RESOURCE ASSESSMENT OF THE IN-PLACE AND POTENTIALLY RECOVERABLE DEEP NATURAL GAS RESOURCE OF THE ONSHORE INTERIOR SALT BASINS, NORTH CENTRAL AND NORTHEASTERN GULF OF MEXICO

Abstract

The University of Alabama and Louisiana State University have undertaken a cooperative 3-year, advanced subsurface methodology resource assessment project, involving petroleum system identification, characterization and modeling, to facilitate exploration for a potential major source of natural gas that is deeply buried (below 15,000 feet) in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas. The project is designed to assist in the formulation of advanced exploration strategies for funding and maximizing the recovery from deep natural gas domestic resources at reduced costs and risks and with minimum impact. The results of the project should serve to enhance exploration efforts by domestic companies in their search for new petroleum resources, especially those deeply buried (below 15,000 feet) natural gas resources, and should support the domestic industry's endeavor to provide an increase in reliable and affordable supplies of fossil fuels. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification. The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The project objectives will be achieved through a 3-year effort. First, emphasis is on petroleum system identification and characterization in the North Louisiana Salt Basin, the Mississippi Interior Salt Basin, the Manila Sub-basin and the Conecuh Sub-basin of Louisiana, Mississippi, Alabama and Florida panhandle. This task includes identification of the petroleum systems in these basins and the characterization of the overburden, source, reservoir and seal rocks of the petroleum systems and of the associated petroleum traps. Second, emphasis is on petroleum system modeling. This task includes the assessment of the timing of deep (>15,000 ft) gas generation, expulsion, migration, entrapment and alteration (thermal cracking of oil to gas). Third, emphasis is on resource assessment. This task includes the volumetric calculation of the total in-place hydrocarbon resource generated, the determination of the volume of the generated hydrocarbon resource that is classified as deep (>15,000 ft) gas, the estimation of the volume of deep gas that was expelled, migrated and entrapped, and the calculation of the potential volume of gas in deeply buried (>15,000 ft) reservoirs resulting from the process of thermal cracking of liquid hydrocarbons and their transformation to gas in the reservoir. Fourth, emphasis is on identifying those areas in the onshore interior salt basins with high potential to recover commercial quantities of the deep gas resource.