GAS HYDRATE RESOURCE AND REGIONAL DEVELOPMENT POTENTIAL, ALASKA NORTH SLOPE

HUNTER, Robert, ASRC Energy Services, AK 995, [email protected], WILSON, Scott James, 995, and DIGERT, Scott A., N/, N/, 995

Methane hydrates may contain significant offshore and arctic regions gas resources. Reservoir and development modeling indicate 0 12 TCF technically recoverable gas from 33 TCF in place Eileen trend gas hydrate beneath industry infrastructure. Potential production methods involve depressurization, thermal, or chemical stimulation of pore filling gas hydrate into gas and water components. Rate forecasts and well schedules, methods typically employed in conventional large gas development projects, help quantify: 1. potential gas hydrate recoverable resource using conventional petroleum technologies and 2. range of potential outcomes that could be narrowed by use of specific recommended data acquisition and field testing. This systematic appraisal plan helps determine whether or not gas hydrate can become a technically and economically recoverable unconventional gas resource. Reference case forecasts with type well depressurization induced production rates of 0.4 2.0 MMSCF/D predict that 2.5 TCF of gas might be produced in 20 years, with 10 TCF ultimate recovery after 100 years. Downside cases envision pilot failure and economic or technical infeasibility. Upside cases identify potential if both pressure induced dissociation and thermal or chemical stimulation yield positive results; extreme upside cases capture full development potential with highly productive, widely spaced wells. Successful gas production from gas hydrate would yield both methane and fresh water for potential use in existing or planned developments. The gas could potentially supplement future export gas, provide nearer term fuel gas to reduce consumption of richer conventional sales gas, provide lean gas for reservoir energy, and provide fuel for potential viscous oil thermal recovery. The fresh water could potentially be used for low salinity water floods and/or in association with produced gas for steam. The gas hydrate bearing reservoirs may also provide a viable CO2 sequestration option during future gas sales and associated production of CO2.