页岩储层纳孔微缝耦合系统全息表征方法研究

The characterization of nano-pores and micro-fractures in shale is essential and difficult for the development of unconventional oil and gas reservoires. Firstly, with the use of FESEM-FBI technology, the 3D reconstructions of shale volumes can be generated, and the organic/inorganic nano-pores and techtonic/diagenic micro-fractrues can be identified. Secondly, the formation mechanism of organic and inorganic nano-pores can be obtained by learning the characteristics and evolution law of keregen and the difference of minaral composition, thus the nano-pore distribution model can be obtained. Thirdly, The micro-fractures caused by techtonic and diagenic effect can be get acording to the failure experiment of shales and the modeling of diagenics process of shale formation, thus method for the micro-fracture identification and model for micro-fracture distribution can be developed. At last, by systomatic anaysis of distribution of the nano-pores and the micro-fractures, the characterization parameter can be get by coupling of nano-pores and micro-fractures. This study adds a new method for charcterization of nano-pores and micro-fractures in shales, and promotes ralative theories of this domain in China.

由于技术方法限制和成因复杂性，页岩储层纳孔微缝耦合系统全息表征一直未能开展有效研究。针对这一问题，选取典型页岩样品，利用FESEM-FBI联做技术，重构页岩储层纳孔微缝三维数字图像，建立不同成因纳孔和微缝识别方法。分析有机质特征及演化规律，探索有机纳孔成因主控因素，基于岩矿组构差异分布规律，揭示无机纳孔成因主控因素，综合两类纳孔主控因素，建立纳孔分布预测模型。通过开展不同组构页岩三轴破裂实验，揭示构造微缝成因机理及分布规律，基于不同矿物成分的细粒沉积物不同成岩条件的成岩过程模拟，揭示成岩微缝成因机理及分布规律；综合分析两类微缝地球物理响应特征，构建页岩储层微缝的地球物理识别方法，利用分形理论建立微缝分布预测模型。综合纳孔微缝成因机理及分布预测模型，探索纳孔微缝耦合方法，构建综合表征参数，建立耦合表征模型，开拓页岩储层纳孔微缝系统全息表征方法，从而推动我国页岩气藏表征技术和开发地质理论发展。

多类型成因纳米孔和微裂缝组成的复杂多孔介质为页岩气提供了储集空间和运移通道，由于纳米孔和微裂缝成因机理不清，导致表征困难。首先应用场发射扫描实验，重构页岩储层纳米孔-微裂缝数字图像，建立有机纳米孔和基质纳米孔识别方法。以此为基础，通过页岩储层岩矿组构差异性分布规律研究，揭示基质纳米孔成因机理；开展有机质特征及演化规律研究，探索有机纳米孔成因机理；构建变差函数模型和数值计算方法，建立页岩储层纳米孔三维模型。通过不同岩矿组构特征的页岩不同应力条件的破裂实验，揭示页岩储层构造微裂缝成因机理；研究不同岩矿组构特征的页岩不同成岩条件的成岩过程模拟，揭示页岩储层成岩微裂缝成因机理；通过页岩储层微裂缝地球物理响应特征研究，构建其识别方法和技术，利用分形理论建立微裂缝三维模型。综合纳米孔-微裂缝成因机理及分布预测研究成果，构建页岩气藏纳米孔和微裂缝表征参数，从而推动我国页岩气藏表征技术和开发地质理论发展。