昆北油田切12井区E_3~1砂岩储层成岩作用研究

Diagenesis of E_3~1 Reservoir,Qie 12 Wellblock, Kunbei Oilfield

通过普通薄片、铸体薄片、扫描电镜、X—衍射等分析,认为昆北油田切12井区E31砂岩储层成岩作用类型主要有压实作用、胶结作用、溶蚀作用、交代作用、破裂作用。结合切12井区储层埋深、古地温以及黏土矿物混层比变化特征等资料,确定E31储层的成岩阶段处于早成岩B亚期,并总结出本区成岩演化序列的特点。中等压实作用、较强的石英次生加大、碳酸盐胶结作用是储层物性变差的重要因素;长石颗粒、变质岩岩屑颗粒、方解石胶结物等溶蚀作用和强烈的破裂作用使砂岩储渗性能得到改善。

Based on some thin-section, casting thin-section,SEM and X-ray diffraction analysis on E31 sandstone reservoir of Qie 12 wellblock in Kunbei oilfield,it is considered that the diagenesis includes compaction, cementation, dissolution, metaomatism and fracturing diagenesis. It is also determined from the burial depth, paleotemperature and mix-layer ratio’s variation of clay minerals that for E31 reservoir,its diagenetic stage is in early diagenetic B substage. And some features of diagenetic evolution are summed up, including (1) middle compaction, stronger secondary enlargement for quartz,and carbonate cementation are the important factors to make petrophysical property poorer;and(2)the dissolution from some cements of feldspar, metamorphic cutting grain and calcite and stronger fracturing diagenesis may make petrophysical property of sandstone reservoir better.