石油学报 ›› 2016, Vol. 37 ›› Issue (6): 715-727,742.DOI: 10.7623/syxb201606003

• 地质勘探 • 上一篇    下一篇

超深层致密砂岩储层构造裂缝特征及影响因素——以塔里木盆地克深2气田为例

王珂1, 张惠良1, 张荣虎1, 王俊鹏1, 戴俊生2, 杨学君3   

  1. 1. 中国石油杭州地质研究院 浙江杭州 310023;
    2. 中国石油大学地球科学与技术学院 山东青岛 266580;
    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
  • 收稿日期:2015-08-05 修回日期:2016-04-16 出版日期:2016-06-25 发布日期:2016-06-30
  • 通讯作者: 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工程师,主要从事储层地质和构造地质研究工作。Email:wangk_hz@petrochina.com.cn
  • 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工程师,主要从事储层地质和构造地质研究工作。Email:wangk_hz@petrochina.com.cn
  • 基金资助:

    国家重大科技专项(2011ZX05015-002,2011ZX05046-003)资助。

Characteristics and influencing factors of ultra-deep tight sandstone reservoir structural fracture: a case study of Keshen-2 gas field, Tarim Basin

Wang Ke1, Zhang Huiliang1, Zhang Ronghu1, Wang Junpeng1, Dai Junsheng2, Yang Xuejun3   

  1. 1. PetroChina Hangzhou Research Institute of Geology, Zhejiang Hangzhou 310023, China;
    2. School of Geosciences, China University of Petroleum, Shandong Qingdao 266580, China;
    3. Research Institute of Exploration and Development, PetroChina Tarim Oilfield Company, Xinjiang Korla 841000, China
  • Received:2015-08-05 Revised:2016-04-16 Online:2016-06-25 Published:2016-06-30

摘要:

构造裂缝发育的影响因素是含油气盆地储层构造裂缝分布规律研究中的关键问题之一。通过岩心和成像测井等资料,分析了塔里木盆地克深2气田超深层致密砂岩储层构造裂缝的类型及基本特征,并在此基础上,探讨了构造位置、地层深度、岩层厚度、沉积微相、储层岩性、储层岩石组分和砂、泥岩互层结构对构造裂缝发育程度的影响。结果表明,克深2气田的构造裂缝以直立和高角度的剪切裂缝为主,主要包括NNW-SSE向、NW-SE向、NNE-SSW向和近EW向共4组走向。边界断层控制区构造裂缝线密度最高,以密集网状缝为主;其次为次级断层控制区、鞍部控制区;背斜高点与次级断层叠合控制区、背斜高点控制区和背斜翼部控制区相对较低。构造裂缝有效性分析表明,背斜高点以及背斜高点与次级断层叠合控制区的构造裂缝整体发育程度要高于翼部、鞍部和断层附近地层。随着地层深度的增加,构造裂缝线密度逐渐增大,而长度、开度和孔隙度逐渐下降;随着岩层厚度的增大,构造裂缝的线密度下降,长度和开度均有不同程度的增大或减小,但平均孔隙度基本不变,表明对于同一地区不同厚度的岩层,其弹性应变能的释放率大致相当。构造裂缝主要发育在水下分流河道及河口坝微相,水下分流河道间微相的构造裂缝发育程度较低;泥质粉砂岩和粉砂质泥岩中的构造裂缝线密度和长度较高,但开度较小,而泥质细砂岩、细砂岩和中砂岩中的构造裂缝线密度相对较低但长度和开度较高,泥岩中的构造裂缝线密度高但长度和开度较低,整体发育程度远低于砂岩构造裂缝,并且构造裂缝倾角通常低于砂岩构造裂缝倾角。脆性砂岩中钙质组分含量较高或含有一定量的泥质组分时,有利于构造裂缝的发育;对于克深2气田,当砂、泥岩厚度比值约为6.5时,构造裂缝发育程度最高。

关键词: 超深层, 致密砂岩, 储层构造裂缝, 发育特征, 影响因素, 克深2气田, 塔里木盆地

Abstract:

The analysis on influencing factors of structural fracture development is one of the key problems in the distribution law research of reservoir structural fractures in petroliferous basins. Based on the coring and imaging logging data, an analysis was performed on the types and fundamental characteristics of ultra-deep tight sandstone reservoir structural fractures in Keshen-2 gasfield, Tarim Basin. On this basis, this study explored the influences of tectonic location, stratum depth, rock thickness, sedimentary microfacies, reservoir lithology, reservoir rock composition and sand-mud inter-bedding structure on the development of reservoir structural fractures. The results indicate that structural fractures of Keshen-2 gasfield are dominated by upright and high-angle shearing fractures, mainly showing NNW-SSE, NW-SE, NNE-SSW and approximately EW strikes. The structural fractures in boundary faults controlling areas have the greatest linear density, dominated by intensive netlike cracks, followed by those in the secondary structural fracture controlling area and saddle controlling area. The anticline high-secondary structural fracture superimposed controlling area as well as anticline high and anticline wing controlling areas have relatively low linear density. The analysis of structural fracture effectiveness shows that fractures in the anticline high and anticline high-secondary fault superimposed controlling area all have a higher degree of development than those in the strata on the wings, saddle and around faults. With the increase of stratum depth, the linear density of structural fractures increases gradually, while the length, aperture and porosity decrease gradually. With the increase of rock thickness, the linear density of structural fractures declines, and the length and aperture have different degrees of increase or decrease, but the average porosity is basically unchanged. It is indicated that the release rates of elastic strain energy are approximately equivalent for the rock strata with different thicknesses in a specific region. The structural fractures are mainly developed in/at micro-facies underwater distributary channels and estuary dam, while the structural fractures in micro-facies underwater interdistributary channels have a lower degreess of development. The structural fractures in argillaceous siltstone and silty mudstone have great linear density and length but small aperture, while those in argillaceous fine-grained sandstone, fine-grained sandstone and medium-grained sandstone have low linear density but great length and large aperture. In contrast, the structural fractures in mudstone have high linear density but small length and aperture, with a lower development degree than those in sandstone, and the dip angle of structural fractures in mudstone is always lower than those in sandstone. When brittle sandstone has high calcareous content or a certain amount of argillaceous component, it is beneficial to the development of structural fractures. In Keshen-2 gasfield, structural fractures reach the maximum development when the ratio between sandstone thickness and mudstone thickness is 6.5.

Key words: ultra-deep, tight sandstone, reservoir structural fracture, development characteristics, influencing factors, Keshen-2 gas field, Tarim Basin

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