济阳坳陷郭7井沙河街组三段泥岩生、储油特性及其意义

CHARACTERISTICS AND THEIR SIGNIFICANCE OF MUDSTONE SOURCE AND RESERVOIR ROCKS IN THE 3rd MEMBER OF SHAHEJIE FORMATION IN GUO 7 WELL,JIYANG DEPRESSION

通过有机岩石学及有机地球化学等实验测试结果的分析 ,济阳坳陷郭 7井沙河街组三段泥岩裂缝段是在局部海侵湖滨环境中沉积形成的 ;泥岩由硬组部和软组部两部分构成 ,具有国外所报道的特殊储层的岩石组成与结构特性。沙河街组三段泥岩中有机质主要表现为两种赋存类型 :其一为赋存在软组部中的分散有机质 (矿物沥青基质 ) ;其二是赋存在硬组部、矿物微孔隙或颗粒微间隙的沥青质体及层间裂隙的游离烃。二者同源 ,且残留在硬组部、裂隙和孔隙中的游离烃赋存量明显高于软组部的沥青含量 ,是以自生、自储为主的非常规储层 ,应引起重视。

The analyses of data from organic petrologic and organic geochemical experiments and testings indicate that the fissured mudstone in the 3rd member of Shahejie Formation encountered in Guo 7well drilled in Jiyang depression was deposited on the lakeshore environment during local transgression.The mudstone is composed of both the harder and the softer components.It has the lithologic composition and textural characteristics of rare reservoirs reported in Santa Maria basin in the U.S.There are two occurrence types of organic matters in the mudstone: one is the dispersed organic matters (mineral-bitumen matrix) that occur in the softer components of mudstone; another are those occur in the harder components of mudstone,including bitumenites in the micropores and microclearances of minerals and free hydrocarbons in the interfissures. Both of them might have come from the same source rock,but the amount of free hydrocarbons that mater occur in the harder components,fissures and pores would apparently be higher than the bitumen in the softer components of mudstone.