歧口凹陷沙一段下部碳酸盐岩储层的成岩后生作用研究

大港油田歧口凹陷沙一段下部碳酸盐岩经历了白云岩化、去白云岩化、胶结、溶蚀、压实、压溶、重结晶及裂缝形成等成岩后生作用。其中溶蚀作用、去白云岩化作用、重结晶作用、裂缝的形成等,对储层有利,尤其是溶蚀作用极大地改善了储层的储集性能;而白云岩化作用、后期胶结作用、压实、压溶作用等,对储层有不利的影响。王徐庄油区为好的储层,歧北凹陷西端为好一中等储层,周清庄油区为中等储层,扣村地区为中一差储层。

EPIDIAGENESIS OF CARBONATE ROCKS IN THE FIRST SUBGROUP OF SHAHEJAI FORMATION IN GIKOU DEPRESSON

The epidiagenesis undergone in conbonate rocks of lower SHA-1 in Gikou depression of Dagang oil field includes dolomitization, dedolomitization, cementation, dissolution, compaction, pressolution, recrystallization and fracturing etc. Furthermore, the dissolution, dedolomitization,recrystallization and fracturing is faborable for the reservoir; espically, the dissolution improved greatly the reservoir properties, while dolomititation, later-cementation, compaction, and pressoluticn are unfavorable to the reservoir, It is shown that the good, good-moderate, moderate and moderate-poor reservoirs are developed respectively in Wangxizhuang, western Gikou depression, Zhougingzhuang and Kouchen areas.