车西地区沙四段碳酸盐岩沉积特征及储集性研究

SEDIMENTARY CHARACTER AND RESERVOIR QUALITY OF THE ES4 CARBONATE RESERVOIR IN CHE-XI AREA

为正确认识车西地区沙四段湖相碳酸盐岩储层,寻找有利储集区,从岩石学特征、储集空间类型及物性特征等方面研究了其特征,并分析了储集物性影响因素,结合勘探实践分析了有利储集部位。指出储集岩主要是颗粒滩亚相的颗粒灰岩,以次生溶孔及裂缝为主要的储集空间类型。储层物性总体表现为中孔中低渗,主要受沉积微相、成岩作用及构造作用的影响,其中构造作用产生的断层对改善储集物性的作用最大。已钻井分析表明,储层的含油特征与储集物性有密切的关系,颗粒灰岩发育且靠近断层的部位储集性能好,是有利的勘探方向。

To understand and find favorable Es4 lacustrine carbonate reservoir in Che-xi area, the characteristics of it in such aspects as petrology, reservoir space and physical properties are studied in the paper, and then the controlling factors of physical properties are analyzed, at last, the favorable reservoirs are pointed out. The reservoir rocks mainly consist of grained limestone developed in grained beach in the shallow lake; the reservoir pore space is mainly made up of secondary dissolved pores and cracks. The porosity of the reservoir is moderate, and the permeability is low, which is mainly dominated by sedimentary subfacies, diagenesis and tectonism. Among them, faults are most effective on phyisical property of reservoir. According to the analysis of drilled wells, hydrocarbon potential of the reservoir is closely related with physical properties. The physical properties of grained limestone near to fault is the best, which is the favorable direction for prospecting.