Medium-deep gas accumulation and exploration prospects in the Jinma-Juyuan district, Sichuan

The prerequisites for the medium-deep gas accumulation in the JinmaJuyuan district, Sichuan include:(1) sufficient gas sources in the Xujiahe Formation; (2) opportune Yanshanian palaeo-traps; (3) well-developed braided river-deltaic conglomerate-sandstone-mudstone reservoir-seal associations, and (4) betterment of the hy drocarbon reservoirs by the Him alayan faults and fractures.The medium-deep intervals are interpreted as the composite structural-lithologic traps governed by the Yanshanian palaeo-uplift and suitable sedimentary facies zones. The Jinma district and other areas west of it may thus be delineated as the target areas of the medium-deep natural gas exploration and development in the Longmen Mountains.