中文摘要：

天然裂缝是油气储层的重要组成部分，天然裂缝的闭合问题关系到油气藏的衰竭。目前，这方面的研究主要局限于室内实验和在数学模型基础上分析裂缝闭合与有效应力之间的关系，而关于微观条件对裂缝闭合影响的研究很少。针对以上研究现状，依托赫兹弹性理论和高斯分布函数，对微观条件下的裂缝上下表面接触状况进行建模，进而模拟裂缝的闭合情况。在模型建立的基础上，就裂缝的微观条件对其闭合的影响进行研究，同时分别探讨在该模型下微观因素对裂缝闭合情况的影响。通过对不同岩石性质、不同微观条件下的裂缝闭合模拟和分析，得出天然储层裂缝在有效应力下的真实闭合情况。研究结果对于油气藏衰竭式开采及后期改造实践具有重要意义。

英文摘要：

Natural fracture is an important part of oil and gas reservoirs ,and the closure of natural fractures is related to the failure ofoil and gas reservoirs. At present,the research in this area is mainly confined to the a- nalysis of the relationship between fracture closure and effective stress on the basis of laboratory experiments and mathematical models, and the influence of microscopic conditions on fracture closure is rare. In view of the above research status ,based on the Hertz elastic theory and the Gauss distribution function, the contact condi- tion of the upper and lower surface of the fracture under the condition of the microscopic condition was mod- eled, and then the fracture closure was simulated. Based on this model, the paper studied the impact of microfracture on the closed condition. Through the simulation and analysis of fracture closure in different rock reser- voir under different micro conditions, the real closure of natural reservoir under effective stress was summa- rized. The practice of oil and gas reservoir development in the above three kinds of rock reservoir has a certain significance.