Chemometric Recognition of Genetically Distinct Oil Families in the Los Angeles Basin*

K. E. Peters1,2

, L. Scott Ramos3, and J. E. Zumberge

4

Search and Discovery Article #41149 (2013)** Posted July 22, 2013

*Adapted from oral presentation given at 2013 Pacific Section AAPG, SEG and SEPM Joint Technical Conference, Monterey, California, April 19-25, 2013

**AAPG©2013 Serial rights given by author. For all other rights contact author directly.

1Schlumberger Information Solutions, Mill Valley, CA 94941 (kpeters2@slb.com) 2Stanford University , Stanford, CA 94305 3Infometrix, Inc., Bothell, WA 98011 4GeoMark Research, Houston, TX 77095

Abstract

Multivariate statistical analysis (chemometrics) of selected source-related biomarker and stable carbon isotope ratios for 112 nonbiodegraded or

mildly biodegraded crude oil samples from the prolific Los Angeles basin identifies five tribes and a total of 12 genetically distinct oil families.

These families occur in different parts of the basin and exhibit different bulk properties, such as API gravity, sulfur, and metal content that are

principally controlled by source rock organofacies rather than secondary processes, such as thermal maturity or biodegradation. Stable carbon

isotope data for saturate and aromatic fractions of the samples suggest Neogene source rock, although not necessarily all from the basal

Mohnian nodular shale unit of the Modelo Formation. Biomarker ratios allow indirect assessment of the character to the source rock for each

family. For example, tribes 1 and 2 straddle the Central Trough to the east of the Newport-Inglewood Fault Zone and show evidence of

elevated clastic and higher-plant input (e.g., elevated C24/C23 tricyclic terpanes and oleanane, respectively). Some families clearly originated

from source rock in different depocenters on opposite sides of the Newport-Inglewood Fault Zone and from different stratigraphic intervals.

For example, unlike tribes 1 and 2, tribe 5 occurs west of the Newport-Inglewood Fault Zone and shows evidence of a more distal, clay-poor

source rock (e.g., lower C24/C23 tricyclic terpanes and oleanane, elevated steranes/hopanes and bisnorhopane). As another example, tribe 5

oils occur in deeper intervals (9007-10,480 ft) than tribe 3 oils (3531-6842 ft) in the Wilmington field. The 112 crude oil samples were used as

a training set to build a chemometric decision tree, which allowed classification of nearly 50 additional samples that were affected to varying

degrees by severe thermal maturation or biodegradation.

Selected References

Blake, G.H., 1991, Review of the Neogene biostratigraphy and stratigraphy of the Los Angeles basin and implications for basin evolution:

AAPG Memoir 52, p. 135-184.

Jeffrey, A.W.A., H.M. Alimi, and P.D. Jenden, 1991, Geochemistry of Los Angeles basin oil and gas systems: AAPG Memoir 52, p. 197-219.

McCulloh, T.H., D.W. Kirkland, A.J. Koch, W.L. Orr, and H.M. Chung, 1994, How oil composition relates to kerogen facies in the world’s

most petroliferous basin: AAPG Search and Discovery Article #90986 (1994), AAPG Annual Convention, Denver, CO, June 12-15, 1994.

(http://www.searchanddiscovery.com/abstracts/html/1994/annual/abstracts/0210b.htm?q=%2BtextStrip%3Amcculloh+%2BtextStrip%3A9098

6).

Peters, K.E., and J.M. Moldowan, 1993, The biomarker guide; interpreting molecular fossils in petroleum and ancient sediments: Englewood

Cliffs, Prentice Hall, 363 p.

Philippi, G.T., 1965, On the depth, time and mechanism of petroleum generation: Geochim. Cosmochim. Acta, v. 29, p. 1021-1049.

Wright, T.L., 1991, Structural geology and tectonic evolution of the Los Angeles Basin, California: AAPG Memoir 52, p. 35-134.

K.E. Peters1,2, L.S. Ramos3, J.E. Zumberge4

1 Schlumberger Information Solutions, Mill Valley, CA 94941; kpeters2@slb.com 2 Dept. Geology & Environmental Sciences, Stanford University, Stanford, CA 94305 3 Infometrix, Inc., Bothell, WA 98011 4 GeoMark Research, Houston, TX 77095

Chemometric Recognition of Genetically Distinct Oil Families in the Los Angeles Basin A

pr

il 2

1-2

5, 2

01

3

Mo

nt

er

ey

, C

A

Sedimentology and Biogeochemistry of the Monterey Formation and

Modern Upwelling Sediments: a Session Dedicated to Bob Garrison

Acknowledgements •Tess Menotti (maps of sample locations)

•Tom Wright (discussions of LA basin stratigraphy)

•Les Magoon (general discussions)

Significant Characteristics of the Los Angeles Basin

• Richest basin in the world based on amount of petroleum

relative to volume of sedimentary fill.

• Classic model of transform-margin basin.

• Since Brea-Olinda in 1880, 67 fields were discovered;

three supergiants include Wilmington, Long Beach, and

Huntington Beach.

• Little exploration since the early 1970’s.

• Significant potential likely remains in deep, especially

offshore areas.

Purpose of the Los Angeles Basin Study

• Measure biomarker and isotope ratios for ~150 crude oil

samples from the basin to evaluate genetic relationships.

• Assess the extent of biodegradation for each sample to

identify a “training set” where source-related biomarker

or isotope ratios are unaffected.

• Identify oil families; create a chemometric (multivariate

statistics) decision tree to classify new samples.

• Map the distribution of oil families; use biomarker and

isotope ratios to infer their source rock organofacies.

Map Shows Families and Base Mohnian (~14 Ma) >12,000 Ft.

F’

F

>12,000 ft

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

Modified from Wright (1991)

A

A’

PALOS VERDES

HILLS

Oil

Sam

ple

Bio

de

grad

atio

n*

Terpanes Steranes Isotopes

C1

9/C

23

C2

2/C

21

C2

4/C

23

C2

6/C

25

C2

6/T

s

Tet/

C2

3

C2

7T/

C2

7

C2

8/H

C2

9/H

X/H

Ol/

H

C3

1R

/H

Ga/

31

R

C3

5S/

C3

4S

C2

7Ts

/Tm

C2

9Ts

/Tm

S/H

%C

27

%C

28

%C

29

S1/S

6

d1

3C

sat

d1

3C

aro

CV

ElS5S 0 0.0350 0.2470 0.7517 0.7903 1.8274 0.1190 0.0378 0.3835 0.5460 0.0192 0.1162 0.2847 0.1006 0.9857 0.4668 0.2008 1.7745 31.1369 41.6277 27.2354 0.1793 -25.02 -23.68 -0.92

LB6M 4 0.0332 0.1781 0.6544 1.1647 2.6412 0.1335 0.0590 0.4458 0.5961 0.0167 0.1319 0.2269 0.6705 0.8730 0.3510 0.1628 1.8849 29.7768 44.5270 25.6962 0.1514 -23.88 -22.94 -2.16

BvH7S 3 0.0263 0.2458 0.9474 0.8300 2.6974 0.1033 0.0329 0.2743 0.5091 0.0256 0.1405 0.2452 0.2843 0.9021 0.5314 0.2110 1.6759 30.0511 43.9406 26.0083 0.2100 -23.87 -23.16 -2.67

BvH26S 0 0.0202 0.2926 0.7979 0.8203 2.0286 0.1268 0.0560 0.3661 0.5678 0.0151 0.1439 0.2741 0.2774 0.9107 0.4159 0.1811 1.3432 31.9467 39.9842 28.0690 0.0125 -25.06 -23.67 -0.80

CvH27S 0 0.0237 0.2735 0.8494 0.9053 2.0887 0.1302 0.0499 0.1838 0.5275 0.0216 0.1478 0.2242 0.4121 0.6551 0.5258 0.1826 1.2655 30.6225 39.4825 29.8950 0.1942 -24.95 -23.64 -1.01

SwN28S 1 0.0202 0.2647 0.7878 0.8106 2.0852 0.1262 0.0559 0.3621 0.5702 0.0139 0.1472 0.2723 0.4088 0.9618 0.3826 0.1758 1.5505 30.6532 40.9345 28.4122 0.1608 -25.04 -23.73 -0.98

Wht42S 4 0.0555 0.2478 0.8727 1.0259 2.8864 0.0908 0.0815 0.2331 0.4251 0.0319 0.2837 0.1736 0.6051 0.6676 0.7019 0.2142 1.3942 32.0455 40.8963 27.0582 0.2966 -23.68 -23.05 -2.91

Wil78S 5 0.0169 0.2394 0.7959 0.7684 3.8077 0.0926 0.0514 0.4284 0.7302 0.0286 0.1976 0.3393 0.5113 0.9033 0.3726 0.1649 0.7196 32.7066 41.3216 25.9717 1.1362 -23.66 -22.96 -2.76

Wil79S 4 0.0166 0.2464 0.8045 0.7615 3.6745 0.0908 0.0573 0.3370 0.6352 0.0256 0.1622 0.2890 0.5523 0.9238 0.4197 0.1587 1.0619 33.0806 40.7143 26.2051 0.4414 -23.59 -22.91 -2.83

Oil Families: 24 Source-Related Biomarker & Isotope Ratios

*0-10 biodegradation scale of Peters and Moldowan (1993)

Light

1

2

3 Moderate

4

5 Heavy

6

(6)

7 Very Heavy

8

9 Severe

10

Dia

ste

ran

es

Ste

ran

es

Iso

pre

no

ids

Te

rpa

ne

s

C2

6-C

29 A

rom

ati

cs

n-Alkanes

Extent of Destruction of Compound Class

Bio

deg

rad

ati

on

Ran

ik

Training Set: No Biodegradation of Steranes or Terpanes

Peters and Moldowan (1993)

Reje

cte

d

Oil Having Biodegradation Rank 5 or More was Rejected

Pristane

Phytane

Wil78S Wilmington

CvH27S Cheviot Hills

SwN28S Sawtelle North

Nonbiodegraded

PM* Rank = 0

1.90 wt.% S

Mildly Biodegraded

PM* Rank = 1

3.00 wt.% S

Moderately Biodegraded

PM* Rank = 5

8.02 wt.% S

nC15

Pristane

Phytane nC15

*PM = 0-10 biodegradation scale

of Peters and Moldowan (1993)

UCM Biomarker

Region

6

5

4

3

2

1

Cluster Distance

We

st

of

NIF

Z

Ea

st

of

NIF

Z

Similarity

line

112-Sample

Training Set

6 Tribes: East/West of Newport-Inglewood Fault Zone (NIFZ)

Oil Tribe

Repeatability

line

-24.0

-23.5

-23.0

-22.5

-22.0

-21.5

-25.5 -25.0 -24.5 -24.0 -23.5 -23.0

d1

3C

aro

mati

cs

d13Csaturates

112-Sample

Training Set

All Samples Have a Miocene Isotopic Signature (13C-Rich)

1

2

3

4

5

6

East

West

d13Csaturates, ‰

d1

3C

aro

mati

cs,

‰

1

2

3

4

5

6

East

West

0.00

0.20

0.40

0.60

0.80

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Ole

an

an

e/H

op

an

e

C19/C23 Tricylic Terpanes

Tribes 1 and 2 are Enriched in Higher-Plant Biomarkers

Nerium oleander

21

5

SIMCA*

SIMCA*

New Sample

11

Chemometric Decision-Tree Classifies New Oil Samples

112-Sample Training Set

Six Tribes; 12 Families

*Soft independent modeling of class analogy

22

12 13 31 33 32

41 42

6

Families East/West of Newport-Inglewood Fault Zone (NIFZ)

>12,000 ft (base Mohnian)

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

Huntington

Beach

Beverly

Hills

Torrance

Wilmington

Seal

Beach

Santa Fe

Springs West

Coyote

Whittier

Las

Cienegas

El Segundo Alondra

Playa del Rey

Venice

Beach

Cheviot

Hills

Sawtelle

San Vicente

Bandini

Union

Station

Rosecrans

East LA

Potrero

Richfield

Long

Beach

Central

Trough

Inglewood

LA

Downtown

Belmont

PALOS VERDES

HILLS

Families in Tribe 1 Originated from Source Rock East of NIFZ

12

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

12

13

Central

Trough

Seal

Beach

Santa Fe

Springs West

Coyote

Whittier

Bandini

Union

Station

Rosecrans

Potrero

Richfield

Inglewood

LA

Downtown

11 Long

Beach

Belmont

Sawtelle

PALOS VERDES

HILLS

Families in Tribe 1 Originated from Source Rock East of NIFZ

11

12

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

13

Central

Trough

Family 11

28.2o API

1.00 wt.% S

MPI = 1.08

Family 12

31.6o API

1.26 wt.% S

MPI = 1.12

Family 13

30.2o API

1.18 wt.% S

MPI = 1.13

11 12

13

0.00

0.05

0.10

0.15

0.20

0.25

0.8 1.0 1.2 1.4

TA

S3

(CR

)

MPI

Seal

Beach

Santa Fe

Springs West

Coyote

Whittier

Bandini

Union

Station

Rosecrans

Potrero

Richfield

Inglewood

LA

Downtown

Long

Beach

Belmont

Sawtelle

PALOS VERDES

HILLS

12

Families in Tribe 2 Originated from Source Rock East of NIFZ

21

22

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

Santa Fe

Springs

Las

Cienegas

Bandini

Rosecrans

LA

Downtown

Central

Trough

PALOS VERDES

HILLS

Families in Tribe 2 Originated from Source Rock East of NIFZ

21

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

Family 21

35.3o API

1.41 wt.% S

MPI = 1.49

Family 22

32.6o API

0.23 wt.% S

MPI = 1.39

21 22

0.00

0.05

0.10

0.15

0.20

0.25

0.8 1.0 1.2 1.4

TA

S3

(CR

)

MPI

22 Central

Trough Santa Fe

Springs

Las

Cienegas

Bandini

Rosecrans

LA

Downtown

PALOS VERDES

HILLS

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

31

33

Wilmington and adjacent fields – 58% of total resource, 10% of area (Wright, 1991)

Tribe 3 Families Originated from Source Rock West of NIFZ

Huntington

Beach

Wilmington

Torrance

Seal

Beach

Long

Beach

32

PALOS VERDES

HILLS

32

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

31

33

Tribe 3 Families Originated from Source Rock West of NIFZ

Family 31

24.7o API

1.42 wt.% S

MPI = 0.99

Family 32

-- o API

1.57 wt.% S

MPI = 1.04

Family 33

-- o API

1.58 wt.% S

MPI = 1.14

Huntington

Beach

Wilmington

Torrance

Seal

Beach

Long

Beach

6

21 22

31

32 33

0.00

0.05

0.10

0.15

0.20

0.25

0.8 1.0 1.2 1.4

TA

S3

(CR

)

MPI

PALOS VERDES

HILLS

Wilmington and adjacent fields – 58% of total resource, 10% of area (Wright, 1991)

Tribe 4 Families Originated from Source Rock West of NIFZ

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

42

41

Torrance

Wilmington

Playa del Rey

Venice

Beach

Sawtelle

El Segundo

PALOS VERDES

HILLS

Tribe 4 Families Originated from Source Rock West of NIFZ

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

42

41

Family 41

17.8o API

-- wt.% S

MPI = 1.07

Family 42

25.9o API

4.27 wt.% S

MPI = 1.04

41

42

0.0

0.5

1.0

1.5

2.0

2.5

0 1 2 3 4 5

V/N

i

Sulfur, wt.%

Torrance

Wilmington

Playa del Rey

Venice

Beach

Sawtelle

El Segundo

PALOS VERDES

HILLS

Tribes 5 and 6 Originated from Source Rocks West of NIFZ

5

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

6

5 Huntington

Beach

Torrance

Wilmington

Beverly

Hills

Cheviot

Hills

Sawtelle

San Vicente

Inglewood

El Segundo

Playa del Rey

PALOS VERDES

HILLS

Tribes 5 and 6 Originated from Source Rocks West of NIFZ

5

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

6

5

Family 5

29.4o API

1.24 wt.% S

MPI = 1.02

Family 6

25.5o API

2.50 wt.% S

MPI = 0.86

6 5

0.0

0.5

1.0

1.5

2.0

2.5

0 1 2 3 4 5

V/N

i

Sulfur, wt.%

Huntington

Beach

Torrance

Wilmington

Beverly

Hills

El Segundo

Playa del Rey

Cheviot

Hills

Sawtelle

San Vicente

Inglewood

PALOS VERDES

HILLS

Cross Sections Reveal Stratigraphy of Some Oil Families

F’

F

Family

11, 12, 13

21, 22

31, 32, 33

41, 42

5

6

Wilmington

Seal Beach

West

Coyote A

A’

Playa del Rey

San Vicente

Inglewood

PALOS VERDES

HILLS

10

20 6

Dep

th, km

Dep

th, x1000 f

t

A A’

Section modified from Wright (1991)

Santa Monica

Bay Inglewood Playa del Rey

San

Vicente

SW East Beverly

Hills

P Q

Tt

Catalina

Schist

Bc

Q

?

?

3

P

R

D

P

Tt

R

Mo

Mo

? ?

R Tt

?

D

Family

13

6

A-A’ Section Reveals Stratigraphy of Tribe 6 and Family 13

Catalina

Schist

Mo

Mo

Mo

Mo

Mo

Mo

D

D D

D

D

Mo

P

P

P

P P Q

R

R

R R

Mo

u

m

l

u

R m

l

M M

Tt Tt

Tt

Tt

Tt

Tm-Tt

Mo

L Tt D

10

20 6

3

Dep

th, k

m

Dep

th, x1000 f

t

San Pedro

Bay

Wil

min

gto

n-

Be

lmo

nt

West

Coyote

Seal

Beach

Sansinena

NIF

Z

Catalina

Schist Bc AN

Tvs Pg-K Tvs

Bc

F F’

NE

Family

11

31, 32

5

F-F’ Section Reveals Stratigraphy of Families 5, 11, 31, 32

Section modified from Wright (1991)

EPOCH

BENTHIC

FORAM

STAGE

LOS ANGELES BASIN

WEST EAST

SANTA

MONICA

MOUNTAINS

PALOS

VERDES

HILLS

Stratigraphy Suggests Source Rocks for Oil Families P

LE

IST

P

LIO

CE

NE

LA

TE

M I

O C

E N

E

DELMONT.

LUISIAN

LA

TE

E

AR

LY

MID

DL

E

LA

TE

E

E

REPETT.

MOHNIAN

RELIZIAN

HALLIAN

WHEEL.

VENT.

FERNANDO

LOWER

TO

PA

NG

A G

P.

(NOT EXPOSED)

M O

D E

L O

CONEJO VOLC.

UPPER

CALABASAS

TOPG. CYN

SAN PEDRO

LOWER

TOPANGA

GP.

LA HABRA

REPETTO

MALAGA

MUDSTONE

UPPER

M O

N T

E R

E Y

VALMONTE

DIATOMITE

MIDDLE

PU

EN

TE

ALT

AM

IRA

REPETTO REPETTO

LOWER

UPPER

MIDDLE

LOWER

UPPER

MIDDLE TOPANGA

GROUP SCHIST

CONG. VOLC. SD.

LOWER

UPPER

MIDDLE

TIMMS PT.

SLT.

PIC

O

LOMITA MARL

LOWER

“NODULAR’

SHALE

UPPER

MIDDLE

PU

EN

TE

P

ICO

Modified from Blake (1991)

Oil-like shale

hydrocarbons

not observed

(Philippi, 1965)

~4 wt.% TOC, up

to 16 wt.%, Type I

and II kerogen

(Global Geochem.

Corp., unpub.)

A-A’ F-F’

6

13

5

11

32

31

11

NIF

Z

NIF

Z

• Suboxic Upper Miocene (Delmontian) shale with significant

angiosperm input generated Tribes 1-2 at moderate-high

maturity in the Central Trough east of NIFZ.

• Anoxic Upper Miocene (M.-U. Puente) marl source rock

generated Tribe 3 west of NIFZ.

• Anoxic Mohnian(?) marl generated Tribe 4 west of NIFZ.

• Anoxic M.-U. Miocene (L. Puente “nodular shale”) marl with

significant terrigenous plant input generated Tribe 5

southwest of NIFZ.

• Anoxic M.-U. Miocene (L. Modelo “nodular shale”) marl with

significant terrigenous plant input generated Tribe 6 at low

maturity northwest of NIFZ.

Source Rock Can be Inferred from Stratigraphy-Biomarkers

Conclusions: Los Angeles Basin Geochemistry

• At least six genetically distinct Miocene petroleum systems

(12 families) occur in different parts of the basin.

• The Newport-Inglewood fault separates tribes 1-2 (families

11, 12, 13, 21, 22) to the east from tribes 3-6 (families 31-33,

41-42, 5, 6) to the west.

• Biomarker and isotope ratios as well as distinct stratigraphic

occurrence help to identify likely source rock for each family.

• Thermally mature source rock samples for direct oil-source

rock correlation and 3D petroleum system modeling with

partner(s) would useful to delineate pods of active source

rock, migration paths, and undiscovered accumulations.

Thanks for Your Attention!

References

• Blake, G.H., 1991, Review of the Neogene biostratigraphy and

stratigraphy of the Los Angeles basin and implications for

basin evolution: AAPG Memoir 52, 135-184.

• Jeffrey, A.W.A. et al., 1991, Geochemistry of Los Angeles

basin oil and gas systems: AAPG Memoir 52, 197-219.

• McCulloh, T.H. et al., 1994, How oil composition relates to

kerogen facies in the world’s most petroliferous basin: AAPG

Search and Discovery Article #90986, AAPG Annual

Convention, Denver, CO, June 12-15, 1994.

• Wright, T.L., 1991, Structural geology and tectonic evolution

of the Los Angeles Basin, California: AAPG Memoir 52, 35-

134.