Hydrocarbon Reservoir SystemHydrocarbon Reservoir System(Basic Approach for Non Petroleum People)(Basic Approach for Non Petroleum People)

P R E P A R E D B Y D . M U L Y O N O ( P E T R O L E U M E N G I N E E R )S E R I E S O F C O N T I N U O U S L E S S O N & L E A R N F O R I F F

D U K H A N C O M M U N I T YJ U N E 2 3 R D 2 0 1 2

Basic elements of Petroleum Systems Describe plate tectonics and sedimentary basins Recognize names of major sedimentary rock types Describe importance of sedimentary environments to petroleum

industry Describe the origin of petroleum Identify hydrocarbon trap types Define and describe the important geologic controls on reservoir

properties, porosity and permeability

Objectives for the participants (at least…..)knowing & if possible having interestTo know further the topics of :

Basic elements of Petroleum Systems Describe plate tectonics and sedimentary basins Recognize names of major sedimentary rock types Describe importance of sedimentary environments to petroleum

industry Describe the origin of petroleum Identify hydrocarbon trap types Define and describe the important geologic controls on reservoir

properties, porosity and permeability

• Petroleum Systems approach• Geologic Principles and geologic time• Rock and minerals, rock cycle, reservoir properties• Hydrocarbon origin, migration and accumulation• Sedimentary environments and facies; stratigraphic

traps• Plate tectonics, basin development, structural geology• Structural traps

• Petroleum Systems approach• Geologic Principles and geologic time• Rock and minerals, rock cycle, reservoir properties• Hydrocarbon origin, migration and accumulation• Sedimentary environments and facies; stratigraphic

traps• Plate tectonics, basin development, structural geology• Structural traps

READY……..

S T A R T……….DOR…DOR…..

1. Hydrocarbon in General & Specific

2. Petroleum Geology System

3. Rock Properties

4. Hydrocarbon Generation, Migration & Accumulation

5. Hydrocarbon Traps & Heterogeneity

6. Reservoir Classification

7. Reservoir Driving Mechanism

8. Reservoir Calculation in General

9. Petroleum System Summary

What need to be learned……??

1. Hydrocarbon in General & Specific

2. Petroleum Geology System

3. Rock Properties

4. Hydrocarbon Generation, Migration & Accumulation

5. Hydrocarbon Traps & Heterogeneity

6. Reservoir Classification

7. Reservoir Driving Mechanism

8. Reservoir Calculation in General

9. Petroleum System Summary

Hydrocarbon in General & Specific

What is Hydrocarbon…?

What is Hydrocarbon Reservoir

What Kinds of Reservoir

Why need study Petroleum Reservoir….?

How it is found by the Petroleum Expertise…?

What is Hydrocarbon…?

What is Hydrocarbon Reservoir

What Kinds of Reservoir

Why need study Petroleum Reservoir….?

How it is found by the Petroleum Expertise…?

Main natural source:

natural gase(up to 97% of methane; ethane,propane, CO2, N2)

petroleum(mixture of aliphatic, alicyclic, andpolycyclichydrocarbons C1-C50; thecomposition varies with its

location).

What is Hydrocarbon……?

fractions of petroleum: gas (C1-C4) ~ cooking gas

petroleum ether (C5-C6) ~solvent for org. chemicals

gasoline (C6-C12) ~ automobilefuel

kerosene (C11-C16) ~ rocketand jet fuel

fuel oil (C14-C18) ~ domesticheating

lubricating oil (C15-C24) ~lubricants for automobiles andmachines

Main natural source:

natural gase(up to 97% of methane; ethane,propane, CO2, N2)

petroleum(mixture of aliphatic, alicyclic, andpolycyclichydrocarbons C1-C50; thecomposition varies with its

location).

fractions of petroleum: gas (C1-C4) ~ cooking gas

petroleum ether (C5-C6) ~solvent for org. chemicals

gasoline (C6-C12) ~ automobilefuel

kerosene (C11-C16) ~ rocketand jet fuel

fuel oil (C14-C18) ~ domesticheating

lubricating oil (C15-C24) ~lubricants for automobiles andmachines

Alkanes – saturated hydrocarbons(CnH2n+2)

methane ethane hexane

3-methylpenthane

! Alkanes are not planar !

A reservoir is that volume of rock that occurs down dip of a sealand up dip of the 100% Sw oil-free level. The HCs in the pore arein pressure and Sw equilibrium with the free water level

A petroleum reservoir is an accumulation of hydrocarbon(oil-gas-water) in porous rock

What is a Hydrocarbon reservoir..?

A reservoir is that volume of rock that occurs down dip of a sealand up dip of the 100% Sw oil-free level. The HCs in the pore arein pressure and Sw equilibrium with the free water level

What Kinds of Hydrocarbon Reservoir….?

Silica clastic

Carbonate

Fracture

Silica clastic

Carbonate

Fracture

Not Deep – Water

Alluvial fanMeandering riverBraided riverStraight riverMix Aeolian/ fluvialLacustrine deltaEstuaryShelf/ShorelineCoastal plainTidal flatBarrier-island/lagoonDeltaMarine fan deltaWave dominated delta

Deep – Water

DebrisMud-rich slope basinSubmarine canyonSubmarine fan channelSubmarine fan lobeGravel-rich slope

Reservoir Classification base on water deep

Not Deep – Water

Alluvial fanMeandering riverBraided riverStraight riverMix Aeolian/ fluvialLacustrine deltaEstuaryShelf/ShorelineCoastal plainTidal flatBarrier-island/lagoonDeltaMarine fan deltaWave dominated delta

Deep – Water

DebrisMud-rich slope basinSubmarine canyonSubmarine fan channelSubmarine fan lobeGravel-rich slope

Not Deep – Water

Deep – Water

Petroleum Geology System

Basic elements of Petroleum Systems Describe plate tectonics and sedimentary basins Recognize names of major sedimentary rock types Describe importance of sedimentary environments to petroleum

industry Describe the origin of petroleum Identify hydrocarbon trap types Define and describe the important geologic controls on reservoir

properties, porosity and permeability

Objectives for the participantsat least…can understand the topics of :

Basic elements of Petroleum Systems Describe plate tectonics and sedimentary basins Recognize names of major sedimentary rock types Describe importance of sedimentary environments to petroleum

industry Describe the origin of petroleum Identify hydrocarbon trap types Define and describe the important geologic controls on reservoir

properties, porosity and permeability

Cross Section Of A Petroleum System

Geographic Extent of Petroleum System

(Foreland Basin Example)

O OOStratigraphic

Extent ofPetroleum

Extent of Prospect/FieldExtent of Play

Overburden Rock

Seal Rock

Reservoir Rock

Source Rock

Underburden Rock

Basement Rock

Top Oil WindowTop Gas Window

Petroleum Reservoir (O)

Fold-and-Thrust Belt(arrows indicate relative fault motion)

EssentialElements

ofPetroleum

System

(modified from Magoon and Dow, 1994)

Sedi

men

tary

Bas

in F

ill

PetroleumSystem

Pod of ActiveSource Rock

0

50

100

150

200

250

0

10

20

30

40

50Cry

ptoz

oic

(Pre

cam

bria

n)

Phanerozoic

Quaternary

Tertiary

Cretaceous

Jurassic

TriassicM

illio

ns o

f yea

rs a

go

Mill

ions

of y

ears

ago

Bill

ions

of y

ears

ago

0

1

2

3 Eocene

Oligocene

Miocene

PliocenePleistoceneRecent

Qua

tern

ary

perio

dTe

rtia

rype

riod

Eon Era Period Epoch

Geologic Time Chart

Mes

ozoi

c

Cen

ozoi

c E

ra

250

300

350

400

450

500

550

600

50

60

Cry

ptoz

oic

(Pre

cam

bria

n)

PermianPennsylvanian

Mississippian

Devonian

Silurian

Ordovician

Cambrian

Mill

ions

of y

ears

ago

Mill

ions

of y

ears

ago

Bill

ions

of y

ears

ago

3

4

4.6

PaleoceneP

aleo

zoic

Cen

ozoi

c E

ra

D I V I S I O N S O F G E O L O G I C T I M EE o n E r a P e r i o d E p o c h

A g e ( a p p r o x . )in m il l io n s o f

y e a r s

Ceno

zoic

Meso

zoic

Paleo

zoic

Phan

erozo

ic

Carbo

nifero

us

P e n n s y l v a n i a n

M i s s i s s i p p i a n

T e r t i a r y

Q u a t e r n a r y

C r e t a c e o u s

J u r a s s i c

T r i a s s ic

P e r m i a n

D e v o n ia n

S i l u r ia n

O r d o v i c i a n

C a m b r i a n

H o lo c e n eP l e i s t o c e n e

P l i o c e n eM i o c e n e

O l i g o c e n eE o c e n e

P a l e o c e n eL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

M i d d l eE a r l yL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

M i d d l eE a r l y

0 . 0 1 01 . 6

52 33 55 76 59 7

1 4 61 5 71 7 82 0 82 3 52 4 12 4 52 5 62 9 03 0 33 1 13 2 33 4 53 6 33 7 73 8 64 0 94 2 44 3 94 6 44 7 65 1 05 1 75 3 65 7 0

Geologic Time ScaleModified From Harland (1990) and Hansen (1991).

D I V I S I O N S O F G E O L O G I C T I M EE o n E r a P e r i o d E p o c h

A g e ( a p p r o x . )in m il l io n s o f

y e a r s

Ceno

zoic

Meso

zoic

Paleo

zoic

Phan

erozo

ic

Carbo

nifero

us

P e n n s y l v a n i a n

M i s s i s s i p p i a n

T e r t i a r y

Q u a t e r n a r y

C r e t a c e o u s

J u r a s s i c

T r i a s s ic

P e r m i a n

D e v o n ia n

S i l u r ia n

O r d o v i c i a n

C a m b r i a n

H o lo c e n eP l e i s t o c e n e

P l i o c e n eM i o c e n e

O l i g o c e n eE o c e n e

P a l e o c e n eL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

M i d d l eE a r l yL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

E a r l yL a t e

M i d d l eE a r l yL a t e

M i d d l eE a r l y

0 . 0 1 01 . 6

52 33 55 76 59 7

1 4 61 5 71 7 82 0 82 3 52 4 12 4 52 5 62 9 03 0 33 1 13 2 33 4 53 6 33 7 73 8 64 0 94 2 44 3 94 6 44 7 65 1 05 1 75 3 65 7 0

Basic Geologic Principles

Uniformitarian's Original Horizontality Superposition Cross-Cutting

Relationships

Uniformitarian's Original Horizontality Superposition Cross-Cutting

Relationships

Cross-Cutting Relationships

GHIJK

Angular Unconformity

A

B

C

D

EF

G

IgneousDike

1. Disconformities- An unconformity in

which the beds above andbelow are parallel

Types of Unconformities

2. Angular Unconformity– An unconformity in

which the olderbed intersect theyounger beds at anangle

3. Nonconformity– An unconformity in

which youngersedimentary rocksoverlie oldermetamorphic orintrusive igneousrocks

Types of Unconformities (Continue….)

2. Angular Unconformity– An unconformity in

which the olderbed intersect theyounger beds at anangle

3. Nonconformity– An unconformity in

which youngersedimentary rocksoverlie oldermetamorphic orintrusive igneousrocks

Types of Unconformities (Continue….)

Correlation Establishes the age

equivalence of rock layers indifferent areas

Methods: Similar lithology Similar stratigraphic

section Index fossils Fossil assemblages Radioactive age dating

Establishes the ageequivalence of rock layers indifferent areas

Methods: Similar lithology Similar stratigraphic

section Index fossils Fossil assemblages Radioactive age dating

Rocks & Properties

Classification of Rocks

SEDIMENTARYIGNEOUS METAMORPHIC

Roc

k-fo

rmin

gpr

oces

sSo

urce

of

mat

eria

l

Molten materials indeep crust andupper mantle

Crystallization(Solidification of melt)

Weathering anderosion of rocks

exposed at surface

Sedimentation, burialand lithification

Rocks under hightemperatures

and pressures indeep crust

Recrystallization due toheat, pressure, or

chemically active fluids

The Rock Cycle

Magma

MetamorphicRock

IgneousRock

Heat and Pressure

SedimentaryRock Sediment

Weathering,Transportationand Deposition

an

i

Sedimentary Rock Types

• Relative abundance Sandstoneand conglomerate

~11%

Limestone anddolomite

~13%

Siltstone, mudand shale

~75%

Limestone anddolomite

~13%

Average Detritus Mineral Compositionof Shale and Sandstone

Mineral Composition Shale (%) Sandstone (%)Clay Minerals

Quartz

60

30

5

65

Feldspar

Rock Fragments

Carbonate

Organic Matter,Hematite, andOther Minerals

4

<5

3

<3

10-15

15

<1

<1

(modified from Blatt, 1982)

Some Common Minerals

Silicates

Oxides Sulfides Carbonates Sulfates Halides

AnhydriteGypsum

HaliteSylvite

AragoniteCalciteDolomiteFe-DolomiteAnkerite

PyriteGalenaSphalerite

HematiteMagnetite

Non-Ferromagnesian(Common in Sedimentary Rocks)

Ferromagnesian(not common in sedimentary rocks)

QuartzMuscovite (mica)Feldspars

Potassium feldspar (K-spar)OrthoclaseMicrocline, etc.

PlagioclaseAlbite (Na-rich - common) throughAnorthite (Ca-rich - not common)

OlivinePyroxene

AugiteAmphibole

HornblendeBiotite (mica)

Red = Sedimentary Rock-Forming Minerals

The Four Major Components

Framework Sand (and Silt) Size Detrital Grains

Matrix Clay Size Detrital Material

Cement Material precipitated post-depositionally, during

burial. Cements fill pores and replace frameworkgrains

Pores Voids between above components

Framework Sand (and Silt) Size Detrital Grains

Matrix Clay Size Detrital Material

Cement Material precipitated post-depositionally, during

burial. Cements fill pores and replace frameworkgrains

Pores Voids between above components

Pores Provide theVolume to ContainHydrocarbon Fluids

Pore Throats RestrictFluid Flow

PoreThroat

Porosity in Sandstone

Scanning Electron MicrographNorphlet Formation, Offshore Alabama, USA

Pores Provide theVolume to ContainHydrocarbon Fluids

Pore Throats RestrictFluid Flow

PRF

KF = PotassiumFeldspar

PRF = Plutonic RockFragment

Sandstone Composition Framework Grains

Norphlet Sandstone, Offshore Alabama, USAGrains are About =< 0.25 mm in Diameter/Length

PRF KF

P

Fragment

P = Pore

Potassium Feldspar isStained Yellow With aChemical Dye

Pores are ImpregnatedWith Blue-Dyed Epoxy

CEMENT

100

10

1

10

100

1000

Perm

eabi

lity

(md)

Authigenic Illite Authigenic Chlorite

Effects of Clays on Reservoir Quality

1

0.1

0.01 0.01

0.1

1

2 6 10 14 2 6 10 14 18

Perm

eabi

lity

(md)

Porosity (%)(modified from Kugler and McHugh, 1990)

Dispersed Claye

ClayMinerals

Detrital QuartzGrains

Influence of Clay-Mineral Distribution onEffective Porosity

Clay Lamination

Structural Clay(Rock Fragments,

Rip-Up Clasts,Clay-Replaced Grains)

e

e

Fluids Affecting Digenesis

Precipitation

Meteoric

EvapotranspirationEvaporation

Infiltration

Water Table

Subsidence

CH4,CO2,H2S

PetroleumFluids

MeteoricWater

MeteoricWater

COMPACTIONALWATER

Zone of abnormal pressure

Isotherms

(modified from from Galloway and Hobday, 1983)

Dissolution ofFramework Grains(Feldspar, forExample) andCement mayEnhance theInterconnectedPore System

This is CalledSecondary Porosity

Pore

PartiallyDissolvedFeldspar

Dissolution Porosity

Thin Section Micrograph - Plane Polarized LightAvile Sandstone, Neuquen Basin, Argentina

Dissolution ofFramework Grains(Feldspar, forExample) andCement mayEnhance theInterconnectedPore System

This is CalledSecondary Porosity

Pore

Quartz DetritalGrain

(Photomicrograph by R.L. Kugler)

Hydrocarbon Gen, Migration, &Accumulation

Source Material

•Non-Biogenic Origins

•Biogenic (Kerogen Types)Type I – Algal (oil prone) sapropelicType II – MixedType III – Woody (gas prone) humic

•Host rock (Shales and Coals)

•Non-Biogenic Origins

•Biogenic (Kerogen Types)Type I – Algal (oil prone) sapropelicType II – MixedType III – Woody (gas prone) humic

•Host rock (Shales and Coals)

Types of Petroleum

Oil and gas are formed by the thermal cracking of organiccompounds buried in fine-grained rocks.

AlgaeAlgae == Hydrogen richHydrogen rich = Oil= Oil-- ProneProne

WoodWood == Hydrogen poor =Hydrogen poor = GasGas -- ProneProne

AlgaeAlgae == Hydrogen richHydrogen rich = Oil= Oil-- ProneProne

WoodWood == Hydrogen poor =Hydrogen poor = GasGas -- ProneProne

Kerogen TypesType 1 Type 2 Type 3

Source material, Transportation & Deposition

From the Paleontological Research Institute <http://www.priweb.org/ed/pgws/history/pennsylvania/pennsylvania.html>

Mahakam Delta PlainEast Kalimantan, Indonesia

(A Rich Source of Kerogen)

Petroleum System Processes

24803

Petroleum System ElementsPetroleum System Elements

120° F120° F

350° F350° FGenerationGeneration

MigrationMigration

Seal RockSeal Rock

ReservoirRockReservoirRock

OilOil

WaterWater

GasCapGasCap

EntrapmentEntrapmentAccumulationAccumulation

24803

Petroleum System ElementsPetroleum System Elements

120° F120° F

350° F350° FGenerationGeneration

MigrationMigration

Seal RockSeal Rock

ReservoirRockReservoirRock

OilOil

WaterWater

GasCapGasCap

EntrapmentEntrapment

SourceSourceRockRock

Cross Section Of A Petroleum System

Geographic Extent of Petroleum System

(Foreland Basin Example)

O OOStratigraphic

Extent ofPetroleum

Extent of Prospect/FieldExtent of Play

Overburden Rock

Seal Rock

Reservoir Rock

Source Rock

Underburden Rock

Basement Rock

Top Oil WindowTop Gas Window

Petroleum Reservoir (O)

Fold-and-Thrust Belt(arrows indicate relative fault motion)

EssentialElements

ofPetroleum

System

(modified from Magoon and Dow, 1994)

Sedi

men

tary

Bas

in F

ill

PetroleumSystem

Pod of ActiveSource Rock

Oil/watercontact (OWC)

Fault(impermeable)

Generation, Migration, and Trapping ofHydrocarbons

Reservoirrock

SealMigration route

Oil/watercontact (OWC)

Hydrocarbonaccumulation

in thereservoir rock

Top of maturity

Source rock

Fault(impermeable)

Interpretation of Total Organic Carbon (TOC)(based on early oil window maturity)

HydrocarbonGenerationPotential

TOC in Shale(wt. %)

TOC in Carbonates(wt. %)

Poor 0.0-0.5 0.0-0.2Poor

Fair

Good

Very Good

Excellent

0.0-0.5

0.5-1.0

1.0-2.0

2.0-5.0

>5.0

0.0-0.2

0.2-0.5

0.5-1.0

1.0-2.0

>2.0

Schematic Representation of theMechanism

of Petroleum Generation and DestructionOrganic Debris

Oil Reservoir

Diagenesis

Prog

ress

ive

Bur

ial a

nd H

eatin

g

(modified from Tissot and Welte, 1984)

Kerogen

Carbon

Initial Bitumen

Oil and Gas

Methane

MigrationThermal Degradation

Cracking

Catagenesis

MetagenesisProg

ress

ive

Bur

ial a

nd H

eatin

g

STOP………………………FOR LUNCH TIME……..

Hydrocarbons Trap

Structural traps

Stratigraphic traps

Combination traps

Structural traps

Stratigraphic traps

Combination traps

Oil

Hydrocarbon Traps - Dome

Gas

SandstoneShale

Structural Hydrocarbon Traps

Oil/WaterContact

GasOil/GasContact

Oil

ClosureOilShale Trap

Fracture Basement Fold Trap

SaltDiapir

(modified from Bjorlykke, 1989)

OilSalt

Dome

Oil/GasOil/Gas

Stratigraphic Hydrocarbon Traps

Uncomformity

Unconformity Pinch out

Oil/Gas

Channel Pinch Out

(modified from Bjorlykke, 1989)

Fault Trap

Oil / Gas

Asphalt Trap

Water

MeteoricWater

BiodegradedOil/Asphalt

PartlyBiodegraded Oil

Other Traps

Hydrodynamic Trap

Shale

OilWater

HydrostaticHead

(modified from Bjorlykke, 1989)

Heterogeneity

Reservoir Heterogeneity in SandstoneHeterogeneity

Segments Reservoirs

Increases Tortuosity ofFluid Flow

Heterogeneity MayResult From:

Depositional Features

Diagenetic Features

(Whole Core Photograph, MisoaSandstone, Venezuela)

Reservoir Heterogeneity in Sandstone

Heterogeneity Also MayResult From:Faults

Fractures

Faults

Fractures

Faults and Fractures maybe Open (Conduits) orClosed (Barriers) to FluidFlow

(Whole Core Photograph, MisoaSandstone, Venezuela)

BoundingSurface

Geologic Reservoir Heterogeneity

BoundingSurface

Eolian Sandstone, Entrada Formation, Utah, USA

Scales of Geological Reservoir Heterogeneity

Fiel

d W

ide

Inte

rwel

lDetermined

From Well Logs,Seismic Lines,

StatisticalModeling,

etc.

100'sm

10's

1-10 km

Well WellInterwell

Area

Reservoir

Inte

rwel

lW

ell-B

ore

(modified from Weber, 1986)

Hand Lens orBinocular Microscope

Unaided Eye

Petrographic orScanning Electron

Microscope

10-100'sm

10-100'smm

1-10'sm

10'sm

100's m

ReservoirSandstone

Scales of Investigation Used inReservoir Characterization

Gigascopic Well Test

Reservoir Model

Relative Volume

1014

300 m

50 m

300 m

Megascopic

Macroscopic

Microscopic

Reservoir ModelGrid Cell

Wireline LogInterval

Core Plug

GeologicalThin Section

1

2 x 1012

3 x 107

5 x 102

300 m

5 m 150 m

2 m1 m

cm

mm - m

(modified from Hurst, 1993)

Classification of Hydrocarbon Reservoir

Petroleum reservoirs are broadly classified asoil or gas reservoirs.

The composition of the reservoir hydrocarbonmixture

Initial reservoir pressure and temperature

Classification of Hydrocarbon Reservoir

Petroleum reservoirs are broadly classified asoil or gas reservoirs.

The composition of the reservoir hydrocarbonmixture

Initial reservoir pressure and temperature

Pressure Temperature Diagram

Figure 1-1• shows a typical pressure-temperature diagram of multi component

system with a specific overall composition. Although differenthydrocarbon system would have a different phase diagram, thegeneral configuration is similar.

These multi component pressure-temperature diagrams are essentiallyused to:

• Classify reservoirs• Classify the naturally occurring hydrocarbon systems• Describe the phase behavior of the reservoir fluid

Pressure Temperature Diagram

Figure 1-1• shows a typical pressure-temperature diagram of multi component

system with a specific overall composition. Although differenthydrocarbon system would have a different phase diagram, thegeneral configuration is similar.

These multi component pressure-temperature diagrams are essentiallyused to:

• Classify reservoirs• Classify the naturally occurring hydrocarbon systems• Describe the phase behavior of the reservoir fluid

Critical point• The critical point for a multi component mixture is referred to as the

state of pressure and temperature at which all intensive properties ofthe gas and liquid phases are equal (point C). At the critical point, thecorresponding pressure and temperature are called the criticalpressure pc and critical temperature Tc of the mixture.

Pressure Temperature Diagram (Continue...)

Bubble-point curve• The bubble-point curve (line BC) is defined as the line separating the

liquid phase region from the two-phase region.

Bubble-point curve• The bubble-point curve (line BC) is defined as the line separating the

liquid phase region from the two-phase region.

Dew-point curve• The dew-point curve (line AC) is defined as the line separating the

vapor-phaseregion from the two-phase region.

Oil Reservoirs• If the reservoir temperature

T is less than the criticaltemperature Tc of thereservoir fluid, the reservoiris classified as an oil reservoir.

Pressure Temperature Diagram (Continue...)

Gas reservoirs• If the reservoir temperature

is greater than the criticaltemperature of thehydrocarbon fluid, thereservoir is considered a gasreservoir.

Gas reservoirs• If the reservoir temperature

is greater than the criticaltemperature of thehydrocarbon fluid, thereservoir is considered a gasreservoir.

Oil Reservoirs• If the reservoir temperature

T is less than the criticaltemperature Tc of thereservoir fluid, the reservoiris classified as an oil reservoir.

Oil Reservoir Base on P-T Diagram

Low-shrinkage oil• Oil formation volume factor less

than 1.2 bbl/STB• Gas-oil ratio less than 200 scf/STB• Oil gravity less than 35° API• Black or deeply colored

• In general, if the reservoir temperature is above the criticaltemperature of the hydrocarbon system, the reservoir isclassified as a natural gas reservoir. On the basis of theirphase diagrams and the prevailing reservoir conditions, naturalgases can be classified into 3 categories:• Retrograde gas-condensate• Wet gas• Dry gas

Gas Reservoirs

• In general, if the reservoir temperature is above the criticaltemperature of the hydrocarbon system, the reservoir isclassified as a natural gas reservoir. On the basis of theirphase diagrams and the prevailing reservoir conditions, naturalgases can be classified into 3 categories:• Retrograde gas-condensate• Wet gas• Dry gas

• If the reservoir temperature T liesbetween the critical temperature Tcand cricondentherm Tct of thereservoir fluid, the reservoir isclassified as a retrograde gas-condensate reservoir.

• The gas-oil ratio for a condensatesystem increases with time due to theliquid dropout and the loss of heavycomponents in the liquid.

• Condensate gravity above 50° API• Stock-tank liquid is usually water-white

or slightly colored.

Retrograde gas-condensate reservoir

• If the reservoir temperature T liesbetween the critical temperature Tcand cricondentherm Tct of thereservoir fluid, the reservoir isclassified as a retrograde gas-condensate reservoir.

• The gas-oil ratio for a condensatesystem increases with time due to theliquid dropout and the loss of heavycomponents in the liquid.

• Condensate gravity above 50° API• Stock-tank liquid is usually water-white

or slightly colored.

• Temperature of wet-gas reservoiris above the cri-condentherm ofthe hydrocarbon mixture. Becausethe reservoir temperature exceedsthe cri-condentherm of thehydrocarbon system, the reservoirfluid will always remain in the vaporphase region as the reservoir isdepleted isothermally, along thevertical line A-B.

Wet Gas Reservoir

• Temperature of wet-gas reservoiris above the cri-condentherm ofthe hydrocarbon mixture. Becausethe reservoir temperature exceedsthe cri-condentherm of thehydrocarbon system, the reservoirfluid will always remain in the vaporphase region as the reservoir isdepleted isothermally, along thevertical line A-B.

Wet-gas reservoirs are characterized by thefollowing properties:• Gas oil ratios between 60,000 to 100,000 scf/STB• Stock-tank oil gravity above 60° API• Liquid is water-white in color• Separator conditions, i.e., separator pressure and

temperature, lie within the two-phase region

Wet Gas Reservoir (Continue…)

Wet-gas reservoirs are characterized by thefollowing properties:• Gas oil ratios between 60,000 to 100,000 scf/STB• Stock-tank oil gravity above 60° API• Liquid is water-white in color• Separator conditions, i.e., separator pressure and

temperature, lie within the two-phase region

The hydrocarbon mixture existsas a gas both in the reservoir andin the surface facilities.Usually a system having a gas-oilratio greater than 100,000scf/STB is considered to be a drygas.

Dry Gas Reservoir

The hydrocarbon mixture existsas a gas both in the reservoir andin the surface facilities.Usually a system having a gas-oilratio greater than 100,000scf/STB is considered to be a drygas.

Reservoir Driving Mechanism

• Many reservoirs are boundedon a portion or all of theirperipheries by water bearingrocks called aquifers. Theaquifers may be so largecompared to the reservoirthey adjoin as to appearinfinite for all practicalpurposes, and they may rangedown to those so small as tobe negligible in their effectson the reservoir performance.Reservoir havea water drive

The Water-Drive Mechanism

• Many reservoirs are boundedon a portion or all of theirperipheries by water bearingrocks called aquifers. Theaquifers may be so largecompared to the reservoirthey adjoin as to appearinfinite for all practicalpurposes, and they may rangedown to those so small as tobe negligible in their effectson the reservoir performance.Reservoir havea water drive

Characteristics Trend

Reservoir pressure Declines very slowly (remains veryhigh)

Gas oil ratio Little change during the life ofthe reservoir (remains low)

The Water-Drive Mechanism (Continue)

Little change during the life ofthe reservoir (remains low)

Water production Early excess water production

Well behavior Flow until water production getsexcessive.

Oil recovery 35 to 75 %

Rock and Liquid Expansion

• When an oil reservoir initially exists at a pressure higher thanits bubble-point pressure, the reservoir is called an undersaturated oil reservoir.

• At pressures above the bubble-point pressure, crude oil,connate water, and rock are the only materials present. Asthe reservoir pressure declines, the rock and fluids expanddue to their individual compressibility's.

• At pressures above the bubble-point pressure, crude oil,connate water, and rock are the only materials present. Asthe reservoir pressure declines, the rock and fluids expanddue to their individual compressibility's.

• The reservoir rock compressibility is the result of two factors:• Expansion of the individual rock grains• Formation compaction

Solution-gas Drive, Gas-Cap Drive, Gravity Drive

This driving form may also bereferred to by the followingvarious terms:

• Solution gas drive• Dissolved gas drive• Internal gas drive

The Depletion Drive Mechanism

In this type of reservoir, theprincipal source of energy is a resultof gas liberation from the crude oiland the subsequent expansion of thesolution gas as the reservoirpressure is reduced. As pressurefalls below the bubble-pointpressure, gas bubbles are liberatedwithin the microscopic pore spaces

Gas Cap Drive

Gas-cap-drive reservoirs can beidentified by the presence of a gascap with little or no water drive asshown in figure on the left. Due tothe ability of the gas cap to expand,these reservoirs arecharacterized by a slow decline inthe reservoir pressure. The naturalenergy available to produce thecrude oil comes from the followingtwo sources:• Expansion of the gas-cap gas• Expansion of the solution gas as it

is liberated

Gas-cap-drive reservoirs can beidentified by the presence of a gascap with little or no water drive asshown in figure on the left. Due tothe ability of the gas cap to expand,these reservoirs arecharacterized by a slow decline inthe reservoir pressure. The naturalenergy available to produce thecrude oil comes from the followingtwo sources:• Expansion of the gas-cap gas• Expansion of the solution gas as it

is liberated

The mechanism of gravity drainageoccurs in petroleum reservoirs as aresult of differences in densities ofthe reservoir fluids. The effects ofgravitational forces can be simplyillustrated by placing a quantity ofcrude oil and a quantity of water in ajar and agitating the contents. Afteragitation, the jar is placed at rest,and the more denser fluid (normallywater) will settle to the bottom ofthe jar, while the less dense fluid(normally oil) will rest on top of thedenser fluid. The fluids haveseparated as a result of thegravitational forces acting on them.

The Gravity-Drainage-Drive Mechanism

The mechanism of gravity drainageoccurs in petroleum reservoirs as aresult of differences in densities ofthe reservoir fluids. The effects ofgravitational forces can be simplyillustrated by placing a quantity ofcrude oil and a quantity of water in ajar and agitating the contents. Afteragitation, the jar is placed at rest,and the more denser fluid (normallywater) will settle to the bottom ofthe jar, while the less dense fluid(normally oil) will rest on top of thedenser fluid. The fluids haveseparated as a result of thegravitational forces acting on them.

Characteristics Trend

Reservoir pressure Variable rates of pressure decline,depending principally upon the amountof gas conservation.

Gas oil ratio Low gas-oil ratio

Water production Little or no water production.

Well behavior Hi Water Cut

Oil recovery Near to 80 %

• Two combinations of driving forces can bepresent in combination drive reservoirs. Theseare (1) depletion drive and a weak water driveand; (2) depletion drive with a small gas cap anda weak water drive. Then, of course, gravitysegregation can play an important role in any ofthe aforementioned drives.

The Combination-Drive Mechanism

The driving mechanism most commonlyencountered is one in which both waterand free gas are available in some degreeto displace the oil toward the producingwells. The most common type of driveencountered, therefore, is acombination-drive mechanism asillustrated in Figure below.

• Two combinations of driving forces can bepresent in combination drive reservoirs. Theseare (1) depletion drive and a weak water driveand; (2) depletion drive with a small gas cap anda weak water drive. Then, of course, gravitysegregation can play an important role in any ofthe aforementioned drives.

Figure 4 Combination drive reservoir

Reservoir Calculation in General

Transition Zone Transition Zone

Volumetric Mechanics(Equations)

GAS:Area (Ac) x Thickness (Ft) x Avg Porosity (%) x Avg Sgi (%) x Bgi(SCF/RCF) x 43,560 sqft/ac = OGIP (SCF)

OIL:Area (Ac) x Thickness (Ft) x Avg Porosity (%) x Avg Soi (%) / Boi(RB/STB) x 7758.4 Bbls/AcFt = OOIP (STB)

Volumetric Mechanics(Equations)

GAS:Area (Ac) x Thickness (Ft) x Avg Porosity (%) x Avg Sgi (%) x Bgi(SCF/RCF) x 43,560 sqft/ac = OGIP (SCF)

OIL:Area (Ac) x Thickness (Ft) x Avg Porosity (%) x Avg Soi (%) / Boi(RB/STB) x 7758.4 Bbls/AcFt = OOIP (STB)

Volumetric Mechanics(Gross Reservoir Volume)

AREA: Productive area (map view), in acresSubdivide overall area into components that are calculated individuallybased on similar average reservoir thickness

THICKNESS: From reservoir or fluid top to contact or saturation cutoff, in feet

SUMMED (AREA(S) X THICKNESS) =

GROSS RESERVOIR VOLUME in AcreFeet

Volumetric Mechanics(Gross Reservoir Volume)

AREA: Productive area (map view), in acresSubdivide overall area into components that are calculated individuallybased on similar average reservoir thickness

THICKNESS: From reservoir or fluid top to contact or saturation cutoff, in feet

SUMMED (AREA(S) X THICKNESS) =

GROSS RESERVOIR VOLUME in AcreFeet

Volumetric Mechanics(Pore Volume)

GROSS RESERVOIR VOLUME (AcFt) x Average Porosity (%) withinproductive reservoir =

GROSS STORAGE (PORE) VOLUME (AcreFeet)

Volumetric Mechanics(Pore Volume)

GROSS RESERVOIR VOLUME (AcFt) x Average Porosity (%) withinproductive reservoir =

GROSS STORAGE (PORE) VOLUME (AcreFeet)

Volumetric Mechanics(Gross Oil/Gas Volume)

GROSS STORAGE (PORE) VOLUME (AcreFeet) xAVERAGE OIL (Soi) or GAS (Sgi) SATURATION (%) =

GROSS OIL or GAS VOLUME (AcreFeet)

===========================

Conversion to standard units of RBbls or RCF

AcreFeet x 7,758 Bbls/AcreFoot = Oil in Reservoir Barrels

AcreFeet x 43,560 Cubic Feet/AcreFoot = Gas in Reservoir Cubic Feet

Volumetric Mechanics(Gross Oil/Gas Volume)

GROSS STORAGE (PORE) VOLUME (AcreFeet) xAVERAGE OIL (Soi) or GAS (Sgi) SATURATION (%) =

GROSS OIL or GAS VOLUME (AcreFeet)

===========================

Conversion to standard units of RBbls or RCF

AcreFeet x 7,758 Bbls/AcreFoot = Oil in Reservoir Barrels

AcreFeet x 43,560 Cubic Feet/AcreFoot = Gas in Reservoir Cubic Feet

Volumetric Mechanics (Oil)(Conversion to Stock Tank Barrels)

FORMATION VOLUME FACTOR (Bo):

Rules of Thumb

‘Dead’ Oil (no dissolved gas): Bo ~ 1.0 (RB/STB)‘Gassy’ (deepish) Oil: Bo ~ 1.4 (RB/STB)‘Typical’ (shallower) Oil: Bo ~ 1.2 (RB/STB)

Oil Volume (RB) / Bo (RB/STB) = OOIP (STB)

Volumetric Mechanics (Oil)(Conversion to Stock Tank Barrels)

FORMATION VOLUME FACTOR (Bo):

Rules of Thumb

‘Dead’ Oil (no dissolved gas): Bo ~ 1.0 (RB/STB)‘Gassy’ (deepish) Oil: Bo ~ 1.4 (RB/STB)‘Typical’ (shallower) Oil: Bo ~ 1.2 (RB/STB)

Oil Volume (RB) / Bo (RB/STB) = OOIP (STB)

Volumetric Mechanics (Gas)(Conversion to Standard Cubic Feet)

FORMATION VOLUME FACTOR (Bg):

Rules of Thumb

• Bg – If normally pressured (hydrostatic)Bg = Depth (in feet) / 36.9 Example: @ 5,000’ FVF = 136 SCF/RCF-----------------------------• Underpressured (Brooken Field example): .23 psi/ft (normal = .43 psi/ft)@ 1,400’ Bgi = 28 SCF/RCF (38 SCF/RCF if normally pressured)-----------------------• Overpressured

Gas Volume (RCF) X Bg (SCF/RCF) = OGIP (SCF)

Volumetric Mechanics (Gas)(Conversion to Standard Cubic Feet)

FORMATION VOLUME FACTOR (Bg):

Rules of Thumb

• Bg – If normally pressured (hydrostatic)Bg = Depth (in feet) / 36.9 Example: @ 5,000’ FVF = 136 SCF/RCF-----------------------------• Underpressured (Brooken Field example): .23 psi/ft (normal = .43 psi/ft)@ 1,400’ Bgi = 28 SCF/RCF (38 SCF/RCF if normally pressured)-----------------------• Overpressured

Gas Volume (RCF) X Bg (SCF/RCF) = OGIP (SCF)

ReservesFrom OOIP / OGIP

(What can you take to the bank ?)

RECOVERY FACTOR (RF): As Function of• Reservoir Quality, Depth, Pressure, Temperature• Fluid Properties• Drive Mechanism(s)• Reservoir Management

Rules of Thumb

The better the reservoir, the better the recovery factor• Even fluid movement• Larger pore throats (better sweep, more moveable oil/gas)• Better water support (if any to be had)• Better effectiveness in secondary/ tertiary recovery projects

ReservesFrom OOIP / OGIP

(What can you take to the bank ?)

RECOVERY FACTOR (RF): As Function of• Reservoir Quality, Depth, Pressure, Temperature• Fluid Properties• Drive Mechanism(s)• Reservoir Management

Rules of Thumb

The better the reservoir, the better the recovery factor• Even fluid movement• Larger pore throats (better sweep, more moveable oil/gas)• Better water support (if any to be had)• Better effectiveness in secondary/ tertiary recovery projects

Recovery Factors(Ballpark Rules of Thumb)

OIL:• Poor reservoir (low poro-perm): < 10%• Dual Porosity (low matrix reservoir quality): ~ 20%• Good Poro-Perm (Primary = Secondary): ~ 30%• Excellent reservoir (good water support): ~ 40-50%• Ideal (good reservoir quality, management): ~ 60-70%• Tar Sands (mined): ~ 100%

GAS:• CBM, Shale Gas: < 10% (generally)• Good Quality (depletion): ~ 70% (GOM average)• Excellent Reservoir (depletion, + compression): 90%+ (Lake Arthur Ex.)

Recovery Factors(Ballpark Rules of Thumb)

OIL:• Poor reservoir (low poro-perm): < 10%• Dual Porosity (low matrix reservoir quality): ~ 20%• Good Poro-Perm (Primary = Secondary): ~ 30%• Excellent reservoir (good water support): ~ 40-50%• Ideal (good reservoir quality, management): ~ 60-70%• Tar Sands (mined): ~ 100%

GAS:• CBM, Shale Gas: < 10% (generally)• Good Quality (depletion): ~ 70% (GOM average)• Excellent Reservoir (depletion, + compression): 90%+ (Lake Arthur Ex.)

Probabilistic Volumetrics(Because there is no single answer)

• Calculate a range of values based on confidence in variables.P = Probability Factor

P 100 – dead certaintyP 70 to 90 – high confidenceP 10 to 30 – low confidence

• For each variable with significant uncertaintyAssign P 90 , P 50, and P 10 values to create distributionExample: Productive area – P 90 = smallest reasonable area, P 50 = mostlikely area, and P 10 = maximum area (but not unreasonable)

• Qualitative (‘fudgability’ - what do you want it to be ?)Usefulness a function of experience in areaRequires objective assessmentMost beneficial when comparing large projects in which data is sparse

Probabilistic Volumetrics(Because there is no single answer)

• Calculate a range of values based on confidence in variables.P = Probability Factor

P 100 – dead certaintyP 70 to 90 – high confidenceP 10 to 30 – low confidence

• For each variable with significant uncertaintyAssign P 90 , P 50, and P 10 values to create distributionExample: Productive area – P 90 = smallest reasonable area, P 50 = mostlikely area, and P 10 = maximum area (but not unreasonable)

• Qualitative (‘fudgability’ - what do you want it to be ?)Usefulness a function of experience in areaRequires objective assessmentMost beneficial when comparing large projects in which data is sparse

Source (Material and Rocks)

Generation (Maturation)

Migration

Trap

Reservoir

Petroleum System Summary

Source (Material and Rocks)

Generation (Maturation)

Migration

Trap

Reservoir

ANY QUESTIONS..??

Confuse..? Or Sleepy…..???

End Of Presentation

THANKS FOR YOURATTENTION

TERIMA KASIHHATUR SUWUNMATUR SUWUN

WASSALAMU’ALIKUMAdios – C U Soon….In next Module

THANKS FOR YOURATTENTION

TERIMA KASIHHATUR SUWUNMATUR SUWUN

WASSALAMU’ALIKUMAdios – C U Soon….In next Module

THANKS FOR YOURATTENTION

TERIMA KASIHHATUR SUWUNMATUR SUWUN

WASSALAMU’ALIKUMAdios – C U Soon….In next Module

THANKS FOR YOURATTENTION

TERIMA KASIHHATUR SUWUNMATUR SUWUN

WASSALAMU’ALIKUMAdios – C U Soon….In next Module

References

Definitions / Conversions (I)

14.7 psi = Atmospheric (@ S.L.)5,280 feet per mile43,560 sq ft per acre640 acres per sq mile – Section (160 ac per quarter section) 247 ac/sqkm3.281 ft per meter (39.37 inches per meter)1.609 kilometers per mile2.54 centimeters per inch35.32 cubic feet per cubic meter7,758 STBarrels per acre-footSpecific Gravity (crude); .80-.97Btu value for gas: avg ~1Btu / cubic foot (1000Btu/MCF), rich - higher, a lot ofnon-hydrocarbons - lowerAPI gravity: 25=specific gravity .904, 42=specific gravity .816BOE: 6,000 cubic feet per barrel (average)

Definitions / Conversions (I)

14.7 psi = Atmospheric (@ S.L.)5,280 feet per mile43,560 sq ft per acre640 acres per sq mile – Section (160 ac per quarter section) 247 ac/sqkm3.281 ft per meter (39.37 inches per meter)1.609 kilometers per mile2.54 centimeters per inch35.32 cubic feet per cubic meter7,758 STBarrels per acre-footSpecific Gravity (crude); .80-.97Btu value for gas: avg ~1Btu / cubic foot (1000Btu/MCF), rich - higher, a lot ofnon-hydrocarbons - lowerAPI gravity: 25=specific gravity .904, 42=specific gravity .816BOE: 6,000 cubic feet per barrel (average)

VolumetricsDefinitions / Conversions

OOIPOGIPRFFVF: (Bo, Bg)Saturations / Residual Saturations (So, Sg, Sw – Soirr, Sgirr, Swirr)EUR

Resources (In-Place) vs.Reserves (Economically Producible)

VolumetricsDefinitions / Conversions

OOIPOGIPRFFVF: (Bo, Bg)Saturations / Residual Saturations (So, Sg, Sw – Soirr, Sgirr, Swirr)EUR

Resources (In-Place) vs.Reserves (Economically Producible)

Volumetric ParametersDefinitions / Conversions (III)

FVFs: Bo - Oil (dead) ~ 1.0 (RSB/STB), oil moderately gassy ~1.2RSB/STB, verygassy ~ 1.4 RSB/STB

Bg – Normally pressured (hydrostatic) FVF = Depth (in ft)/36.9

Example @ 5,000’ FVF = 136 RCF/SCF

Underpressured (Brooken Field example): .23 psi/ft (normal = .43 psi/ft)@ 1,400’ Bgi = 28 RCF/SCF (38 RCF/SCF if normally pressured)

Overpressured

Volumetric ParametersDefinitions / Conversions (III)

FVFs: Bo - Oil (dead) ~ 1.0 (RSB/STB), oil moderately gassy ~1.2RSB/STB, verygassy ~ 1.4 RSB/STB

Bg – Normally pressured (hydrostatic) FVF = Depth (in ft)/36.9

Example @ 5,000’ FVF = 136 RCF/SCF

Underpressured (Brooken Field example): .23 psi/ft (normal = .43 psi/ft)@ 1,400’ Bgi = 28 RCF/SCF (38 RCF/SCF if normally pressured)

Overpressured