石油学报 ›› 2016, Vol. 37 ›› Issue (6): 695-705.DOI: 10.7623/syxb201606001

• 地质勘探 •    下一篇

准噶尔盆地中拐-西北缘地区二叠系沸石胶结物分布与控制因素

郭沫贞, 寿建峰, 徐洋, 郭华军, 邹志文, 韩守华   

  1. 中国石油杭州地质研究院 浙江杭州 310023
  • 收稿日期:2015-11-11 修回日期:2016-04-12 出版日期:2016-06-25 发布日期:2016-06-30
  • 通讯作者: 郭沫贞,男,1974年3月生,1997年获江汉石油学院学士学位,2000年获石油大学(北京)硕士学位,现为中国石油杭州地质研究院高级工程师,主要从事油气储层及油藏评价研究。Email:guomz_hz@petrochina.com.cn
  • 作者简介:郭沫贞,男,1974年3月生,1997年获江汉石油学院学士学位,2000年获石油大学(北京)硕士学位,现为中国石油杭州地质研究院高级工程师,主要从事油气储层及油藏评价研究。Email:guomz_hz@petrochina.com.cn
  • 基金资助:

    国家重点基础研究发展计划(973)项目(2014CB239002)资助。

Distribution and controlling factors of Permian zeolite cements in Zhongguai-Northwest margin of Junggar Basin

Guo Mozhen, Shou Jiangfeng, Xu Yang, Guo Huajun, Zou Zhiwen, Han Shouhua   

  1. PetroChina Hangzhou Research Institute of Geology, Zhejiang Hangzhou 310023, China
  • Received:2015-11-11 Revised:2016-04-12 Online:2016-06-25 Published:2016-06-30

摘要:

准噶尔盆地中拐-西北缘地区深层二叠系碎屑岩中普遍发育沸石类胶结物,主要有浊沸石、片沸石及方沸石。成岩后期由于烃源岩热演化及大气淡水作用导致成岩介质环境由碱性环境部分转化为酸性环境,形成沸石次生孔隙发育带,这对在二叠系深层碎屑岩中寻找有利储集体意义重大。通过对该区120余口井1400多片铸体薄片分析,结合岩心、扫描电镜、电子探针、黏土矿物及物源区母岩性质等综合研究,认为:①3类沸石胶结物在时空上呈规律性发育。横向上从盆缘向盆内,沸石成带分布,依次发育片沸石、方沸石和浊沸石;纵向从下至上,浊沸石胶结程度减弱,方沸石胶结程度增强。②母岩成分的差异是形成不同沸石矿物的物质基础。在碱性成岩环境中,富中基性火山岩屑的碎屑岩,易形成以浊沸石为主的沸石胶结物;富中酸性、酸性火山岩屑的碎屑岩,易形成以方沸石为主的沸石胶结物。③在同一性质岩屑组成的情况下,成岩流体性质决定了沸石的纵横向分布特征。湖盆中心pH值高、盐度高及钙离子富集,易形成浊沸石胶结;湖盆边缘pH值降低、盐度降低及钙离子富集程度减少,易形成方沸石、片沸石胶结。通过对各类沸石胶结物分布特征及形成条件研究,提出了中拐-西北缘地区碎屑岩沸石胶结物的发育规律,这对认识中拐-西北缘地区碎屑岩岩矿特征、成岩环境及寻找沸石溶蚀孔型储层有重要指导意义。

关键词: 沸石胶结物, 分布规律, 控制因素, 二叠系, 准噶尔盆地

Abstract:

The zeolite cements are well developed in deep Permian clastic rocks of Zhongguai-Northwest margin of Junggar Basin, including laumontite, heulandite and analcite. Due to the thermal evolution of source rocks and meteroric fresh water action in late diagenesis stage, diagenetic medium environment was partially changed from alkaline environment to acidic environment, thus forming the development zones of zeolite secondary pores. This has great significance to find favorable reservoir bodies in deep Permian clastic rocks. Based on the thin slice analysis of 1400 pieces of castings in more than 120 wells in combination with core observation, scanning electron microscopy, electron probe, clay mineral and provenance parent rock lithology analysis, and etc., the following conclusion is obtained:(1) Three types of zeolite cements show a regularity in spatiotemporal development. Horizontally from basin edge to basin center, zeolite shows a belt-like distribution; in this zone, heulandite, analcite and laumontite are developed sequentially; vertically from bottom to top, the cementation degree of laumonite is decreased, while that of analcite is increased. (2) Differences in parent rock components provide the material basis to form various zeolite minerals. In the alkaline diagenetic environment, clastic rocks rich in intermediate-basic volcanic debris were prone to form zeolite cements dominated by laumontite; clastic rocks rich in intermediate-acid and acid volcanic debris were prone to form zeolite cements dominated by analcite. (3) Under the condition of debris components with the same properties, the horizontal and vertical distribution characteristics of zeolite are determined by diagenetic fluid properties. The lacustrine basin center is characterized by high pH value, high salinity and rich calciumion, and an advantage for forming laumontite cements; the basin edge is characterized by a reduction in pH value, salinity and calciumion enrichment degree, and an advantage for forming analcite and heulandite cements. Through the research on the distribution characteristics and formation conditions of various zeolite cements, the development law of clastic zeolite cements in Zhongguai-Northwest margin of Junggar Basin was put forward in this study, which has an important guiding significance for understanding the characteristics and diagenetic environment of clastic rocks as well as finding favorable zeolite solution-pore reservoirs in Zhongguai-Northwest margin of Junggar Basin.

Key words: zeolite cement, distribution law, control factors, Permian, Junggar Basin

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