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库车坳陷是塔里木盆地油气勘探的三大阵地之一,近年来在大北—克深区带白垩系巴什基奇克组持续取得重大突破,已形成万亿方大气区。但位于库车坳陷中部的秋里塔格构造带一直未能获得重要进展,特别是秋里塔格东段先后3口探井均未能在白垩系获得工业油气流。前人主要认为该区构造类型是以基底卷入形成的大型背斜圈闭为主,目前实践证明这一认识制约了该区勘探发展。由此可见,取得油气地质新认识是获得突破的首要前提条件。基于地震资料重新处理的基础上,以前陆盆地系统体系为理论划分基础,开展对东秋里塔格构造样式的精细分析。通过地震精细解释、盐岩三角带分析、地表地质分析、平衡剖面分析和已钻井分析5个方面研究,表明该区与大北—克深构造样式相似,均发育塑性滑脱叠瓦冲断构造。并落实了东秋里塔格断裂下盘冲断圈闭具体形态和位置。进一步综合分析后该区油气地质条件优越:油源充足,紧临生烃中心,处于构造高部位,一直是油气运移的指向区;主要目的层巴什基奇克组发育与大北—克深相同的辫状河三角洲前缘砂体;并具有古近系和新近系2套膏盐岩区域盖层。由此得出东秋里塔格是目前库车坳陷新区中最有利、最现实的勘探区带。
The Kuqa Depression is one of the three major oil and gas exploration positions in the Tarim Basin. In recent years, the Cretaceous Bashijiqike Formation in the Dabei-Keqian District has made major breakthroughs and has formed a teraflopic atmosphere. However, the Qiulitag structural belt located in the middle of the Kuqa Depression has not been able to make any significant progress. In particular, three consecutive exploration wells in the eastern part of Qiurtatang failed to obtain industrial oil and gas flow in the Cretaceous. The predecessors mainly believe that the tectonic type of the area is dominated by large anticlinal traps formed by the involvement of the basement. At present, practice has proved that this understanding restricts exploration and development in this area. Thus it can be seen that obtaining new understanding of oil and gas geology is the primary precondition for obtaining a breakthrough. Based on the re-processing of seismic data, based on the theoretical system of the foreland basin system, a detailed analysis of the tectonic styles of the East Qiu Litigat was carried out. Through the careful interpretation of seismic data, the analysis of the delta of salt rock, the analysis of surface geology, the analysis of balance profile and the analysis of the well drilled, it is shown that this area is similar to the Dabei-Kenshen structural style and both developed the plastic-slip-off shoal-shingian fault structure. And the implementation of the East Qiu Litige fault rupture disk under the trap of the specific shape and location. After further comprehensive analysis, the geological conditions of oil and gas in this area are superior: the oil source is abundant, close to the hydrocarbon generation center and in the tectonic high position, and has been the point of hydrocarbon migration. The main target layer is Bashijiqike Formation, The same braided river delta front sand body; and with Paleogene and Neogene 2 sets of gypsum rock cover. It is concluded that Dongqiulitag is the most favorable and realistic exploration zone in the new area of Kuqa Depression.