井筒中电缆磨损风险评估技术

生产管柱下入时受复杂井眼轨迹影响,电缆磨损失效等情况时有发生,造成不必要的返工,影响作业成本与时效.针对这种情况,建立了井下生产管柱受力有限元分析模型,并采用间隙单元处理接触非线性问题,用以准确地分析井筒中生产管柱与井壁接触力大小及具体接触位置.通过定量评估不同井周处电缆磨损风险,并结合钻井平台的艏向,确定电缆最佳安放位置,使电缆在井下尽量避开管柱与井壁接触较为密集的位置,降低磨损风险.现场应用表明本评估方法可靠,能够为现场电缆安放提供参考.

ASSESSMENT TECHNIQUES OF CABLE WEAR RISK IN WELLBORE

Cable failure often occurs when the production string runs into an inclined wellbore. A finite element model for the string stress is proposed. A clearance unit is introduced to resolve the contact force and contact position between string and wellbore.By the cable wear risk assessment,combined with the drilling rigs heading, a reasonable riding position of cable when running into the well is calculated, which reduces wearrisk. According to our analysis, the upper part of the string contacts with the higher edgeor side edge of wellbore, while the lower part contacts with the lower edgeor the side edge of the wellbore. The reliability of the evaluation method is testified,and the analysis result can be used for reference when riding the cable in field operations.