A NEW METHOD FOR ANALYZING CRUSTAL STRESS IN FORELAND STRUCTURAL COMPRSSIVE AREA BASED ON LOGGING DATA
Zhao Jun1, Zhang Li2, Wang Guiwen3, Li Jun4
1. Department of Petroleum Engineering, Southwest Petroleum Institute, Chengdu 610500;
2. Tarim Oil Field Branch Company, China National Petroleum Corp., Korla, Xinjiang 841000;
3. Department of Earth Sciences, University of Petroleum, Beijing 102249;
4. Department of Geophysics, Jianghan Petroleum Institute, Jingzhou, Hubei 434102
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.