歧口凹陷西南缘沙一段下部碳酸盐岩储层特征及控制因素

Characteristics and controlling factors of carbonate rock reservoirs in the lower part of Es1of southwest Qikou sag

歧口凹陷西南缘是岩性油气藏发育区,尤其是沙一段下部发育湖相碳酸盐岩储层,是油气勘探开发的有利目的层段.利用岩心、薄片、扫描电镜等资料,分析沙一段下部碳酸盐岩储层的岩性、物性及储集空间特征.结果表明:研究区主要发育生物碎屑灰岩、鲕粒灰岩、泥晶灰岩和泥晶云岩,其中生物碎屑灰岩和鲕粒灰岩的物性最好,泥晶灰岩和泥晶云岩物性较差.优质储层是沉积作用、成岩作用和构造作用三者共同作用的结果,但储层的类型和规模主要受沉积相的控制,为预测有利储集相带提供依据.

Structural lithologic pools developed in the southwest Qikou sag,especially the carbonate reservoirs developed in the lower part of Shahejie 1formation,which is favorable objective layer segment in the process of petroleum exploration and development.A detailed study is conducted of their characteristics of lithology,physical property and diagenesis,as well as reservoir space type,mainly used core,thin section and scanning electron microscope.The result showed:the main carbonate types include bioclastic limestone,oolitic limestone,micrite limestone and micrite dolomite.The porosity and permeability of bioclastic limestone and oolitic limestone are higher than micrite limestone and micrite dolomite.The synthesis effect of sedimentation,diagenesis and tectonic process on reservoir quality is analyzed,showing that high quality reservoirs are the result of interactive effect of sedimentation,diagenesis and tectonic process,thus providing a basis for predicting favorable reservoir facies belt.