双台阶水平井分层注水管柱设计及优化

Optimization of Multilayer Water Injection String for Two-step Horizontal Well

塔里木油田双台阶水平井的分注工艺无法满足分层注水要求,区块欠注问题严重。为此,设计了双台阶水平井分层注水管柱及其配套工具,并采用Wellcat软件模拟计算出单独注停上层、注停下层时上、下封隔器的受力情况,对伸缩管长度和封隔器剪钉进行配比优化,即上伸缩管控制伸缩距3 m,下伸缩管控制伸缩距1 m,上封隔器解封力108 kN,下封隔器解封力81 kN,满足该区块双台阶水平井200 m^3/d、25 MPa条件下的分层注水。实际应用结果表明,注水管柱及配套工具设计合理,配合钢丝投捞并更换水嘴即可满足双台阶水平井分层注水。

Several two?step horizontal water injection wells have been drilled to waterflood thin sand reservoirs in Tarim Oilfield, and all were operated with general water injection, which could not meet the requirements of multilayer water injection, resulting in serious water injection regulation problem?To address the issue, taking multilayer water injection in the Well × × 1 in Tarim Oilfield as objective, a multilayer water injection string and supporting tools for two?step horizontal well has been designed?The forces on the upper and lower packer under wa?ter injection in upper or lower layer have been calculated by using Wellcat?The telescoping tube length and packer shear pin have been optimized?The upper and lower telescopic tube should has telescopic length of 3 m and 1 m re?spectively?The upper and lower packer should have releasing force of 108 kN and 81 kN respectively?The devel?oped string could meet the multilayer water injection in the two?step horizontal wells under the injection rate of 200 m3/d and pressure of 25 MPa?The application results showed that the designed multilayer water injection string for two?step horizontal well is rational and could meet the requirements for multilayer water injection in two?step hori?zontal well with slickline operation for replacing nozzle.