石油学报 ›› 2016, Vol. 37 ›› Issue (1): 17-29.DOI: 10.7623/syxb201601002

• 地质勘探 • 上一篇    下一篇

四川盆地震旦系灯影组白云岩岩溶储层特征及溶蚀作用证据

单秀琴, 张静, 张宝民, 刘静江, 周慧, 王拥军, 傅卓文   

  1. 中国石油勘探开发研究院 北京 100083
  • 收稿日期:2015-06-16 修回日期:2015-11-12 出版日期:2016-01-25 发布日期:2016-02-02
  • 通讯作者: 单秀琴,女,1964年9月生,1984年获华东石油学院学士学位,1999年获中国地质大学硕士学位,现为中国石油勘探开发研究院高级工程师,主要从事碳酸盐岩储层研究工作。Email:sxq69@petrochina.com.cn
  • 作者简介:单秀琴,女,1964年9月生,1984年获华东石油学院学士学位,1999年获中国地质大学硕士学位,现为中国石油勘探开发研究院高级工程师,主要从事碳酸盐岩储层研究工作。Email:sxq69@petrochina.com.cn
  • 基金资助:

    国家重大科技专项(2011ZX05004)资助。

Dolomite karst reservoir characteristics and dissolution evidences of Sinian Dengying Formation,Sichuan Basin

Shan Xiuqin, Zhang Jing, Zhang Baomin, Liu Jinjiang, Zhou Hui, Wang Yongjun, Fu Zhuowen   

  1. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
  • Received:2015-06-16 Revised:2015-11-12 Online:2016-01-25 Published:2016-02-02

摘要:

四川盆地震旦系灯影组广泛发育,是重要的天然气储产层。对其进行储层岩石学与沉积学、储集空间类型和成岩作用及演化序列的综合研究,尤其是薄片、扫描电镜鉴定和元素、碳氧同位素及流体包裹体分析,获得了溶蚀作用的微观岩石学与流体包裹体盐度资料新证据。认为储层成因具有相控型白云岩岩溶储层的典型特点,发育主控因素为特殊的沉积、成岩环境与多期多类溶蚀及破裂作用。特殊的沉积环境突出表现为干热/干燥古气候背景控制下的大型微生物礁滩体、丘滩体,这些沉积具有造架成孔特点与早期(海底)硬化功能,从而造就了原生基质空隙型储层;特殊的成岩环境则为干热/干燥古气候背景下水-岩相互作用弱、矿物稳定化进程慢和渗流豆粒、文石及高镁方解石的完好保存,尤其是有利于空隙的保存;同生-准同生期溶蚀尤其是3幕桐湾运动所导致的3期风化壳岩溶作用,致使空隙进一步溶扩,且沿断裂、裂缝还形成了大量非组构选择性的溶缝和溶洞,由此从根本上决定了储层的形成;多期裂缝尤其是晚燕山-喜马拉雅期构造缝,沟通孔隙、孔洞和溶洞而极大地提高了储层的连通性。

关键词: 白云岩, 岩溶储层, 溶蚀作用, 灯影组, 震旦系, 四川盆地

Abstract:

Sinian Dengying Formation was developed extensively as an important natural gas reserving and producing formation in Sichuan Basin.New evidences for micro-petrography and fluid inclusion salinity data in terms of dissolution were obtained through comprehensive research of reservoir petrography and sedimentology,reserving space types,diagenesis and evolutionary sequence,especially thin section identification,SEM identification,and the analysis of element,carbon and oxygen isotope as well as fluid inclusion.It is considered that Dengying Formation has the typical characteristics of facies-controlled dolomite karst reservoirs in terms of reservoir genesis.The main control factors for reservoir development include special sedimentary and diagenetic environment as well as multiphase and multi-type dissolution and failure.Special sedimentary environment is prominently represented as large microbe reef flat and mound flat bodies under the control of dry-hot/arid paleo-climate.These sediments possess frame-building and pore-forming characteristics and early(sea floor) hardening function,thus creating primary matrix porosity reservoir.Special diagenetic environment is featured by poor water-rock interaction,slow mineral stabilization process and excellent preservation of vadose pisolite,aragonite and magnesium-rich calcite under the background of dry-hot/arid paleo-climate,especially beneficial for porosity conservation.Moreover,pore expansion and massive non-texture selective dissolution fissures and caverns are resulted from syngenetic and para-syngenetic dissolution,especially three-phase weathering crust dissolution caused by three-episode Tongwan movement,which fundamentally determines the reservoir formation.Multiphase fissures,especially Late Yanshan-Himalayan tectonic fissures,establish the connection between pores,vugs and dissolution caves to largely enhance reservoir connectivity.

Key words: dolomite, karst reservoir, dissolution, Dengying Formation, Sinian, Sichuan Basin

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