海上分层注水井高效打捞技术

Efficient fishing technology for offshore layered water injection wells

海上油田分层注水井管柱结构比较复杂,在防砂段内下入分层注水管柱,双层管柱间隙小,加之注水井段较长,分层多,大多是定向斜井,长期注水结垢和筛管破裂出砂,是造成注水管柱卡钻的主要原因,卡点准确位置难以判断,常规施工周期长,费用高。针对这种双层管串结构特点,优化施工方案,两层管柱分开处理,先解卡打捞注水管柱,采用连续油管冲砂、酸化挤注化垢、整体活动解卡;再处理防砂管柱,采用补接、分段切割、连续套铣、割捞一体等工艺进行快速处理。通过10余井次的实施,总结出较成熟的高效处理工艺,对后续井和其他类似井具有一定的借鉴作用。

The strings of layered water injection wells in offshore oilfields are structurally complicated.Layered water injection strings are set in sand control strings.The main reasons for the sticking of water injection string are small gap between sand control string and water injection string,long water injection hole section,multiple layers,directional well,long-term scaling of water injection and sand production from broken screen pipe.It is difficult to judge the location of sticking point accurately,and the conventional method takes long operation time and high operation cost.The operation plan was optimized based on the structural characteristics of the double layer pipe string.According to the optimized plan,water injection string and sand control string are treated separately.Firstly,release the jam and fish the water injection string by using the coiled tubing sand washing,acidizing extrusion and scaling,and overall removal of the jam.Then,treat the sand control string quickly by means of patching,sectional cutting,continuous milling,and integrated cutting and fishing.Through the operation of more than 10 times,a mature and efficient treatment process is summarized.And it can be used as the reference for subsequent wells and other similar wells.