塔中地区奥陶系储层特征及其与油气聚集关系

为了进一步研究塔里木盆地塔中地区不同储层间特征的对比及各储层在平面上的变化特征,通过收集和整理各单井储层岩心孔渗测试、平面沉积相、断裂分布、薄片分析和油气藏特征等资料,详细地描述了塔里木盆地塔中地区奥陶系碳酸盐岩3套油气储层的基本特征.分析表明:裂缝型储层是塔中地区主要的储层类型,各储层的孔隙度和渗透率之间均不存在线性关系,储层渗透率变化区间较大,裂缝发育控制了该区渗透率的变化.在此基础上,对目前比较关注的几个与油气聚集有关的储层问题进行了讨论,结果表明:塔中地区奥陶系碳酸盐岩储层的物性高值区均沿I号坡折带分布;沉积相是控制这些碳酸盐岩储层物性的主要因素;塔中地区奥陶系碳酸盐岩储层的油气分布与储层类型密切相关.

Characteristics of the Ordovician Carbonate Reservoir Beds in Tazhong Areas of Tarim Basin and Hydrocarbon Accumulation

In order to further study the comparison of characteristics among different reservoir beds and their horizontal distribution features, basic characteristics of three sets of the Ordovician carbonate reservoir beds of Tazhong areas in Tarim Basin, Northwest China were described by collecting and processing plenty of existing data, including single-well test data of porosity and permeability, horizontal distribution of sedimentary facies, fracture distribution, thin-section observation, characteristics of oil and gas reservoirs. The results show that the main reservoir beds is of the fracture type. The linear relationship can not be found between porosity and permeability of different reservoir beds. The change of permeability is relatively larger and the changes in permeability is controlled by the development of fracture. Several issues related to reservoir bed and oil-gas accumulation were discussed based on the reservoir bed characteristics. The results indicate that the carbonate reservoir beds with good physical properties all distribute along the No. 1 slope break belt, and the sedimentary facies is a major fac- tor controlling physical properties of the carbonate reservoir bed. In Tazhong areas, the oil-gas distributions within Ordovician carbonate rocks closely related to reservoir bed type.