black "line" is a temperature iso-line. One clearly sees how the
area between the tubes is subject to inter-tube heating.
Initial ConditionsThe requirement for initial conditions is a
fundamental difference between a transient and a steady state
model, e.g. the results of a steady state calculation may serve as
the initial condition (at t=0 ) for a transient simulation. With
OLGA the user decides, and later specifies in the input, whether
the simulation is to start from a user defined condition (for
instance a specific shut-in condition), or from a steady state
multiphase flowing situation calculated by the program. The steady
state pre-processor in OLGA can be used to provide good initial
values for most production situation. In addition, the user may
specify the initial condition in detail, for example for a shut-in
system, by defining the initial values for pressures, temperatures,
mass flow and gas fractions. Tools for interpolation are available,
for filling in the initial values in all numerical sections of the
system. Finally, the restart capability may be used to start a
simulation from conditions saved during a previous simulation.
Boundary ConditionsThe boundary conditions define the interface
between the simulated system and its surroundings and they are
crucial to the relevance to any type of simulations. For a network
of pipelines and wells there are several options available, but
basically flow rate or pressure, in addition to temperature and
gas-liquid ratio must be specified at each flow path inlet and
outlet boundary (at least one pressure must be given). The boundary
conditions, e.g. a pressure, can be given as time series to model a
certain transient situation.
Moreover, the ambient temperature along the flow paths and
ambient heat transfer coefficient (film heat transfer resistance)
must be specified and OLGA provides a number of options for this,
including water and air velocity profiles and seasonal variations
of temperature. Inflow from reservoirs to well-bores define the
most important boundary in a petroleum production network. In
addition to various well-inflow correlations and options OLGA comes
with an implicit coupling facility to the OLGA Rocx module which is
a complete 3-D, 3-phase reservoir simulator. Separators, pumps,
compressors and valves, all with controllers, can be modelled to
improve the relevance of the outlet boundaries.
Fluid propertiesThe necessary fluid properties (gas/liquid mass
fraction, densities, viscosities, enthalpies etc.) are normally
assumed to be functions of temperature and pressure only, and have
to be supplied by the user as tables in a special input file. Thus,
the total composition of the multiphase mixture is assumed to be
constant both in time and space for a given part of the network.
The user may specify different fluid property tables for each flow
path, but has to ensure that a realistic fluid composition has been
used to make a table for a flow path with a fluid mixture coming
from two or more pipeline branches merging upstream.
It is also possible to perform simulations using Compositional
Tracking, where the basic information on the chemical components is
provided in a separate text file and then OLGA calculates the fluid
properties internally with PVT routines provided by Calsep A/S.
This means that the total composition may vary both in time and
space, and that no special considerations are needed for the
downstream system. Special models are also available for tracking
hydrate inhibitors like MEG and methanol. The numerical solution of
the OLGA model is generally able to handle multi component fluid
systems but will normally have problems with single component
systems or systems with a very narrow phase envelope.
RheologyThe standard OLGA flow models assume a Newtonian
rheology (viscosities are well defined fluid characteristics).
Dispersions and non-Newtonian behavior are quite common in
petroleum production and OLGA provides several semi-empirical
models to account for more complex rheologies. In some cases the
model takes care of the rheology with a minimum of user
interference (e.g. for oil-water dispersions and also for waxy
oils). For other systems the user needs to specify the various
parameters for such fluids to describe e.g. Bingham or power law
non-Newtonian behavior.
NetworkIn OLGA the network comprises flow paths coupled with
nodes which have a volume. General networks with closed loops can
then be modelled, see below. The flow paths have a user defined
direction but the flow is invariant to direction as such and any
fluid phase may flow co-currently or counter-currently with respect
to the predefined direction at any time and position. Pipe-bends
are not accounted for as such (except for differences in static
head). The user may apply pressure loss coefficients at boundaries
between numerical sections. Equipment is positioned on the flow
path usually on a pipe-boundary. However, the separator in OLGA is
a network component similar to a node. Controllers are specified as
integral parts of the simulation model and they have their own
network formalism.
Threaded ExecutionPipe sections belonging to the same branch may
be updated in parallel. Suppose a branch has 100 sections, and that
two threads are available to the OLGA engine:
Section 1 and section 51 will be updated simultaneously, then
section 2 and section 52 are updated, and so on. Depending on the
computer hardware, this method can drastically reduce the time OLGA
takes to advance one time-step. Normally, you do not need to change
the default settings of neither OLGA nor your operating system.
Parallel updating of segments is usually activated in the OLGA
engine if your PC supports it.
Controlling the degree of parallelismThe Windows operating
system decides how many threads will be used. If your PC is
equipped with a quad-core CPU, typically four threads will be
simultaneously running to update four sections in parallel. Is your
CPU a single-core Intel Xeon processor with "hyper-threading" (HT),
probably two engine threads will be used. It is possible to
overrule the choice of the operating system by setting the
environment variable OMP_NUM_THREADS; use Windows' Control Panel to
do this. However, the preferred way to change the degree of
parallelisation is do so from the OLGA menu system. Setting the
value here takes precedence over the OMP_NUM_THREADS environment
variable. A situation where you might want to reduce the number of
threads, arise if you execute parametric studies. Given that your
license permits, it would be preferable to spend the CPU's cores on
simultaneous simulations, rather than on speeding up each
simulation in the study. Another situation could be when you don't
want OLGA to consume all your computing power, e.g., if you want to
write a report while OLGA is working. Most large cases will benefit
from the parallelisation. Still, please note that some of your PC's
cache memory will be used for forking and joining the threads, and
doing the necessary book-keeping. As a consequence, special cases
will run faster with a single engine thread.
Parallel speed-upThe parallelisation encompasses heat
calculations in section walls, updating fluid properties and
flashing, and, most importantly, calls to the flow model which
decides friction factors, liquid holdup and the flow regime. If the
flow model calculations dominate the overall simulation, the
utilization of the CPUs is most efficient.
Monitoring the OLGA processThe Task Manager can be used to check
how OLGA loads your CPU. When the number of engine threads equals
the number of cores (or equals two on a single core HTCPU) you
should see the CPU usage being clearly over fifty percent when OLGA
is simulating. In the Task Manager's list of processes it is
possible to view the number of threads for each process. With 1
engine thread, it uses a total of 5 threads in batch mode, and 8
threads while running under control of the GUI. With 2 engine
threads allowed, the task manager would display 6 threads for a
batch run and 9 threads for a GUI run; with 4 engine threads the
total number of threads would be 8 and 11, respectively.
ApplicationsWhen the resources become more scarce and
complicated to get to careful design and optimisation of the entire
production system is vital for investments and revenues. The
dimensions and layout of wells and pipelines must be optimised for
variable operational windows defined by changing reservoir
properties and limitations given by environment and processing
facilities. OLGA is being used for design and engineering, mapping
of operational limits and to establish operational procedures. OLGA
is also used for safety analysis to assess the consequences of
equipment malfunctions and operational failures. REFERENCES
contains a list of papers describing the OLGA model and its
applications.
Design and EngineeringOLGA is a powerful instrument for the
design engineer when considering different concepts for hydrocarbon
production and transport - whether it is new developments or
modifications of existing installations. OLGA should be used in the
various design phases i.e. Conceptual, FEED [2] and detailed design
and the following issues should be addressed: Design Sizes of
tubing and pipes Insulation and coverage Inhibitors for hydrate /
wax Liquid inventory management / pigging Slug mitigation
Processing capacity (Integrated simulation) Focus on maximizing the
production window during field life Initial Mid-life Tail Accuracy
/ Uncertainty management Input accuracy Parameter sensitivity Risk
and Safety Normally the engineering challenge becomes more severe
when accounting for tail-end production with reduced pressure,
increasing water-cut and gas-oil ratio. This increase the slugging
potential while fluid temperature reduces which in turn increase
the need for inhibitors and the operational window is generally
reduced.
Operation
OLGA should be used to establish Operational procedures and
limitations Emergency procedures Contingency plans OLGA is also a
very useful tool for operator training Training in flow assurance
in general Practicing operational procedures Initial start up
preparations When systems become more complex and critical e.g.
with long and deep Flow lines/risers, start-up situations need to
be forecasted on a short-term basis and OLGA is regularly being
used for assistance at start-up. Some typical operational events
suitable for OLGA simulations are discussed below.
Pipeline shut-downIf the flow in a pipeline for some reason has
to be shut down, different procedures may be investigated. The
dynamics during the shut-down can be studied as well as the final
conditions in the pipe. The liquid content is of interest as well
as the temperature evolution in the fluid at rest since the walls
may cool the fluid below a critical temperature where hydrates may
start to form.
Pipeline blow-downOne of the primary strategies for hydrate
prevention in case of a pipeline shut-down is to blow down. The
primary aim to reduce the pipeline pressure below the pressure
where hydrates can form. Main effect that can be studied are the
liquid and gas rates during the blow-down, the time required and
the final pressure.
Pipeline start-upThe initial conditions of a pipeline to be
started is either specified by the user or defined by a restart
from a shut-down case. The start-up simulation can determine the
evolution of any accumulated liquid slugs in the system. A start-up
procedure is often sought whereby any terrain slugging is minimised
or altogether avoided. The slug tracking module is very useful in
this regard. In a network case a strategy for the start-up
procedure of several merging flow lines could be particularly
important.
Change in productionSometimes the production level or type of
fluid will change during the lifetime of a reservoir. The
modification of the liquid properties due to the presence of water,
is one of the important effects accounted for in OLGA. A controlled
change in the production rate or an injection of another fluid are
important cases to be simulated. Of particular interest is the
dynamics of network interactions e.g. how the transport line
operation is affected by flow rate changes in one of several
merging flow lines.
Process equipmentProcess equipment can be used to regulate or
control the varying flow conditions in a multi-phase flow line.
This is of special interest in cases where slugging is to be
avoided. The process equipment simulated in OLGA includes critical-
and sub-critical chokes with fixed or controlled openings,
check-valves, compressors with speed and antisurge controllers,
separators, heat exchangers, pumps and mass sources and sinks.
Pipeline piggingOLGA can simulate the pigging of a pipeline. A
user specified pig may be inserted in the pipeline in OLGA at any
time and place. Any liquid slugs that are created by the pig along
the pipeline can be followed in time. Of special interest is the
determination of the size and velocity of a liquid slug leaving the
system ahead of a pig that has been inserted into a shut-down flow
line.
Hydrate controlHydrate prevention and control are important for
flow assurance. Passive and active control strategies can be
investigated: Passive control is mainly achieved by proper
insulation while there are several options for active control which
can be simulated with OLGA: Bundles, electrical heating, inhibition
by additives like MEG.
Wax depositionIn many production systems wax would tend to
deposit on the pipe wall during production. The wax deposition
depends on the fluid composition and temperature. OLGA can model
wax deposition as function of time and location along the
pipeline.
TuningEven if the OLGA models are sophisticated models made for
conceptual studies and engineering will be based on input and
assumptions which are not 100% relevant for operations. Therefore
OLGA is equipped with a tuning module which can be used on-line and
off-line to modify input parameters and also critical model
parameters to match field data.
Wells- Flow stability e.g. permanent or temporary slugging, rate
changes - Artificial lift for production optimization -
Shut-in/start-up - water cut limit for natural flow - Cross flow
between layers under static conditions - WAG injection - Horizontal
wells / Smart wells - Well Clean-up and Kick-off - Well Testing -
Well control and Work-over Solutions
Safety AnalysisSafety analysis is an important field of
application of OLGA. OLGA is capable of describing propagation of
pressure fronts. For such cases the time step can be limited by the
velocity of sound across the shortest pipe section. OLGA may be
useful for safety analysis in the design phase of a pipeline
project, such as the positioning of valves, regulation equipment,
measuring devices, etc. Critical ranges in pipe monitoring
equipment may be estimated and emergency procedures
investigated.
Consequence analysis of possible accidents is another
interesting application. The state of the pipeline after a
specified pipe rupture or after a failure in any process equipment
can be determined using OLGA. Simulations with OLGA can also be of
help when defining strategies for accident management, e.g. well
killing by fluid injection. Finally it should be mentioned that the
OLGA model is well suited for use with simulators designed for
particular pipelines and process systems. Apart from safety
analysis and monitoring, such simulators are powerful instruments
in the training of operators. [2] Front End Engineering and
Design
Input filesThe OLGA simulator uses text files for describing the
simulation model: .opi; generated and used by the OLGA GUI .inp;
input format used by OLGA 5 and earlier versions .key; input format
used by OLGA The .key format has been introduced as the new input
file format for the OLGA engine. The OLGA GUI will automatically
generate files in this format (with the extension .genkey). The
.key format reflects the network model described in the simulation
model and should be the preferred format. In addition to the
simulation file, OLGA handles input in several other formats as
described in Data files.
Simulation descriptionThe input keywords are organised in
Logical sections, with Case level at the top, followed by the
various network components and then the connections at the end.
Case levelCase level is defined as the global keywords specified
outside of the network components and connections. Case level
keywords can be found in the CaseDefinition, Library, FA-models and
Output sections. The following keywords must or can be defined at
Case level: CaseDefinition; CASE, FILES, INTEGRATION, OPTIONS,
DTCONTROL, RESTART Library; MATERIAL, WALL, SHAPE, TABLE,
DRILLINGFLUID, HYDRATECURVE Compositional; COMPOPTIONS, FEED,
BLACKOILOPTIONS, BLACKOILCOMPONENT, BLACKOILFEED, SINGLEOPTIONS
FA-models; CORROSION, FLUID, WATEROPTIONS, SLUGTRACKING, TUNING,
SLUGTUNING Output; OUTPUT, TREND, PROFILE, PLOT, OUTPUTDATA,
TRENDDATA, PROFILEDATA Drilling; TOOLJOINT CASE PROJECT="OLGA
Manual", TITLE="Example case", AUTHOR="SPT Group AS" INTEGRATION
STARTTIME=0, ENDTIME=7200, DTSTART=0.1, MINDT=0.1, MAXDT=5 FILES
PVTFILE=fluid.tab MATERIAL LABEL=MAT-1, DENSITY=0.785E+04,
CAPACITY=0.5E+03, CONDUCTIVITY=0.5E+02 WALL LABEL=WALL-1,
THICKNESS=(0.9000E-02, 0.2E-01), MATERIAL=(MAT-1, MAT-1)
Network componentsThe network components are the major building
blocks in the simulation network. Each network component is
enclosed within start (NETWORKCOMPONENT) and end
(ENDNETWORKCOMPONENT) tags as shown below. Each data group
belonging to this network component will be written within these
tags. NETWORKCOMPONENT TYPE=FlowPath, TAG=FP_BRAN ...
ENDNETWORKCOMPONENT The following network component keywords can be
specified (see links for further details on each component):
FlowComponent;FLOWPATH, NODE ProcessEquipment;PHASESPLITNODE,
SEPARATOR Controller;CONTROLLER ThermalComponent;ANNULUS,
FLUIDBUNDLE, SOLIDBUNDLE FLOWPATHPiping
The flowpath can be divided into several pipes, which can have
an inclination varying from the other pipes in the flowpath. Each
pipe can again be divided into sections as described above. All
sections defined within the same pipe must have the same diameter
and inclination. Each pipe in the system can also have a pipe wall
consisting of layers of different materials. The following keywords
are used for Piping: BRANCH; Defines geometry and fluid labels.
GEOMETRY; Defines starting point for flowpath. PIPE; Specifies end
point or length and elevation of a pipe. Further discretization,
diameter, inner surface roughness, and wall name are specified.
POSITION; Defines a named position for reference in other keywords.
BRANCH LABEL=BRAN-1, GEOMETRY=GEOM-1, FLUID=1 GEOMETRY LABEL=GEOM-1
PIPE LABEL=PIPE-1, DIAMETER=0.12, ROUGHNESS=0.28E-04, NSEGMENT=4,
LENGTH=0.4E+03, ELEVATION=0,
WALL=WALL-1Boundary&Initialconditions
For the solution of the flow equations, all relevant boundary
conditions must be specified for all points in the system where
mass flow into or out of the system. Initial
conditions at start up and parameters used for calculating heat
transfer must also be specified. The following keywords are used
for Boundary & Initial conditions: HEATTRANSFER; Definition of
the heat transfer parameters. INITIALCONDITION; Defines initial
values for flow, pressure, temperature and holdup.
INITIALCONDITIONS is not required when a steady state calculation
is performed. NEARWELLSOURCE; Defines a near-wellbore source used
together with OLGA Rocx. SOURCE; Defines a mass source with name,
position, and data necessary for calculating the mass flow into or
out of the system. The source flow can be given by a time series or
determined by a controller. WELL; Defines a well with name,
position and flow characteristics. HEATTRANSFER PIPE=ALL,
HAMBIENT=6.5, TAMBIENT=6, HMININNERWALL=0.5E+03 SOURCE
LABEL=SOUR-1-1, PIPE=1, SECTION=1, TIME=0, TEMPERATURE=62,
GASFRACTION=-1, TOTALWATERFRACTION=-1, PRESSURE=70 bara,
DIAMETER=0.12, SOURCETYPE=PRESSUREDRIVENProcess Equipment
In order to obtain a realistic simulation of a pipeline system,
it is normally required to include some process equipment in the
simulation. OLGA supports a broad range of different types of
process equipment, as shown below. It should be noted that the
steady state preprocessor ignores the process equipment marked with
(*) in the list below. The following keywords are used for Process
equipment: CHECKVALVE (*); Defines name, position and allowed flow
direction for a check valve. COMPRESSOR (*); Defines name, position
and operating characteristics of a compressor. HEATEXCHANGER;
Defines name, position and characteristic data for a heat
exchanger. LOSS; Defines name, position and values for local
pressure loss coefficients. LEAK; Defines the position of a leak in
the system with leak area and back pressure. The leak can also be
connected to another flowpath to simulate gas lift etc. PUMP (*);
Defines name, type and characteristic data for a pump. TRANSMITTER
(*); Defines a transmitter position. VALVE; Defines name, position
and characteristic data for a choke or a valve. VALVE
LABEL=CHOKE-1-1, PIPE=PIPE-1, SECTIONBOUNDARY=4, DIAMETER=0.12,
CD=0.7, TIME=0, OPENING=1.0Output
OLGA provides several output methods for plotting simulation
results. The following keywords are used for Output: OUTPUT(DATA);
Defines variable names, position and time for printed output. PLOT;
Defines variable names and time intervals for writing of data to
the OLGA viewer file. PROFILE(DATA); Defines variable names and
time intervals for writing of data to the profile plot file.
TREND(DATA); Defines variable names and time intervals for writing
of data to the trend plot file. TRENDDATA PIPE=1, SECTION=1,
VARIABLE=(PT bara, TM, HOLHL, HOLWT) PROFILEDATA VARIABLE=(GT, GG,
GL) NODEBoundary&Initialconditions
PARAMETERS; A collection keyword for all node keys. This keyword
is hidden in the GUI.Output
OLGA provides several output methods for plotting simulation
results. The following keywords are used for Output: OUTPUTDATA;
Defines variable names, position and time for printed output.
TRENDDATA; Defines variable names and time intervals for writing of
data to the trend plot file. NETWORKCOMPONENT TYPE=Node,
TAG=NODE_INLET PARAMETERS LABEL=INLET, TYPE=CLOSED
ENDNETWORKCOMPONENT NETWORKCOMPONENT TYPE=Node, TAG=NODE_OUTLET
PARAMETERS LABEL=OUTLET, GASFRACTION=-1, PRESSURE=50 bara,
TEMPERATURE=32, TIME=0, TOTALWATERFRACTION=-1, TYPE=PRESSURE,
FLUID=1 ENDNETWORKCOMPONENT
PHASESPLITNODEBoundary&Initialconditions
PARAMETERS; A collection keyword for all phase split node keys.
This keyword is hidden in the GUI.Output
OLGA provides several output methods for plotting simulation
results. The following keywords are used for Output: OUTPUTDATA;
Defines variable names, position and time for printed output.
TRENDDATA; Defines variable names and time intervals for writing of
data to the trend plot file.
SEPARATORBoundary&Initialconditions
PARAMETERS; A collection keyword for all separator keys. This
keyword is hidden in the GUI.Output
OLGA provides several output methods for plotting simulation
results. The following keywords are used for Output: OUTPUTDATA;
Defines variable names, position and time for printed output.
TRENDDATA; Defines variable names and time intervals for writing of
data to the trend plot file.
CONTROLLERBoundary&Initialconditions
PARAMETERS; A collection keyword for all controller keys. This
keyword is hidden in the GUI.Output
OLGA provides several output methods for plotting simulation
results. The following keywords are used for Output: OUTPUTDATA;
Defines variable names, position and time for printed output.
TRENDDATA; Defines variable names and time intervals for writing of
data to the trend plot file. NETWORKCOMPONENT
TYPE=ManualController, TAG=SetPoint-1 PARAMETERS
SETPOINT=(2:0.1,2:0.2,0.3), TIME=(0,2000,2010,4000,4010) s,
STROKETIME=0.0, MAXCHANGE=1.0 ENDNETWORKCOMPONENT
ANNULUSInitialconditions
PARAMETERS; A collection keyword for all annulus keys. This
keyword is hidden in the GUI.AmbientConditions
AMBIENTDATA; A collection keyword for specifying the Annulus
ambient conditions.AnnulusComponents
COMPONENT; A component to place within the annulus
definition.Output
PROFILEDATA; Defines variable names and time intervals for
writing of data to the profile plot file. TRENDDATA; Defines
variable names and time intervals for writing of data to the trend
plot file. FLUIDBUNDLEInitialconditions
PARAMETERS; A collection keyword for all fluid bundle keys. This
keyword is hidden in the GUI.AmbientConditions
AMBIENTDATA; A collection keyword for specifying the fluid
bundle ambient conditions.BundleComponents
COMPONENT; A component to place within the fluid bundle
definition.Output
PROFILEDATA; Defines variable names and time intervals for
writing of data to the profile plot file. TRENDDATA; Defines
variable names and time intervals for writing of data to the trend
plot file. SOLIDBUNDLEInitialconditions
PARAMETERS; A collection keyword for all solid bundle keys. This
keyword is hidden in the GUI.AmbientConditions
AMBIENTDATA; A collection keyword for specifying the solid
bundle ambient conditions.BundleComponents
COMPONENT; A component to place within the solid bundle
definition.Output
PROFILEDATA; Defines variable names and time intervals for
writing of data to the profile plot file. TRENDDATA; Defines
variable names and time intervals for writing of data to the trend
plot file.
ConnectionsThe CONNECTION keyword is used to couple network
components, such as a node and a flowpath. Each flowpath has an
inlet and an outlet terminal that can be connected to a node
terminal. Boundary nodes (i.e. CLOSED, MASSFLOW, PRESSURE) has one
terminal, while internal nodes has an arbitrary number of terminals
where flowpaths can be connected to. CONNECTION TERMINALS =
(FP_BRAN INLET, NODE_INLET FLOWTERM_1) CONNECTION TERMINALS =
(FP_BRAN OUTLET, NODE_OUTLET FLOWTERM_1) Separator and
PhaseSplitNode has special handling of terminals.
The CONNECTION keyword is also used for coupling signal
components. CONNECTION TERMINALS = (FP_BRAN SOUR-1-1@INPSIG,
SETPOINT-1 OUTSIG_1) See also connecting the controllers for more
information.
Example fileThe keyword examples shown above can be combined to
an OLGA .key file. CASE PROJECT="OLGA Manual", TITLE="Example
case", AUTHOR="SPT Group AS" INTEGRATION STARTTIME=0, ENDTIME=7200,
DTSTART=0.1, MINDT=0.1, MAXDT=5 FILES PVTFILE=fluid.tab MATERIAL
LABEL=MAT-1, DENSITY=0.785E+04, CAPACITY=0.5E+03,
CONDUCTIVITY=0.5E+02 WALL LABEL=WALL-1, THICKNESS=(0.9000E-02,
0.2E-01), MATERIAL=(MAT-1, MAT-1) NETWORKCOMPONENT TYPE=FlowPath,
TAG=FP_BRAN BRANCH LABEL=BRAN-1, GEOMETRY=GEOM-1, FLUID=1 GEOMETRY
LABEL=GEOM-1 PIPE LABEL=PIPE-1, DIAMETER=0.12, ROUGHNESS=0.28E-04,
NSEGMENT=4, LENGTH=0.4E+03, ELEVATION=0, WALL=WALL-1 HEATTRANSFER
PIPE=ALL, HAMBIENT=6.5, TAMBIENT=6, HMININNERWALL=0.5E+03 SOURCE
LABEL=SOUR-1-1, PIPE=1, SECTION=1, TIME=0, TEMPERATURE=62,
GASFRACTION=-1, TOTALWATERFRACTION=-1, PRESSURE=70 bara,
DIAMETER=0.12, SOURCETYPE=PRESSUREDRIVEN VALVE LABEL=CHOKE-1-1,
PIPE=PIPE-1, SECTIONBOUNDARY=4, DIAMETER=0.12, CD=0.7, TIME=0,
OPENING=1.0 TRENDDATA PIPE=1, SECTION=1, VARIABLE=(PT bara, TM,
HOLHL, HOLWT) PROFILEDATA VARIABLE=(GT, GG, GL) ENDNETWORKCOMPONENT
NETWORKCOMPONENT TYPE=Node, TAG=NODE_INLET PARAMETERS LABEL=INLET,
TYPE=CLOSED ENDNETWORKCOMPONENT NETWORKCOMPONENT TYPE=Node,
TAG=NODE_OUTLET PARAMETERS LABEL=OUTLET, GASFRACTION=-1,
PRESSURE=50 bara, TEMPERATURE=32, TIME=0, TOTALWATERFRACTION=-1,
TYPE=PRESSURE, FLUID=1 ENDNETWORKCOMPONENT NETWORKCOMPONENT
TYPE=ManualController, TAG=SetPoint-1 PARAMETERS
SETPOINT=(2:0.1,2:0.2,0.3), TIME=(0,2000,2010,4000,4010) s,
STROKETIME=0.0, MAXCHANGE=1.0 ENDNETWORKCOMPONENT CONNECTION
TERMINALS = (FP_BRAN INLET, NODE_INLET FLOWTERM_1) CONNECTION
TERMINALS = (FP_BRAN OUTLET, NODE_OUTLET FLOWTERM_1) CONNECTION
TERMINALS = (FP_BRAN SOUR-1-1@INPSIG, SETPOINT-1 OUTSIG_1)
ENDCASE
Simulation modelAn OLGA simulation is controlled by defining a
set of data groups consisting of a keyword followed by a list of
keys with appropriate values. Each data group can be seen as either
a simulation object, information object, or administration object.
Logical sections The different keywords are divided into logical
sections: CaseDefinition; administration objects for simulation
control Library; information objects referenced in one or more
simulation objects Controller; controller simulation objects
FlowComponent; network simulation objects
Boundary&InitialConditions; simulation objects for flow in and
out of flowpath ProcessEquipment; simulation objects for flow
manipulation ThermalComponent; thermal simulation objects
FA-models; administration objects for flow assurance models
Compositional; administration and information objects for component
tracking Output; administration objects for output generation
Drilling; drilling simulation object OLGA Well; OLGA Well
simulation object
Network modelA simulation model is then created by combining
several simulation objects to form a simulation network, where
information objects can be used within the simulation objects and
the administration objects control various parts of the simulation.
The simulation objects can again reference both information and
administration objects. The network objects can be of the following
types: Flowpath; the pipeline which the fluid mix flows through
Node; a boundary condition or connection point for 2 or more
flowpaths Separator; a special node model that can separate the
fluid into single phases Controller; objects that perform
supervision and automatic adjustments of other parts of the
simulation network Thermal; objects for ambient heat conditions The
simulation model can handle a network of diverging and converging
flowpaths. Each flow path consists of a sequence of pipes and each
pipe is divided into sections (i.e. control volumes). These
sections correspond to the spatial mesh discretization in the
numerical model. The staggered spatial mesh applies flow variables
(e.g. velocity, mass flow, flux) at section boundaries and volume
variables (e.g. pressure, temperature, mass, volume fractions) as
average values in the middle of the section.
The figure below shows a flow path divided into 5 sections.
Each flowpath must start and end at a node, and there are
currently three different kinds of nodes available: Terminal;
boundary node for specifying boundary conditions Internal; for
coupling flowpaths (e.g. split or merge) Crossover; hybrid node for
creating a closed-loop network The figure below shows a simple
simulation network consisting of three flowpaths and four
nodes.
The flowpath is the main component in the simulation network,
and can also contain other simulation objects (e.g. process
equipment, not shown in the figure above). It is also possible to
describe the simulation model with a text file. See Input files for
further descriptions.
IntroductionWith OLGA 5 a new graphical user interface (GUI) was
introduced that replaced the OLGA 2000 GUI. OLGA 6 uses the same
GUI as OLGA 5 with some additional features. The main new features
in the OLGA 6 GUI are: Plot configurations (variables, colours,
etc) may be saved as templates for easy recreation of plots
Graphical configuration of signal network (controllers) New
graphical configuration of Bundles New utility for running cases in
batch (without having to start the GUI) The main new features of
the OLGA 5 GUI compared with the OLGA 2000 GUI are: Graphical
configuration and visualization of complex networks with Drag and
drop Graphical copy paste Automatic detection and classification of
internal nodes Positive flow direction can be indicated on flow
path Pressure boundary nodes are distinguished Network coupling
table with configuration capability Design time verification of
model and listing missing items Errors are detected while the model
is created Action buttons for missing items GEOMETRY Editor with
spreadsheet type input Copy directly from Excel Both XY and
Length-Elevation input are displayed. Automatic Sectioning without
simplification Direct access to simplification procedure with new
angle distribution details Automatic inversion of pipe profiles
which facilitates e.g. annular models
New Plotting Functions Select variables from a complete list
with descriptions Make your own standard sets of variables with
units Within a graph - copy directly to and from Excel Spreadsheet
type input and visualization of input series New Parametric study
function New RESTART function Context sensitive help
New ProjectA new project is defined by: Select File/New/Project
Ctrl+Shift+N Click the New Case icon
or New Project at the base of the Start Page.
When starting a new project a new folder can optionally be
created by checking the Create folder box.
New caseA new case is defined in one of the following ways:
Select File/New/Case (you will be taken into a dialog to create a
new project if not already done) Ctrl+N Click the New Case icon
Then, the window below appears:
Enter a case name (or use default), fill in location (or use
default) and select template. OLGA Case File. This generates an
empty case. OLGA Basic Case. This generates a complete basic case.
Ready for simulation. OLGA Network case. This generates a complete
basic case with an internal merge node.
Open existing caseYou may open an existing Project, an existing
OLGA case or an existing OLGA 2000 case (*.inp). If you open an
existing case after you have opened or created a project the case
will be added to the project. However, if you open an existing case
without having a project, a project with the case name is created.
You should save this project immediately. Open project Select
either of these: Select File/Open/Project Ctrl+Shift+o and open a
file with extension .opp. Open case Select either of these: Select
File/Open/Case Ctrl+o Click the Open Case icon and open a file with
extension .opi, .key or .inp.
Start pageWhen opening the OLGA graphical user interface the
Start page will appear. The central window contains a list of
recent projects and the date when they were last modified. A
project can be opened by double clicking on the case name. A new
project can be started from the New Project button at the bottom of
the screen.
See also Moving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Model view
The Model View is used for navigation between the objects of the
system. The objects are ordered hierarchically with a Project on
top comprising one or more cases. A case contains Case Definitions,
Libraries, Output, Network Connections and Network Components. Case
Definitions describe information common to the whole system
simulated. Network Components describe the properties of the flow
network (currently either a node or a flow path). Libraries contain
keywords that can be accessed globally (for instance Material and
Wall). Output contains global output definitions, such as plotting
intervals for trend, profile and output. FA-models contains input
to flow assurance models. Compositional has input to the
compositional model. Advanced thermal contains input to the
FEMTherm and bundle models and input to annulus calculations.
When selecting an object in the project explorer, the object is
made active and its properties may be edited in the Properties
view. The model view contains input for all cases in the project.
Switching between the different cases is done by clicking on the
file name in model view.
See also Moving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
File viewThe File View shows the input files of the project. By
right clicking on a file the file can be removed or opened. If the
file is a .opi-file (case-file) you get the option to open it as a
text file. The text file is the OLGA 6 .keyformat which resembles
the OLGA 2000 inp-format. You may edit the key-file, save it and
then reopen the case from the edited key fileby selecting 'reload
from text file'
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Component view
Simulation objects may be fetched from the Components window by
Drag&Drop onto the Graphical Editor. Only objects available at
the network level presented are available. This means that e.g.
process equipment can be introduced this way only when the Flowpath
is open.
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Property editorThe Properties window is a common interface to
all simulation objects (keywords). Here the objects are defined
setting values on the different keys. The left column gives the
property name (currently the key name), the right its value. Units
may be altered as shown in the figure. By default the value will
update when the unit is changed. To keep the value: Press the Shift
key while changing the unit. When a property is selected, a
description is shown in the field at the bottom. Values may be
inserted by typing or by selecting one or several values presented
by the interface. The colours of the keys are the following
meaning: Black : Key can be given but not required. Red : Key
required. Grey : Key can not be given. Note that the colours will
change as input is given. As an example: Two keys are mutually
exclusive and one of them must be given. Both will then initially
be red (required). When a value is given for one of the keys its
colour will change to black (key is given and no more input
required for that key) while the other key will turn grey (can not
be given).
Some keywords have a special property page to make the process
of entering data easier. These property pages can be accessed
through the property editor button at the top bar of the property
editor window.
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Network viewBelow you see a snapshot from the GUI with the
template case Case0 loaded. All the windows are described in the
following sections. The windows may be moved around (outside or
inside the frame) and may be docked as described in Moving windows
.
Click left button on canvas and use mouse wheel to zoom
in/out
The central view in the figure above shows the Network view with
its Graphical editor functions. Zooming in and out is done by the
mouse wheel. Moving the mouse while the left mouse button is held
down will move the layout within the window. Pressing Q adjusts the
graphical view to the frames. Holding Shift and pressing Q zooms
out in steps. Focus is shifted away from selected objects by
pointing to the background while holding down the Shift key. Nodes
and flow lines are drawn schematically. Network components (Nodes
and Flowpaths) can be dragged into this view from the Components
window. Sources,
Pressure boundaries and Process equipment are visible and their
properties may be entered or modified by selecting the object
(left-click) and filling in their "Properties. In the figure the
properties of the NODE OUTLET are shown to the right.
The window above is the 2-dimensional Flowpath view which shows
one Flowpath at the time. The functions for "moving" the graph are
the same as for the Network view, see flowpath view for more
details. You can drag equipment to the canvas from the Process
Equipment Components on the left. When e.g. a valve is dropped on
the canvas it "attach" to the middle of the Flowpath as illustrated
below. The actual position and other data for the valve can be
entered in the Properties window for the Valve which now is in
focus (to the right). By entering the data e.g. the PIPE and
SECTIONBOUNDARY the valve will take its specified position on the
Flowpath.
Each graphic view has its own tab and if you click on the
Case0-tab (see below) you get back to the Network view.
We shall show how you make a new Flowpath: Start with dragging a
Node from the Components window and drop it on the canvas, see
above.
Then you make a new Flowpath by following the instructions in
the drawing below:
The new Node and Flowpath also appears in the Model View window,
see below:
An alternative method for adding a Flowpath. Select the
Components window
Select a FLOWPATH and drag it to the canvas. Then drag a new
node to the canvas.
Then do as illustrated below.
Re-configure the network:
Connecting Nodes and Flowpaths can be done as follows: Point to
the red dot at one end of a Flowpath (the red dot indicates that
this end of the Flowpath is not connected). Hold down the right
mouse button, initially pointing to the blue square that has
appeared at the end of the Flowpath. Move the mouse pointer to the
Node which the Flowpath should be connected to and release. Select
connect from the pop-up box that appears. The dot at the end of the
Flowpath turns green, indicating that a connection is established.
Alternatively: Right-click on the view background and select
Network Connections. Select the "from-to" nodes for each Flowpath
and click OK. The network should appear as specified.
Select Red dot on Flowpath
Right-click within the blue square and move pointer towards
NODE_0. Select Connect to and release mouse button.
Do the same with the other end of the Flowpath.
Disconnect a Flowpath from a Node by left-clicking on the
Flowpath and then point to the green dot at the end of the
Flowpath. Hold down the left mouse button while moving the end of
the Flowpath away from the node and release. The dot at the end of
the Flowpath should now be red, indicating that it is not
connected.
Left-click on Flowpath, select green dot (left-click) and drag
endpoint away from Node.
Right-click while pointing to an object in the Network view
brings up various menus depending on the object: - Add : Add items
to the network object. - Verify : Checks input file and reports
errors and missing input in the output window. - Copy : Copy
selected item. - Paste : Past the copied item onto the currently
selected item. - Delete : Delete selected object. - Properties :
Starts property editor for selected object. For a Flowpath this
would be to Geometry Editor while for other items it would
typically be a time series editor. For example: pointing to a
Flowpath gives the alternatives below.
Text labels in the Network view (which reside in their separate
text boxes) can be rotated and scaled in addition to moved (except
those for Flowpaths). Move is the default edit mode. You can either
select the edit mode on the toolbar
or you can type one of the following letters to change the edit
mode for the selected text box.
s:
Scale: (left-click in the triangle and drag while keeping the
mouse button down)
r:
Rotate: (left-click in the sector and drag horizontally)
m:
Move: (left-click in the square and drag)
You can add fixed points on a Flowpath by pressing Ctrl while
double-clicking anywhere on it. A fixed point, indicated by a small
square, appears on the Flowpath.
The fixed points can be moved to shape the Flowpath (this does
not change the actual geometry of the Flowpath).
More points are added by repeating the Ctrl double clicking. You
remove the fixed points by Ctrl double click within its blue
square. Right-click in the Network view activates a menu with the
following items:
Copy as picture: Network Connections:
A "Case.jpg" file with the Network view is copied to the folder
where the project resides. Opens the network overview/connection
window
Network plot allows for a quasi-animated plotting of profiles in
the Network view.
Configure:
Allows for (re)configuration of e.g. colours and line
interpolation.
3D View described in Moving view in 3D . Show directions
Direction arrows are displayed on each Flowpath.
Changes to 3D view as
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Flowpath viewThe actual profile of the geometry may be viewed by
opening the Flow path; double click FLOWPATH in the Model View.
This opens a new tab in the Graphical Editor
showing the selected flow path only (including equipment). In
the Flowpath view equipment may be added by drag and drop from the
Components window (the available components are now the ones that
are located on a specific Flowpath).
Focus an object by a left mouse click to bring up the Property
editor, and the properties of the object can be entered or
modified.
Focus is shifted away from selected objects by pointing to the
background while holding down the Shift key. Zooming in and out is
done by the mouse wheel and moving the mouse while the left mouse
button is held down will move the layout within the window.
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Connection viewThe connection view is used for showing
connections for a single component or all connections in a case.
The connection view can also be used to create new connections. The
connection view has two modes. The above figure shows connections
for a selected component. When a component is selected, all
terminals for the component is shown in left column in the view.
The column "Connected NC" shows the name of the network component
which is connected. The column "Connected terminal" shows which
terminal is used on the connected network component. In a signal
connection a variable is given. This variable is shown in the
column "Variable". Creating a new connection for a selected
component: 1. Select a network component from the column "Connected
NC". Only network components with compatible terminals are shown in
the list of available network components. 2. Select a terminal on
the component from the column "Connected Terminal". After selecting
a terminal, the connection is made. 3. Select a variable (only for
signal connections) from the column "Variable". The other mode is
for showing all connections in the case. In this mode it is easier
to see the direction of the signals (see figure below) Creating a
new connection when showing all connections: 1. Select a network
component in the column "From". 2. Select the out-signal (terminal)
from this component in the column "Out". 3. Select a network
component to receive the signal in the column "To". 4. Select the
in-signal (terminal) in the column "In" 5. Select a variable (only
for Transmitters) from the column "Variable".
Output windowThe output window (not to be confused with the
OUTPUT keyword/OUTPUT File) gives information about the state of
the cases, modeling and simulations. The information comes out
three categories:
Error messages (and task list) : Cannot simulate o Errors in
input o Errors from initialization phase o Errors during simulation
o List of incomplete keywords. o Click on the symbol to go to the
incomplete keyword. Warnings - : The simulation may still be
performed [1] Information o Simulator state changes o Progress
during simulation
o
Any messages during simulation (info previously directed to DOS
window)
The windows can be cleared from the context menu (right click).
Text can be copied: Mark text Right click and copy
Which Output categories are active are indicated by the "orange"
background around the category names in the top bar of the output
window. A left mouse click on the text will activate and
deactivate.
By default the output from the active case is shown. Output from
other cases is selected from the pull-down menu at the top of the
output window.
[1] Warnings from the OLGA interpretation of fluid files which
takes place when the simulation has started are categorized as
Information
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Time series editorInput keys that have time series can be edited
in a time series editor. The time series editor is accessed through
the properties for the relevant keyword.
If there are several independent time-varying parameters within
one keyword the graph of these can be displayed by checking them in
the graph legend (which shows the minimum necessary input
parameters).
You can insert columns in the spreadsheet by right-clicking on a
column-header, see below.
Selecting "cancel" nullifies all actions performed within the
time series editor.
A trick: to fill in the same value for several time points:
enter the value in the column for the last time-point and then
enter.
See also Moving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
PlottingTrend and profile plot output as defined by the user can
be viewed during and after simulation. The plotting buttons on the
top menu will show red lines when plot files are available for the
active case.
TREND Plot PROFILE Plot Plot PVT file Multi-case plotting
General features of the plotting tool Export/import data
See alsoMoving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
Active case trend plotSelect trend plot with the buttons in the
top menu. Trend plot gives you the menu below. Select the variables
you want to plot. Move the selection over to the upper right hand
side window where you may change units. Click OK to see the
graph.
The default time unit for a Trend plot is Seconds which you
change at the lower left.
Active case profile plotYou select the profile button and then
select variable(s) to plot:
You may now "play-back" the profile plot, either by dragging the
slide or by clicking the green triangle. You may also freeze a
curve by clicking the "needle"
button.
You get a frozen curve each time you click it. You "un-freeze"
by disable the needle profiles simultaneously, but the speed will
of course depend on your PC-capacity.
. The play-back is stopped by clicking the blue square. You may
play-back several
Fluid propertiesYou can use the plot-tool to plot
fluid-properties. Select PVT file plot with the buttons in the top
menu (.tab). You then select the property or properties you want to
see and proceed as usual.
You may use the freeze-function as for profile plots. You click
the nail and then the green triangle. You repeat clicking the nail
to freeze more curves. The default x-axis is temperature. You can
change this by moving the column header fields in the right-hand
side window to locate the "X-Axis" field (which is in the far right
position by default) and select Pressure instead of
Temperature.
Multi-case plottingIt is possible to plot results from several
cases/projects simultaneously. For example you can plot data from
all the cases in your project (use the Plot Project button in the
select variables dialog), the in-active as well as the one active.
You can open several results files by the Tools -> Plot menu
(select several files, either trend (.tlp) or profile (.plt) or
from within the plot tool itself by adding files, see below. You
plot as for single cases.
Note that for profile plots where different plotting intervals
have been used in the different files the profile closest to the
selected time will be used and no interpolation is currently
applied.
Some general features of the plotting toolThe plotting tool is a
quite sophisticated program and you have access to several
functions for modifying your graph Add/remove data to plot: o Right
click and select Dataset /Select or o Menu Options/Select Plot
Variables View values: Right click and select Track values For
profile plots: select plot time point with slider at bottom right
Collapse/expand axes: Right click and select o Axes/Collapse all or
o Axes/Expand all Display legend: Right click and select Show
legend Modify settings o Right click and select Configuration
(window as below) or o Menu Options/Configuration Zoom: o o o
Select upper left corner with left mouse button Drag to lower right
corner while holding button Release
Un-zoom: Do as for zoom, but drag to the left (any start and end
point works) Zoom in/zoom out/un-zoom buttons are also
available
Export/import data to/from MS ExcelExport data: In the Select
variable dialog, mark the variables that you want to export and
then press the Export button. The marked variable data are then
copied to the clipboard and can easily be pasted into MS Excel.
Some examples are shown below. Paste from Excel: Select data
columns in and select copy. In Plot window right click and select
Dataset->Paste. Trend:
All the variables marked in the selection dialog are copied to
separate columns in the Excel-worksheet. Profile:
When exporting profile variables, there are some options. First,
choose the points in time that are of interest. Secondly, choose
the output grouping. On time copies the variables sorted on time,
while the On variable option copies the variables sorted on
variables. See examples below:
Showing data sorted on time
Showing data sorted on variable
Parametric StudiesParametric studies are defined through
Tools-Studies, where new studies can be added or previously
performed studies reopened.
The input screen for parametric studies is shown below.
The number of parameters is given in the field labelled
"#Parameters. At present studies can only be performed on the local
machine, but the number of simultaneous simulation can be given
(#Parallel simulations). This can be useful for machines with
multiple processors or multithreading.
The quick way to enter an equidistant parameter variation is
given below:
Right-click in MASSFLOW below and select Set Value(s)
Set the e.g. the values below:
This results in the definition of 4 cases ready for running. You
may save the study by clicking OK. The study is saved in a separate
folder together with the Project/Case.
Click Run Study and observe the progress:
For more information on XY-plot and Matrix see the Tutorial
(accessed from the Help menu).
Geometry editorActivating Enter a new profile Edit Geometries
Edit the table Edit the graph Check angle distribution Filter the
data Complete the data Define sectioning Use the new geometry Menus
Limitations
See also Moving windows, Hot keys, Moving view in 3D, Menus,
Toolbars or Properties and settings
ActivatingPipeline profiles are edited in the Geometry Editor.
The tool can be started like this: Tools/Geometry Editor (opens
with only default data) or Select the Property page for the active
geometry (opens with data for the selected geometry)
You may also select FLOWPATH (or GEOMETRY) in the Model-View and
right click and then select Properties:
You will now see this graph of the default geometry for the
single branch template:
Enter a new profileYou can work with an existing profile in the
.xy-format by File/Import and opening the relevant xy-file with the
browser (e.g. Profile-A.xy - this Geometry is given below).
You should save this new Geometry with a new label while in the
Geometry Editor (e.g. GEOM-A. The saved geometry file has the
extension .geo:
You must also give the new Geometry relevant sections,
diameters, roughness and walls. How to do this is described below.
You can also copy directly from an Excel worksheet: Open the
Geometry Editor and select File New. You will get a new Geometry
with one pipe and default values as given below. The geometry is
now presented in a tabular format and you can toggle between this
and the graphic format by clicking on the relevant tab.
Open the Excel-file with your profile-data, select the X-Y
columns and copy.
Select the Start Point 0, 0 in the Geometry Editor with the
default geometry open and then Paste. You will get the question
below. Answer yes and the data will be pasted directly over to your
open geometry.
Please observe that if your excel geometry contains fewer pipes
than the one you paste over you must delete the obsolete pipes. You
can now save this Geometry (e.g. GEOM-B) and use it for one or
several Flowpaths in any model. First you must of course complete
it with sections, diameters etc., see below.
Edit GeometriesWhen opening the Geometry Editor you have seen
that two views are available i.e. the graph of the profile and a
table of pipes. The two windows can be viewed simultaneously by
selecting the e.g. plot tab and drag it towards the bottom of the
window (as has been done below).
See alsoEdit the table Edit the graph Check angle distribution
Filter the data Complete the data Define sectioning Use the new
geometry
Edit the tableNew pipes are added, renamed or deleted, by
right-clicking in the Pipe column and selecting the relevant
action.
X and Y in the table give the data for the end point of the
pipe. Changing Length-Elevation affects X-Y and vice-versa. Units
are changed by right clicking in the title cell (e.g. r;Diameter
[m]) and selecting a unit.
Edit the graphYou can also edit the Geometry by the following
actions under the Actions menu:
Normal (no change) A: Add a point M: Move a point D: Delete a
point
Restrictions on the graphic editor can be imposed (Actions ->
Restrictions):
X Fixed (X remains fixed, Y can be changed) X Bound (Point
X-value can not be moved upstream or downstream neighbors) Y Fixed
(Y remains fixed, X can be changed) Y Bound (Point Y-value can not
be moved above or below neighbors) Recursive (all points downstream
will follow the point that is being moved)
Check angle distributionYou can check the angle distribution of
a Geometry by selecting Tools -> Check angle distribution. You
can see the angle groups that are used by right clicking when in
the output window from the angle distribution calculation. You can
also change the angel groups. The colour of the bars and the %
values in the output window indicate the difference between the
average angle of the pipes within a group and the mean value of the
angle group. Green (and a low % deviation) means a good relevance
of the angle group. The % value is a numerically calculated
standard deviation divided by half of the angle group span.
Filter the dataSelect Tools/Filter. You have two options: a Box
filter or a preservation of angle distribution / total flowpath
length (the algorithm is identical to the one used in the OLGA
2000 Grid Generator). Box filter: This filter is more relevant
for removing relatively small disturbances from a pipeline survey.
Enter the horizontal sample distance and the vertical sample
height. These values define a moving rectangle (a box) within which
all data points will be filtered out. The filtered data appear as a
new geometry which may be further filtered/edited. Angel
distribution: Enter the maximum pipe length that shall be used to
filter the profile while maintaining the angle distribution and the
total pipe length. When filtering has been completed it is a good
idea to compare the angle distributions of the original geometry
and the filtered ones. The filter with the best reproduction of the
original geometry should be used keeping in mind that the angel
groups should be representative.
Complete the dataYou may want to open the e.g. GEOM-A.geo file.
All fields except the r;Length of sections are editable directly,
and copy/paste may be used for single cells. The "Length of
sections" has its own input support-tools In contrast to OLGA2000
all Pipes must have a Diameter, a Roughness and a Wall (if
relevant). You can use copy-paste functions to achieve this. If
defined in the OLGA case, walls may be selected from the drop down
menu. Within the Graph window the profile may be edited activating
either of the four menu functions (found under Actions ->
Graphical):
Define sectioningThe pipe sectioning can be performed in two
ways: 1. 2. Manually enter number of sections in the r;# Sections
column. This gives you equally long sections for a given pipe. If
you double click in the Length of Section list you enter a tool to
distribute sections of various lengths over the pipe-length.
Change (the nominal) no of sections to 3 and enter 4.75 m in
Section 1 and click OK.
You get 2 sections of 4.75 m and 1 0f 4.64214 m.
The main rule is that the tool ensures that you get a sum of
sections which is equal to the pipe length. Moreover, open section
lengths mean that you repeat the value above. The "remaining of
total" is the total pipe length minus length accumulated over the
section lengths specified (including the open ones).
If you double-click in the Length of Sections field again
You get the window below and you see that the remaining now is
very close to zero.
To start over again you can set # of sections to 0. 3. Use the
discretization tool (Tools/Discretize). Then all pipes are given
the same selected number of sections.
Use the new geometryA new geometry may be imported to a case as
follows: Open the geometry files you want to use (you can open them
from the Geometry editor or in explorer) Right click on FLOWPATH or
Piping in the Model View, select r;Exchange Geometry and pick the
desired geometry. If you use the same Geometry file for several
branches you must re-label the Geometries afterwards to secure that
the labels are genuine. You can also exchange geometries between
flow paths in the same case. Select the flow path and its Property
Page of the Geometry you want to distribute to other flow paths.
Then you select the flow paths that you want to import to and
select Exchange Geometry. Select FLOWPATH and click on Properties.
This opens the Geometry GEOM-1_2
Select destination FLOWPATH and click on Exchange Geometries and
then on GEOM-1_2.
MenusThe Geometry Editor features the following menus: File New
Import Open Close Save Save As Print Print Preview Print Setup Send
Exit Edit Undo Cut Copy Paste Configure View Standard Restrictions
Graph Status Bar Labels Actions Graphical Normal/Add/Move/Delete
Restrictions X Fixed/X Bound/Y Fixed/Y Bound/Recursive Tools Angle
groups Check Angle Distribution Check section lengths calculate the
length ratio of adjoining sections. Discretize Automatic pipe
sectioning (all equal) Filter Filter data Reset Pipe Labels Use
default pipe labeling Reverse geometry Creates a geometry that is
the mirror image of the original geometry (in x-direction). Window
New window New window with active data (works on same data set) New
window Select graph or table representation New Horizontal Tab
Group New Vertical Tab Group More Windows Help Help Topics Not
implemented About Geometry Version Information New geometry Import
xy-data Open geometry file (*.geo) Close geometry Save geometry
Save geometry as new file Print active window
Configure graph window
LimitationsThe following important limitation applies: 1. For
export to Excel, dot (r;.) must be selected as decimal separator
for Excel
Moving windowsWindows may be hidden and re-opened through the
view menu. They may be detached from the frame (floating) and may
be docked again by moving the window to the border of the frame.
Double click on a floating window to move it back to the last
docked position. In the picture below the blue area indicates where
the window will end up if dropped at the current location. If the
cursor is moved over one of the arrows towards the edge of the
screen the window will dock on the corresponding border of the
frame. If dropped on one of the four arrows in the centre of the
screen the window will dock towards the corresponding side of the
frame of the pipeline schematic window. Double clicking on the top
bar of a docked window makes it float and double clicking on the
top bar of a floating window makes it dock.
Hot keysCtrl+z z Leftshift+z Mouse wheel Delete Undo Enable zoom
in graphical editor; mark area with mouse Enable un-zoom in
graphical editor; mark area with mouse Zoom in or out in graphical
editor Deletes object
Moving view in 3DThe following illustration shows how to
navigate the camera in fly mode. In Orbit Mode left mouse button +
moving the mouse will make the camera orbit around the pivot point.
If you release the left mouse button you can use the key
combinations to move around. Camera maneuvering: Mouse wheel Arrows
Right shift Left shift Left mouse button Zoom in/out Move camera
in/out/left/right Move up Move down (or: Insert move down) No
selection: Rotate camera Network selected: Rotate network (see
below)
Camera Movement Speed Slow to Fast Keys 1 9 Rotate/Move/Scale
Rotate Move Scale Select object + key R+ left mouse button + move
mouse Select object + key M + left mouse button + move mouse Select
object + key S + left mouse button + move mouse
Scene View Shortcuts Fly Mode Key F Orbit Mode Key O Field of
View Mouse wheel, or key Z + left mouse button + mark area, or key
Z + left mouse click (zoom in) Left Shift + key Z + left mouse
click (zoom out) Space Deselect interaction mode Escape Deselect
objects Q (in 2D View) Zoom to extent Delete [Del] Delete selected
object.
Graphic ConfigurationThe graphical layout of individual flow
paths can be changed through the Graphical configuration dialog.
The choices made her will affect only the selected flow path.
If one want to change the layout of all the flow paths, this can
be done in Tools -> Options ->Graphics.
MenusFileNew > Project... New > Case... Open >
Project... Open > Case... Save Case Save Case As... Duplicate
Case... Save Project Close Project Print... Print Preview Print
setup... Recent projects Recent cases Exit Create new project
Create new case Open project Open case Save case Save a new case
Makes a copy of the selected case Save project Close (and save)
project Disabled Disabled List of projects recently opened List of
cases recently opened Exit
EditStandard windows commands Undo Redo Cut Copy Paste Paste
special...
Disabled Disabled
ViewSelect what windows and toolbars to be visible.
ProjectAdd New Item... Add Existing Item... Project Dependencies
Close Project Same as New Case Open an existing file e.g. an .opi
file Option to specify the dependencies between the cases
SimulationRun Stop Pause Start simulation (Start simulation in
batch- messages from simulation are sent to the Output window) Stop
simulation. Returns to initial state Pause simulation. Simulation
may be resumed (Not implemented for OLGA).
Run Project Run Batch Run Project Batch
Start to run all cases in a project in a given order Start
simulation in a DOS-control window. Start to run all cases in a
project in a DOS-control window
ToolsThe tools available are listed below.
WindowsStandard windows operations.
HelpHelp topics GUI Manual Tutorial About OLGA OLGA User Manual
Opens OLGA GUI USer Manual (pdf). Starts OLGA 6 Tutorial Release
information
ToolbarsStandard
New case Open case Save Save Project Copy Paste Undo Redo Model
view Property editor Components File view Output view Connection
view
Saves Case
Disabled
Simulate
Run Stop Pause Run Batch Verify
Start simulation Stop simulation. Returns to initial state.
Disabled Run batch in DOS window Verify case
Plot
Plot current trend plot Plot current profile plot Plot current
PVT file View current Output File
Layout
Fit window Move Moves a graphic object Scale Scales an object
Rotate Rotates an object Circular For systems with defined Grid
Nodes placed in grid Hierarchical type 1 Hierarchy Hierarchical
type 2 Hierarchy Radial For systems with defined center V Layout
algorithm direction is vertical. H Layout algorithm direction is
horizontal. Layout of equipment Toggle between relative and
sequential layout of inline equipment Snap to grid Toggle snap to
grid
Properties and settingsThe overall simulator settings are
specified under Tools->Options; making it possible to work with
different simulation engines under the same GUI (this includes OLGA
2000 versions as long as it accepts the keywords you actually use).
Settings under the General tab are: My Project locations: Location
where file dialogs will open. Show start page at start-up: If
applied - start-page with recent projects will appear when starting
the GUI. A sub-setting is "show the project list on the
start-page". Use cached static data: This is set by default during
installation. The GUI will then store certain data the first time
the simulator is started. This speeds up file loading and is
recommended to obtain the best performance from the program. The
General tab can also be used to specify if the program shall
execute auto-save at specified intervals. In the OLGA version tab
one can specify which version to use by marking one of the
displayed versions. External programs that should be available from
the Tools menu can be specified under the External Tools tab. Some
programs are set by default during installation and the user can
specify additional programs like Excel, a text-editor etc. The
Graphics tab is used to specify the pipeline layout view: Turn the
background grid on and off and specify the colours of the
gridlines. Set the canvas colour. Choose the interpolation method
for the flowpath lines. Set flowpath colour.
Simulation with bundlesThis description covers Fluid Bundles,
Solid Bundles and Annuluses. In OLGA 6 these bundle types are
network components. In this chapter the simulation of bundles is
illustrated by a SOLIDBUNDLE example. To add a SOLIDBUNDLE right
click the case level tab and choose Add > ThermalComponent >
SOLIDBUNDLE (see figure below).
When the Solid Bundle is added, go to the property window and
specify the required fields: DELTAT and DTPLOT. These parameters
govern the frequency of updates of output from the FEMTherm
computation (i.e. the computation of temperatures in the solid).
The LABEL and MESHFINENESS fields may also be updated. A bundle in
OLGA 6 consists of several components. The components of the bundle
are flowpaths, shapes and possibly internal bundles. Note that all
the components that constitute the bundle must be defined (added)
elsewhere. Flowpaths and Lines must be defined as FlowComponents,
Shapes must be defined under Library and bundles must be defined as
ThermalComponents. Position labels to use for the specification of
TO and FROM must be defined for each flowpath under "Piping".
To add a component to a bundle (i.e. to specify that it is a
part of the current bundle) choose Add > BundleComponents >
COMPONENT in the Model View as shown in the figure below.
In the property window for the new component, specify the
required fields: The type of the component (specify either a
FLOWPATH, a LINE, a FLUIDBUNDLE, an ANNULUS or a SHAPE) The start
and stop position of the Bundle (TO and FROM) The geometric center
of the component (XOFFSET and YOFFSET) The OUTERHVALUE of the
component (optional) Note that the position of the origin of any
cross-sectional coordinates is irrelevant as long as all
coordinates within one and the same bundle refers to the same
coordinate system. It is only the relative cross-sectional position
that matters.
About SHAPES A SHAPE in OLGA 6 defines the circumference of an
area where a cross-sectional temperature profile may be computed by
the FEMTherm module. Within this area heat is assumed to be
transported by conduction in the radial direction. To add a SHAPE
to a case right click the Library in the Model View and choose Add
> SHAPE. In the property window for the new shape, fill out the
type of the shape (CIRCLE, ELLIPSE, RECTANGLE, POLYGON) and the
material. For any type of SHAPE the layout of the cross-section
must also be defined. As illustrated by the property window to the
right, a Circle requires the specification of a radius, an ellipse
requires a width and a height, a rectangle requires the
specification of coordinates of the lower left and upper right
corners, and a polygon must be defined by a series of
coordinates.
About LINES A LINE in OLGA 6 is a flowpath for which a
simplified one-phase computation is performed. LINEs can be
connected in networks, just as regular flowpaths can, but in a LINE
network all the network components must have the parameter LINE set
to YES. A complete case may contain several LINE-networks and
several multiphase networks, but the two types of networks can not
be coupled to each other. To add a line to a case in the GUI, right
click the FlowComponent in the Model View and choose Add >
FLOWPATH. In the property window for the new flowpath select
LINE=YES. Then select FLUIDTYPE (gas, oil or water). Connect the
LINE to a node in the same manner as other flowpaths are connected.
Note, however, that the connected nodes must also have the
parameter LINE set to YES.
About CROSSOVER nodes A CROSSOVER node in Olga 6 is a special
type of single phase node which can be used in LINE networks only.
The CROSSOVER node is a pressure boundary node with the following
additional features: It must be connected to two LINES, and it
imposes a given pressure difference (called MAXPRESSUREBOOST)
between these two lines (at the connection point). A crossover node
is added to a case in the same manner as any node is added: right
click the FlowComponent in the Model View and choose Add > NODE.
In the property window for the new node select TYPE=PRESSURE and
LINE=CROSSOVER, then enter the rest of the required fields.
Simulation with ControllersIn OLGA 6 the controllers are signal
components. Signal components are a special kind of network
components, able to transfer signals between each other. Coupling
in the signal network is possible between the following components
(notice that a controller is always involved): Pipeline section
variable (via a transmitter) to controller Inline component (ex.
valve, pump, compressor etc.) to controller Sources (source and
well) to controller Node variable to controller Separator variable
to controller Controller to controller Controller to inline
component Controller to separator Controller to source This chapter
describes how to connect signal components in the GUI. Signal
network terminology The following explanations of the terminology
used for signal networks can make it easier to understand how
controllers are connected to other components. A signal component
is a component that can send and/or receive a signal. A signal
component (e.g. a controller) is connected to other signal
components (e.g. a flowpath) via terminals. Terminals are best
explained with an example; A PID Controller has 3 terminals, 2 for
receiving signals (the setpoint signal terminal and the measured
signal terminal) and one for sending signals (the output signal
terminal). Another signal component like a separator can send its
holdup value as a signal to the PID Controller. The holdup will be
sent via the measured signal terminal of the controller. The PID
Controller will calculate an output signal based on the measured
value and send it via the output signal terminal to e.g. a valve. A
signal is just a value. There isnt much difference between a signal
in a signal network and a flow in a flow network. The flow
represents a physical flow of oil, gas or water while the signal
can represent anything. The meaning of the signal to the signal
component depends on which terminal that is used to send the
signal. In the example above the signal represented a measured
value since it was sent via the measured signal terminal. A
flowpath may send measured values as signals. To do this one must
add a transmitter to the flowpath. The transmitter acts as an
output signal terminal for the flowpath. Most inline process
equipment added to the flowpath can act as a signal terminal for
the flowpath in the same way as a transmitter (you may for example
connect a controller directly to a valve). Graphical configurations
of controller connections Coupling of signal components is possible
with two different techniques in the graphical user interface; i)
Coupling with drag and drop - or ii) Coupling through the
connection view Drag and drop coupling The drag and drop coupling
between two signal components is done in the same manner as between
two multiphase network components: 1. Click a component and drag
towards another component in the signal network (see list of legal
couplings above) 2. Release on the second component. A context menu
is shown with available terminals to connect from and to
3.
Choose one of the available terminals to connect from (only
OUTSIG_1 is available in the figure above) and a terminal to
connect to (MEASRD and SETPOINT is available in the figure above).
A connection between the two components is created.
4.
Select variable to transmit. If the coupling is between a
transmitter and a controller, a variable to be transmitted has to
be given. Setting this variable must be done in the connection
view
Coupling using the connection view The drag and drop technique
for coupling components in the signal network is less practical
when the case is large with many components. Dragging from one
component to another may involve zooming to view both components,
and thereby making the coupling difficult. It is possible to
connect signal components using the connection view without seeing
the other components. In the figure below the connections for a
PID-controller is shown. All terminals (in-/out-signals) for
controller CNTRL-1 are listed in column one (Terminal). Column two
(Connected NC) and three (Connected terminal) lists which network
components and terminals the controller is connected to. If a
user-chosen variable is supposed to be transmitted column four
(Variable) is us