Reservoir Characterization of the Hedong Coalbed Methane Prospect, Ordos Basin, China

摘要

A multi-year pilot and appraisal program is underway to assess the potential of the Hedong Coalbed Methane Prospect. Previous drilling has shown good cumulative coal thickness (8 to 20 meters), adequate gas content (12 to 18 cubic meters per ton) and potentially high permeability (<1 to 90 md). The gas-in-place volume for potentially productive coals (depths of 250 to 1250 meters) may exceed to 10 TCF. The current program will determine 1) if the coals can be dewatered, 2) whether commercial gas rates can be attaine,d and 3) if a large enough area can be proven-up for commercial development. The targeted coals are of Permo-Carboniferous age and consist of 10 seams distributed over a 150 to 200 meter interval. Recovered coal and rock core show that the deeper coals are thicker, more continuous, and of higher quality than shallower coals. Interbedded sandstones and limestones have low matrix permeability, but fractured limestones may contribute significant volumes of water in some areas. Coal maturity increases southward from high volatile A bituminous to semi-anthracite rank. Ash content ranges from 5 to 25