西南石油大学学报(自然科学版)

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Influences of Clay Minerals on Physical Properties of Low
Permeability and Tight Sandstones

Jiang Yuqiang1, Zhang Chun2, Deng Haibo3, Wang Meng1, Luo Mingsheng4   

  1. 1. College of Resources and Environment,Southwest Petroleum University,Chengdu,Sichuan 610500,China
    2. Exploration and Development Research Institute,Southwest Oil & Gas Field Company,PetroChina,Chengdu,Sichuan 610041,China
    3. Southwest Oil & Gas Field Company,PetroChina,Chengdu,Sichuan 610054,China
    4. South Sichuan Gas Field,Southwest Oil & Gas Field Company,PetroChina,Luzhou,Sichuan 646000,China
  • Online:2013-12-01 Published:2013-12-01

Abstract:

The clay mineral is the most important interstitial material of clastic reservoir,and is widely distributed in the Xujiahe
Formation,which plays a major impact on sandstone reservoir. Taking the typical blocks of Yingshan structure as the research
object,with the casting thin sections,scanning electron microscopy,X–ray diffraction and electron probe experiments,we carried
out an in-depth research on the type,the occurrence and nature of its formation mechanism of clay minerals in sandstones,
and made systematic analysis of clay minerals on reservoir development. The research show:(1)The clay minerals include
mainly illite and then chlorite,with rare mixed-layer illite/smectite and kaolinite flakes pages.(2)Authigenic chlorite is mainly
formed by the precipitation of newborn,with four major possible sources of iron.(3)Authigenic chlorite major growth period
may be in the early diagenetic stage before in diagenesis,and generally continue to grow in the late stage.(4)Authigenic chlorite
and illite formation has a dual role in reservoir development,the protective effect of chlorite and illite on primary intergranular
porosity must be formed in the early diagenesis,with certain thickness and quantity. Illite and mixed-layer illite/smectite filling
the intergranular play a blocking effect on reservoir.

Key words: tight sandstones, chlorite, illite, formation mechanism, reservoir property