Analysis and measures of abnormal opening of unlimited-stage sliding sleeve in Nanchuan shale gas wells
During the process of shale gas fracturing,the unlimited-stage sliding sleeve sectioning tool of-ten fails to open.For this reason,abnormal opening conditions were analyzed in this paper.Combined with the working principles of unlimited-stage sliding sleeve and fracturing pressure data,common malfunctions were summarized.There was 5 types in abnormal opening:the dart got stuck,the sliding sleeve not opened immediately,the sliding sleeve not fully opened,the dart opened wrong sliding sleeve and the dart passed through the matching sliding sleeve.The reasons for the opening failure were explained,and the improve-ment measures and countermeasures were proposed,which provided technical guidance for the hydraulic fracturing practices using unlimited-stage sliding sleeves in shale gas wells in the future.