| Author's Name: XU Lulu, ZHOU Xianghui, CHEN Wei, REN Zhijun, WEN Yaru, WEN Jianhang,
LUO Fan, WANG Yi, XIE Tong, DUAN Ke,YANG Jie |
| The Lower Cambrian Niutitang Formation is an important shale gas exploration target in the Western Hubei.
Based on the data of survey wells and outcrops in the Western Hubei, the rock formation, sedimentary facies, gas-bearing
characteristics and shale gas preservational conditions of Niutitang Formation are analyzed, and the favorable areas for
shale gas accumulation are comprehensively evaluated. The results show that the Niutitang Formation ( Э
1n) can be
divided into 2 sections ( Э
1n1 and Э
1n2) vertically, and the lower part ( Э
1n1)develops black carbonaceous shale of deepwater argillaceous shelf facies, which is the main shale gas bearing interval. Vertically, the field canister desorption gas
content of the Niutitang Member 1 gradually increases from top to bottom, and decreases sharply down to the Yanjiahe
Formation. On the plane, the area with good gas bearing property is mainly located in the deep-water shelf facies in the
southeast margin of Huangling anticline. It is pointed out that the favorable area of riching in shale gas must meet the
following conditions: deep water shelf facies; fold being gentle and wide; more than 5 km away from regional normal
fault; low core fracture density and undeveloped high angle fractures; good sealing of roof and floor, continuous and no
sedimentary loss in formation; Ro less than 3.0%; buried depth greater than 500 m. The favorable blocks are mainly located
in the southeast margin of Huangling anticline, the area of east of Xiannüshan fault, southwest of Wuduhe fault and west
of Tongchenghe fault. |
