川西坳陷新场地区须家河组四段储层特征及评价

Reservoir characteristics and evaluation of the forth member of Xujiahe formation in Xinchang area of west Sichuan depression

上三叠统须家河组四段是川西坳陷新场地区重要的含油气层段,根据岩心分析、岩石薄片、压汞、油气测试和分析化验等资料,对新场地区须四段砂岩储层特征进行了详细的研究,结果表明:该套储层以岩屑砂岩和岩屑石英砂岩为主,成分成熟度较低-中等,结构成熟度中等;储层物性差,属低孔低渗-特低孔特低渗极度致密储层,储层非均质性强;储层孔隙结构差,以微孔喉为主。利用储层物性和孔隙结构参数,将须四上亚段、下亚段砂岩分别评价为4类储层,其中Ⅰ、Ⅱ类储层为相对优质储层,是增储上产的首选储层。

The forth member of upper Triassic Xujiahe formation is an important oil/gas bearing segment in Xinchang area of the western Sichuan depression.The studies of the data of core analysis,petrographic thin section,mercury penetration,oil and gas testing and analysis of the forth member of Xujiahe formation sandstone reservoir indicate that the lithology of this reservoir is mainly lithic sandstone and lithic quartz sandstone,characterized by low-medium mineral maturity,medium structure maturity,lower to medium porosity and permeability,poor pore structure and heterogeneity is intense.According to petrophysical properties of reservoir and pore structure parameters,upper and lower of the forth member of Xujiahe formation sandstone reservoir were classified into four types separately.Type I and type Ⅱ reservoirs are the relatively high-quality reservoirs can be taken as the major target zones.