鄂尔多斯盆地苏里格气田西区与天环坳陷北段二叠系地层水地球化学特征、成因及来源对比  

Geochemical Characteristics,Genesis and Source Correlation of Permian Formation Water in the Western Sulige Gas Field and the Northern Part of Tianhuan Depression,Ordos Basin,China

作　　者：颜凯 李博偲 徐建斌[3] 徐学敏 丁佳伟 郑少威 潘志强 何大祥[1,2] YAN Kai;LI Bo-cai;XU Jian-bin;XU Xue-min;DING Jia-wei;ZHENG Shao-wei;PAN Zhi-qiang;HE Da-xiang(Hubei Key Laboratory of Petroleum Geochemistry and Environment,Yangtze University,Wuhan 430100,Hubei,China;College of Resources and Environment,Yangtze University,Wuhan 430100,Hubei,China;Research Institute of Oil Exploration and Development,Liaohe Oilfield Company,PetroChina,Panjin 124010,Liaoning,China;National Research Center for Geoanalysis,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]长江大学油气地球化学与环境湖北省重点实验室,湖北武汉430100 [2]长江大学资源与环境学院,湖北武汉430100 [3]中国石油辽河油田分公司勘探开发研究院,辽宁盘锦124010 [4]中国地质调查局国家地质实验测试中心,北京100037

出　　处：《地球科学与环境学报》2024年第5期663-676,共14页Journal of Earth Sciences and Environment

基　　金：国家重点研发计划项目(2021YFA0719004)。

摘　　要：鄂尔多斯盆地苏里格气田西区与天环坳陷北段是鄂尔多斯盆地重要的天然气富集区,其气水关系复杂,气水共存在二者上古生界二叠系气藏中大量存在,目前对上述两个地区二叠系地层水成因及来源的对比研究较为薄弱。通过对苏里格气田西区与天环坳陷北段二叠系35口井地层水样品开展地球化学特征研究,进一步揭示上述两个地区地层水成因、来源及保存条件的异同。结果表明:苏里格气田西区与天环坳陷北段二叠系地层水主体为CaCl_(2)型,总矿化度平均值分别为31.4和34.6 g·L^(-1);不同类型水化学参数指示了天环坳陷北段地层封闭性更好,两个地区整体经历了强烈的水-岩相互作用,油气保存条件好;苏里格气田近源运移成藏以及生烃强度与储层非均质性的特点控制了气、水分布格局,天环坳陷北段存在的一系列构造裂缝系统对该区域的气、水分布具有一定的调整作用;上述两个地区地层水主体为原始沉积地层水,地层中发生了斜长石的钠长石化及白云石化等作用,具有Ca^(2+)富集、Na^(+)轻微亏损、Mg^(2+)亏损的特点。综合研究表明,苏里格气田西区地层水没有统一的气、水界面,局部井位遭受了外来水等流体影响;天环坳陷北段各井位地层水可能属于统一的流体场。The western Sulige gas field and the northern part of Tianhuan depression are significant natural gas rich zones within Ordos Basin.The relationship between gas and water is complicated,with gas-water coexistence observed in the Upper Paleozoic Permian gas reservoirs.At present,the study on the genesis and source correlation of Permian formation water in these two regions is relatively weak.By analyzing geochemical characteristics of Permian formation water samples from 35 wells in the above two regions,and the differences in formation water genesis,source,and preservation conditions were furtherly elucidated.The results show that the formation water from both regions are mainly CaCl_(2)-type,and the average TDS is 31.4 and 34.6 g·L^(-1),respectively.The northern part of Tianhuan depression exhibits superior sealing characteristics based on various hydrochemical parameters,and the data also indicate strong water-rock interaction in the above two regions and good preservation conditions for oil and gas.The distribution pattern of gas and water in Sulige gas field is controlled by near-source migration characteristics,hydrocarbon generation intensity,and reservoir heterogeneity.Additionally,a series of structural fracture systems in the northern part of Tianhuan depression play a significant role in regulating the distribution of gas and water within this region.The formation water in the above two regions is mainly the original sedimentary formation water,and the albitization and dolomitization of plagioclase occur in the formation,showing the characteristics of Ca^(2+)enrichment,Na^(+) slight loss and Mg^(2+)loss.The analysis data consistently indicate that the interface between gas and water in the western Sulige gas field lacks uniformity,and local well locations are affected by external water and other fluids,while the formation water in the northern part of Tianhuan depression may belong to a unified fluid field.

关 键 词：地球化学 地层水 离子组成 保存条件 二叠系 苏里格气田 天环坳陷 鄂尔多斯盆地 

分 类 号：P641[天文地球—地质矿产勘探] P618.13[天文地球—地质学]