含裂缝的硬脆性泥页岩理化及力学特性研究

Chemical and Mechanical Properties of Brittle Fractured Mud Shale

硬脆性泥页岩的理化及力学特征对深入研究深部地层泥页岩井壁稳定机理、裂缝性泥页岩漏失等问题具有至关重要的意义。采用泥浆化学、微观结构扫描及岩石力学试验手段,对某工区易失稳泥页岩地层的理化及力学特性进行了系统的研究和分析。结果表明,该工区泥页岩属于硬脆性泥页岩,粘土矿物以伊利石为主,基本不含蒙脱石,具有低膨胀易分散的特性,微观结构显示微裂缝发育;流体浸泡导致裂缝扩展延伸,降低了泥页岩的强度,随着时间的增加,强度降低得越显著。

To study the chemical and mechanical characteristics of brittle fractured mud shale was important for solving problems of wellbore stability mechanism and drilling fluid leakage in deep mud shale formation.The physical,chemical and mechanical properties of brittle mud shale were systematically studied and analyzed by slurry chemical,microstructure scanning and rock mechanic experiments.The results show that mud shale in the area is brittle and cracked,and its clay minerals mainly contain illite and montmorillonite bsically is free.Microstructure scanning shows that micro fractures are developed in mud shale;its soaking in fluid results in crack propagation,it reduce the strength as time increasing.