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4.0 OIL FIELD DEVELOPMENT AREA
Oil, water, and limited gas will be produced in each of the Kom, Miandoum, and Bolobo fields.In the Kom and Miandoum fields, there will be gathering stations where free water is separated
from the oil, then treated and disposed of into the oil reservoir via injection wells. Water content
in the oil will be reduced to about 10 percent at the gathering stations. The remaining oil and
water, in the form of an emulsion, is piped to the CTF for processing to produce crude oil of a
quality suitable for export sales. The general layout of the oil field development area is shown in
Figure 4-1. A schematic illustrating the various steps in the product flow path is presented in
Figure 4-2.
In the oil field development area, approximately 1,080 ha are needed for facilities and their
related infrastructure (195 ha); of this, 325 ha of land will be made available for most pre-
construction uses, with the restriction that the use not interfere with normal operations and
maintenance. Another 490 ha will be reclaimed after construction and made available to pre-
construction customary land users.
4.1 FACILITIES DESCRIPTION
4.1.1 Well Site / Flowlines
Approximately 300 producing wells will be located in the oil field area. Fiberglass flowlines will
connect individual wells to the field manifolds. If required, the flowlines can be serviced using
portable launchers and receivers. Production from the Kom LK wells will be gatheredseparately using carbon steel flowlines and sent to the CTF where the gas will be used for
power plant fuel and the oil combined with other incoming emulsion.
4.1.2 Remote Manifolds / Well Testing
Field manifolds will be used as part of the gathering systems. The field manifolds serve two
purposes:
To collect production from several individual wells and direct it via a production manifold to a
gathering line, a gathering station, or a field pump station
To direct production via a test header from a selected well to a well test skid located at each
manifold
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Well testing installation at each manifold site will consist of a vertical separator, proportional
velocity flowmeter, a watercut meter, a ratio tube-type densitometer, and associated
instrumentation and controls.
4.1.3 Kom and Bolobo Field Pump Stations
For the wells and manifolds located at the southern and northern ends of the Kom field, two
field pump stations (KP-1 and KP-2) will pump the production fluids to the Kom gathering
station. The pump stations will receive production from other field manifolds including the
manifold located at the pump station. The field pump stations will be designed to pump amultiphase mixture of oil, water, and gas using rotary screw pumps. Storage of field production
will not be provided at the pump stations. A similar multiphase pump station (BP-1) will be
utilized in the Bolobo field, sending all Bolobo production fluids to the Kom gathering station for
processing. No field pump station will be required in the Miandoum field.
4.1.4 Gathering Stations
Two gathering stations will be constructed, one in Kom and one in Miandoum. The gathering
stations will receive production from individual wells via field manifolds and field pump stations.
The Kom field gathering station will also receive production from the Bolobo field pump station.
The function of a gathering station is to:
Separate produced gas and sand from incoming well fluids
Dewater incoming well fluids to produce a 10 percent watercut emulsion and pump it via the
emulsion trunkline to the CTF
Measure the emulsion production rate and watercut to determine oil production from the
field
Treat produced water to remove oil and sand, and pump it to an injection well
Compress the produced gas for transportation to the CTF.
Major features of the gathering station design are discussed below.
4.1.4.1 Free-Water Knock-Out
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station, lower crude viscosities will allow the use of unheated FWKO tanks to separate free
water from the inlet emulsion to produce a 10 percent watercut emulsion.
4.1.4.2 Emulsion Pumping
At the Miandoum gathering station, rotary screw pumps will be provided to pump the emulsion
from the FWKO tanks to the CTF via an emulsion trunkline. At the Kom gathering station, 10
percent watercut emulsion will gravity-flow from the second stage FWKO tanks to the CTF
emulsion inlet tanks.
4.1.4.3 Produced Water Treatment
Produced water from the FWKOs will be pumped to skim tanks removing solids and oil prior to
reinjection of produced water. Clear-water surge tanks will be installed downstream of the skim
tanks to provide surge capacity for the water system and suction for the water injection pumps.
Plot space will be provided in the water plant should it be determined that additional water
treatment equipment is needed.
4.1.4.4 Sand Handling
At the Kom and Miandoum gathering stations, the majority of the sand will be removed in the
FWKO tanks. As required, the tanks will be shut down and manually cleaned. The sand will be
disposed of in the landfill or another environmentally acceptable manner. Sand and other solids
carried to the produced water system will be removed in the skim tanks.
4.1.4.5 Water Injection Pumps
At each gathering station, a pumping system consisting of booster pumps and main injection
pumps will be provided to pump the treated produced water to injection wells. The Bolobo
produced water will be reinjected at Kom.
4.1.4.6 Gas Compression Facilities
At the Miandoum gathering station, vapor recovery units and multi-stage reciprocating
compressors will be provided to collect produced gas from the FWKO tanks and compress it for
transport to the CTF where it will be used as fuel gas for the power plant and tank blanketing.
At the Kom gathering station Kom and Bolobo produced gas from the FWKO system will be
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Pressure Relief and Flare
Instrument and Utility Air
Fuel Gas
Chemical (Demulsifier) Storage and Injection
Hot Water Process Heating (Kom Gathering Station and CTF)
Electric Power
Open Drain System.
4.1.5 Water Injection System And Disposal Wells
Both dry holes and converted high-watercut producers will be used as water disposal wells. The
total number of disposal wells is estimated to be 36 (including nine recompletions): 27 in the
Kom UK field, and nine in the Miandoum field. Water disposal at Bolobo is not envisioned.
Total produced water production is expected to approach 900 kbd. The total number of disposalwells and distribution between the individual fields may change as the development drilling
program progresses. A manual choke and a meter will be provided at each wellhead.
For the Kom field, the water disposal system will consist of a water injection trunkline and
lateral system from the Kom gathering station out to the disposal wells. For Miandoum,
individual injection lines from the gathering station will run to each well.
4.1.6 Operations Center
The Operations Center (OC), located in the Kom field, will include the following, as shown in
Figure 4-3:
Kom Gathering Station
Central Treating Facility
Power Plant
Pump Station No. 1 (PS No.1)
Community
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Avoid existing villages
Avoid cultivated areas and utilize existing large pad
Be close to the field having the largest reserves and the highest fluid viscosity
Have minimal impact on the environment.
4.1.7 Central Treating Facility
The CTF will receive emulsion and produced gas from the Kom and Miandoum gathering
stations, as well as produced oil and gas from the Kom LK.
The main functions of the CTF are:
Dehydrate the incoming 10 percent watercut emulsion from each field to produce pipeline
quality crude meeting a one percent maximum basic sediment and water (BS&W)
specification
Separate the Kom LK oil and gas
Receive the incoming produced gas and direct it to the power plant and CTF fuel gas
systems.
The key design features of the CTF are:
The emulsion production from each field will be commingled and treated in electrostatic
emulsion treaters.
The incoming emulsion will be combined and mixed in emulsion tanks upstream from the
emulsion treating system. The emulsion will be pumped from the tanks, split, and processed
in seven identical parallel treating trains. Each train will have an emulsion heating system
and a treater. The inlet emulsion will first be preheated in plate exchangers by hot-treated
crude and then by produced water from the treaters. Final heating to treating temperature
will be accomplished using a hot water heating medium in shell and tube exchangers.
The BS&W content of the oil will be measured after treating. Off-specification oil (wet oil)
will be directed to a separate wet oil system. The wet oil will be further treated in the tanks
by providing heat and retention time or it will be recycled to the inlet of the emulsion treaters.
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Short-term surge capacity for the treated crude will be provided at the CTF, but there will be
no storage facilities for treated oil within the CTF. Treated oil will be sent to PS No. 1 for
storage. The BS&W content of the treated oil flowing to PS No. 1 will be measured and wet
oil will be automatically diverted to the wet oil system.
Gas production from the fields will be handled separately from the emulsion. The Miandoum
gas and the Kom UK/Bolobo gas will have separate inlet systems. The gas streams from
the inlet separators will be combined and used as fuel gas for the power plant and the CTF.
Any liquids collected in this system will be sent to the emulsion treating system.
The following utility systems will be provided at the CTF:
Fire Water
Potable and Utility Water
Pressure Relief and Flare
Instrument and Utility Air
Chemical Storage and Injection
Fuel Systems (Oil and Gas)
Process and Open Drain System
Sanitary Sewer
Hot Water Heating System
Electric Power
Diesel Crude Oil Topping Plant
Waste Incinerator (located in Kom field)
Landfill remote from CTF.
4.1.8 Automation
The Automation System will be designed to meet the functional requirements of the process
design with safety of personnel, environment, and equipment paramount in the philosophy.
Other major considerations are reliability cost and accuracy over the life of the development
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location will have a standalone, programmable logic controller (PLC) based system for
emergency shutdown.
The Automation and Control System will be a hybrid system based on PLCs. An operator
controls facilities located at the CTF, gathering stations, and field sites (wellsites, manifolds, and
pump stations) from the CTF control room. The field information for wellsites, pump stations,
and manifolds will be relayed via telecommunications through the CTF Control System to the
gathering stations. Packaged equipment PLCs will either be connected directly to the Control
System via serial link or interfaced via the Telecommunications System.
Each gathering station Control System will communicate with the CTF Control System via
redundant digital microwave links. Wellsites, manifolds, and pump stations will be polled using
digital VHF (very high frequency) radios.
4.1.9 Power System Facilities
This section provides an overview and the associated details pertaining to the electrical power
generation, transmission, and distribution system.
4.1.9.1 Overview
A power plant of 120 megawatts (MW) capacity will be installed to meet a peak electric power
demand of approximately 105 MW. Sixty-hertz electric power will be generated at the OC power
station and transmitted by high voltage pole line to the Kom, Miandoum, and Bolobo fields
facilities and wells. Approximately 70 percent of the power demand is for the well ESPs.
The power system will be dedicated and isolated because no existing power system is available
in the Doba Basin. The power system is designed to the necessary reliability to meet oil
production needs. Waste heat recovery from power generation will supply process heat to the
CTF and Kom gathering station.
4.1.9.2 Power Generation
Four combustion gas turbine generators (30 MW each, site rated) will be installed to meet the oil
field development area and PS No. 1 power requirements. During most of the projects life,
there will be at least one spare generator since the power demand in the oil field development
area is estimated to be below 90 MW However during years four through seven all four units
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system, fuel selection and forwarding skids, and diesel and treated crude storage tanks. The
fuel treatment equipment will be part of the CTF operation.
4.1.9.3 Fuel Systems
Combustion turbine generators (CTGs) will be operated on Miandoum crude, Kom LK gas, and
other associated gas. The turbines are fueled on either gas, crude or a combination of both.
The Miandoum crude will be treated by centrifuging, filtering, and heating before injection into
the turbines. Natural gas availability is limited; however, all available gas will be consumed in
the turbines. The CTG will also be capable of operating on #2 diesel fuel oil. Diesel fuel will beused during plant commissioning, and to start and stop the units.
4.1.9.4 Prime Mover Auxiliaries
All turbines will be supplied from the following common equipment:
Fuel gas filtration and preheat package
Diesel oil storage
Crude oil storage, preheat, and treatment
Instrument air system.
A black-start diesel engine-driven generator for starting under blackout conditions will be
required. This generator will provide the necessary station service and engine auxiliary power to
allow one generator set to be started.
4.1.9.5 Power Plant Building
The power plant will include a 33-kilovolt (kV) switchgear building and a combined control room
and electrical equipment building. The latter building will include the power system central
control room. The gas turbine generator sets will be housed in individual, free-standing factory
enclosures with a fire detection and suppression system.
4.1.9.6 Control
The power plant will be designed to operate with minimum operator intervention. One full-time
l t t ill b l t d t th l t t l Th l t t l
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plant. The power plant main operator panel will control and monitor auxiliaries common to all
generator sets. The power plant control room will house the electrical distribution control panel
that remotely controls and monitors 66-kV and 33-kV switching operations at the five fielddistribution substations. Adjacent to every generator set, there will be a standard,
manufacturer-supplied local generator set control panel.
4.1.9.7 Power Plant Electrical
Generators will be connected to the buswork in a manner that allows a high degree of flexibility
for generator, bus, and load switching. Generators will be bussed together through generatorstep-up transformers. Auxiliaries for each generator will be supplied from a central power plant,
service motor-control center located near the generator set supplied from the power plant
station service bus and with alternate supply from the black-start system.
4.1.9.8 Power Transmission System
Electric power will be transmitted from the power plant to the field locations as follows:
To 66-kV / 33-kV field distribution substations at Miandoum (M-1) and Bolobo (BP-1) by 66-
kV overhead transmission lines
To 33-kV field distribution substations at Kom (KP-1 and KP-2) by 33-kV overhead
transmission lines.
The overhead power lines will be designed for the high incidence of lightning in the area.Transmission lines will share a common utility corridor with the pipelines when possible.
4.1.9.9 Power Distribution System
Overhead distribution feeders (33-kV) will supply power from each of the five field distribution
substations to the producing wells. Each feeder will supply between 6 to 12 ESPs. For each
ESP, the 33-kV overhead feeder will be tapped. The tap will be terminated approximately 50 m
from the well at a pole-mounted, fused disconnect. Other voltages for operating wellhead
equipment, such as 24-volt direct current for the ESP-PLC, will be made available by
transforming from the ESP supply lines.
4.1.9.10 Facility Power Distribution
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Switchgear and motor control centers will be in substation buildings. All power transformers will
be oil-filled and located outdoors.
4.1.10 Operations Center Infrastructure
The field Operations Center (OC) infrastructure facilities will include the following:
Community
Airfield
Utilities (see Section 4.1.7)
OC plant buildings
Primary and secondary field roads.
4.1.10.1 Community
The community will be located within the OC as shown in Figure 4-3. It will provide the followingfacilities:
Living quarters to accommodate 200 single-status people
Cafeteria and kitchen to serve midday meals for 385 people (185 day workers and 200
residents) and morning and evening meals for the 200 residents
Recreation center and outdoor sports facilities for the residents
Accommodations for support services staff and equipment
Laundry facilities to wash linens and personal clothing of residents and work clothes of all
employees
Fire protection for the community including the following:
- Hydrants- Hose reels
- Sprinkler systems
- Smoke detectors
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4.1.10.2 Airfield
An airfield will be constructed to provide air transport during construction and subsequentoperations. This airfield will provide for freight transport, personnel rotation, medical emergency
evacuation, and total emergency evacuation of expatriate employees.
The airfield will be a completely fenced, private facility and will operate during daylight hours
under visual flight rules. The runway bearing surface will permit operation throughout the entire
year. Its length will be approximately 3,200 m allowing material transportation by an
Anotonov 124 aircraft. The airfield will be located southeast of the community as shown inFigure 4-3.
4.1.10.3 OC Plant Buildings
The OC plant will have the following major buildings:
Administration Building
CTF Control Center and Motor Control Center Buildings
Mechanical, Electrical, and Instrumentation Maintenance Building
General Warehouse
Training Center and Vehicle Maintenance Building
ESP Maintenance Building
Power Plant Building
Guard House.
4.1.10.4 Roadways
An all-weather laterite road will connect the OC facilities to the Moundou-Sahr road at Bbdjia.
The OC facilities will in turn be connected to field facilities and wellsites by upgraded existing
laterite roads or new laterite roads. The road connecting the airfield, the community, and the OC
plant will have an asphalt surface on a laterite base. Major roads within the OC plant and
gathering stations will also have an asphalt surface on a laterite base.
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gathering station, bringing them close to mechanical completion. The majority of the interfield
pipelines, manifolds, and overhead electrical power lines will be installed during this time. Work
in the final six months will shift to precommissioning activities to prepare the facilities for start-up. Throughout the construction phase, wells will continue to be drilled and civil work
associated with drill pad and road construction will be ongoing. Forty percent of the drilling will
be completed at first oil.
4.2.1 Site Preparation
Site preparation includes clearing and grubbing, contouring, and laying down a laterite base toseal underlying soils, provide for water runoff, and establish a stable platform for construction.
Depending on subsoil conditions, excavation and recompaction will be required where large
tanks and heavy equipment are located.
Erosion control features will include localized silt fences and drainage course impediments to
slow runoff and contain sediment prior to reaching the sediment basins. Temporary drainage
channels will direct runoff to sediment basins to be used where possible for dust control.
Topsoil from the clearing and grubbing operations will be stockpiled for later use. The grading
operations and extent of the site preparation effort will be dependent upon the rainy season.
Excavation and other earthmoving activities will be kept to a minimum during the rainy season.
Borrow sources for construction materials, such as sand and gravel, will be selectively
developed to minimize the number of disturbed areas. Where possible, local businesses will
supply and transport materials to the job site.
During construction, old exploration infrastructure, well pads, and borrow pits will be
rehabilitated. Laterite from abandoned well pads or airstrips will be reused in developing new
facilities to reduce the number of new borrow pits. Topsoil stripped from clearing and grubbing
operations will be used for rehabilitation of old facility sites and borrow pits. Excess topsoil
stored for more than six months will be fortified with fertilizers, soil enhancers, or other organic
materials to maintain viability.
4.2.2 Roads
Upgrading of existing roads and construction of new roads will conform to a typical roadway
cross section (Figure 4-4). Topsoil will be stockpiled and erosion control features will be
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for the operations staff. Also included in these initial facilities will be the construction material
laydown area and establishment of a fuel storage facility. Rather than using trailers for a
construction camp, preferentially buildings will be constructed using local materials. The initialphase of activity will also include construction of a sanitary landfill as part of the overall waste
management program.
4.2.4 Plant and Pipeline Construction
After completion of site preparation activities, underground utilities and flowline work will begin
with trenching and establishment of a pipe fabrication shop. Along with this underground work,foundation excavations and concrete pours will be completed. Field pipeline activities will follow
the same general construction techniques used for the Transportation System pipeline. Tank,
structural steel, and building construction will follow foundation preparation.
Setting of mechanical and electrical equipment such as turbine generators, pumps, vessels,
and heat exchangers will commence once quality checks are complete for concrete and
structural steel work. Plant piping, electrical, and instrumentation work will conclude themechanical completion of the facilities. Final pre-commissioning activities, such as instrument
calibration, equipment alignment, and startup verification of equipment will then take place.
4.2.5 Construction Staffing
The construction contractors will determine the size of the construction staff used for the project.
The anticipated construction staff for the oil field development area will consist of approximately
2,000 Chadian nationals and 1,000 expatriates during the peak construction period. Chadians
generally will provide their own housing, with the construction contractor providing transportation
from collection points in the villages. For expatriates, the existing Kom drilling camp will be
utilized prior to completion of the main construction camp. This camp will continue to be used
by drilling personnel during the development phase. Most expatriates will be housed in the
main construction camp at Kom which will house 800 to 1,000 people during peak occupancy.
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Section TOC
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SCHEMATIC FLOW DIAGRAMFOR
OIL PRODUCTION AND TREATMENT
MIANDOUMPRODUCING
WELLS
KOMPRODUCING
WELLS
BOLOBO
WELLSPRODUCING
KOM FIELDMANIFOLDS
ANDFIELD PUMP
STATIONS
BOLOBOFIELD
MANIFOLDS
MIANDOUMFIELD
MANIFOLDS
STATION
KOMGATHERING
BOLOBO
STATIONFIELD PUMP
MIANDOUM
STATIONGATHERING
MIANDOUMPRODUCED WATER
REINJECTION WELLS
KOMPRODUCED WATER
REINJECTION WELLS
CENTRALTREATINGFACILITY
No. 1
PUMP STATION
99% OIL
99% OIL
PIPELINE
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0 1 2
Approximate Scale in Kilometers
OPERATIONS CENTER
COMPONENTS
N
S
EW Kom Gathering StationCentral Treating FacilityPower PlantPump Station No. 1Administrative OfficesClinicOperations / Maintenance Center
Airfield(3200 meter airstrip)
Pipeline
Community
FIGURE 4-3
DM
GROGRO P
D & MAMES OOREDD O O OP C POR R
Chad Export Project
Section TOC
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TYPICAL
OIL FIELD DEVELOPMENT AREAROADWAY CROSS SECTION
Not to Scale
2.50 m3.00 m
2.50 m3.00 m1.00 m 1.50 m 1.00 m
5.00 mVegetation Clearing
0.50 m 0.50 m
Earthmoving Level
NOTES
1. Laterite thickness variable from 15-30 cm.
2. Road widths reduced through villages as required.
3. Regional roads inside oil field development area to include pedestrian path (not shown).
4. Ditch size/slope variable and sized to accommodate water level.
3%3%
1 13 22 3
1 1
FIGURE 4-4
DM
GROGRO P
D & MAMES OOREDD O O OP C POR R
Chad Export Project
(Field Roads)(Regional Roads)
Next ChapterSection TOC