Research And Application Of CBM Well Overhaul Technology

During the production of Coalbed methane wells,with the downhole fall,sand-buried production string,casing fault and other factors resulted in CBM wells failure and underground accident,which reduced and stopped CBM production even CBM wells scrapped.Therefore,investigating well overhaul technology has important influences on improving the efficiency of CBM exploration and the overall exploration and development of the gas field.Consequently,this paper analyses conventional downhole fishing technology in oil and gas fields,understands the current situation of underground complex fishing at home and abroad by investigating.Combined with hydraulic fracturing and drainage situation,analyses causes of complex underground and finds out ways to simplify downhole problems.Ultimately,uniting with advanced downhole technology and CBM wells characteristic in the Baode Block,tests and analyses applicability,advantage and disadvantage of downhole technology of CBM wells,aims to improve,optimize,combine of different technologies under corresponding well conditions.In response to different situations and treatments,special well conditions self-made fishing tools to meet the needs of well conditions and fishing results,and finally four sets of complex downhole fishing techniques are formed and applied in practice.