Exploration and development practice of normal pressure shale gas in Dongsheng structural belt, Nanchuan area, southeast Chongqing

Abstract

The Dongsheng structural belt in Nanchuan area, southeast Chongqing, is located in the transitional zone of the southeastern margin of Sichuan Basin. It has experienced multi-period tectonic reformation and has typical geological characteristics of complex structure, complex preservation conditions and complex in-situ stress field, which leads to a significant difference in single well production. In order to increase the single well production of normal pressure shale gas wells in Dongsheng complex structural belt and realize profitable development, through target processing of seismic data, analysis of structural characteristics, study of accumulation regularity and analysis of production dynamics, as well as the strengthening of basic research and exploration and development practice, four key technical countermeasures for realizing profitable development of normal pressure shale gas in Dongsheng complex structural belt are defined: (1) improve the accuracy of shallow velocity model and structure interpretation; (2) optimize well pattern deployment, increase well-controlled reserves; (3) integrate geology and engineering, and coordinate drilling, orientation and steering to improve the drilling rate of sweet spots; (4) establish a zonal differentiated fracturing scheme to improve fracture complexity. These four countermea-sures provide technical support for the profitable development of normal pressure shale gas in complex structural zones, and provide reference for the exploration and development of other similar areas along the basin margin.

Keywords

• normal pressure shale gas
• exploration and development
• dongsheng structural belt
• nanchuan area
• southeast chongqing