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/
P
Geological
Circular
75-8
GEOTHERMAL RESOURCES:
FRIO =FORMATION,
MIDDLE TEXAS GULF COAST
s
BY
D. G. BEBOUT
0. K. AGAGU
M. H. DORFMAN
RESEARCH ASSISTANTS
G. E. GRANATA
G. B. SANDERS, JR.
J. H. SEO
BUREAU OF ECONOMIC GEOLOGY
THE UNIVERSITY OF TEXAS AT AUSTIN
C. G. GROAT, ACTING DIRECTOR
1975
JYSlJIBUJION OF THIS DOCUMENS IS
OBJECTIVE-TO EVALUATE THE GEOTHERMAL RESOURCES OF THE
FRIO FORMATION, MIDDLE TEXAS GULF COAST
Knowledge of the regional sand distribution and i t s relationship
to formation temperature and p r e s s u r e is a preliminary s t e p
in evaluating the geothermal resources of the F r i o Formation.
At depths generally g r e a t e r than
7,000 feet, the sands and shales of the
F r i o Formation a r e overpressured and
undercompacted. The insulating effect
of these overpressured and undercompacted sediments results in the accumulation of subsurface heat and, thus, hightemperature water. The local variations
of depth to top of ge0pressur.e a r e related
to the distribution of sand and shale
lithologies and to the location of growth
faults. F o r m o r e information concerning
origin of geopressure o r high temperatures, s e e Jones (1970) and Dorfman
and Kehle (1974). Bruce (1973) disc u s s e s the nature of growth faults in
detail. The resource i n the geopressured
zone consists of high-temperature water
with relatively low salinity and with dis
solved methane gas.
The objectives of this study were to
determine regional sand distribution of
the F r i o Formation (fig. l), identify
depositional environments, and delineate
the geopressured zone and i t s relationship to sand/shale distribution, growth
faults, and fluid temperatures i n the
Middle Texas Gulf Coast (fig. 2). This
study i s essentially an extension of that
completed e a r l i e r for South Texas
(Bebout, Dorfman, and Agagu, 1975);
all correlation and mapping units a r e
the same a s those represented i n the
South Texas report.
The Energy Research and Development
Administration,
through
the
Law r ence
Live m o r e
Laboratory,
supported this study of the geothermal
r e s o u r c e s of the F r i o Formation in
Middle Texas Gulf Coast.
-
2
CENOZOIC
I
I
AGE
Quaternary
- TEXAS GULF COAST
SERIES
Recent
I
GROUP/FORMATION
I
Undifferentiated
Miocene
I
Figure 1.
w
-li:r
Tertiary,
................................
:............................................
.:.:.:.:..:.:......................
F~~~~~~
....................
T e r t i a r y formations-Gulf Coast of Texas. The F r i o F o r m a tion is shown in the d a r k e r pattern; formations summarized
i n other Bureau reports a r e shown with the lighter pattern.
LOWER TEXAS GULF COAST
(Soulh Texas repwl, Bureauof
Economlc Geology, Geologic
Circular 75-1
I
Figure 2.
Middle Texas Gulf Coast study area of this r e p o r t and Lower
Texas G u l f Coast area reported on previously by Bebout,
Dorfman, and Agagu (1975).
3
REGIONAL DEPOSITIONAL PATTERNS-MIDDLE
TEXAS GULF COAST
The Texas Gulf Coast T e r t i a r y is made up of many
terrigenous wedges of sand and shale which thicken
downdip into the Gulf.
The T e r t i a r y of the Texas Gulf Coast
consists of many wedges of genetically
related sands and shales. Each of these
wedges thickens and dips i n t h e gulfward
direction. Studies resulting f r o m exploration f o r hydrocarbons have divided the
T e r t i a r y into formations based mainly
on foraminifer zonation (fig. 3). The
F r i o is one of the thickest of these formations in the Middle Texas Gulf Coast
a r e a and is h e r e considered to beOligocene in age.
The total thickness of the Frio F o r mation ranges f r o m about 200 feet n e a r
the outcrop to g r e a t e r than 9,000 feet
n e a r the present Gulf Coast (fig. 4).
The top of the F r i o dips 1/2 to 3 degrees
toward the Gulf so that Frio-age sediments which outcrop along a belt approximately 100 miles inland f r o m and
parallel to the coast a r e time equivalent
to those which occur 8,000 and 9,000
f e e t below s e a l e v e l at the coast (fig. 5).
8
0
V
8
0
V
W
Y
B
0
4
5
Figure 4.
Total thickness of the Frio Formation, ' Middle T e x a s Gulf
Coast.
6
Figure 5.
Structure on top of the Frio Formation.
7
GROWTH FAULTS-CAUSE O F IRREGULAR GULFWARD THICKENING
AND LOCAL CHANGES IN DIP
Sediment thickening on the down o r coast side of m a j o r
growth faults interrupts the regularity of downdip thickening toward the Gulf.
-
Growth faults are contemporaneous
s t r u c t u r e s which occur during sedimentation probably as a result of sediment
loading on a soft terrigenous mud substrate. Subsidence along these faults results i n the accumulation of abnormally
thick bodies of sediment along the down
side of the fault; sand bodies along the
gulfward side of these faults a r e d i s placed downward f r o m their updip equivalent thus forming structural/stratigraphic
t r a p s f o r fluid accumulation.
Bruce
(1973)h a s described the m a n n e r inwhich
these faults f o r m and the resulting sand/
shale configuration.
The presence of
hydrocarbon r e s e r v o i r s along the downdip side of these faults has been well
known i n the petroleum industry f o r
years.
The l a r g e r growth faults are
recognized on seismic sections and by
well-log correlation; smaller faults are
m o r e difficult to identify.
In South Texas, deltaic and strandplain sand bodies prograded gulfward for
considerable distances probably resulting i n the formation of s e v e r a l growth
faults. Several of these m a j o r growth
faults have been mapped to the south i n
Mexico by Busch (1975). To the north i n
the Middle Texas Gulf Coast, many of the
m a j o r faults recognized i n South Texas
die out, and only one m a i n growth fault
zone is recognized (fig. 6). Most of the
thickening i s j u s t gulfward of this m a i n
fault and there, f o r the m o s t part, the
sand bodies are stacked one upon the
other. The regular gulfward d i p of sand
bodies is interrupted n e a r the growth
faults by counterregional dips resulting
f r o m rollover structures.
8
Figure 6.
Generalized location of major growth faults along the Middle
Texas Gulf Coast (this report), Lower Texas Gulf Coast
(Bebout, Dorfman, and Agagu, 1975), and northern Mexico
(Busch, 1975).
9
ELECTRICAL LOGS-THE
BASIC CORRELATION TOOL
Regional electrical-log sections provide the b a s i c correlation
grid n e c e s s a r y f o r determining the sand distribution and i n t e r preting the depositional environments.
Obtaining a n -understanding of the
regional sand distribution is a n essential
s t e p i n determining the r e s o u r c e potential
of geothermal energy along the Gulf
This is best accomCoast of Texas.
plished by constructing a network of
c r o s s sections using electrical logs to
locate m a j o r sand bodies.
Previous
studies of this nature by Fisher and
McGowen (1967), Guevara and Garcia
(1972), and Bebout, Dorfman, and Agagu
(1975) indicate that well spacing of 8 to
10 miles a p a r t is optimal for a regional
study. With this i n mind, wells selected
f r o m the Middle Texas Gulf Coast area
w e r e spaced 5 to 10 miles apart(fig. 7).
Wherever possible wells which penetrate
the e n t i r e F r i o w e r e selected; i n the
downdip area, however, many wells do
not extend through the total F r i o section.
In the Middle Texas Gulf Coast, the
top of the F r i o is picked at the occurrence
of Marginulina vaginata i n o r d e r to main-
tain consistency with the top of the f o r mation picked i n the South Texas study.
In South Texas, the Marginulina vaginata
zone is high i n sand and, because of
similar characteristics, i s thought to
belong to the F r i o system. However,
this zone becomes less sandy to the north
i n the Middle Texas Gulf Coast area and
lithologically a p p e a r s to be p a r t of the
Anahuac shale wedge. Consequently, i n
this area the first sand beneath the
Anahuac shale wedge contains Cibicides
hazzardi, a m a r k e r which o c c u r s s e v e r a l
hundred feet below the top of the F r i o i n
South Texas.
Correlations between wells w e r e
accomplished p r i m a r i l y by m e a n s of a
grid of regional electrical-log c r o s s
sections consisting of nine dip and four
s t r i k e sections (fig. 7). The remaining
'linfillllwells w e r e then correlated into
closest c r o s s sections.
LO
i
L I V E
a.
1.
Figure 7.
Well-log control and cross sections constructed for the
Middle Texas Gulf Coast study.
12
LIST OF WELLS
Aransas County
1
1. UnionProd. Co.
2. Prairie Prod. Co.
C. G. Glasscock
Sun Oil Co.
Prairie Prod. Co. &
Convest Energy
6. sun Oil Co.
7. Western Natural Gas Co.
8. Brazos Oil & Gas Co.
9. Geo. W. Graham &
Rysn. Hays & Burke
10. Amerada Petr. Corp.
11. Jake L. Hamn
12. Aransas South Copano Bay
13. Heep Oil Corp.
14. Hmble Oil & Rfg. Co.
15. Neil E. Hanson
Tatton I10
State Tract 12 I1
State 129-8
State 1363-1
State Trace 374 I1
State I385-1
St. olarles I14
Mesquite Bay State Trace 26 I1
R. A. Bible I2
Bankers Mortgage Co. I1
Bankers Mortgage Co. I1
State Tract 101 I1
Zeph W t t e et al. I4
Aransas Bay State Tract 166 I1
State Tract 129 I1
6. John W. Mecom
7. Bering Co.
8. Unim Carbide Corp.
Olefins Division
9. Republic Natural Gas
Co. et al.
10. Edwin L. cox
11. Monsanto Co. & Ada Oil Co.
12. Midwest Oil Corp
13. Coastal States
14. W l e Oil & Rfg. Co.
15. The Texas Co.
16. W l e Oil & Rfg. Co.
17. Forrest Oil Corp. &
Ham Bros.
18. Texas Oil & Gas Co.
19. Brazos Oil 6 Gas Co.
20. C. G. Glasscock-Tidelands
Oil Co. &Arkansas
Fuel Oil Co.
21. Southern Production cd.
22. Continental Oil Co.
23. Tennessee Gas
Transmission Co.
24. George R. Bmwn
25. Arkansas Fuel Oil Corp.
26. Texas Eastern
Transmission Corp.
27. W l e Oil & Rfg. Co.
Bee County
1. Coastal States Gas
Prod. Co.
2. Cannercia1 Prod. Co.
3. Wynn D. Miller
4. Bright & Schiff
5. Millitan oil Co.
6. MDxeen Oil Co.
7. smith-story & wood
8. Hallcock & Young
9. Tennessee Gas
Transmission Co.
10. Dale Gas 1970 A. Ltd.
11. W. L. Bates et al.
12. Armld H. Bruner & Co.
13. Pan American Production
1. Republic Natural Gas Co.
2. .Lone Star Prod. Co.
3. Aluninun Co. of America
& Superior Oil Co.
4. Tennessee Gas
Transmission Co.
5. The Superior Oil Co.
Sudie Scott X1-A
C. A. Pressey I4
S. P. Farish I1
Schoolfield #1
Mccord I4
Airstin E. Brown X1
RobinSon tl
Klipstein I1
G. C. McCoy Trust
et al. I1
Ethel E. McCoy I1
D. V. Baker I1
J. G. Roundtree I1
F. W. Heldenfelds I2
28. Standard Oil Co. of Texas
29. Gulf Board Oil Corp.
30. Sunray DX Oil Co.
C. E. Heard I2
Laura D. 'Ihomson IB-9
L. T. B a r n 18-27
Clara Driscoll Estate I1
1.
2.
3.
4.
5.
6.
Laura T. Barrcu I10
8.
Carrie Stubenthal I1
7.
SOUthWOrth
19. Ihble Oil & Rfg. Co.
Maude R. Traylor 'C'
Well I1
Maude R. Traylor Lease '9''
Well A-1
Minnie S. Uelder I12
Wilburn I1
Clyde Bauer I1
Foester I1
Fisher Il-A
State Tract 37 I1
State Tract 21 I1
rncanI1.
Elizabeth K. Hardie I12
State of Texas-Amerada
Unit I1
Daniel E. Schicke I1
State Tract 2 I1
J. Glen Turner I1
J. H. Tigner I1
State Tract 131 I1
M e l h m I1
B. Kingswell-Smith I1
C. H. Stiernberg I1
State Tract 81 I1
J. J. Welder I1
State Tract 108 I1
Shoalwater Bay State
Tract 169 I1
State Trace 138 I1
State 11-114
State Tract 122 I1
Colorado County
co.
14. W. Earl R m e &
W. C. McBride
15. L o p 6 Patterson
16. W l e Oil & Rfg. Co.
17. Exxon Co., U.S.A.
18. J. P. Petkas-Harrell &
M. F. Canion I1
L. J. Fcester I1-A
Alcoa Fee I1
9.
10.
Irwin & Budc
shell oil Co.
Mobil Oil Corp.
Hatston Oil Co. of Texas
Southern Natural Gas Co.
R. H. Eaglehart
Chambers & K e ~ m d y
Flaitz & Mitchell
W l m y Co. of Texas
h i s H. Haring, Jr.
Duncan I1
Hayes Stephens I2
Chesterville Unit I 8
H. H. Bmwnson et al. I1
L. A. Johnston I1
Lehrer I1
Dalco Oil Co. I1
Stiles I1
Kallina Gas Unit I1
c. w. McDemtt I1
DeWitt County
1.
2.
3.
4.
5.
6.
Brazoria County
1. Southwest Gas h.od. Co.
2. L o n e S t a r M . Co.
3. Pan American Petr. Corp.
Md)onald I1
H. A. Frede I1
B.R.L.D. Co. #A-1
7.
8.
9.
10.
11.
American Petrofina of Texas
Billy Bridewell
Standard Oil Co. of Texas
Sinclair et al.
Kirkwood & Co.
George Mitchell &
Associates
Shell Oil Co.
R. L. Foree
La Gloria Oil & Gas Co.
Francis J. Hynes
Kirkwood & Co.
Edwin L. Boldt I1
J. W. Burns Estate I1
Lebrecht Pieper I1
Cattle Co. I1
Buehrig I1
Gohlke Heirs A-4
W. L. Hartanan I1
H. Ferguson I1
Egg "1
Ahla RabelI1
LIST OF WELLS (cont'd.)
13
Live Oak County
Goliad County
1.
2.
3.
4.
5.
6.
7.
8.
'9.
10.
11.
12.
William D. Johnson
Nonnandy Oil & Gas Co. Inc
W l e Oil E Rfg. Co.
W. C. McBride, Inc.
Harkins & Co. and
A. B. Alker
The Atlantic Rfg. CQ.
Lewis Lawlor
Robert J. Hewitt
A. B. Alkek
PlymDuth Oil Co.
Ginther. Warren & Ginther
D. H. Braman, Jr.
Hugo Wagener. et al. I1
Alton Fnmne X1
Hugo-McMillan t2
Nancy Jane Busby 14
T. P. Appleby t1
G. E. Diebel X1
Berger #1
Mrs. Freida Hall tl
Sol Parks I4
Tholnpson I1
Carrie G. Wood 112
Dennis O'Connor. et al. t3
1. Billings Oil Service, Inc.
2. Qristie, Mitchell &
Mitchell
3. Blanco-Buchanan &
Kirkwwd & Co.
4. Rhcdes & Hicks Drlg. Corp.
E G. M. McGarr
5. Kirkwood & Morgan
6. Lee Bros. Oil & Gas Co.
7. Frank Waters Oil Co.
8. W l e Oil & Rfg. Co.
9. Kirkwwd & Morgan
Mary Ethel Nester I1
Hailer I1
Frank K. Mobis I1
Hattie Hinnant "A" I1
Ross Boothe I1
Jennings 11
Mary Reynolds I3
c. L. Mccaslin I9
C. F. Manp I1
Jackson County
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Hennan Pmler
J. M. Rher Corp.
Magnolia Petr. Co.
Magnolia Petr. Co.
Triad Oil & Gas Co.
J. M. kber Corp.
H. H. -11,
Cecil J. Cox.
H. B. Rudman, et al.
Gravis & Mitchell
Horace Coon Jr.
Gus Glasscock, Inc.
H. H. Howell
Millsap Oil & Gas Co.
D. M. Wallace
H. H. Howell et al.
H. H. Howell &
Glenn G. Mortimer, Jr.,
DeLange 6
Southland Drlg. Co.
Texxan Oil Co. &
Caracus Petr. (VS)
Inc
Texas Oil & Gas Corp.
salt Dame Prod. Co.
Windfohr Oil Co.
Reese M. Rarling
H. M. Maylor Oil Co.
C. G. Gilger
Bettis & Shepherd
Forest Oil Co.
Texaco Inc.
Sun Oil &.-The Texas Co.
Union Oil Co. of Calif.
The Superior Oil Co.
Mowanto chemical co.
.
18.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
Johnson I1
J. E. Wearden dl
Aaron Kolle I1
Henry Peters I1
C. D. Holzheuser I1
John Grant Unit I1
Ben N. Good I1
Mcculloch I1
S. G. Sample I1
0. W. Freeman I1
J. M. Heard I1
A. L. Claybrook I1
Miller X1-A
Rose & Sample WF-1
August Spree Estate I1
Ora Mae Oliver I1
Clark 11
Miller & Howle t1
4-Way Ranch I1
E. R. Eversberg I1
Vincik tl-A
R. J. Stepan I1
Deunar I1
J. R.. Davis I1
Cornish I1
L. Ranch IB-1
Tnnnble Unit I1
Bennett tl
Leola Weaver X2
Texas Gulf Sulphur Fee tl
Matagorda County
1. Jack W. Frazier &
J. B. Ferguson
2. Mid-Century Oil & Gas CO.
3 . Bradco Oil & Gas Co.
4. Lenoir M. Josey, Inc.
5. Cerro De Pascn Corp.
6 . Ancon Oil & Gas Inc. &
Andrews & Smith
7. Lario Oil & Gas Co. &
Felmont Oil Corp.
8. Manco Corp.
9. Lenoir M. Josey Inc. &
John B. Coffee
10. Sun Oil Co.
11. Fullerton Oil Co.
12. Monsanto chemical Co.
13. Continental Oil Co.
14. Pan American Petr. Corp.
15. Hanmlan Oil & Rfg. Co.F. A. Callert Inc.J. Hamnan, Jr.
16. Gulf Oil CQrp.
17. Mmble Oil & Rfg. Co.
18.
19.
20.
21.
22.
Lavaca county
1. Oil Drlg. Inc.
2 . Holmes Drlg. Co.
3. Pel-Tex,Inc.
4. salt Dame Prod. Co.
5. Sutton prod. Co.
6. CQrmercialPetr. &
Transport Co.
7. Hugh Goodrich
8. North Central Oil Corp.
9. H. J. Chavanne Trustee
et al.
10. North Central Oil Corp.
et al.
Allen 13
Ruth C . Robertson I 2
Agnes Aschbacher tl
Hancock Unit X14, Well I1
Wier-Landry #1
A. E. Evans 13
Peter C. Krupp W1
Frmch-Nemms Unit I1 Well tl
Enmu Borchers et al. I1
G. E. Cranz Estate et al. #A-1
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
Mobil Oil Co.
E. cockrell, Jr.
George R. Brown
Travis Oil Co.Tidewater Oil Co.
Mowanto chemical Co.
Magnolia Petr. Co.
Magnolia Petr. Co.
Pan American Petr. Corp.
Gulf Oil Corp.
Falcon Seaboard Drlg. Co.
Phillips Petr. Co.
Gulf Oil Corp.
Pan American Petr. Corp.
Skelly Oil Co. &
Sunray DX Oil Co.
Tidewater Oil Co.
Brazos Oil & Gas Co.
American Petrofina
Fxploration Corp.
North Central Oil Corp.
Pierce Est. I1
Florence W. €bward "A" I1
Elizabeth Burkhart et al. I1
Pierce Est. I2
I1 J. C. Lewis
Mary Payne Tew Unit I1
Corbett I1
Kountze I1
Gloria Stoval Reifslager I1
Clara Junek I1
Heffelfinger 11
Cornelius Cattle Co- I1
W. W. Fondren, Jr. et al. I1
Sherrill Gas Unit I1
Wbner I1
Mae Gilmore et al.
Gas Unit 12, Well I1
First City National Bank of
Houston Trustee I1
Ethel Cornelius I15
L. P. kuszer et a l . I1
Jennie Grant I1
Bertha L. Backen I1
Buckeye I1
W. W. Rugeley 11
Cornelius I1
T. J. Petruchka I1
H. B. Hawkins 12
J. J. LeTulle I1
State 'W'el-A
C. G. Hamile, et al. I1
Silver Lake Ranch 11
Gulf "D" State Tract 291 I1
J. Nelson Unit $1
Stewart Salvage 12
D. H. Braman I1
Hans
State Tract 105 I1
14
LIST OF WELLS (cont'd.)
Nueces County
17. Driscoll et al.
29. Cities Service and Sunray
Smith et al. No. 1
State Tract 16, No. 1
Victoria County
1.
2.
3
:
4.
5.
6.
7.
8.
9.
10.
11.
12.
Refugio County
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
W l e Oil & Rfg. Co.
Mana Oil Corp.
Union Oil Co. of Calif.
Tennessee Gas
Transmission Co.
Southern Petr.
Exploration Inc.
Morgan Minerals Corp.
et al.
Texas Oil & Gas Corp.
P. H. Welder
Harkin & Co.
Dallas Husky
Continental Oil Co.
Wndette Graham
Seaboard Oil Co. &
Roy w. Young
Union Prod. Co.
Pan American Petr. Co.
Union Prod. Co.
Magnolia Petr. Co.
Texaco Inc.
khmt
Edwin E. Cox
4-B Trust
Harkins & Co.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23. SunrayMid-Continent Oil Co.
24. Sun Oil Co.
25. F. P. Zoch & J. C. Wynne
San Patricio h
1. Jake L. Hamon
2. S t a n d a d Drlg. co.
3 . Ames Oil & Gas
4. Marathon Oil Co.
5 . Luling Oil & Gas Co.
et al.
6 . Tan Graham
7. Hewit 4 Dougherty
8. Midland Production Corp.
9 . R. L. & J. L. Rush
10. Plymouth Oil Co.
11. Austral Oil & Arkansas
Fuel
12. Atlantic Richfield Co.
13. Plymuth Oil Co.
14. MccUllo~h-105
15. Mobil Oil Co.
16. Lonnie Glasscock
17. Skelly Oil Co.
18. Getty Oil Co. et al.
19. Spartan Drlg. Co.
20. The Atlantic Rfg. Co.
21. Mobil Oil Corp.
22. Republic Natural Gas &
Forest Oil
23. Tenneco Oil Co.
Mary Agnes Paver Shay tl
Mary s. Huff t1
Thelma W. Heard Well #A-1
James A. Hynes F-25
Mrs. Jamie Hynes Xl
Tolbirt t1
J. Glen Turner tl
John L. Zanky I1
Rae Wood Welder #l-A
Wilson Heard I1
C. E. Heard et al. I1
Fox I1
Jamie Hynes #A-4
Tatton 18
Tatton Ranch I1
Tatton Ranch C-1
J. W. Callmay I1
K. D. Roche #2
woods 11
W. E. h m n n t1
Rooke tl
Julia Veselka
W. F. Hartman U1
Frank U. Palfrey I1
1. L. Heinlein tl
t y
Beulah Hodges YB-1
N. cantu I1
G. R. Taylor I1
Welder #E-20
C. S. B r m tC-1
R. Morgan t1
J. E. Smith I1
Hunt I1
San Antonio Loan &
Trust Co. tl
R. H. Welder IH-1
Joseph Green Est. Ul
L. E. Fite I1
R. H. Welder #E-18
Boehm e t al. ill
Agnes Bren ?1
Lewis Weir tl
F. J. Smith I1
Wilkerson tl
E. H. Granberry I1
J. H. Coward tl
Mayu-Owen Gas Unit I1
S. G. Floerke Xl
W. G. kcampbell Y1
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
Edwards, Hamilton & Ford
Morgan Minerals Corp.
Arnold 0. Morgan
R. B. Roos
Rodney D. Iange et al.
Logue & Patterson, Inc.
Robert Riesenberg Trustee
Abner Foster &A. W. Gregg
Sohio Petr. Co.
H. L. "Ike" Poole
Logue & Patterson, Inc.
H. H. b e l l &
Cecil J. Cox
J. L. Ha&
Bobby M. Burns
Jefferson Lake
Danciger Oil & Rfg. Co.
Paul J. Fly &
R. E. Cliburn et al.
Fort Bend Oil Co.
Golden Trend Oil &
Gas Corp.
Harkins & Co.
George C. Ayres
Lone Star Prod. Co.
Vaughn Petr., Inc.
Mrs. James R. Dougherty
Harkins & Co. &
Edwin L. Cox
Champlin Petr. Co.
Union F'rd. Co. et al.
$1 Hamilton Fee-Nursery Ranch
M. M. Wallis 11
R. H. Welder C-1
Ben McCormick I1
C. K. McCan I3
Joe Filgas tl
John & E. L. Obsta tl
Sidney Benbow tl
A. J. Albrecht tl
L. V. Small et al. I1
Leroy L. Beyer t1
Jack C. Goodson 1 2
Dolly Angerstein tl
Jones P1
Keeran X1
J. Baass I1
Leopold & Rose Morris I1
J. E. Schmjsa t1
J. 0. E. Warburton X1
Henderson-Pickering#I
Keeran t1
L. J. Foester Xl-A
D. W. Surmers t1
Marach X1
Mrs. Mary sinumns tl
J. A. McFaddin A-10
McFaddin A-34
Wharton County
1. Scurlock Oil Co.
2. Western Oil Corp.
3. Sunray Mid-Continent
Oil Co.
4. Robert Merritt
5. Tidewater Assoc. Oil Co.
6. Acco-Colorado-Amurex
7. Geo. R. B m Co.
8. Claud B. Hamill
9 . Lenoir M. Josey, Inc.
10. Mackey Oil Co.
11. Claud B. Hamill &
Sunray D-X Oil Co.
12. Greenbrier Oil Co.
13. Mid-AmericanOil Co.
14. Guy F. Stwall
15. Md)annald Oil Co.
16. J. S. Michaels
17. artis Hankamer
18. George Haggarty
19. Texxan Oil Co.
20. Davidor & Qavidor, Inc.
21. Cerro de Pasco
22. Acco Oil & Gas Corp.
23. Acco Oil & Gas Co. &
Colorado Oil &
Gas Corp.
24. Sun Oil Co.
25. L. M. Joskey et al.
26. Lloyd H. Smith Inc.
27. C. C. Winn
28. F. S. Pratt
29. Texas Republic Petr.
Co., Inc.
30. R. B. Mitchell
31. Mac Drlg. Co. & John Mayo
32. Acco Oil & Gas Co.
33. Marlin Exploration Co.
34. Marks
35. W. M. Keck
36. Moore & Ahern
37. Brazos Oil & Gas Co. &
M. T. Halbouty
Waddell I1
Sklar Alliance Trust I2
I. v. h c a n t1
Otto 11
Vacek X1
J. W. Elliott t1
Peter Gerston, Jr. t1
F. B. & D. Duncan t2,
"B" Lease
Keprta X1
R. Matusek 1 2
J. P. Henderson I1
E. Wendel $1
Ilse Miller I1
Mary Lichnovsky I1
Dortex 11
F. B. & Donald h c a n t2
Hobbs & Le Fort I1
Lily B. (XltlarI1
Mary D. h e tl
ti
Gary Est. t1
Schmidt I1
R. E. Meek t2
Hawes I1
Bergwall-Montgomery112
Rufus Johnstone et al. t1
Selma Kainer I1
Fleer I1
G. R. Hawes #1
H. C. Cockbum
Gary Estate $1
J. K. Allen I1
Braden XI
Kountze & Stewart X 1
Leissner Xl
Hans Johnson $1
Blue Creek Ranch t 2
15
FRIO SUBDIVIDED ON REGIONAL CROSS SECTIONS
Regional electrical -log c r o s s sections and micropaleontological
control provide the basis f o r subdivision of the F r i o into six
units
.
The entire F r i o Formation considered as one depositional unit is too
thick to provide meaningful data for sandfacies analysis and interpretation of depositional environments. Therefore, the
formation was subdivided into six c o r r e lation units using paleontologicalmarkers
(fig. 8) and m a j o r shale breaks. These
correlation units are the same as those
used f o r the South Texas study (Bebout,
Dorfman, and Agagu, 1975). Several
assumptions have been made when establishing the correlations: (1) the F r i o
thickens downdip and, therefore, each
unit should also thicken i n a similar
manner downdip (exceptions occur locally
along growth faults); (2) m a j o r shale
breaks a r e m o r e continuous and thus
m o r e reliable f o r correlation than sands;
(3) foraminifers used as m a r k e r s are
present only in the marine portion of the
units and, although facies control their
occurrence, are reliable for identifying
m a j o r correlationunits; '(4) along any one
correlation unit there is generally one
m a j o r sand depocenter.
The dip sections (figs. 9 and 10)
show a general change f r o m thin, dis-
continuous sands separated by thick
shales i n the updip portion of each unit,
to a main sand depocenter whichextends
a c r o s s only two wells i n the center of
the sections, and to thick shales with
scattered thin sands i n the downdip
portion. The area of maximum sand
deposition did not prograde downdip h e r e
as much as it did in South Texas but instead remained in essentially the same
location along s t r i k e resulting i n the
vertical stacking of many thick sand
bodies. Major shifts in the location of
sand depocenters i s well illustrated on
the strike section (fig. ll), although as
a general rule sand/shale facies are
m o r e continuous along s t r i k e than dip.
In spite of the fact that the m a i n
depocenter migrated very little, the
major overall pattern of offlapping c o r r e lation units is present i n the Middle Texas
Gulf Coast as i t was i n the Lower Texas
Gulf Coast.
This trend is well illustrated by the m a p showing the updip limit
of "Ttl m a r k e r s (fig. 12) and is supported
by the similar pattern shown on the m a p
of updip limits of m a r k e r foraminifers
(fig. 13).
16
Miocene
Anahuac
Heterostegina texana"
Frio
Marginulina vaginata
Cibicides harrardi
Nonion struma
Nodosaria blanpiedi
Textularia mississippiensis
Anomalia bilateralis
Vicksburg
Textularia warreni'
Oligocene
I
Figure 8.
Foraminifer zonation, Texas Gulf Coast Miocene and Oligocene.
Dewitti victoria
0
lp
20
3P
j oMILES
HORIZONTAL SCALE
Figure 9.
Frio sand distribution along dip section K-K'. The Frio is
subdivided into six units indicated by the 'ITtt correlation
lines. Occurrence of marker foraminifers is also shown.
17
I
Lavaca Wharton
R
Wharton
I
R'
Matagorda
!
L3
MW
M 4
)950
\
\
i/
\
AB Anomalia bilateralis
CH Cibicides hazardi
HT Heterostegim texana
M V M q i n u l k wghato
MT Marginufim rexana
NB Nodosoria blanpiedi
NS Nonion srruma
TM nxtuhk~mississiMiensis
\
\
\
-I-
I-
2000 L
0
L
IO
I
x)
I
39
40
I
I
50 Mile
L
HORIZONTAL SCALE
Figure 10.
Frio sand distribution along dip section R-R'. The correlation lines whichserve to subdivide the Frio are indicated
by the ItT" markers. Marker foraminifers and persistent
shale breaks were used to subdivide the formation into six
units.
o w
m o
18
Figure 12.
Updip limits of IIT" markers.
20
Figure 13.
Updip limits of foraminifer markers.
21
DEPOSITIONAL ENVIRONMENTS DERIVED FROM SAND-PERCENTAGE
AND NET-SAND MAPS
Sand-percentage and net-sand maps of each correlation unit
aided in the identification of three main depositional environments -fluvial, strandplain, and shelf.
A sand-percentage map, net-sand
map, and facies c r o s s section have been
constructed f o r the total F r i o (figs. 14
and 15) and f o r each of the correlation
units-T5-T6,
T4-T5, T3-T4, T2-T3,
Tl-T2, and TO-T1 (figs. 16-33). The
sand units were identified p r i m a r i l y by
a high negative spontaneous potential response on the electrical logs. However,
in the geopressure zone the S P response
is commonly subdued because of the
presence of f r e s h e r water, higher temperatures, and modifications i n drilling
procedures; h e r e the gamma-ray log
was commonlyused to identify the sands.
The sand distribution as shown on
the maps, verticaland l a t e r a l facies rela tionships, and sediment characteristic
as interpreted f r o m electrical-log response were features used to i n t e r p r e t
the depositional environments within
these F r i o correlation units.
Three
g r o s s depositional environments a r e
recognized -fluvial plain, s trandplain,
and shelf. The fluvial plain consists of
a broad a r e a on the updip portion of the
maps and c r o s s sections m a d e u p p r e dominantly of shale; scattered sand bodies
are thin and discontinuous and a r e concentrated i n dip-oriented trends. This
a r e a under the influence of fluvial proc e s s e s is extensive i n the lower units
(T5-T6, T4-T5) but becomes narrower
i n the upper units.
Units T1-T2 and
TO-T1 do not show dip-oriented sand
bodies. The lack of fluvial sand bodies
in the uppermost correlation units m a y
be the result of truncation of these units
by the overlying Anahuac transgression.
However, the sand-percentage maps for
T1-T2 and TO-T1 show a d e c r e a s e i n
sand content to the north suggesting the
absence of fluvial feeder systems. This
is also indicated on the m a p showing the
updip limits of foraminifers (fig. 13) by
the landward encroachment of the M a r ginulina vaginata ma rke r i n the low sand
areas.
The strandplain environment consists of a narrow band 10 to 15 m i l e s
wide oriented parallel to strike. It is
made up of thick sands 40- to s e v e r a l
hundred feet thick and separated by thin
shales 10 to 50 feet thick. Very little
basinward progradation of these thick
sands took place throughout the entire
F r i o Formation, possibly because of
contemporaneous movement along the
l a r g e growth fault just landward of the
On the other
main sand depocenter.
hand, this lack of progradation, the
stacking of sand bodies, and the high
sand/shale ratio m a y be due to the low
sediment supply suggested by the lack
of dip-oriented feeder systems i n this
area. These sand bodies are dominantly
strike oriented and probably accumulated
a s a complex of beach ridges and barrier
is lands
,-Gulfward of the strandplain sands
the section changes abruptly into shelf
sediments consisting predominantly of
shale with mostlythin sands 10 to 30 feet
thick. The configuration of the sands i n
the shelf environment is difficult to determine because of the lack of adequate
well control. However, local thicker
sand bodies which a r e probably reworked
f r o m the strandplain system do occur
he re.
-
-
.
22
Sand percentage
Frio Formation.
?igure 1 5 .
N e t sand
of the entire Frio
Format ion.
23
'.
'.-.
SCALE
0
Figure 16.
Sand percentage in unit T5-T6.
50 miles
FLUVIAL
0
oe4
De7
10,230-I
@ Cmoco =WIIO3 Turk
@ caxlu, sW1186 Lanphoff
@ CaDM 'W1107 Rathkamp
Co *I E Race
@ I E R w e *ISParkw
@Pure 09
Figure 18. Sand distribution and interpreted depositional environments
in unit T5-T6 along section K-K'.
1.21
25
Figure 19.
Sand percentage in unit T4-T5.
26
STRAND PLAIN
MILES
Figure 21.
Sand distribution and interpreted depositional environments
in unit T4-T5 along section J-J'.
It il
27
‘.
Figure 22.
Sand percentage in unit T3-T4.
'.
?-.
.
28
/'
(-I
/
/
B
E
X
A
R
M C M U L L E N
Figure 23.
STRAND PLAIN
VIS
v21
co I
I
Net sand in unit T3-T4.
SHELF
Co I3
co 21
I.
0
MILES
Figure 24.
Sand distribution and interpreted depositional environments
in unit T3-T4along section K-K'.
29
I
i
i
i
i
i
j
I
i-i
i
i
i
i
i
Figure 25.
Sand percentage in unit T2-T3.
31
Figure 28.
Sand percentage in unit T1-T2.
Figure 30.
Sand distribution and interpreted depositional environments
along section J-J’.
in unit ‘Tl-T2
33
Figure 31.
Sand percentage in unit TO-Tl.
t
B
E
.
A
X
A
'.
T
.
A
S
C
-.-.-
M C M U L L E N
J I M
D
U
V
h
L
W E L L S
'
i
8
N
V
E
C
E
S
-.
',
,---l.
i
i
Figure 32.
Net sand inunit TO-T1.
L
STRAND PLAIN
Figure 33.
1
I
SHELF
Sand distribution and interpreted depositional environments
in unit TO-T1 along section 1-1'.
35
GEOPRESSURED FRIO RELATED TO SAND DISTRIBUTION
Along the Middle Texas Gulf Coast, only the sands seaward of
the main sand depocenter i n the shelf environment occur beneath the top of geopressure.
Geopressure is defined as the zone
in which the subsurface fluid p r e s s u r e
significantly exceeds that of the normal
hydrostatic p r e s s u r e of 0.464 psi/ft
(Jones, 1969). F o r this study, 0.7 p s i /
ft is considered to indicate geopressure.
The top of geopressure is picked f r o m
various c r i t e r i a shown on the electrical
logs such as gradual reduction i n the
negative self -po tential deflection, inc r e a s e i n drilling mud weight above
13.5 lbs/gal, location of the intermediate
casing point, and reduction of the density
and resistivity of the shale.
In the Middle Texas Gulf Coast area,
the top of geopressure occurs between
-7,000 and -11,000 feet (fig. 34). The
shallowest occurrence of geopre s s u r e
corresponds to thick shale sections beneath the F r i o updip f r o m the m a j o r
strike-oriented sands. Throughout the
a r e a of occurrence of m a j o r strandplain
sediments, the top of geopressure occurs
i n shallow troughs at subseadepth ranging f r o m -8,500 to -9,000 feet, resulting i n the top of geopressure being located beneath the sand sections.
This
relationship, as noted in theSouth Texas
study (Bebout, Dorfman, and Agagu,
1975), is characteristic of strandplain
sediments primarily because of lack of
effective shale seals, allowing fluid
leakage f r o m the r e s e r v o i r and displacing the top of geopressure downward.
Downdip of the strandplain trend, the
top of geopressure occurs within the
section of thick shale and thin sands of
the F r i o shelf sediments.
36
Figure 34.
Top of geopressure, Middle Texas Gulf Coast.
37
ISOTHERMAL MAPS
Isothermal maps constructed f r o m well-log bottom-hole temperatures indicate low temperatures within high-sand a r e a s
and steepening of geothermal gradients below 225OF in downdip
F r i o sections.
Isothermal maps have been constructed for units T5-T6, T4-T5, and
T3-T4 (figs. 35-37), based on uncorrected well-log bottom-hole temperatures.
These temperatures were not m e a s u r e d
under stable hole conditions and a r e
expected to be slightly lower than the
actual subsurface temperature. Because
of the difficulty encountered i n c o r r e c t ing temperatures, it i s not felt that this
procedure is necessary f o r the g r o s s
evaluations required here.
Data points
for these isothermal maps a r e s p a r s e
because there is commonly only one
temperature reading p e r well i n the
F r i o interval; consequently, the data
density is approximately one -third that
used i n the preparation of other maps.
F r o m these isothermal maps (used
with the sand-distribution maps), three
(1) fluid
observations can be made:
temperatures within the m a i n sand depocenter a r e generally lower than 200°F,
(2) the temperature gradient steepens at
temperatures above 225OF, principally
i n the thick shale section downdip f r o m
the m a j o r sand depocenter, and (3) temperatures higher than 250°F occur only
in the shelf environment where the sand
bodies a r e relatively thin.
38
Figure 35.
Isothermal map-unit T5-T6.
39
7 ,
Figure 36.
Isothermal map-unit T4-T5.
SCALE
I
,
I
,
I
,
,
,
y-
40
Figure 37.
Isothermal map-unit T3-T4.
41
CONCLUSIONS AND POTENTIAL GEOTHERMAL FAIRWAYS
F r o m this study of the F r i o of the Middle Texas Gulf Coast,
three a r e a s (gulfward of the main sand depocenter) have been
identified as potential geothermal prospects.
F r i o sand along the Middle Texas Gulf
Coast was deposited in three main depositional environments: fluvial, strandplain, and shelf. The fluvial environment
consists of a relatively narrow fluvial
plain crossed by sand-filled dip-oriented
The strandplain enfeeder channels.
vironment comprises many thick s t r i k e oriented sand bodies which are stacked
one upon the other along a narrow band
10 to 15 miles wide. The shelf environment is composed primarily of shale
with thin sands of local l a t e r a l distribution.
Some g r o s s conclusions canbe drawn
concerning the geothermal potential of
these m a j o r depositional systems. The
sands of the fluvial system are thin and
discontinuous and have fluid temperat u r e s too low to be prospective.
The
strandplain sands a r e thick and extensive but, like the fluvial system, have
fluid temperatures too low to be prospective. Most of the sands in the shelf
system are thin, and l a t e r a l continuity
is not known largely because of the lack
of control: however, some of the sand
bodies are thickenough and containwater
temperatures high enough to be conside r e d prospective.
A r b i t r a r y c r i t e r i a for geopressured
geothermal sand r e s e r v o i r s , based on
preliminary res e rvoir studie s, indicate
that a minimum volume of 7.5 cubic
miles and a minimum temperature of
275°F should be used in delineating prospective a r e a s f o r detailed studies. This
aquifer volume corresponds with a sand
thickness of 200 f e e t over a n a r e a of 200
square miles; however, i n c r e a s e s in
sand thickness will subs tantially reduce
the a r e a required. Within the limits of
these minimum standards we have identified three a r e a s which merit further
study to delineate potential geothermal
r e s e r v o i r s (fig. 38). A l l of these areas
a r e gulfward of the main sand depocenter i n the shelf environment.
Area 1. The vicinity of the intersection
of Aransas, San Patricio, and
Nueces Counties, imludingmost
of Corpus Christi Bay. The sand
bodies considered h e r e occur
between -10,000 and -16,000
feet, are m o r e than 500 feet
thick, and a r e known to occur
over an area of at least 200
square miles. Recorded fluid
bottom-hole temperatures are
between 300 and 320°F.
Area 2. South-central Matagorda County.
This sand body is known to extend over a n a r e a of 100 square
m i l e s at -15,700 feet, is 200
feet thick, and h a s fluid temperatures g r e a t e r than 300OF.
Although this sand body appears
not to m e e t the minimum requirement of 200 square miles,
the actual boundaries of the
prospective res e r voi r have not
yet been delineated by well
cont r o 1.
Area 3. Northeast Matagorda County.
This sand bodyis recognized i n
only one wellwhere i t o c c u r s at
-13,700 feet, is 150 feet thick,
and has fluid temperatures of
approximately 300°F.
The
lateralextent of this s a n d i s unknown because of lack of control.
42
t
Figure 38.
Potential geothermal fairways, Middle Texas Gulf Coast.
43
P
REFERENCES
-
Bebout, D. G., Dorfman, M. H., and
as Univ. Texas, Bur. Econ. Geology
1975, Geothermal
Agagu, 0. K.,
Geol. Circ. 67-4.
resources-Frio
Formation, South
Guevara, E. H., and Garcia, R., 1972,
Depositional s y s t e m s and oil-gas
Texas:
Univ. Texas, Austin, Bur.
r e s e r v o i r s i n the Queen City FormaEcon. Geology Geol. Circ. 75-1,
36 p.
tion (Eocene), Texas:
Gulf Coast
Bruce, C. H., 1973, P r e s s u r e d shale
Assoc. Geol. SOCS., Trans., V. 22,
p. 1-22. Reprinted as Univ. Texas,
and related sediment deformation:
Bur. Econ. Geology Geol. Circ. 72-4,
mechanism f o r development of re22 p.
gional contemporaneous faults: Am.
Houston Geological Society, 1954, StraAssoc. Petroleum Geologists Bull.,
tigraphy of the upper Gulf Coast of
V. 57, p. 878-886.
Texas and s t r i k e and dip c r o s s secBusch, D. A., 1975, Influence of growth
tions, upper Gulf Coast of Texas:
faulting on sedimentation and prospect
Houston Geol. SOC.Spec. Group Rept.
evaluation: Am. Assoc. Petroleum
(1953-1954), 26 p.
Geologists Bull., V. 59, p. 217-230.
Jones, P. H., 1969, Hydrodynamics of
Dorfman, Myron, and Kehle, R. O.,
geopressure i n the northern Gulf of
1974, Potential geothermal r e s o u r c e s
Mexico:
Jour.
P e t r o l e u m Techof Texas: Univ. Texas, Austin, Bur.
nology, V. 21, no. 7, p. 803-810.
Econ. Geology Geol. Circ. 74-4, 33 p.
1970, Geothermal r e s o u r c e s
F i s h e r , W. L., and McGowen, J. H.,
of the northern Gulf of Mexico basin:
1967, Depositional s y s t e m s i n the
U. N. Symposium on the Development
Wilcox Group of Texas and their relaand Utilization of Geothermal Retionship to the occurrence of o i l and
sources, Pisa 1970, v. 2, pt. 1, p.
gas: Gulf Coast Assoc. Geol. SOCS.,
14-26.
Trans., V. 17, p. 105-125. Reprinted