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Basin and Petroleum System Modeling in the Los

Angeles Basin, California

Lauren Schultz

Basin and Petroleum System Modeling Group (BPSM)

Introduction

• Education

• Washington and Lee University ‘13• B.S. Geology, German minor

• Senior Honors Thesis: Sequence Stratigraphic and Structural Interpretation, Modeling and Restoration in the National Petroleum Reserve in Alaska (NPRA)

• Stanford University• Advisor: Steve Graham, Basin and Petroleum System

Modeling Group

• Current work: Basin and petroleum system modeling of the Los Angeles Basin, California

• Basin and Petroleum System Modeling Group (BPSM)

Outline

• Basin Background• Structure

• Stratigraphy

• Petroleum System

• Recent/Active Work• Data Collection and Digitization

• 1D Basin Modeling

• Future Plans

Project Goals

• Create 1D and 2D Petromod models of L.A. Basin

• Incorporate wide variety of available subsurface data, including formation tops, ages, lithology, TOC, etc. and calibration data, including pressures, temperatures and vitrinite reflectance

• Better understand unique L.A. Basin Petroleum System• Geochemical diversity of oils

• Role of structural evolution of basin in traps

Los Angeles Basin Background

Edited from Biddle, 1991

• Strike-slip basin, formed in Neogene (Wright, 1991)

Luyendyk et al., 1980Biddle, 1991; Crowell, 1974

Los Angeles Basin Background

Yerkes et al., 1965

Basement Structure

NW trending synclinal depression near center of basin, as deep as 31,000 ft below sea-level

N

Yerkes et al., 1965

Basement Structure

NW trending synclinal depression near center of basin, as deep as 31,000 ft below sea-level

N

Deep NW trending trough

Depth to Basement

• Newport-Inglewood deformation zone cuts through eastern part of basin, separating southwestern and central blocks• 3000-5000 ft right-lateral displacement for faults in

deformation zone

• Active since late-middle Miocene

• Whittier fault zone cuts through basin to the West, separates central and northwestern blocks• ~15,000 ft net right-lateral displacement

• Active since Miocene

• Series of east-trending faults form boundary between Transverse Ranges and Peninsular Ranges

Yerkes et al., 1965

Structural Features

Yerkes et al., 1965

Yerkes et al., 1965

Yerkes et al., 1965

Yerkes et al., 1965

Shaw and Shearer, 1999

Puente

Lower Fernando

Upper Fernando

Stratigraphy

Beyer, 1995

• Source rocks are middle to late Miocene, include Monterey, Modelo and Puente Formations• TOC as high as 10-16%

• Miocene-Pliocene submarine fan sands form important reservoir units• Include Fernando, Pico and Repetto

Fm sands

Jeffrey et al., 1970

Petroleum Background

• Rapid accumulation of sediment in deep (1600+ feet), cool water, as well as poor circulation resulted in excellent preservation of organic matter (Yerkes et al., 1965)

• Long history of oil exploration and production, first oil discovered 1880 (Barbat, 1958)

(Yerkes et al., 1965)

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Mag

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nes

Vie

nn

a

Pers

ian

Gu

lf

Hyd

roca

rbo

n P

rod

uct

ivit

y(1

00

0 O

EB/C

U M

I To

tal S

ed

)

Individual Basins0

200

400

600

4000

L.A. Basin Petroleum Background

LA Basin Petroleum Province

• Roughly triangular in shape, covers ~2200 mi2

• Assessed in 1995 by USGS NOGA

• Estimated 1.4-5.6 BBO undiscovered reserves still in Basin (Gautier et al., 2012)

Beyer, 1995

980 1610 60

L.A. Basin Petroleum Background

LA Basin Petroleum ProvinceL.A. Basin Oil Geochemistry

Project Objectives

• Collect relevant data, including archiving historical data

• Create 1D and 2D Petromod models of L.A. Basin

• Incorporate subsurface data, including formation tops, ages, lithology, TOC, etc. and calibration data, including pressures, temperatures and vitrinite reflectance

Current Work

• Field trip with Rick Behl to view Monterey Fmoutcrops in LA Basin• Collected phosphatic source rock sample for possible

kinetics analysis

• LA Basin Overview field trip with Ray Ingersoll

Current Work: Field Observations

Current Work

Base of Upper Miocene Structure MapCreated by Tom Wright

Current Work

Base of Upper Miocene Structure MapCreated by Tom Wright

• Cuts through depocenter of basin

• Runs perpendicular to strike of major fault trends

PS-AAPG Cross-Section CS-3R

PS-AAPG Cross-Section CS-3R

• T.D. 21,215’

• Bottoms out in basal Repettounit

• Cross-section runs perpendicular to strike of many major faults

• Selected for preliminary 1D basin model

American Petrofina Central Corehole #1

1D Basin Model: Boundary Conditions

• Estimated using benthic foraminifera assemblages

• Estimated using mean surface temp (Wygrala, 1989) and paleo water depth

• Subduction through early Paleogene associated with lower heat flow

• High heat flow (~65W/m2) became significant at ~20Ma (Wright, 1991)

Paleo Water Depth

Dep

th (

m)

Hea

t Fl

ow

(W

/m2)

Tem

per

atu

re (

C)

Sediment-Water Interface Temperature (C)

Heat Flow

Time (Ma)

Time (Ma)

10.0

10.0

5.0

5.0

0

0

050

Time (Ma)100150200

0

0

0

2000

3000

4000

1000

10

20

60

40

40

20

30

80

-Spreading center

-Subduction Zone

-Fault

Explanation

(Modified from Dickinson, 1981; USGS)

• Low heat flow during subduction (estimated at 30 W/m2)

• Higher heat flow during Miocene-recent with initiation of strike-slip faulting (estimated at 65 W/m2)

1D Basin Model: Heat Flow

1D Basin Model: Preliminary Results

Temperature (C) Vitrinite Reflectance (%Ro)

Dep

th (

m)

1D Basin Model: Preliminary Results

Time (Ma)

Dep

th b

elo

w S

edim

ent

Surf

ace

(m)

1D Basin Model: Preliminary Results

Time (Ma)

Dep

th b

elo

w S

edim

ent

Surf

ace

(m)

Future Plans

• Refine current 1D model with additional calibration data and supplement with further 1D models in areas of interest

• Generate 2D Basin Model along CS-3R cross-section of LA Basin

• Supplement with additional 1D models where necessary

Thank You!