Acta Petrolei Sinica ›› 2021, Vol. 42 ›› Issue (7): 885-905.DOI: 10.7623/syxb202107005

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Geological characteristics and exploration potential of the northern tectonic belt of Kuqa depression in Tarim Basin

Wang Ke1,2, Yang Haijun3, Li Yong3, Zhang Ronghu1,2, Ma Yujie3, Wang Bo1, Yu Chaofeng1,2, Yang Zhao1,2, Tang Yan'gang3   

  1. 1. PetroChina Hangzhou Research Institute of Geology, Zhejiang Hangzhou 310023, China;
    2. Tarim Basin Research Center, PetroChina Research Institute of Petroleum Exploration & Development, Xinjiang Korla 841000, China;
    3. Research Institute of Petroleum Exploration & Development, PetroChina Tarim Oilfield Company, Xinjiang Korla 841000, China
  • Received:2020-05-20 Revised:2020-12-03 Online:2021-07-25 Published:2021-08-04

塔里木盆地库车坳陷北部构造带地质特征与勘探潜力

王珂1,2, 杨海军3, 李勇3, 张荣虎1,2, 马玉杰3, 王波1, 余朝丰1,2, 杨钊1,2, 唐雁刚3   

  1. 1. 中国石油杭州地质研究院 浙江杭州 310023;
    2. 中国石油勘探开发研究院塔里木盆地研究中心 新疆库尔勒 841000;
    3. 中国石油塔里木油田公司勘探开发研究院 新疆库尔勒 841000
  • 作者简介:王珂,男,1987年7月生,2009年获中国石油大学(华东)学士学位,2014年获中国石油大学(华东)博士学位,现为中国石油杭州地质研究院高级工程师,主要从事碎屑岩储层研究工作。Email:wangk_hz@petrochina.com.cn
  • 基金资助:
    国家重点研发计划项目"盐下超深层碎屑岩规模储层成因与油气成藏机理"(2019YFC0605501)和中国石油天然气股份有限公司科技重大专项"大型陆相沉积盆地砂体类型及控藏机制"(2019B-0309)资助。

Abstract: The northern tectonic belt of Kuqa depression is a key field for increasing oil and gas reserves and production in Tarim Basin. Using the latest data of outcrop and drilling, in combination with previous research results, this paper analyzes hydrocarbon accumulation models and exploration potentials by systematically summarizing the basic geological characteristics and petroleum geological conditions of the northern tectonic belt of Kuqa depression, then makes a comparison between it and the Kelasu tectonic belt in the adjacent area, and further clarifies the key issues that need to be solved in the current exploration. The results show that the main hydrocarbon-bearing series in the northern tectonic belt of Kuqa depression includes the braided river delta plain deposits in the Lower Jurassic Ahe Formation, the braided river lower delta plain, delta front, shore-shallow lacustrine deposits in the Lower Jurassic Yangxia Formation and Middle Jurassic Kezilenur Formation. Complex and simple basement-involved thrust structures are developed in Bashi tectonic segment and Dibei-Tuzi tectonic section, respectively, and basement-involved anticlines are developed in Tugeerming tectonic segment under the background of paleohigh. The structural forming stage is from the deposition period of Neogene Kuqa Formation to the Quaternary. The source rocks are mainly Triassic-Jurassic lacustrine mudstone and coal-measure strata, and the Middle-Lower Jurassic reservoirs are fractured tight sandstone reservoirs. There are three main sets of source-reservoir-cap assemblages. The combination mode of the adjacent source, reservoir and cap is favorable for the formation of tight sandstone gas reservoirs. There are three types of reservoirs. The structural-lithological reservoirs are mainly distributed in the Tugeerming anticline and its peripheral areas, the fractured continuous tight sandstone condensate gas reservoirs are mainly in the Dibei-Tuzi area, and the structural tight sandstone reservoirs are mainly in the Bashi tectonic segment. They are characterized by "densification first and accumulation later". As a whole, the northern tectonic belt of Kuqa depression has the potential to form large-scale contiguous reservoirs. Twenty-two new oil and gas traps have been discovered, with the total area of 240 km2. The predicted oil resources are 3 200×104t, and the natural gas resources are 3 500×108m3. With the implementation of 3D seismic deployment in the whole region, more traps are expected to be discovered. The northern tectonic belt of Kuqa depression, like the Kelasu tectonic belt, has the geological basis for the formation of large-medium-sized oil and gas fields. For the oil and gas exploration in the northern tectonic belt of Kuqa depression, it is required to carry out further systematic studies on oil and gas preservation conditions, fine structure modeling, reservoir genesis, drilling and completion, and improvement of reservoir reconstruction technology. The exploration should focus on the Middle-Lower Jurassic horizons, taking into account both shallow and deep target strata, thus broadening the field of oil and gas exploration.

Key words: sedimentary facies, geological structure, tectonic evolution, source rock, reservoir, source-reservoir-cap assemblage, hydrocarbon accumulation, exploration potential

摘要: 库车坳陷北部构造带是塔里木盆地油气增储上产的重要领域。利用最新的露头、钻井等资料,结合前人的研究成果,通过系统梳理和总结库车坳陷北部构造带的基础地质特征和石油地质条件,分析油气成藏模式和勘探潜力,并与邻区克拉苏构造带进行类比,明确了目前勘探需要解决的关键问题。结果表明,库车坳陷北部构造带的主要含油气层系为下侏罗统阿合组辫状河三角洲平原沉积、下侏罗统阳霞组—中侏罗统克孜勒努尔组辫状河三角洲下平原、三角洲前缘和滨、浅湖沉积;巴什构造段和迪北—吐孜构造段分别发育复杂和简单的基底卷入冲断构造,吐格尔明构造段发育古隆起背景下的基底卷入背斜;新近系库车组沉积期—第四纪为构造定型期;烃源岩主要为三叠系—侏罗系湖相泥岩和煤系地层,中—下侏罗统储层为裂缝性致密砂岩储层;发育3套主要的生-储-盖组合,"源、储、盖"紧邻的组合模式是形成致密砂岩气藏的有利条件;发育3类油气藏,构造-岩性油气藏主要分布在吐格尔明背斜及周缘地区,裂缝性连续型致密砂岩凝析气藏主要分布在迪北—吐孜地区,构造型致密砂岩油气藏主要分布在巴什构造段,均具有"先致密后成藏"的特点。库车坳陷北部构造带整体具备形成规模连片油气藏的潜力,新发现油气圈闭22个,总面积为240 km2,预测石油资源量为3 200×104t、天然气资源量为3 500×108m3,随着全区三维地震部署的实施,有望发现更多圈闭。库车坳陷北部构造带与克拉苏构造带一样,具备形成大—中型油气田的地质基础。对于库车坳陷北部构造带的油气勘探,需要在油气保存条件、构造精细建模、储层成因机制、钻完井与储层改造工艺优化方面开展进一步的系统研究;勘探层位应以中—下侏罗统为主,兼顾浅层、深层多目的层系,拓宽油气勘探领域。

关键词: 沉积相, 地质结构, 构造演化, 烃源岩, 储层, 生-储-盖组合, 油气成藏, 勘探潜力

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