Carbonate karst reservoirs of the Tarim Basin, northwest China: Types, features, origins, and implications for hydrocarbon exploration
Carbonate karst reservoirs of the Tarim Basin, northwest China: Types, features, origins, and implications for hydrocarbon exploration
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DOI：
10.1190/int-2013-0177.1
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发表时间：
2014-08
期刊：
影响因子：
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通讯作者：
Wenzhi Zhao;Anjiang Shen;Zhanfeng Qiao;Jianfeng Zheng;Xiaofang Wang
中科院分区：
文献类型：
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作者：
Wenzhi Zhao;Anjiang Shen;Zhanfeng Qiao;Jianfeng Zheng;Xiaofang Wang
岩溶储层是世界各国海相含油气盆地碳酸盐岩勘探的重要目标。利用200多口井的岩心、薄片、电缆测井、钻井测井和生产资料，圈定了塔里木盆地4种类型的碳酸盐岩岩溶储层；这些数据还补充了地震和其他数据。所描述的四种岩溶储层类型均由大气水循环形成，但不局限于气包或潜水带，包括埋塔岩溶、层间岩溶、上覆水层封闭岩溶和断层相关岩溶。埋塔岩溶发育于区域不整合（埋塔区）下的碳酸盐岩层序中，类似于中国南方桂林地区的活动岩溶。与埋塔岩溶相比，层间岩溶发育时间相对较短，但也位于古隆起上。上覆水层封闭性岩溶本质上是埋塔岩溶的副产物，位于埋塔岩溶的边缘，虽然表面上均匀分布在不整合面下方，但其成因与不整合面无关。断层相关岩溶发育在高陡背斜的碳酸盐岩序列中，断层穿过水包体进入碳酸盐岩；溶蚀作用沿断层和背斜峰顶集中。通过对三种岩溶类型的研究，证明塔里木盆地岩溶储层既存在于区域不整合下的碳酸盐岩演替中，也存在于未发现明显不整合的地区。类似的例子已在中国其他盆地中发现，预计在世界其他盆地中也会出现，特别是在地质历史复杂的地区。
Karst reservoirs are important exploration targets in marine carbonates of hydrocarbon-bearing basins around the world. In the Tarim Basin of northwest China, four types of carbonate karst reservoirs were delineated using data from more than 200 wells, including cores, thin sections, wireline logs, drilling logs, and production data; these were supplemented with seismic and other data. The four types of karst reservoirs described were all formed by meteoric water circulation but not limited in the vadose or phreatic zones, including buried tower karst, interlayer karst, overlying-aquiclude confining karst, and fault-related karst. Buried tower karst occurred in the carbonate successions underneath a regional unconformity (buried tower area), resembling the active karsting in the Guilin Region of South China. Interlayer karst developed during a relatively shorter exposure period compared with buried tower karst but is also situated on a paleouplift. Overlying-aquiclude confining karst is essentially a by-product and on the fringes of buried tower karst, and though it appears to be distributed evenly below a disconformity, it is not related to the disconformity in origin. Fault-related karst occurred in the carbonate succession of a high steep anticline with faults cutting through aquicludes and into the carbonates; dissolution is concentrated along faults and the crest of the anticline. We studied three previously undocumented types of karst and proved that karst reservoirs in the Tarim Basin occur not only in the carbonate succession under a regional unconformity, but also where no significant unconformity is recognized. Similar examples have been found in other basins of China and are expected to occur in other basins worldwide, particularly in areas of complex geologic history.