煤储层渗透性与现代构造应力场之耦合特征及作用机理

The permeability of coal reservoirs is a key factor by which the effect of the coalbed gas exploitation in China is decided, and Qinshui basin is one of the most potential areas in China for realizing the large-scale exploitation of the coalbed gas resources at present. Thus, the Qinshui basin was chosen as the major object studied in this project, where coupling relation and mechanism of coal reservoir permeability to tectonic stree field and its main stree direction were studied. It was discovered that the reservoir permeability is directly controled by the tectonic stree field through the main stree direction and difference of the field. The concept of the ternary structure of the fissure-hole system in coal reservoir was suggested, and the non-linearity and fractal dimensions in the system were found. The academic viewpoint and geological mechanism on the directional coupling among effective stree, self-adjusted cola matrix effect and reservoir perpeabily under the multiphase medium were put forward and discussed, and the relative mathematical models were established, which has been prelimitarily applied to the optimization of the potential coalbed districts in the Qinshui basin. At one time, some studied productions were preferably extended to the tectonic-mining coupling of the coal reservoir permeability and the physical properties of the low-rank coal reservoirs. The results in the projiect will be affluent in the theroy of coalbed gas geology suitable to the geological properties of China, and be significative to resolving the mechanism of the coalbed gas accumulation and high production in high-rank coal reservoir.

基于多方位对比研究思路，以沁水盆地这一典型实例为依托，剖析现代构造应力场与煤储层天然裂隙之耦合的地质特征，查证煤的受力状况、煤中裂隙发育状况、渗透性发育物征三者之间耦合的动态平衡关系，深入探讨其耦合的物理机理和地质机理，构建煤储层与现代构造应力场之间动态平衡的数学模型，建立煤储层渗透性预测的理论体系。