惠民凹陷沙一段碳酸盐岩的早期成岩作用

通过对惠民凹陷商河地区沙一段碳酸盐岩成岩作用的研究 ,结合沉积特征 ,建立了其成岩作用和油气成藏模式 .认识碳酸盐岩隐蔽油气藏较发育规律 .由于快速进积的碳酸盐浅滩表面水体在大气水的影响下逐渐淡化 ,碳酸盐物质沉积不久即发生强烈溶解 .准同生期和浅埋藏阶段 ,在孔隙中形成薄层栉壳状白云石和少量蛋白石、绿泥石胶结物 .沙一段沉积末期 ,沿断裂运移上来的深部油气在沙一段碳酸盐岩孔隙中储集并形成岩性油气藏 ,未被油气充填的孔隙则被从油层水中沉淀的粗大晶粒状方解石所完全充填 .沙一段碳酸盐岩中的隐蔽油气藏应从沙一末期至东营组沉积初期的构造高点来寻求突破 ,而不是现今的构造高点

Early Diagenesis of the Carbonate Rock of 1st Member of Shahejie Formation in Shanghe Area, Huimin Sag

There are many subtle reservoirs in the carbonate rock of 1 st member of Shahejie formation in Shanghe area, but the regulation of the hydrocarbon reservoirs is not known. In this paper, by studying diagenesis and sedimentary feature of the carbonate rock, the patterns of diagenesis and hydrocarbon reservoir formation are found. Because shoal water was gradually freshed by atmospheric water, and carbonate substance dissolved soon after it deposited. Thin ctenoid dolomite and a little amount of opal or chlorite cement was gradually formed in pores during penecontemporaneous and shallow burial stages. The hydrocarbon that migrated along faults from depths is stored in the pores of carbonate rock and formed reservoirs. The pores not filled by hydrocarbon are stuffed by coarse crystalline calcite that deposited from pore water. Subtle reservoirs in carbonate rock should be found in the structural high that formed from late Shahejie formation to early Dongying formation, and not in the present structural high.