Research on Long Open Hole Clad Technology Based on High Performance Solid Expandable Tubular in Shale Gas Reservoir

Abstract

AbstractThe open hole clad technology based on high performance solid expandable tubular is an innovative technology developed rapidly in recent years. It is focus on solving difficult problems that weak and complex formation and severe drilling loses which cannot be effectively plugged or controlled. Especially in shale gas drilling, with that the formation pressure system is more complex and more difficulty to predict accurately, the severe drilling loses and diverse well-bore structure design difficulties are more common. It is urgent to apply this technology to deal with multiple down-hole complex situations and optimize the well-bore structure in shale gas reservoir. This paper studies the long open hole clad technology based on high performance solid expandable tubular in shale gas reservoir by using the methods of theoretical research and field trials. According to the characteristics of shale gas reservoirs, we firstly systematically studied the technical principle, tool structure design and construction process of the open hole clad technology. Then, aiming at improving the ground bearing capacity of CX~ LS formation of shale gas wells of H-3 and H-4, we carried out the open hole clad technology field experiment and analyzed the effect. The research results show that: (1) By optimizing the tool structure and construction process, the open hole clad technology can effectively deal with the risks and challenges brought by severe drilling loses on the safe drilling in shale gas reservoirs. (2) H-3 and H-4 shale gas wells have successfully created conditions for safe drilling in the target formation of LMX group by using open hole clad technology to preventively seal the CX~LS formation with low ground bearing capacity. The ability to seal complex formations in shale gas reservoir using long open hole clad technology based on high performance solid expandable tubular can be deployed economically in shale gas reservoir with complex formation or severe drilling loses.