Study On Horizontal Well Multistage Fracturing Technology Of Coal Bed Methane

On the issue of low production of coalbed methane wells and immaturity of horizontal well multistage fracturing technology in Zhaozhuang block which is located at the south-east of Qinshui Basin.In this paper,the author has used the method of theoretical analysis,laboratory experiments and numerical simulation to study the proper horizontal well multistage fracturing technology systematically.By taking laboratory experiments,the characteristic of coalbed methane reservoir,rock mechanical properties and coal sensitivity of Zhaozhuang block were studied;Coiled tubing hydraulic multistage fracturing technology was selected as the proper technology for this block under the analysis of different technology application results,and the key tools,fracturing string structure were designed and checked;As the high friction and low proppant carrying capability of normal active water fracturing fluid,the formula of this fracturing fluid was optimized by optimizing the antiswelling agent,friction reducer and cleanup addictive,and the rheological parameters,proppant carrying capability,reservoir damage and compatibility of this optimized active water fracturing fluid were evaluated;The fracture length,fracture conductivity,fracture numbers were optimized by using the numerical simulation software Eclipse,and the best fracture parameters were seized under the designed orthogonal test;On the base of optimized fracture parameters,using fracturing numerical simulation software FracproPT to optimize construction parameters and analyze the orthogonal multi-factor of construction parameters.Furthermore,the pumping injection process was designed which can realize the optimized parameters.