摘要
针对塔里木盆地致密气勘探开发中地应力测试需求,利用非弹性应变恢复(ASR)和钻井诱发裂缝(DITF)地应力测试方法,分析塔里木盆地7 km深部的地应力状态。研究表明:(1)SN-X井6 293~6 955 m深度范围内最大主应力近垂直,中间和最小主应力近水平,最大水平主应力方向在N E 51°~79°范围。(2)在区域挤压构造环境下,塔里木盆地内部存在与碰撞造山后应力松弛或构造旋转逃逸引起的正断层应力环境。(3)通过与DITF法地应力测量结果的对比分析,验证了ASR法用于7 km深部地应力测量的有效性,预期ASR法以其成本低、效率高且不受钻井深度和温度限制的优点,在深部科学钻探、非常规油气开发及地热资源开发等领域具有广阔的应用前景。
To obtain the state of in-situ stress during the exploration of dense gas reservoir under Tarim Basin,the anelastic strain recovery(ASR) and the methods of drilling induced tensile fractures(DITF) were applied to measure the in-situ stress at depth of 7 km.The results show that the maximum principle stress is close to vertical and the medium and the minimum principle stresses are close to horizontal in SN-X well at 6 293–6 955 m depth.The orientation of maximum horizontal principal stress is NE51°–NE79°.The normal faulting stress regime exists in the inner Tarim Basin caused possibly by the stress releasing after the orogenic period or the escaping structures of Tarim basin by the long distance effect of Himalaya collisional orogeny.The effectiveness of ASR method at the ultra-depth was confirmed by the close results from the ASR and DITF methods.The ASR method has the advantages of low cost,high efficiency,and no depth and temperature limitation,and hence,will have broad prospect of application at ultra-depth in scientific drilling,unconventional oil and gas exploration and geothermal development.