尾管固井技术中胶塞失效分析

对尾管固井施工中钻杆胶塞被卡死、胶塞损伤与复合后尾管胶塞未释放等3种典型胶塞失效案例进行分析,找出了失效的原因,并提出以下改进措施及建议:减少胶塞下行时环境内的固相沉积与脱落,增加通径规刮刷功能,以去除钻杆内壁附着物;提高胶塞综合性能,如耐温性能、冲击强度和皮碗橡胶扯断强度等,防止胶塞在替浆过程中损伤,尽量避免送入工具及尾管柱内径变化较大与直台阶;当钻杆胶塞与尾管胶塞复合时,应根据尾管胶塞剪钉的剪切压力合理优化顶替排量,确保剪断尾管胶塞剪钉。

Analysis of Plug Failure in the Liner Cementing

Three typical cases of rubber plug failure were analyzed,including drillpipe plug sticking,plug damage and liner plug un-releasing after compounding in the operation of liner cementing.The reasons for the failure were found and the following improvement measures and suggestions were given.The solid deposit and detachment within the environment in the process of plug running should be reduced.The scraping and brushing functions of the drift diameter gauge should be increased in order to eliminate the attachment on the inner wall of drillpipe.The comprehensive performance of plug should be improved,such as heat resistance,impact strength and cup rubber's tensile strength at break,in order to prevent plug from being damaged in cementing.The remarkable change of the inner diameter of running tool and liner string as well as straight steps should be avoided.The replacing displacement should be reasonably optimized according to the shearing pressure of liner plug shear pin in order to ensure the snipping of liner plug pin.