地质力学层定量划分方法及其超深层油气勘探开发应用

Quantitative division method of geomechanical strata and its applications in exploration and development of oil and gas in ultra-deep layers

鞠玮 张辉 徐珂 宁卫科 相如

JU Wei ZHANG Hui XU Ke NING Weike XIANG Ru

1. 煤层气资源与成藏过程教育部重点实验室, 江苏 徐州 221008; 2. 中国矿业大学 资源与地球科学学院, 江苏 徐州 221116; 3. 中国石油天然气股份有限公司 塔里木油田分公司 勘探开发研究院, 新疆 库尔勒 841000; 4. 中国科学院 地理科学与资源研究所, 北京 100101

1. Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of Ministry of Education, Xuzhou, Jiangsu 221008, China; 2. School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China; 3. Institute of Exploration and Development, PetroChina Tarim Oilfield Company, Korla, Xinjiang 841000, China; 4. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China

超深层油气高效勘探开发是当前全球能源地质研究关注的焦点，“地质力学层与油气勘探开发”是国际前沿研究领域，形成地质力学层的有效划分方法，对超深油气高效勘探和效益开发具有理论和实际意义。现今地应力状态影响天然裂缝有效性，裂缝发育分布影响岩石力学性质，而岩石力学性质又控制着现今地应力的分布，但当前“岩石力学层理论”不能完整涵盖三者之间耦合联系。为此，基于水平最小主应力、水平主应力差、弹性模量、现今地应力优势方位与天然裂缝走向的夹角、天然裂缝密度和应力集中系数等6种参数，构建储层地质力学层指标，形成一种地质力学层定量划分方法。基于塔里木盆地库车坳陷克拉苏构造带大北区块W井的实例分析，表明该井目的层白垩系巴什基奇克组垂向呈现强地质力学非均质性，储层地质力学层与气层发育段具有较好的对应关系。因此，借助地质力学层划分结果，可指导超深层油气甜点层段的优选。

Efficient exploration and development of ultra-deep oil and gas reservoirs are key objectives in current global energy geological research. The concept of “geomechanical strata and oil and gas exploration and development” represents a cutting-edge research area internationally. Establishing an effective method for dividing geomechanical layers holds both theoretical and practical significance for the efficient exploration and economical development of ultra-deep oil and gas reservoirs. Currently, the state of in-situ stress affects the effectiveness of natural fractures, while the development and distribution of fractures impact the mechanical properties of rocks, which influence the the distribution of in-situ stress. However, the existing “rock mechanical stratigraphy theory” fails to comprehensively cover the coupling relationships among these three factors. In response, this study introduced a method for the quantitative division of geomechanical strata based on six parameters: minimum horizontal principal stress, difference in horizontal stress, elastic modulus, angle between the current dominant stress orien- tation and the natural fracture orientation, natural fracture density, and stress concentration factor. An analysis of well W in the Dabei area of the Kelasu structural belt, Kuqa Depression, Tarim Basin, demonstrated that the target layers at the Cretaceous Bashijiqike Formation exhibited strong vertical geomechanical heterogeneity. The geomechanical strata of the reservoir correlated well with the development sections of the gas layers. Therefore, with the results of geomechanical strata division, it is possible to guide the optimization of sweet spots in ultra-deep oil and gas reservoirs.

国家自然科学基金面上项目(42372185)和中国石油天然气股份有限公司重大科技专项(2018E-1803)联合资助。

https://doi.org/10.11781/sysydz202404880