一种基于测井信息的山前挤压构造区地应力分析新方法

A NEW METHOD FOR ANALYZING CRUSTAL STRESS IN FORELAND STRUCTURAL COMPRSSIVE AREA BASED ON LOGGING DATA

中国西部前陆盆地主要以挤压构造应力为主,地表与地下构造异常复杂。在油气的勘探与开发过程中既需要精细的地应力研究与预测,也需要简单易行、经济实用的近似方法。本文通过对稳定构造地区与挤压构造区地球物理测井信息的深度域特征进行分析和对比,提出了一种基于测井信息来计算最大岩石主应力的近似方法:统计模型法。应用该方法对塔里木盆地库车山前挤压应力区进行了实际计算,其结果与实验结果相符,还分析了岩石的最大主应力方向,据此对山前挤压区地应力分布与油气藏分布的关系进行了探索。

Compressive structural stress is a main stress in foreland basins in the west part of China during Cenozoic, which is very complicated in surface and underground. In the course of the exploration and development for oil and gas, not only it needs fine study and prediction for formation stress, but also needs some simple, practical and approximate methods. Through a comparison between distribution characteristics of logging data in the structural stable field and those in the structural compressive field, a new method for determining maximum horizontal crustal stress based on statistical analysis of resistivity and acoustic slowness-time was presented. The method and the model were used to calculate crustal stress in the Lunnan area, the Kuqa oil field of Tarim Basin. The calculated stress results were coincident with the results of the acoustic experiment. The azimuth of the maximum compressive horizontal principal stress was also obtained by using enlarged well bore breakouts in the area. The work showed an intimate relationship between the stress distribution and the distribution of oil-gas pools in the foreland area.