Suqiao Gas Storage Group Geology

Abstract

The Suqiao gas reservoir group is located about 70 km south of Beijing. It consists of five gas reservoirs: the Su1, Su4, Su20, Su49, and Guxinzhuang reservoir. The reservoir group is composed of carbonate and sandstone reservoirs. The Ordovician lithology of buried hill Su1 is mainly limestone, dolomite, and argillaceous carbonate, with burial depths of more than 4,200 m, a well test permeability of 3.45 mD, and reserves of 16 × 10⁸ m³. The gas bearing layer of fault block Su20 is the lower member of the upper stone box formation of the carboniferous-superimbedded system. The lithology of the reservoir is mainly Liuqiying quartz sandstone and quartz-pebbled coarse sandstone, with burial depths of more than 3300 m, a well test permeability of 67 mD, and natural gas reserves of 2 × 10⁸ m³. The Ordovician lithology of buried hill Su4 is composed of limestone, dolomite, and argillaceous carbonate, with burial depths of over 4,900 m, a well test permeability of 3.7 mD, and natural gas reserves of 63.52 × 10⁸ m³. The reservoir rocks of buried mountain Su49 are limestone and dolomite, and the reservoir space is dominated by structural fractures, intercrystalline pores, and dissolution pores. The burial depths are more than 5,000 m, and the water body energy is relatively strong. Similar to Su1, the Guxinzhuang geology has natural gas reserves of 9.7 × 10⁸ m³. The gas reservoir has a normal pressure system containing condensates and no hydrogen sulfide gas.