3. Sistemas de Producci+¦n 3 Fluidos.pptx

8/11/2019 3. Sistemas de Producci+¦n 3 Fluidos.pptx

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SISTEMAS DE PRODUCCION

EL RESERVORIO Y SUCOMPORTAMIENTO



PETROLEUM FLUIDS



GAS-OIL CONTACT

OIL-WATER CONTACT

SPILL POINT

BOTTOM WATER EDGE WATEREDGE WATER

GAS CAP

OIL ZONE

WATER ZONE

GAS

OIL

WATER WATER

CLOSURE

Typical Petroleum in Reservoirs



Types of Reservoir Fluids

• The behavior of a reservoir fluid during production is

determined by the shape of its phase diagram and the

position of its critical points

• Type and size of surface equipment, calculation

procedures to determine OOIP or OGIP, estimation of

reserves, selection EOR method all depend on the typeof reservoir fluids



The Five Reservoir Fluids

Black oil Volatile oilGas condensate (condensate)Wet gas

Dry gas



Phase Diagram

Bubble point pressureThe pressure at which gas bubbles start to form from liquid

Dew point pressure

The pressure at which liquid droplets start to form from gasQuality lines

Lines of constant liquid volume fractionCritical point

A point where gas and liquid properties are identicalPressure path

Line of constant temperature drawn from reservoir pressure



Black Oils – consist of wide variety of chemical species including

large, heavy, nonvolatile molecules. The phase diagram predictably

covers a wide temperature range.



Black Oils

Undersaturated reservoirReservoir pressure is above the bubble point

Saturated reservoirReservoir pressure is below the bubble point



OIL-WATER CONTACT

SPILL POINT

OIL

WATER WATER

Undersaturated Oil Reservoir

High Press.&Temp

Pressure

Temperature

OIL

Gas-Small Vol.- Flare or- use as Fuel



OIL-WATER CONTACT

SPILL POINT

OIL

WATER WATER

Saturated Oil Reservoir

High Press.&Temp

Pressure

Temperature

OIL

Gas- Large

- Sales

Gas



Volatile Oils – contain relatively fewer heavy molecules and

more intermediates (defined as ethane through hexanes). Volatile

oils have been called high-shrinkage crude and near-critical oil



Retrograde Gases – are also called retrograde condensate

gases, gas condensates, or condensates. The phase diagram of a

retrograde gas is somewhat smaller than that for oils, and the critical

points is further down the left side of the envelope



OIL-WATER CONTACT

SPILL POINT

Gas

WATER WATER

Gas Condensate Reservoir

High Press.&Temp

Pressure

Temperature

Condensate

Gas

Press.Drop





OIL-WATER CONTACT

SPILL POINT

Gas

WATER WATER

Wet Gas Reservoir

High Press.&Temp

Pressure

Temperature

Condensate

Gas



Dry Gas – is primarily methane with some intermediates.



OIL-WATER CONTACT

SPILL POINT

Gas

WATER WATER

Dry Gas Reservoir

High Press.&Temp

Pressure

Temperature

Water

Gas



PROPERTIES

OF PETROLEUM FLUIDS



Properties of Oil

Specific gravityFormation volume factor

Solution gas oil ratioTotal formation volume factorIsothermal compressibility of oil

Viscosity of oil





Formation Volume Factor of Oil

conditionsstandardatoilof volumeconditionsreservoiratgas)dissolvedof volumeoilof (volume

oB



Solution Gas Oil Ratio

conditionsstandardatstock tank enteringoilof volumeconditionsstandardatsurfaceat producedgassolutionsolutionof volume

s R





Isothermal Compressibility of Oil

T T o p

V pV

V c

ln1



Isothermal Compressibility of Oil

T T o p

V pV

V c

ln1



Viscosity of Oil



Properties of Gas

Compressibility factorDensity of real gas

Apparent molecular weightSpecific gravity of gasGas formation volume factorIsothermal compressibility of gas

Viscosity of oil



Compressibility factor

pV = znRT

ideal

actual

V V

z

pc pr p

p p pc

pr T T T

jcj j pc T yT

jcj j pc p y p

G C ibili F



Gas Compressibility Factor





Pseudocritical Pressure



Pseudocritical Pressure





Pseudocritical Temperature





Gas Formation Volume Factor

sc

R g V

V B

scf bblres00502.0

p zT B g

scf ftcu

0282.0 p

zT B g





T

g p z

z pc

11

T

g pV

V c

1

Isothermal compressibility of gas



Isothermal compressibility of gas



Gas Viscosity



Gas Viscosity



Fluid Sampling

Subsurface Sampling- Subsurface sampling chamber- Repeat formation tester (RFT)- Modular dynamic testing tool (MDT)

Surface Sampling- Take samples of the two phases (gas and liquid)- Recombine the two fluids



Reservoir Fluid Study (PVT Analysis)

Flash Vaporization

- A sample is placed in a laboratory cell- Pressure is adjusted to a value equal to or greater than

initial reservoir pressure- Temperature is set at reservoir temperature- Pressure is reduced by increasing the volume in increments- No gas or liquid is removed from the cell

- At each step, the pressure and volume are measured- These measurements are used to determine fluid properties



Reservoir Fluid Study (PVT Analysis)

Differential Vaporization

- A sample is placed in a laboratory cell

- Pressure is adjusted to the bubble point pressure- Temperature is set at reservoir temperature- Pressure is reduced by increasing the volume in increments- Gas is removed from the cell while the pressure is held

constant by reducing the cell volume- At each step, the quantity and specific gravity of the gas

and the volume remained the cell are measured- These measurements are used to determine fluid properties



Rock Properties

PorosityFraction of the void space in the reservoir rockFluid Saturation

Fraction of the pores of the rock that are filled withspecific fluidsPermeability

Ability to allow fluid to flow through interconnectedporesRock Compressibility

Ability of the rock to compress or expand as thepore pressure increases or decreases



Porosity

= porosity, fraction Vb = bulk volume of the reservoir rock Vgr = grain volume

Vp = pore volume

b

p

b

gr b

V V

V V V



Fluid Saturation

So = oil saturationSg = gas saturationSw = water saturation

Vo = volume of oil in the rock

Vg = volume of gas in the rock Vw = volume of water in the rock Vp = pore volume of the rock

p

ww

p

g g

p

oo V

V S V V S

V V S



Permeability

q = flow ratek = permeability

A = cross sectional area

µ = viscosityp = change in pressureL = length

L pkAq



Rock Compressibility

p

V

V c p

pr

1

cr = rock compressibility Vp = pore volume



Fluid Flow in Porous Media

Darcy’s law - Linear flow

- Radial flow Vogel modelFetkovich model

Jones, Blount, and Glaze model



Darcy’s Law for Linear Flow

L B

p p Ak q

oo

oo

21310127.1

22

1622

21

10247.193.8 sc

g sc

g

g q A

T L Z q

Ak

T L Z p p



Darcy’s Law for Radial Flow

weoo

wf eoo r r B

p phk q/ln

00708.0

weoo

wf Ro

o r r B

p phk

q /472.0ln

00708.0

we g

wf R g sc

r r T Z

p phk q

/472.0ln

10703 226



Reservoir Pressure Profile



Productivity Index (PI)

wf R

oo

p pq

J weoo

oo r r B

hk J

/472.0ln00708.0

22

wf R

g g

p p

q J

we g

g g

r r T Z

hk J

/472.0ln

10703 6



Vogel Equation

2

m ax,

8.02.01

R

wf

R

wf

o

o

p

p

p

p

qq

2

8.02.018.1 b

wf

b

wf bbo p

p

p

p p J qq

wf Roo p p J q

For saturated reservoirs,

For undersaturated reservoirs,



Vogel’s Dimensionless IPR



Inflow Equation

Fetkovich Model

Jones, Blount, and Glaze Model

n

wf R p pcq 22

2q Bq A p p wf R



Volumetric Depletion Gas Reservoir



OIL-WATER CONTACT

Gas

p

High Press.&Temp

Pressure

Temperature

Gas

Water Drive Gas Reservoir



OIL-WATER CONTACT

SPILL POINT

Gas

WATER WATER

High Press.&Temp

Pressure

Temperature

Water

Gas

h



Drive Mechanisms

Oil reservoirs

Solution gas driveGas cap driveWater drive

Solution Gas Drive Reservoir



OIL-WATER CONTACT

OIL

Solution-Gas Drive Reservoir

High Press.&Temp

Pressure

Temperature

OIL


Gas Cap Drive Reservoir



OIL-WATER CONTACT

OIL

Gas-Cap Drive Reservoir

High Press.&Temp

Pressure

Temperature

OIL

Gas- Large- Sales

Gas

W t D i U d t t d R i



OIL-WATER CONTACT

SPILL POINT

OIL

WATER WATER

Water-Drive Undersaturated Reservoir

High Press.&Temp

Pressure

Temperature OIL


Water

Water Drive Saturated Reservoir



OIL-WATER CONTACT

SPILL POINT

OIL

WATER WATER

Water-Drive Saturated Reservoir

High Press.&Temp

Pressure

Temperature OIL

Gas- Large- Sales

Gas

Water



Recovery Factor

Solution Gas Drive 5 – 20%Gas Cap Drive 20 – 40%

Water Drive 40– 60%Compaction Drive Up to +10%

Also depend on reservoir rock and fluid

properties, development plan, andeconomic conditions

3. Sistemas de Producci+¦n 3 Fluidos.pptx

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