地应力在地质断层构造发生前后的变化 - 岩石力学与工程学报.PDF

第23 卷 第23 期 岩石力学与工程学报 23(23) ：3964～3969 2004 年12 月 Chinese Journal of Rock Mechanics and Engineering Dec. ，2004 地应力在地质断层构造发生前后的变化 孙宗颀 张景和 ( 中南大学资源与安全工程学院 长沙 410083) (石油勘探开发科学研究院 北京 100083) 摘要 现有文献中都有介绍不同断层构造和主应力的相应关系，但没有强调这是各种断层发生前的主应力和断层 构造的关系；更没有介绍各种断裂发生后它们的相应关系，这往往使一般人认为断裂发生后的主应力的方向仍保 持不变。对全国13 个大油区86 个断块油田近千口钻井在正断层和逆断层地区进行了水压致裂测试地应力的试验。 地应力测试结果表明，无论这些油田的断层是正断层还是逆断层，压裂裂缝的方向基本是垂直于断层走向的，即 最小主应力均是平行于断层迹线的水平应力。这与现有文献中介绍正断层和逆断层发生前主应力的方向显然是不 同的。提出了断层发生后地应力的计算方法，较好地回答了这个问题。 关键词 岩石力学，地应力，正断层，逆断层，主应力 分类号 TD 311 文献标识码 A 文章编号 1000-6915(2004)23-3964-06 VARIATION OF IN-SITU STRESSES BEFORE AND AFTER OCCURRENCE OF GEOLOGIC FAULT STRUCTURE 1 2 Sun Zongqi ，Zhang Jinghe 1 ( College of Resource and Safety Engineering ，Central South University， Changsha 410083 China) (2Institute of Scientific Study of Petroleum Exploration and Development ， Beijing 100083 China) Abstract Literatures always introduce the relationships between different fault structures and principal stresses. But it was not emphasized that these relationships exist only before occurrence of these faults. No literature introduces the relationships between different fault structures and principal stresses after occurrence of these faults. It makes people always think that the directions of principal stresses keep unchanging after occurrence of the faults. In the area of normal and reversed faults，about thousand tests of in-situ stress measurements by hydrofracture in oil wells were conducted in 86 oil fault fields of 13 big oil regions in China