Study on technology of screen completion of CBM ultra-short radius horizontal well

In order to solve the problems of coal seam methane short radius horizontal well collapse and frequent work-over caused by pulverized coal production,and to maintain the continuous stable production of ultra-short radius horizontal wells,this paper discusses the feasibility of the completion technology of the screen pipe in the ultra-short radius horizontal well.The yield bending radius of different material columns is studied and Wellplan software is used to analyze the pass ability of the tube column under the condition of ultra-short radius of curvature.and the design of the pipe column combination is optimized.Thescreen parameters of high-density polyethylene(HDPE) were designed based on the distribution of pulverized coal particles,the speed of movement and the overflow area.The finite element analysis was used to analyze the yield strength of the screen.The design of special running-in tool and running-in process for high density polyethylene(HDPE) screen tube is studied,and case design analysis is carried out to explore the feasibility of the process.The results show that the wells with a diameter of 116 mm can be drilled into a 40 mm high-density polyethylene (HDPE) screen tube with a radius of curvature of not less than 12 m.The screen body does not plastically deform and some plasticity appears near the screen hole.The volume of plastic deformation accounts for 14.58% of the solid volume of the screen,providing a stable passage for the well-bore fluid to pass.The mesh hole can block the larger coal powder particles from entering the borehole and avoidblockage.The T-shaped slotting has a certain cleaning function.The results of this paper are intended to promote the development of process technology for ultra-short radius horizontal wells of coalbed methane.