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CBM pinnate horizontal wells with multi- well production high , recovery , good economic returns and other advantages, so the United States has been widely used, and in our high- rank coal seams Qinshui basin were tested , and achieved good demonstration effect . However, due to geological structure of coal is much more complex than in the U.S. , and has yet to fully grasp the multi-branch horizontal wells pinnate key technologies, drilling practice less in urgent need of development of coalbed methane plumes multi-lateral horizontal well technology . This paper first wellbore profile design theory, design theory completions , seam Stability and Security density window design theory, multi-branch horizontal wells cloth four aspects of well design theory constructed multi-branch CBM pinnate horizontal wells engineering design theory . Shinpei two wells were set CBM pinnate multi-branch horizontal wells engineering design, including casing design , wellbore profile design , pinning process design, BHA design , drilling fluid design, well control and cementing and completion design aspects of the design . Shinpei two well group tracked the plume multi-branch horizontal wells drilled in the real situation , for straight hole section of the well , whipstocking segment , horizontal drilling process solidified completions , casing and borehole trajectory , BHA , drilling fluid , drilling parameters and other aspects of the design to make a rational evaluation, and analysis of Shinpei two wells drilled in the real cause of the accident , summed up the multi-lateral horizontal wells plume stage design and application experience and lessons for the future pinnate multi-branch horizontal drilling engineering is suggested.
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