光弹物理模拟实验法在古应力场研究中的应用

APPLICATION OF PHOTOELASTIC EXPERIMENTS METHOD TO STUDY OF PALAEOTECTONIC STRESS FIELD

古应力场的研究是当今构造地质学和石油构造地质学的研究热点。作用在岩石或地层中的应力可以导致其不同样式和特性的变形 ,并且驱动油气的运移和成藏。从地质体中直接获得古应力场各项参数相当困难。将光弹物理模拟实验方法应用于古应力场研究中 ,介绍了光弹物理模拟实验的装置、材料、边界条件和相似理论 ,给出了实验结果。对该实验结果进行了物理学和动力学分析 ,结果表明 :①最大主应力σ1作用方向和强度控制着非均匀介质中应力集中区和高势能区的分布 ;②应力轨迹描述了应力传递方向与油气运移方向之间的几何关系 ;

A method of photoelastic experiment for study of palaeotectonic stress field are presented. This paper introduces the apparatus, materials, condition of the boundary, and similar theory about photoelastic experiment. The dynamic and physical analysis of experimental results may be summarized as follows: (1) The orientation and magnitude of maximum principal stress \%σ\-1 \%controlled the distribution of the stress concentration and high potential energy in the non\|homogeneous media. (2) The map of the stress trajectories could be used to describe geometric relationship between the orientation of the stress transfer and the orientation of the migration of oil\|gas. (3) It is very important to determine the area of low potential energy and to predict favorable structural area for oil and gas accumulations in accordance with the isopleth map of the stress.