缝面摩滑:深部裂缝性地层钻井液漏失加剧的新机制  

Friction & Sliding on Fracture Surfaces:A New Mechanism for Increasing Drilling Fluid Leakage in Deep Fractured Reservoirs

作　　者：康毅力[1] 田国丰 游利军[1] 闫霄鹏 许成元[1] KANG Yili;TIAN Guofeng;YOU Lijun;YAN Xiaopeng;XU Chengyuan(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan,610500,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(西南石油大学),四川成都610500

出　　处：《石油钻探技术》2022年第1期45-53,共9页Petroleum Drilling Techniques

基　　金：四川省科技计划项目“保护储层并改善优势天然裂缝导流能力的钻井预撑裂缝堵漏基础研究”(编号:2018JY0436);国家自然科学基金“基于逾渗和固液两相流理论的裂缝性储层工作液漏失损害预测与控制”(编号:51604236);非常规油气层保护四川省青年科技创新研究团队项目(编号:2016TD0016)联合资助。

摘　　要：针对深层裂缝性地层在初次堵漏失败后多发生漏失量更大的重复性漏失的问题,设计并进行了裂缝面间摩擦滑动(简称缝面摩滑)前后的裂缝封堵模拟试验,以钻井液环境下岩板与岩块的摩擦滑动试验、基于微压痕的岩石力学参数测试、表面三维扫描等手段为辅,分析了钻井液侵入对天然裂缝缝面摩滑的诱发作用,探讨了缝面摩滑对裂缝性储层钻井液漏失的影响。油基钻井液或水基钻井液侵入天然裂缝,均能使岩石缝面摩擦因数减小,油基钻井液使岩石缝面摩擦因数减小的作用更强,这会诱发缝面摩滑形成错位裂缝,为钻井液漏失加剧提供通道和空间;缝面摩滑可使裂缝渗透率升高,导致钻井液封堵能力降低,钻井液漏失加剧;摩滑后缝面更光滑,可能会进一步扩大错位程度,使裂缝长度和宽度大幅增大,造成钻井液漏失加剧。研究结果表明,缝面摩滑是导致深部裂缝性地层钻井液漏失加剧的原因之一,提高天然裂缝面之间的摩擦因数、有效控制缝面摩滑可控制深部裂缝性地层的钻井液漏失。Because repetitive leakage in greater volume often occurs in deep fractured reservoirs after the failure of initial plugging, fracture plugging simulation before and after the sliding with friction happens on fracture surfaces(referred to as friction & sliding on fracture surfaces) was designed and carried out. Supported by the friction & sliding experiments of rock plates and blocks in drilling fluid environment, rock mechanics parameter test based on micron indentation and the three-dimensional surface scanning, the inducing effect of drilling fluid intrusion on the friction &sliding on fracture surfaces was analyzed, and the influence on drilling fluid leakage in fractured reservoirs brought by friction & sliding on fracture surfaces was explored. Experiments showed that when the drilling fluid invaded natural fractures, both oil-base and water-base drilling fluids could decrease the friction factors of fractured rock surfaces, and the oil-base drilling fluid could brought a stronger effect, which would induce friction & sliding on fracture surfaces to form dislocated fractures, providing channels and space for the aggravation of drilling fluid leakage. Also, friction &sliding on fracture surfaces can increase the permeability of fractures, resulting in a decrease in the plugging capacity of drilling fluid and increasing drilling fluid leakage. Moreover, fracture surfaces were smoother after friction & sliding,which may further intensify the degree of dislocation. With the huge increase in the length and width of fractures, the leakage of drilling fluid was exacerbated. The research results showed that friction & sliding on fracture surfaces was one of the reasons for the exacerbation of drilling fluid leakage in deep fractured reservoirs. Drilling fluid leakage in deep fractured reservoirs could be controlled by increasing the friction factors of natural fracture surfaces and effectively controlling the friction & sliding on fracture surfaces.

关 键 词：深部 裂缝性地层 摩擦 滑动 钻井液漏失 机制 

分 类 号：TE21[石油与天然气工程—油气井工程]