Gulf of Mexico Basin, Alabama

Ayobami .T. Folaranmi* and Jack Pashin. Boone Pickens School of Geology, Oklahoma State University, Stillwater Oklahoma *ayobami.folaranmi@okstate.edu

The purpose of this study was to characterize a saline formation that is actively being used to store CO2 as part of the SECARB III

Anthropogenic test in Alabama. The study is aimed at understanding the potential of Lower Cretaceous redbeds to store commer-

cial quantities of anthropogenic CO2. Citronelle Dome is a simple salt-cored anticline that lacks faults and contains abundant reser -

voir sandstone bodies and mudstone, evaporite, and carbonate seals.

The Paluxy Formation has an average thickness of about 1,100 feet in Citronelle Dome. Core analysis indicates that the Paluxy

Formation is a coarsening-upward, succession composed of numerous stacked, aggradational sandstone-mudstone packages. In-

Three wells were drilled for injection, monitoring, and reservoir characterization. Cores from the Paluxy were retrieved, and a

full suite of open-hole geophysical logs was acquired. Detailed petrologic and well log analysis was performed to analyze frame-

work sandstone composition, sandstone diagenesis, and reservoir architecture. High porosity and permeability in the sandstone

units facilitate high CO2 capacity and injectivity, and multiple reservoir seals ensure safe permanent storage in Citronelle dome.

Sandstone body geometry is complex, and understanding reservoir heterogeneity is an essential component of reservoir manage-

ment in Citronelle Dome.

CHOCTAW

CLARKE

WASHINGTON

MOBILE

BALDWIN

CitronelleDome

Wiggins Arch

Hatchetigbee

anticline

Mo

bil

e G

rab

en

West Bend Fault

Gilbertown Graben

ALA

BA

MA

MISSISSIP

PI

MISSISSIPPIINTERIOR

SALT BASIN

PLANTBARRY

CITRONELLEFIELD

Index Map

0 im 0201 10

EXPLANATION

Citronelle Field

C red power plant(~14 MMst CO2/yr)

Normal fault;bar on downthrown side

Fold; arrow points inplunge direction

010 20 30 km10

Research Supported by Advanced Resources International through grants from the U.S. Department of Energy and Southern Company

CONCLUSIONS

STUDY AREA

GEOPHYSICAL LOGS

PETROLOGY

MODERN BRAIDED FLUVIAL SYSTEM ANALOG

CORE PHOTOGRAPHS

Well D-9-8 #2

The Paluxy Formation was deposited in continental environments that

Petrographic analysis indicates that the sandstone units are

composed of arkose to quartzarenite.

Porosity and permeability are well-developed in the sandstone, with

values commonly exceeding 20% and 200 mD.

Provenance analysis indicates that most of the detritus originated in

transitional continental to craton interior settings.

Many Cretaceous sandstone units in the eastern Gulf Coast resemble

the Paluxy Formation at Citronelle, indicating exceptional storage

capacity exists in the Cretaceous redbeds of the region.

ABSTRACT

Quartzarenite

Subarkose Sublitharenite

Ark

ose

Ark

osic

litha

ren

iteLit

hic

ark

ose

Lith

are

nite

Q

F L25 50 25

25

5 Craton

interior

Basement

uplift

Quartzose

recycled

Transitional

recycled

Lithic

recycled

Mixed

Dissected

arc

Transitional

arc

Undissected

arc

23 47 13

11

42

29

20

43

Transitional

continental

Qm

F Lt

ClassificationThin section photomicrograph Core Plug Analysis Plot

SEM Photographs

ProvenanceIntraclastic

conglomerateCross-bedded

sandstone

Ripple cross-beddedsandstone

Burrowedsandstone

Red mudstone

Calcareous mudstone

Core width = 10 cm

Washita-

Fredericksburg

interval

Paluxy

Formation

Ferry LakeAnhydrite

Donovan sand

Mooringsport

Formation

GRAPHIC CORE LOGS

9620

9610

9580

9590

9600

9570 ft

9630

SandstoneMud vf f m c Cgl

SandstoneMud vf f m c Cgl

SandstoneMud vf f m c Cgl

SandstoneMud vf f m c Cgl

D-9-7 #2

9450

9440

9410

9420

9430

9400 ft

9460

D-9-8 #2 Core 1

10450

10440

10430 ft

10460

Braided channel

Braided channels

Braided channels

Longitudinal

bars

Longitudinal

bars

Longitudinal

bars

Longitudinal

bars

Longitudinal

bars

Longitudinal

bars

Braided channels

(vertisol, sheet-

Vertisol

Vertisol

Vertisol

Vertisol

Vertisol

Vertisol

D-9-8 #2 Core 2

Ganges River, India

9440

9410 ft

9420

9430

D-9-9 #2

Mudstone

Sandstone

Intraclastic conglomerate

Roots

Caliche

Horizontal laminae

Cross-beds

Pebbles

Ripples

Rock type

Color

Sedimentary structure

Meniscate burrows

Pedogenic Slickensides

Very Dusky Red

Dusky Red

Dark Red

Weak Red

Pale Red

Light Reddish Brown

Pale Brown

Very Pale Brown

Gray

Inter-

D-9-7 #2, 9624.5 ftD-9-7 #2, 9624.5 ft

D-9-7 #2, 9570 ftD-9-7 #2, 9570 ft D-9-7 #2, 9568 ftD-9-7 #2, 9568 ft

D-9-9 #2, 9424.5 ftD-9-9 #2, 9424.5 ft

D-9-8 #2, 9449 ftD-9-8 #2, 9449 ft

D-9-7 #2, 9634 ftD-9-7 #2, 9634 ft

Quartz overgrowth

Pore-filling Kaolinite Euhedral quartz

overgrowth

Carbonate rhomb

Illite-lined pore

Grain-size pore

Vacuolized feldspar

Illite coat

D-9-7 #2, 9595.60 ft

D-9-7 #2, 9621 ft D-9-8 #2, 9439.50 ft D-9-8 #2, 9401 ft

REGIONAL GEOLOGY

CO2 Capture Plant Facility

D-9-7 #2 Injector Well

Structural contour mapTop Ferry Lake Anhydrite

Stratigraphic columnof saline formations and seals

Shale

Limestone and

Chalk

Anhydrite

Sandstone and conglomerate

EXPLANATION

Bashi MarlHatchetigbee Sand

Selma Group

Wilcox Group

Midway Group

Salt Mountain Limestone

Porters Creek Clay

Claiborne Group

Jackson Group

Oligocene

Miocene

Pliocene Citronelle Formation

Pensacola

Clay

Eutaw Formation

upper Tuscaloosa

Lower

Tuscaloosa

marine shale

Paluxy Formation

Mooringsport Formation

Washita-

Fredericksburg

interval

Pilot sand

massive sand

Dantzler sand

Ferry Lake Anhydrite

Lo

we

r

CR

ET

AC

EO

US

Up

pe

rP

ale

oce

ne

Eo

cen

eO

lig

oce

ne

Mio

cen

e-

Pli

oce

ne

Lithology Geology

2000

Depth (ft)

11000

10000

9000

8000

7000

6000

5000

4000

3000

1000

0

Tuscaloosa

Group

Tallahatta Formation

TE

RT

IAR

Y

ME

SO

ZO

ICC

EN

OZ

OIC

Proven injection zone

Ca

rbo

n S

equ

estr

ati

on

Ta

rget

Inte

rva

lP

rote

cted

wa

ter

Proven injection zone

Potable water

Locally potable water

Saline formations

below 2000 ft

Regional seal

Regional seal

Regional seal

Regional seal

Regional seal

Proven injection zone

-10500

-10500

-10

50

0

-11000

-11000

-11000

-11500

-11500

-12000

-12500

-13000

-12000

-12500

T.

3

N.

T. 1 W.T. 2 W.T. 3 W.T. 4 W.

T.

2

N.

T.

1

N.

T.

1

S.

T.

2

S.

T.

3

S.

0 5 mi

0 10 km

> -10500 ft (-3.2 km)

-10500 to -11000 ft (-3.2 to -3.4 km)

-11000 to -11500 ft (-3.4 to -3.5 km

-11500 to -12000 ft (-3.5 to -3.7 km)

-12000 to -12500 ft (-3.7 to -3.8 km)

-12500 to -13000 ft (-3.8 to -4.0 km)

< -13000 ft (-4.0 km)

Normal fault; bar on downthrown side

Citronelle domeAnticline; arrow indicates plunge

Syncline; arrow indicates plunge

CD

CD

Hatter's Pond fault

Contour interval = 100 ft

HPF

HPF

Pilot area

Longitudinal

InterfluveInterfluve

Braided channel

0.5 mi

complex

bars