Petroleum Reservoir Evaluation and Development ›› 2021, Vol. 11 ›› Issue (4): 559-568.doi: 10.13809/j.cnki.cn32-1825/te.2021.04.012

• Exploration & Development of Shale Oil and Gas • Previous Articles     Next Articles

Analysis on geological and engineering factors of development effects on normal pressure shale gas in Nanchuan Block, eastern Suchuan Basin

HU Chunfeng1,2(),MEI Junwei1,LI Shizhao1,LU Bi1,2,MA Jun1,2,QIAN Jin2   

  1. 1. Research insititute of Exploration and Development, Sinopec East China Oil and Gas Company, Nanjing, Jiangsu 210000, China
    2. Sinopec Chongqing Shale Gas Co., Ltd., Chongqing 408400, China
  • Received:2021-04-06 Online:2021-08-19 Published:2021-08-26

Abstract:

Nanchuan Block is rich in shale gas resources, and the proven reserves of Pingqiao and Dongsheng structural belts are nearly 2 000×108 m3, mainly in normal pressure shale gas reservoir, with complex structure and stress, and relatively poor resource quality. Affected by the preservation conditions, burial depth, in-situ stress, complex structure, uneven fracture development and fracturing effect, the productivity of single wells on the same platform is quite different, and the test production, productivity and single well EUR of some wells have not been able to meet the expectation, all these above greatly limit the scale production and benefit development. By the comparative analysis of production effects of typical wells in geology, development and engineering, it is considered that formation pressure coefficient, development degree of natural fracture network, local complex structure and in-situ stress are the main factors affecting normal pressure shale gas development in resource implementation area. The pressure coefficient represents the driving energy of the formation, and a certain degree of natural fracture network can effectively improve the development effects. The local complex structure leads to a low drilling rate of high-quality shale, and the stress increase caused by extrusion deformation, deepening burial depth and excessive angle between horizontal section azimuth and minimum principal stress azimuth will limit the complexity of artificial fracture network to a certain extent. According to the plane difference distribution characteristics of main controlling factors, the basis of improving the development effects of normal pressure shale gas is to select the best from sweet spot and adjust the local optimization.

Key words: normal pressure shale gas, pressure coefficient, fracture development degree, crustal stress, development effect

CLC Number: 

  • TE25