适用于页岩气分段压裂工况的高强度套管研究

Research on High Strength Casing Suitable for Working Condition of Staged-fracture Exploitation of Shale Gas

针对页岩气井在分段压裂过程中套管受周期性复杂应力的作用下易发生损坏和结构失效等问题.采用循环水压试验、抗挤毁试验,研究分析了某公司TP110T高强度套管的抗循环内压、抗疲劳、抗挤毁性能,以及影响其性能的钢种、组织、规格、残余应力等关键因素,提出了提高套管在分段压裂复杂服役条件下使用性能的优化方法,为页岩气的安全开采提供了一定的技术支持。

During the process of staged-fracturing in the shale gas well,the casing is being loaded with periodic and complex stress,which may very possibly cause damage and structural failure thereof.Researched and analyzed via the circulating hydraulic pressure test and the collapse test are the circulating internal pressure-resistance,the fatigue resistance and the collapse resistance of the TP110T hi-strength casing,and the key factors as affecting the performance of the pipe such as steel grade,microstructure,size and residual stress,etc.Accordingly relevant optimization method is proposed to enhance the service performance of the casing as used under the complex staged-fracture working condition,which provides certain technical support for the shale gas production.