• 责任者：Xi Shengli (Department of Exploration ; Changqing Oilfield Branch ; PetroChina ; Xi’an 710021 ; China) ; Li Rongxi
• 刊名：Chinese Journal of Geology
• 出版年：2013
• 卷期：48(4)
• 关键词：低渗透储集层 ; low permeability reservoirs ; 鄂尔多斯盆地 ; Ordos Basin
• 页码：p.1164-1176
• 图表：8 illus., 33 refs.
• 分类号：1003
• issnNo：ISSN0563-5020
• isbnNo：CN11-1937/P

     Diagenesis of clastic rock reservoir was complex and intense and it had important influence on reservoir property. On the basis of quantitative research to diagenesis and its influence on physical properties of low permeable sandstone reservoir Chang 4＋5 in Jiyuan region, Ordos Basin, the low permeability reservoir formation mechanism was discussed. Researches to diagenesis and pore evolution show that the residual porosity after compaction was still as high as 15% -23% though 12% -20% of porosity loss caused by compaction. Early cementation made porosity loss only 2% -5%. Compaction and early cementation didn＇t make the reservoir compacted and didn＇t affect oil/gas flow. The porosity of sandstone reservior Chang 4＋5 was only 4% - 6% after formation of late cements such as albite, sparry calcite, dolomite and authigenic clay of kaolinite, illite and chlorite. The reservoir sandstone became condensed which influenced oil/gas infiltration after formation of later cements. Late fractures contributed about 6% -8% to reservoir porosity. The reservoir physical property was improved to become effective reservoir. Studies to basin evolution and diagenetic events indicated that the diagenesis of sandstone reservior Chang 4＋5 in Jiyuan region was at the shallow burial stage which period early compaction and cementation before lndosinian movement. Thermal degree of Chang 7 hydrocarbon source rocks was in immature to low-mature stage. The geofluid riched with organic acid formed from Chang 7 hydrocarbon source rocks flowed into the reservoir which was dissolved to form secondary pore. The diagenesis of sandstone reservior Chang 4＋5 in Jiyuan region was at the deep burial diagenetic stage and large amount of late cement formed and it made the reservoir condensed before later Early Cretaceous. Development degree of fractures, formed because of hydrocarbon generation pressurization and tectonic movement after the early late cretaceous, were very important for formation of effective reservoir Chang4 ＋5 in Jiyuan region. It is also significance for guiding exploration for low permeability reservoir.