黄骅坳陷砂岩储层的成岩作用与孔隙分带性

DIAGENESIS AND PORE ZONATION OF SANDSTONE RESERVOIRS IN HUANGHUA DEPRESSION

黄骅坳陷第三系砂岩储层的成岩作用随埋深的增加具有明显的规律性，属正常埋藏成岩系列。不同埋深孔隙类型及发育程度有明显差异，可划分为３个孔隙演化带：浅部带（小于２２００ｍ）以原生孔隙为主；过渡带（２２００～３０００ｍ）次生孔隙占３０％～５０％和深部带（大于３０００ｍ）以次生孔隙为主。２２００～２５００ｍ是早成岩阶段Ａ，Ｂ期的分界，３０００ｍ是早成岩与晚成岩阶段的分界。埋深控制成岩作用，成岩作用决定孔隙演化，沉积环境对储层的影响在一定埋深后居于次要地位。

The diagenesis of Tertiary sandstone reservoirs in Huanghua Depression varied obviously with the increase of buried depth and it should belong to normal buried diagenesis. Thecharacteristics and evolution degrees of the reservoir porosity differ differently with theburied depth of the reservoirs,and based on this,the reservoir porosity could be classified into three zones: 1. shallow zone with the buried depth less than 2 200 m and primary porosityplaying the main part; 2. transitional zone with buried depth between 2 200-3 000 m and secondary porosity occupying 30%-50% ; 3. deep zone with buried depth greater than 3 000 mand secondary porosity occupying the main part. It is suggested that the boundary betweeneogenetic A and B stages should be in 2 200-2 500 m depth;the boundary between early andlate diagenetic stages should be at 3 000 m depth. The study results show that the diagenesisis controlled by buried depth,the pore evolution is controlled by diagenesis. Sedimentary environment has less influence on reservoirs beyond certain depth.