渤海C地区沙河街组一段湖泊滩相碳酸盐岩及云质碎屑岩勘探均有发现,依据钻井、岩心、薄片观察、元素分析等资料,对储层的类型、特征及控制因素进行了研究.结果表明:沙河街组一段滩相储层主要为生屑滩生屑云岩、砾屑滩云质砾岩,整体属中孔、低渗储层,物性明显受控于不同滩相沉积类型;碳酸盐岩基底及湖平面变化控制了不同滩相储层的发育,白云石化、有机酸溶解作用为原生孔隙的保存及次生孔隙的发育提供了有利条件,构造活动产生的裂缝进一步改善了各类型储层的储集性能;准同生成因及浅埋藏成因的白云石化是优质生屑云岩储层形成的关键,云质砾岩虽裂缝相对发育,但在富含碳酸根的地层水重力下渗过程中白云石和方解石沉淀,多数裂缝被充填,胶结程度相对较高;生屑云岩储层质量优于云质砾岩,可作为下步该区块勘探与开发的有利目标.%Lake shoal facies carbonate rocks and dolomitic elastic rocks were discovered in the exploration of Member-1 of Shahejie Formation in Bohai Area C,with the help of the drilling,cores,thin section observation,element analyses and so on,the reservoir type,feature and controlling factors were studied.The results show that this member of the reservoir was mainly composed of the bioclastic-shoal bioclastic dolostone and gravel-beach dolomitic conglomerate,in a whole,the reservoirs belong to the middle-porosity and low-permeability ones,the physical properties are obviously controlled by different shoal facieses of sedimentary types;the carbonate basement and lake level change controls the development of different shoals of the reservoir,the dolomitization and organic acid dissolution have provided the favorable conditions for the preservation of the primary pores and the development of the secondary pores,the fractures caused by the tectonic activities can further improve the various types of the reservoir accumulating properties;the penecontemporaneous dolomitization and shallow burial one are the keys to the accumulation of the high-quality bioclastic-dolostone reservoirs,although the fractures of the dolomitic conglomerate are relatively well-developed,the dolomite and calcite are precipitated in the infiltration process of the formation water with rich HCO32-,many factures are infilled and the cementation degree is relatively higher;the quality of the bioclastic dolostone reservoir is higher than that of the dolomitic conglomerate,so it can be regarded as the favorable target of the further exploration and development in the area.
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