Petroleum System Modeling in the Interior Salt Basins, North Central ...

Petroleum System Modeling in the
Interior Salt Basins, North Central and
Northeastern Gulf of Mexico
Peng Li
Department of Geological Sciences
University of Alabama

Overview
Introduction
Methodology of Basin Model
Organic Geochemical Data (TOC, Ro, and kerogen type)
Burial, Thermal Maturation, Expulsion Profiles
Conclusions

Introduction

Stratigraphy

Methodology of Basin Model

Methodology: Burial History
‣ Assigned absolute age to each formation and
unconformity
‣ Recognized the tops of each formation from
well logs
‣ For major unconformities − interpreted original
thickness of section
‣ Lithology interpretation
‣ Burial depths corrected for compaction

Absolute Age
- Geologic time scale:
Harland (1990)
- Formation ages:
Mancini and Tew (1991)
Christopher (1982)
Puckett (1995)
Mancini et al. (1996)
Mancini and Payton (1981)
Imlay (1940)
Young (1972)
Imlay and Herman (1984)
Young and Oloritz (1993)

Structure Map
Top of UK in NLSB
Top of LK in NLSB

Structure Map
Top of UK in MISB
Top of LK in MISB

Isopach Map
LK - UK
Cotton Valley - LK

Isopach Map
LK - UK
Cotton Valley - LK

Mid-Cretaceous Unconformity
North Louisiana

Lithology
45% LST
50%SHL
5% SST
End member lithologies
-SS, SH, LS, ANH
50% LST
45%SHL
5% SST
Tuscaloosa Formation
Smackover Formation

Compaction
(from BasinMod 1-D manual)

0
porosity
0.00 0.10 0.20 0.30 0.40 0.50 0.60
Limestone
Shale
5000
Reciprocal Compaction
depth (ft)
10000
15000
Sandstone
1 ⎛
= ⎜
φ ⎝
1
φo
⎞
⎟+
⎠
Kz
Where:
φ = porosity
φ 0
= Initial porosity
K = compaction factor
z = depth
20000

Burial History: Decompaction
Present-day
depths
t1
Remove 2 & 3
Decompact 1
t2
Add 2
Partially
compact 1
y’ 1
1
3
y’ 2 2
1
2
porosity
y 1
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70
0
y 2
1
t3
Add 3
Compact 2 and 1
3
2
1
5000
depth (ft)
10000
15000
20000

Methodology: Thermal History
‣ Heat flow approach: Transient heat flow
‣ Present-day heat flow
W
meters 2
Heat Flow
= T 2 -T 1 (103 . deg K)
y 2
-y 1
(meters)
•Corrected
BHTs
•Surface temp = 20 o C
•Thermal conductivity
Temperature
Gradient
x
W
meter (10 3 . deg K)
Thermal
Conductivity
T 1
, y 1
T 2
, y 2
•Porosity and lithology are major variables controlling thermal conductivityc
•Thermal conductivity computed by BasinMod

Organic Geochemistry

Potential Source Rocks
Visual
Formation
TOC Kerogen Ro
(wt.%) Type a (%)
Smackover (91) 0.08-8.43 (0.56) Am, H 1.07-1.89 (1.37)
Cotton Valley (26) 0.25-1.80 (0.58) Am, H, I 0.75-1.80 (1.07)
Bossier (11) 0.28-0.91 (0.45) H, I, W/I, Am/I 1.15-1.89 (1.62)
Hosston (4) 0.17-4.09 (1.62) H, Am 1.29-1.37 (1.31)
Sligo (3) 0.23-0.45 (0.30) Am/H, H 1.29-1.37 (1.32)
Glen Rose (1) 0.10 Am 1.14
Rodessa (1) 0.46 Am 1.14
Austin (1) 0.26 H 0.86
Mooringsport (1) 1.00 H/I 1.00
James (1) 0.17 H 1.00

Calibration of Basin Model
%Ro
0.00 0.50 1.00 1.50 2.00
0
2,000
Depth (ft)
%Ro
0.55 0.7 1.0 1.3
Maximum 8789 12564 15907 19174
Modeling Minimum 3480 4810 6743 8346
Average 5897 8084 10875 12805
4,000
From TAI
7149 8132 10099 12066
6,000
2.50
DEPTH (feet)
8,000
10,000
12,000
14,000
%Ro (calc)
2.00
1.50
1.00
y = 1.0162x
R 2 = 0.7036
16,000
0.50
18,000
20,000
0.00
0.00 0.50 1.00 1.50 2.00 2.50
%Ro (meas)

Burial, Thermal Maturation,
Hydrocarbon Expulsion Profiles

North Louisiana Salt Basin
Cross Section Location

North Louisiana Salt Basin
Cross Section

Thermal Maturation Profile Cross
Section North Louisiana Salt Basin
Average Maturation Depth
6,500ft
12,000ft

Source Rock Thermal Maturity

Burial History Profile
North Louisiana Salt Basin
API: 1706920079
- Sediment accumulation
rates were greatest in the
Jurassic (196-264 ft/my)
- 50-60% of the tectonic
subsidence occurred in the
Late Jurassic (135-157 ft/my)

Thermal Maturation History Profile
North Louisiana Salt Basin

Hydrocarbon Expulsion Profile
North Louisiana Salt Basin
Peak Oil
Peak Gas

Monroe Uplift Cross section Location

Monroe Uplift Cross section

Thermal Maturation Profile Cross
Section on Monroe Uplift

Burial History Profile Monroe Uplift
API: 1706700008

Thermal History Profile
Monroe Uplift
Depth Unit Kerogen Type
TAI Ro
(ft) Liptinite (%) Vitrinite (%) Inertinite (%) (%)
6,116.50 Smackover 80 15 5 2- to 2 0.63
6,210.50 Smackover 80 15 5 2- to 2 0.60
6,304.50 Smackover 80 15 5 2 0.66
6,530.50 Smackover 75 20 5 2 0.70
6,609.50 Smackover 70 25 5 2 0.69
6,649.50 Smackover 70 25 5 2- to 2 0.51
6,725.50 Smackover 85 10 5 - - - -

Hydrocarbon Expulsion Profile
Monroe Uplift

Mississippi Interior Salt Basin

Mississippi Interior Salt Basin Cross
Section Location

Mississippi Interior Salt Basin
Cross Section

Thermal Maturation Profile Cross Section
Mississippi Interior Salt Basin
Average Maturation Depth
8,000ft
16,000ft

Source Rock Thermal Maturity

Burial History Profile
Mississippi Interior Sal Basin

Thermal Maturation History Profile
Mississippi Interior Salt Basin

Hydrocarbon Expulsion Plot
Mississippi Interior Salt Basin
Peak Oil
Peak Gas

Event Chart for Smackover Petroleum
System in the North Louisiana and
Mississippi Interior Salt Basins

Conecuh and Manila Sub-basins
basins

Manila Sub-Basin Cross Section

Manila and Conecuh Sub-Basins Cross
Section Location

Thermal Maturation Profile Cross Section
Manila Sub-Basin
Average Maturation Depth
8,000ft
16,000ft

Source Rock Thermal Maturity

Burial History Profile
Manila and Conecuh Sub-Basins

Thermal Maturation History Profile
Manila and Conecuh Sub-Basins

Hydrocarbon Expulsion Plot
Manila and Conecuh Sub-Basins

Event Chart for Smackover Petroleum
System in the Manila and Conecuh Sub-
Basins

Conclusions
‣ Upper Jurassic Smackover lime mudstone beds
served as an effective regional petroleum source
rock
‣ Initiation of the generation of hydrocarbon from
Smackover in the Early to Late Cretaceous and
continuing into the Cenozoic
‣ Peak oil expulsion occurred in the mid Early to
Late Cretaceous, and peak gas expulsion in
Early-Mid Tertiary.