江苏龙潭组致密砂岩孔隙结构和因子分析

致密砂岩碎屑类型主要为长石岩屑质石英砂岩,次为长石质岩屑砂岩,且以细粒为主。Φ<5%的样品占63%,K<0.1×10^-3μm²的占78%,R_M=0.007～0.472μm,瞩细-微喉道致密砂岩。部分孔隙结构参数间相关很好,但它们与常规物性参数间均不相关或不甚相关。借助R型和Q型因子分析选择评定孔隙结构质量的参数,并以R_M>0.15μm,C<0.45作为确定(差)储集岩的标准。(差)储集岩以中粒和部分细粒的石英加大粒间孔-长石溶孔砂岩为主,普遍具较高级别的油显示,主要分布于镇江煤矿和宜兴川埠地区,应作为重点勘查对象。

FACTOR ANALYSIS ON THE PORE TESTURE OF THE TIGHT SANDSTONES IN THE LONGTAN FORMATION(JIANGSU)

The clastic type of tight sandstones is dominantly made up by feldspathic lithic quart-zose sandstone with fine grain size rather than feldspathic litharenite,As for fine-micro-throat tight sandstones,samples with value of Φ fewer than 5% occupy 63%of the total,those with value of K fewer than 0.1×10-3μm occupy 78%,and the value of R_M is 0.007to 0.472μm,A part of porous parameters have good correlations among themselves,butthey have no correlation to the parameters of conventional physical property or even far.With the assistance of R-factorQ-factor analysis,we select the parameters to evaluatethe quality of pore structure,and set the standard with the value of R_M more than 0.15μmand the value of C fewer than 0.45 to ascertain(poor)reservoir rocks.The(poor)reser-voir rocks are mainly medium-grained and partly fine-grained quartzose sandstone of in- creased interstice─feldspathic solution opening,and generally have fair-level oil showswhich are common in Zhenjiang Coal Mine and Yixing Chuanbu region,Therefore it is be-lieved these two areas should be good prospecting targets for exploration.