石油学报 ›› 2015, Vol. 36 ›› Issue (9): 1090-1097.DOI: 10.7623/syxb201509006

• 地质勘探 • 上一篇    下一篇

致密砂岩储层石英溶蚀成因及对孔隙发育的影响——以川中-川南过渡带须家河组为例

刘金库1, 彭军2, 石岩1, 鲍作帆1, 孙永亮1, 刘学敏1, 张泽1   

  1. 1. 中国石油集团渤海钻探工程有限公司工程技术研究院, 天津 300345;
    2. 西南石油大学地球科学与技术学院, 四川成都 610500
  • 收稿日期:2015-04-16 修回日期:2015-07-29 出版日期:2015-09-25 发布日期:2015-09-30
  • 通讯作者: 彭军,男,1968年9月生,1989年获湖南科技大学学士学位,2000年获成都理工大学博士学位,现为西南石油大学地球科学与技术学院教授、博士生导师,主要从事储层沉积学与层序地层学的教学、科研和科技管理工作。Email:pengjun@swpu.edu.cn
  • 作者简介:刘金库,男,1978年8月生,2002年获西南石油学院学士学位,2010年获西南石油大学博士学位,现为中国石油集团渤海钻探工程有限公司工程技术研究院高级工程师,主要从事沉积储层、开发地质研究及井位部署工作。Email:565816635@qq.com
  • 基金资助:

    中国石油天然气集团公司科技创新基金项目(2010D-5006-0103)资助。

The genesis of quartz dissolution in tight sand reservoirs and its impact on pore development:a case study of Xujiahe Formation in the transitional zone of Central-Southern Sichuan Basin

Liu Jinku1, Peng Jun2, Shi Yan1, Bao Zuofan1, Sun Yongliang1, Liu Xuemin1, Zhang Ze1   

  1. 1. Engineering Technology Research Institute, CNPC Bohai Drilling Engineering Company Limited, Tianjin 300345, China;
    2. School of Geoscience, Southwest Petroleum University, Sichuan Chengdu 610500, China
  • Received:2015-04-16 Revised:2015-07-29 Online:2015-09-25 Published:2015-09-30

摘要:

通过岩石(铸体)薄片鉴定、扫描电镜及X射线衍射分析等手段,对川中-川南过渡带须家河组致密砂岩储层石英溶蚀特征、成因机理及对储层孔隙发育的影响进行了详细研究,结果表明:储层中存在大量石英溶蚀现象,石英沿颗粒边缘、颗粒内部、次生加大边等部位进行溶蚀,石英溶蚀主要发生在中成岩A2亚期;石英溶蚀的成因机制有两种,第一种是碱性成岩环境下的直接溶蚀,溶蚀程度相对较弱;第二种是黏土矿物和碳酸盐矿物的交代溶蚀,其中黏土矿物对石英颗粒交代溶蚀作用较强;石英颗粒溶蚀后形成大量的次生孔隙,有效增加储集空间,改善孔隙结构,提高储层孔渗性能,尤其是黏土矿物交代溶蚀石英后形成的次生孔隙对储层孔隙的贡献较为可观。

关键词: 石英溶蚀, 成因机制, 交代溶蚀, 次生孔隙, 致密砂岩, 须家河组, 四川盆地

Abstract:

By means of rock (casting) thin-section identification, scanning electron microscope and X-ray diffraction, a detailed study was carried out on the characteristics and genetic mechanism of quartz dissolution in tight sand reservoirs of Xujiahe Formation in transitional zone of the Central and Southern Sichuan Basin as well as its impacts on pore development. Research results have indicated that massive quartz dissolution existed along grain edges and secondary enlarged edges, as well as in the interior of grains. Quartz dissolution mainly took place in subage A2 of the middle diagenetic stage. There are two genetic mechanisms of quartz dissolution. One is the direct dissolution in alkali diagenetic environment with weak dissolution degree. The other is the metasomatic dissolution by clay minerals and carbonate minerals, of which the metasomatic dissolution of clay minerals against quartz grains is more intense. After the dissolution of quartz grains, a large number of secondary pores are formed to effectively increase reservoir spaces and improve pore structure as well as reservoir porosity and permeability. In particular, the secondary pores that were generated by metasomatic dissolution of clay minerals against quartz made considerable contributions to reservoir pores.

Key words: quartz dissolution, genetic mechanism, metasomatic dissolution, secondary pores, tight sand reservoir, Xujiahe Formation, Sichuan Basin

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