论文部分内容阅读
煤层气开发效果很大程度上受控于煤层裂缝发育特征,沁水盆地南部同样如此。根据相似露头区野外地质调查、岩心观测以及成像测井、常规测井等资料,对比分析该区煤储层裂缝发育特征及其常规测井裂缝响应,建立了煤储层裂缝的常规测井识别方法,分析了该方法的应用效果。结果表明,研究区煤储层裂缝以构造剪切缝为主,发育北东—南西向、北西—南东向、近东—西向和近南—北向4组;裂缝多为有效裂缝,以高角度和倾斜裂缝为主,规模较小,密度变化大。常规测井裂缝的响应特征主要表现为低电阻、深浅侧向电阻率呈现正幅度差,三孔隙度测井向孔隙度变大偏转但不明显,高伽马值、扩径现象明显,测井曲线会出现波动。在此基础上,重构了异常变化指数,对常规测井曲线进行处理,经过加权合成裂缝预测指数对煤储层裂缝发育情况进行预测,预测结果得到了岩心及成像测井资料的验证。
The development of CBM is largely controlled by the development of coal seam fractures, as is the southern Qinshui Basin. According to the field geological survey, core observation, imaging logging and conventional logging in similar outcrops, the developmental characteristics of the fractures in the coal reservoirs and their response to conventional logging fractures are compared and analyzed. The conventional logging identification of coal reservoir fractures is established Method, analyzed the application effect of this method. The results show that the fractures of coal reservoirs in the study area are dominated by shear faults and developed in the north-south-west direction, north-west-southeastern direction, near-east-west direction and nearly south-north direction. Most of the fractures are effective fractures, And mainly inclined cracks, smaller, large changes in density. The response characteristics of conventional well fractures are mainly characterized by low resistivity, deep and shallow lateral resistivity with positive amplitude difference, three-porosity well porosity with larger deflection but not obvious, high gamma and obvious diameter expansion, Curves will fluctuate. On this basis, the abnormal change index is reconstructed, the conventional well logging curves are processed, and the prediction of fracture development in coal reservoirs is predicted through weighted synthetic fracture prediction index. The prediction results are verified by core and imaging logging data.