定向射孔体积压裂复杂裂缝扩展机理试验研究  

Experimental Study of Fracture Initiation and Propagation Mechanisms by Oriented Perforation Technology for SRV Fracturing

作　　者：常鑫[1] 程远方[1] 时贤[1] 韩修廷[1,2] 

机构地区：[1]中国石油大学(华东),青岛266580 [2]大庆油田有限责任公司技术发展部,大庆163453

出　　处：《科学技术与工程》2015年第20期116-122,共7页Science Technology and Engineering

基　　金："十二五"国家科技重大专项大型油气田及煤层气开发(2011ZX05037-004);教育部长江学者和创新团队发展计划(RT1086)资助

摘　　要：基于线弹性岩石力学和定向射孔增产理论,提出了利用定向射孔诱导地层形成复杂体积裂缝的增产设计思路。通过大型真三轴水力压裂物理模拟实验对其压裂机理进行了研究,分析了射孔方位、水平地应力差、射孔深度等对破裂压力以及裂缝扩展形态的影响。结果表明:定向射孔方位角和水平地应力差对破裂压力的影响最为明显;并且控制着裂缝转向半径。随着射孔方位角的增大,破裂压力逐渐升高;随着射孔深度的增加,破裂压力逐渐降低;同时存在一个最佳射孔方位角范围,在此范围内可以诱导地层产生"S"型、"X"型等复杂裂缝形态。研究成果可为定向射孔压裂施工参数优选提供理论支撑。A fracturing technology by Oriented Hydrajet Perforation method was presented based on the elastic rock mechanism and oriented perforating stimulation. This theory was validated analytically and experimentally, and the influence of perforation orientation, perforating length and horizontal stress difference on the final fracture geom- etry was investigated by the large-scale real triaxial hydraulic fracturing experiment and fracture breakdown pressure was also analyzed. The results show that the perforation orientation and the horizontal stress difference have a strong influence on the fracture pressure and control the fracture propagation path. In addition, the perforating length only affects the fracture breakdown pressure. Thus, according to the horizontal stress and perforation condition, a critical fracture breakdown pressure exist at the wellbore where ＂X＂ shaped fracture can be created, the two asymmetric fractures can propagate to further dimensions,thereby enhancing the final stimulation effectiveness.

关 键 词：体积压裂 定向射孔 水力压裂 裂缝扩展机理 多裂缝 

分 类 号：TU432[建筑科学—岩土工程]