Characteristics of carbonate reservoirs of Cambrian Loushanguan Formation to the west of Xuefeng Mountain

The carbonate reservoirs of the Cambrian Loushanguan Formation to the west of Xuefeng Mountain were studied.Two types of reservoirs were identified including oolitic beach and dolomite.Intercrystalline pore,dissolution pore and fracture worked as reservoir room and were usually well connected.The oolitic dolosparites and intraclast dolomites of Loushanguan Formation in Hefeng of Hubei province and Sangzhi and Zhangjiajie of Hunan province were studied.The maximum pore radius of oolitic dolosparite was over 200 μm with the average of 9.61 μm.The pore radius of intraclast dolomite ranged from 100 μm to 200 μm,accounting for 33%.The maximum throat was 81.43 μm and the average was 21.28 μm.The maximum porosity was 10.3% and the average was 3.4%.The maximum permeability was 18.6×10^-3 μm² and the average was 1.4×10^-3 μm².Both porosity and permeability were good and were judged as reservoir of type Ⅱ.The reservoirs of the Cambrian Loushanguan Formation distributed mainly in the tidal flat facies areas to the west of the Cili-Baojing Fault,and had good potential for exploration.