Deep Gas Reservoir Play, Central and Eastern Gulf

Summary Introduction Petroleum System Analysis Resource Assessment Exploration Strategy

Introduction

Gulf Coast Interior Salt Basins

Stratigraphy

Petroleum System Analysis

Petroleum Source Rocks Upper Jurassic Smackover lime mudstone beds served as an effective regional petroleum source rock Upper Cretaceous Tuscaloosa Marine shale beds served as a local source rock Upper most Jurassic and Lower Cretaceous beds were possible source rocks

Burial History

North Louisiana Salt Basin Cross Sections Location K’

North Louisiana Salt Basin Cross Section Well logs have been digitized. The types of logs used are SP and resistivity. Tops of each formation at individual well are recognized by well log signals. The strata thickness increases from updip to downdip. In the updip of the basin, parts of the Lower Cretaceous strata have been eroded. VE: 32X

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) Fastest subsidence rates late Jurassic and Early Cretaceous Mid-Cenomanian and Late Cretaceous Uplift resulted in slower subsidence rates Subsidence increased in early Paleocene Subsidence continued through Miocene, although at slower rates Present-day depths are maximum burial depths

North Louisiana Salt Basin, Sabine Uplift Cross Section VE: 22X

Burial History Profile NLSB, Sabine Uplift

North Louisiana Salt Basin, Monroe Uplift Cross Section VE: 30X

North Louisiana Salt Basin Cross Section W E VE: 22X

Burial History Profile NLSB, Monroe Uplift

Mississippi Interior Salt Basin Cross Section Location

Mississippi Interior Salt Basin Cross Section VE: 16X

Burial History Profile Mississippi Interior Salt Basin

Thermal Maturation and Expulsion History

North Louisiana Salt Basin Cross Section Location K’

Model Calibration

Thermal Maturation History Profile North Louisiana Salt Basin

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

Hydrocarbon Expulsion Profile North Louisiana Salt Basin Peak Oil Peak Gas To adjust for the loss of organic carbon due to thermal maturation process, the original TOC values in the study area were estimated according to the method of Daly and Edman (1987) for thermal maturation modeling. The results show that original TOC was reduced by 1.5-1.8 times during the thermal maturity process.

Thermal Maturation History Profile NLSB, Sabine Uplift

Hydrocarbon Expulsion Plot NLSB, Sabine Uplift

Thermal Maturation History Profile NLSB, Monroe Uplift

Hydrocarbon Expulsion Plot NLSB, Monroe Uplift

Mississippi Interior Salt Basin Cross Section Location

Thermal Maturation History Profile Mississippi Interior Salt Basin

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

Hydrocarbon Expulsion Plot Mississippi Interior Salt Basin Peak Oil Peak Gas

Comparison of NLSB and MISB Modified from Mancini et al. (2006a)

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

Geologic Model SSW-NNE Section (B-B’)

Oil Migration SW-NE Section (B-B’)

Gas Migration SW-NE Section (B-B’)

Gas Migration at 99 Ma SW-NE Section (B-B’)

Geologic Model NW-SE Section

Gas Migration Profile NW-SE Section

Gas Migration at 99 Ma NW-SE Section

Geologic Model N-S Section

Oil Migration N-S Section

Gas Migration at 99 Ma N-S Section

Geologic Model N-S Section (Monroe Uplift)

Oil Migration N-S Section (Monroe Uplift)

Gas Migration at 52 Ma N-S Section (Monroe Uplift)

Resource Assessment

Production Data

Production Data

Methodology for Resource Assessment

Schmoker (1994) The mass of hydrocarbons generated from a petroleum source rock can be calculated by using the following equations: 1. (TOC wt%100)(FD)(VU) = MOG 2. HI Original – HI Present = HG 3. (MOG) (HG) (10-6kg/mg) = HCG Where: TOC = total organic carbon FD = formation density VU = volume of unit MOG = mass of organic carbon HI = hydrogen index HG = hydrocarbons generated per gram of organic carbon HCG = hydrocarbon generated by source rock unit

Key Parameters

Basin Parameters

NLSB Platte River Software — Gas Generated TOC = 1.0% Type II kerogen Transient heat flow 6,400 TCF By P. Li

NLSB Platte River Software — Gas Expelled TOC = 1.0% Type II kerogen 1,280 TCF By P. Li

MISB Platte River Software — Gas Generated TOC = 1.5% Type II kerogen Transient heat flow 3,130 TCF By P. Li

MISB Platte River Software — Gas Expelled TOC = 1.5% Type II kerogen Transient heat flow 843 TCF Saturation threshold = 0.1 By P. Li

Comparison of Hydrocarbon Generation & Expulsion Volumes Modified from Mancini et al. (2006b)

Gas Resource *Assuming that 75% of total gas calculated with the Platte River Software Approach is from late cracking of oil in the source rock. **Assuming a 1 to 5% efficiency in expulsion, migration and trapping processes.

Exploration Strategy

NLSB Thermal Maturation

MISB Thermal Maturation

Manila-Conecuh Thermal Maturation

Reservoir Characteristics

Deep Gas Reservoir Areal Distribution

Conclusions In the North Louisiana Salt Basin, Upper Jurassic and Lower Cretaceous Smackover, Cotton Valley, Hosston, and Sligo have high potential to be deeply buried gas reservoirs (>12,000 ft). In the Mississippi Interior Salt Basin, Upper Jurassic and Lower Cretaceous Norphlet, Smackover, Haynesville, Cotton Valley, Hosston, and Sligo have high potential to be deeply buried gas reservoirs (>16,500 ft).