多轮次注热水平井防砂筛管强度校核方法研究

Research on Strength Check Method of Sand Control Screen in Multiple Heat Injection Horizontal Well

合理的机械筛管强度校核方法是进行多轮次注热水平井防砂筛管设计优化的基础。根据热采井实际生产条件,建立筛管抗内压、抗外挤和轴向屈服强度等单项强度校核方法以及三轴应力条件下的组合强度校核方法;考虑残余应力影响,建立多轮次注热条件下残余应力破坏强度校核方法。用渤海某油田典型井对CMS筛管强度进行校核,校核结果表明:单轮次350℃注热条件下,筛管单项抗拉、抗内压和抗外挤安全系数较高,不会发生损坏,但不安装热补偿器会导致筛管轴向压缩屈服破坏;三轴应力条件下的组合强度校核结果与单项校核结果一致;按照10个轮次350℃注热开采计算,筛管发生残余应力拉伸破坏的可能性较大。研究结果可为热采水平井入井防砂管设计优化提供理论依据。

The reasonable strength check method of mechanical sand controf screen is the basis for the optimi-zation of sand controf screen lor horizontal well with multiple heat injection. Based on the actual production condi-tions of the screen in thermal recovery well, the methods for its anti-burst/anti-coflapse strength check, axial yield strength check and the combined strength check under triaxial stress condition have been established. Considering the influence of the residual stress, residual stress damage strength check method for multiple heat injection condi-tion has been presented. The strength check results of CMS screen in a typical well in a certain oilfield in Bohai are-a showed that, under the condition of single-round 350 ^ heat injection, the salety lactor of tensile, anti-burst and anti-coflapse strength were high, and the screen would not be damaged. But the screen would result in axial com-pression yield lailure without the thermo compensator. The combined strength check result of the screen under triax-ial stress condition was the same as that of the single check. According to the calculation of ten cycles of 350℃ heat injection, the screen tube is more likely to lead to residual stress tensile lailure. The study results could pro-vide theoretical basis lor the design and optimization of sand controf screen in thermal recovery horizontal well.