Hubbert Analysis (1940)Hubbert Analysis (1940)

Gw flow porous media is a mechanic Gw flow porous media is a mechanic process that overcomes frictional forces process that overcomes frictional forces along a flow pathalong a flow path

Hydraulic potential is defined as the Hydraulic potential is defined as the mechanic energy per unit mass or per mechanic energy per unit mass or per unit volume of fluidunit volume of fluid

Gw moves from areas with high potential Gw moves from areas with high potential energy to areas with low potential energy to areas with low potential energyenergy

Physical Quantities define hydraulic Physical Quantities define hydraulic potentialpotential

ElevationElevation Fluid pressureFluid pressure

Gravity(elevation effect)

p

g

Real flow direction

Hubbert analysis (How much work required to lift fluid from a standard state to a new elevation z)

• work to lift fluidw1 = mgz

• work to compress fluidw2 =

• Work to accelerate fluidW3 =

Z = 0, P = P0

z

P, v

p

p

p

p

dPmVdP

0 0

2

2mv

Hydraulic potential ()

p

pm

dPvgzwww

m 02

1 2

321

P

gzm

Pgz

(hyd. potential per unit mass)

(hyd. potential per unit volume)

Elevation Pressure

~0

Heads at point A

• Hydraulic head h– Water table surface to

sea level

• Elevation head z– Bottom of piezometer

(point A) to sea level

• Pressure head – Water table surface to

point A

h

zSea level

A

gzPgh

Piezometer

)( zhggP

Relationship between and h

gh

gzPgh

zg

Ph

Hydrodynamics of oil migration (Hubbert, 1954)

If no hydraulic gradient

0dl

dh

Slope (dip) of tilted oil-water interface

dl

dh

dl

dz

ow

w

(no water movement)

0dl

dzHorizontal interface

Hydrodynamics of oil Hydrodynamics of oil migrationmigration

Oil-water interface dips in the same direction as Oil-water interface dips in the same direction as hydraulic gradienthydraulic gradient

Faster gw flow (dh/dl increases), steeper oil-water Faster gw flow (dh/dl increases), steeper oil-water interfaceinterface

Required conditions to trap oilRequired conditions to trap oil Geologic structure dip in the same direction as the Geologic structure dip in the same direction as the

hydraulic gradient (or oil-water interface)hydraulic gradient (or oil-water interface) dip of geologic structure > dip of oil-water interfacedip of geologic structure > dip of oil-water interface

zg

Ph

Multiphase Flow

gaswDNAPL

gaswDNAPL

PPP

g

DNAPL(sinker)

Water

Gas(floater)

Mechanisms of basin-scale Mechanisms of basin-scale fluid migrationfluid migration

Gravity (topographically-driven)Gravity (topographically-driven) CompactionCompaction Density-drivenDensity-driven Tectonic-drivenTectonic-driven

Hydraulic potential, atm

0 10050

Topographic-driven flow

Rock type: sh, fraction

0 1.5

Compaction-driven flow (Gulf of Mexico)

Pressure, atm

0 1500750100 km

2 km

cm/yr

5.2

N S

Groundwater flow and overpressure in the Gulf of Mexico Basin

-4 0 -2 0 0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0-6 0

-4 0

-2 0

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

Distance along strike (km)

Dsi

tan

ce a

lon

g d

ip (

km

) +2e-6

+4e-6

-2e-6

-4e-6

(a) Volumetric Strain

-4 0 -2 0 0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0-6 0

-4 0

-2 0

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

-10

-20

+10

+20

Distance along strike (km)

Dis

tan

ce a

lon

g d

ip (

km

)

(b) Induced heads

Temperature, °C

20 190105

Density-driven flow (hydrothermal convection)

Salinity, molal

0 6.53.2510 km

.1 km

ƒwell 1

ƒwell 2

ƒwell 3

ƒwell 4

ƒwell 5

ƒwell 6

ƒwell 7

M o b ile

W a sh in g to n

C h o c ta w

S u m te r

G re e n e

C olb e r t

F r a n k lin

L a m a r

P ick e n s

1

2

3

4

5

6

7

8

9

1 00 4 0 m i.

Louann Salt

100 km

2 km

t = 0 years

Salinity (ppm)

2e4 3.4e51.8e5

1 2 3 4 5 6 7 8 9 10

carbonategroundwater

Meteoric water affected by mixing

Groundwater associatedwith evaporites

N S

Louann Salt

Organic maturation

• Time temperature index (TTI)

– n= 0, T = 100-110C– n = 1, T= 110-120C– n = 2, T= 120-130C– TTI = 15-160, oil generation window– TTI = 500-1000, deadline for preserving oil– TTI =1,500, deadline for preserving wet gas

n

nntTTI 2

Organic maturation

• Arrhenius model – track the fraction Xo (or %) of oil generated by a source rock

– A0 is the pre-exponential factor (hr-1)

– EA is the activation energy (kJ/mol)

– R is the gas constant (8.31432 J K-1 mol-1)

kA RTEeAk /0

oo Xk

dt

dX 1

Organic maturationOrganic maturation

Ao and Ea differ among various source rocksAo and Ea differ among various source rocks Obtained by hydrous pyrolysis experimentsObtained by hydrous pyrolysis experiments

Woodford Shale (EWoodford Shale (EAA = 218, A = 218, A00 = 6.51 = 6.5110101616))

The timing of oil generation is not the same The timing of oil generation is not the same for all source rocksfor all source rocks kerogen with low Ekerogen with low EAA and high A and high A00 tend to reach tend to reach

peak generation earlierpeak generation earlier Higher EHigher EAA and lower A and lower A00 allow Slow thermal allow Slow thermal

crackingcracking

Organic maturationOrganic maturation

Vitrinite reflectance (VR)Vitrinite reflectance (VR) Vitrinite is not strongly prone to oil and gas Vitrinite is not strongly prone to oil and gas

formation, is common as a residue in source rocks formation, is common as a residue in source rocks the vitrinite becomes increasingly reflective as the vitrinite becomes increasingly reflective as

thermal rank increases. Therefore, the % thermal rank increases. Therefore, the % reflection of a beam of white light from the reflection of a beam of white light from the surface of polished vitrinite is a function of the surface of polished vitrinite is a function of the rank (maturity) rank (maturity)

The VR is expressed as Ro%, the percentage of The VR is expressed as Ro%, the percentage of light reflected from the sample, calibrated against light reflected from the sample, calibrated against a material with ~100% reflectance (i.e. a mirror)a material with ~100% reflectance (i.e. a mirror)

Oil window: Ro = 0.65-1.3%Oil window: Ro = 0.65-1.3%

Time (m.y.)

Fra

ctio

nof

Oil

and

Gas

Gen

erat

ion

-10 -8 -6 -4 -2 00

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Ag = 4x10

Ag= 4x10

Ag=4x10

12

9

6

(B)

Oil

Gas

Gas

Gas

Overpressure, atm

0 650325

400

300

200200

100

100

0

50 km

3 km

TTI = 15-160

Organic maturation of Niger basin

Overpressure, atm

0 650325

400

300

200200

100

100

0

50 km

3 km

Ro = 0.65-1.3%

Hydrodynamics and Fluids-Hydrodynamics and Fluids-Sediments-Bacteria Interaction Sediments-Bacteria Interaction

in the Permian Basin, West in the Permian Basin, West Texas: Mechanisms for Sulfur Texas: Mechanisms for Sulfur

OreOre Genesis Genesis

Permian Basin

Why oil and mineral reservoirs are locatedalong basin’s margins far away from their deep sources?

How overpressures are maintained in this tectonically stable basin?

Bioepigenetic sulfur (Culberson Bioepigenetic sulfur (Culberson mine)mine)

MVT mineralization, Bird mine MVT mineralization, Bird mine (Glass Mt.)(Glass Mt.)

Calcite

(from Hill, 1996)

Galena/Sphalerite

2.5 cm

A A'

20 km

1 km

A

A'

P r i an

Pe rmi an

r s ic

Delaware Basin Central Basin Platform

West Platform Fault

ShaleSandstoneLimestoneDolomite Red shale Evaporite Salt

1 2 3 4 5 6 7 8 9 10 11 12 13 14 1615 17 18 19 20 21 22 23 24 25 26

Permian

Permian

Miss. Devon.

Silurian

Penn.

Ord.

(after Matchus & Jones, 1984)

Guadalupe Mountains National Park, Capitan Reef Complex

Hydrogeological evidence of fluid Hydrogeological evidence of fluid migrationmigration

• Petroleum reservoirs found far from source rocks (Hill, 1990)Petroleum reservoirs found far from source rocks (Hill, 1990)

• Biogenetic sulfur, calcite, and metal sulfates (barite, celestite) Biogenetic sulfur, calcite, and metal sulfates (barite, celestite) deposits (Crawford and Wallace, 1993)deposits (Crawford and Wallace, 1993)

• Karst features (Carlsbad caverns) carved by sulfuric acid (Hill, Karst features (Carlsbad caverns) carved by sulfuric acid (Hill, 1990)1990)

• MVT mineralization (sphalerite, pyrite, galena) by migrating MVT mineralization (sphalerite, pyrite, galena) by migrating brines along basin marginsbrines along basin margins (Hill, 1996)(Hill, 1996)

• Regional dissolution of halite by eastward recharge of meteoric Regional dissolution of halite by eastward recharge of meteoric water (Chaturvedi, 1993)water (Chaturvedi, 1993)

Hypothesis: groundwater migration over long distance (tens to hundreds of kilometers) driven by overpressure system and gravity, provides a framework for understanding a number of geologic phenomena

Objectives:• Investigate long-distance hydrocarbon migration on the

basis of basin hydrodynamics (overpressure and gravity flow) and geochemical and isotopic correlations of crude oils

• Characterize groundwater geochemistry and the microbiology of Culberson sulfur ore district

• Assess the distribution of overpressure zone using geophysical anomalies

• Create a model of bacterial sulfate reduction and oxidation reactions for the formation of bioepigenetic calcite, native sulfur, barite, and celestite

Field dataField data

Geophysical dataGeophysical data Pore pressurePore pressure SeismicSeismic sonic, resistivity, sonic, resistivity,

conductivity and gamma conductivity and gamma logs logs

Geochemistry dataGeochemistry data Geochemistry of crude Geochemistry of crude

oilsoils Groundwater Groundwater

geochemistry and geochemistry and microbiologymicrobiology

Isotope geochemistry of Isotope geochemistry of bioepigenetic mineralsbioepigenetic minerals

Fluid inclusions of Fluid inclusions of biogenetic calcitebiogenetic calcite

Geochemical and Isotopic Geochemical and Isotopic Correlation of Crude Oils Correlation of Crude Oils

(provide by TNOR)(provide by TNOR)

Sample County Formation Age Basin Bed Type

66001 Loving Bell Canyon Permian DB Carrier

66003 Ward Bell Canyon Permian DB Carrier

66051 Reeves Bell Canyon Permian DB Carrier

66064 Ector Woodford Shale Devonian CBP Source

66072 Ector San Andres Permian CBP Reservoir

66121 Culberson Castile Permian DB Reservoir

67015 Winkler Strawn Pennsylvanian DB Source

67150 Ward Not Specified Pennsylvanian DB Source

68171 Ward Yates Permian CBP Reservoir

71057 Winkler Seven Rivers Permian CBP Reservoir

13C composition of bulk oil samples

SSourc

e Bed

s

ourc

e Bed

s

Carr

ier B

eds

Carr

ier B

eds

Reser

voirs

Reser

voirs

1313C

(PD

B)

C(P

DB

)

-32

-30

-28

-26

Gas Chromatogram AnalysisGas Chromatogram Analysis

computer

10.00 20.00 30.00 40.000

100

%

15.5418.75

% d

ete

ctor

resp

onse

TimeIncreasing temperature (30 to 280°C)

• Mass Mass fragmentogramsfragmentograms

• Used to compare heavy fractions (biological markers)Used to compare heavy fractions (biological markers)• tri- and pentacyclic terpanes (m/z 191)tri- and pentacyclic terpanes (m/z 191)• steranes (m/z 217)steranes (m/z 217)

• Complete spectrum gas chromatograms Complete spectrum gas chromatograms

• Show variations in biodegradationShow variations in biodegradation• Not very helpful in identifying links between Not very helpful in identifying links between

reservoir, carrier bed and source-rock oilsreservoir, carrier bed and source-rock oils

10.00 20.00 30.00 40.000

100

%

15.28

12.679.81

8.573.942.02

17.37

10.00 20.00 30.00 40.000

100

%

15.5418.75

Ward 24.30

18.82

8.104.561.68 12.13

28.61

10.00 20.00 30.00 40.000

100

% 35.43

45.41

10.00 20.00 30.00 40.000

100

%

24.30

18.63

1.89 10.104.76

28.61

35.44

43.76

Source bed oil from DBCulberson reservoir oil

Culberson oil (66121), Castile Formation m/z 191

10.00 20.00 30.00 40.000

100

%

24.30

18.63

1.89 10.104.76

28.61

35.44

43.76

Ward county oil (67150), Pennsylvanian source bed 24.30

18.82

8.104.561.6812.13

28.61

10.00 20.00 30.00 40.000

100

% 35.43

45.41

Time (min)

tri- and pentacyclic terpanestri- and pentacyclic terpanes

Mass Fragmentograms

Culberson (66121)

10.00 20.00 30.00 40.000

100

%

33.52

28.60

21.28

5.792.52 14.8810.81

32.04

39.33

Ward (67150)

10.00 20.00 30.00 40.000

100

%

33.51

27.7221.32

6.253.09 11.4616.86

23.67

38.07

43.88

Time (min)

steranessteranes

m/z 217

Delaware basin Delaware basin Central Basin Central Basin PlatformPlatform

WW E E

66121 66121 CastileCastile

67150 Pennsylvanian67150 PennsylvanianOverpressure Overpressure zonezone

Delaware basin Delaware basin Central Basin Central Basin PlatformPlatform

WW E E

67015 Strawn67015 Strawn

68171 Yates68171 Yates

OverpressureOverpressurezonezone

24.29

20.25

9.902.99

28.61

35.45

40.02

24.30

18.26

13.138.911.87

28.61

34.3339.60 43.32

10.00 20.00 30.00 40.00

0

100

%

Time (min)

10.00 20.00 30.00 40.00

0

100

%

Time (min)

tri- and pentacyclic terpanestri- and pentacyclic terpanes

Winkler source bed oil (67015), Penn. Strawn

Ward reservoir oil (68171), Perm.Yates Formation

M/Z 191

10.00 20.00 30.00 40.00

0

100

%

Time (min)

10.00 20.00 30.00 40.00

0

100

%

Time (min)

steranessteranes

M/Z 217Winkler source bed oil (67015), Penn. Strawn Form.

Ward (68171)

Delaware basin Delaware basin Central Basin Central Basin PlatformPlatform

WW E E

66121 66121 CastileCastile

67150 Pennsylvanian67150 Pennsylvanian67015 Strawn67015 Strawn

68171 Yates68171 Yates

OverpressureZone

Pressure (bars)

Dep

th(m

)

0 500 1000 1500

0

1000

2000

3000

4000

5000

6000

7000

Mesozoic-Cenozoic

Ochoan

Delaware Mountain

Bone Spring

Wolfcampian

Pennsylvanian-Mississippian

Woodford

Fusselman, Montoya-Simpson

Cambrian

Stra

tigr

aphy

Lithostatic

Hydrostatic

Overpressurezone

(after Luo et al., 1994; Lee & Williams, 2000)

Ellenburger

Overpressure in the eastern Delaware basin

(modified from Doser et al., 1991; Hansom 2004)(modified from Doser et al., 1991; Hansom 2004)

Depth

(km

)D

epth

(km

)

4

Overpressure system in the War-Wink oil field

Hydrofracturing?

5

50 60 70 80 90 100 110 0 500 1000 15006 8 10 12 14

2000

3000

4000

5000

API millisec/foot ohm-m

Gamma RayInterval

Transit TimeResistivity

dept

h (m

)

Ward County Well, Ward County Well, Eastern Delaware basin Eastern Delaware basin

50 100 1500 500 1000 50 60 70 8020000 1000

2500

3000

3500

4000

4500

Gamma RayInterval

Transit TimeConductivity

millihos/m ohm-m millisec/foot API

Resistivity

dept

h (m

)

Culberson CountyCulberson CountyWell: Bateman #1-28 Well: Bateman #1-28 Western Delaware basin Western Delaware basin

Sulfur isotopic compositions of Sulfur isotopic compositions of minerals at Culberson mineminerals at Culberson mine

-20

0

20

40

60

80

34S

(C

DT

)

Barite Celestite Native Sulfur

Bacterial sulfate reductionBacterial sulfate reduction

CaSOCaSO44 · 2H · 2H22O (gypsum) + hydrocarbons O (gypsum) + hydrocarbons

HH22S + CaCOS + CaCO33 (calcite) + H (calcite) + H22OO

SRBD. desulfuricans

Depleted in 34S Depleted in 13C

C and O Isotopes of Biogenetic Calcite at C and O Isotopes of Biogenetic Calcite at Culberson MineCulberson Mine

Basin Hydrology ModelingBasin Hydrology Modeling

Thermal maturationThermal maturation Effects of sediment compaction and Effects of sediment compaction and

hydrocarbon (oil and gas) generation hydrocarbon (oil and gas) generation on overpressure developmenton overpressure development

Effects of Tertiary Laramide orogeny Effects of Tertiary Laramide orogeny on regional groundwater flow on regional groundwater flow

A A'

20 km

1 km

A

A'

P r i an

Pe rmi an

r s ic

Delaware Basin Central Basin Platform

West Platform Fault

ShaleSandstoneLimestoneDolomite Red shale Evaporite Salt

1 2 3 4 5 6 7 8 9 10 11 12 13 14 1615 17 18 19 20 21 22 23 24 25 26

Permian

Permian

Miss. Devon.

Silurian

Penn.

Ord.

(after Matchus & Jones, 1984)

40 km

2 km

Present-dayGas Window(0.01≤Xg≤0.99)

W

E

Central BasinPlatform

Delaware Basin

Permian evaporites

Permian sandstonesPermian shales

Present-day gas window

(B) Present-day Flow System

20 km

1 km

Central BasinPlatformDelaware Basin

Permian Evaporites

Permian sandstone

Third Sand

350

320

290260

W E

(A) Permian Flow System

Permian shale

Culberson Ore

Permian oil windowXo = 0.01 to 0.99

Present oil windowXo = 0.01 to 0.99

Summary

Fluid sources and migration, biochemical processes, and ore Fluid sources and migration, biochemical processes, and ore genesisgenesis

Oils from reservoir rocks in the western Delaware Basin and CBP can be Oils from reservoir rocks in the western Delaware Basin and CBP can be correlated geochemically to oils from source beds in the eastern Delaware Basincorrelated geochemically to oils from source beds in the eastern Delaware Basin

Ore genesis in the western Delaware basin was driven by bacterial sulfate Ore genesis in the western Delaware basin was driven by bacterial sulfate reduction at relatively low temperaturesreduction at relatively low temperatures (<70 (<70°°C)C)

SummaryBasin Hydrodynamics - Basin Hydrodynamics - Overpressures and tectonic uplift control fluid migration and ore genesis.Overpressures and tectonic uplift control fluid migration and ore genesis.

Observed geophysical anomalies such as low resistivity, high conductivity, and high seismic transit time indicate the presence of overpressured, fractured and Observed geophysical anomalies such as low resistivity, high conductivity, and high seismic transit time indicate the presence of overpressured, fractured and mechanically weak rocks in the eastern Delaware basinmechanically weak rocks in the eastern Delaware basin

Present-day overpressure is likely maintained by gas generationPresent-day overpressure is likely maintained by gas generation

Overpressure and episodic dewatering may move deep-basin brines and hydrocarbons eastward into the CBP and westward into the shallow margin of the Overpressure and episodic dewatering may move deep-basin brines and hydrocarbons eastward into the CBP and westward into the shallow margin of the Delaware BasinDelaware Basin

Sulfur genesis likely occurred late in the basin’s history during or after Laramide orogeny, in response to the westward migration of hydrocarbons and basin Sulfur genesis likely occurred late in the basin’s history during or after Laramide orogeny, in response to the westward migration of hydrocarbons and basin fluids driven by overpressure hydrodynamics and eastward (basinward) flow of meteoric water flow set up by tectonic upliftfluids driven by overpressure hydrodynamics and eastward (basinward) flow of meteoric water flow set up by tectonic uplift

The model of basin-scale fluid migration could potentially provide a framework for understanding a number of significant geologic phenomena in the basin The model of basin-scale fluid migration could potentially provide a framework for understanding a number of significant geologic phenomena in the basin