东濮凹陷北部沙三段硬石膏发育特征及对储层的影响

发布时间：2018-07-09 13:49

本文选题：东濮凹陷 + 沙三段　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：本文通过岩心观察与描述、铸体薄片鉴定、扫描电镜观察、实测物性分析及地层水资料的统计等,对东濮凹陷北部地区沙三段储层硬石膏的发育特征、形成机理、分布及其与储层物性的关系进行了研究。研究表明,东濮凹陷北部地区沙三段储层硬石膏以斑块状胶结为主,发育深度主要为2700-4400m,处于中成岩A-中成岩B期。硬石膏的沉淀的地层流体环境主要为CaSO4的过饱和。硬石膏发育的储层,地层水硫酸钙饱和系数(SCCS)均大于140。其物质来源主要包括:古沉积水、膏盐岩溶解、阳离子交替吸附作用、长石与碳酸盐胶结物的溶蚀及斜长石钠长石化等。硬石膏较为发育的储层,其分布主要与膏盐岩层的分布有关。纵向上,硬石膏较为发育的储层,大多分布在膏盐岩层的上部、下部或位于膏盐岩之间;平面上,硬石膏胶结较为发育的储层,主要分布在膏盐岩层的边缘,与膏盐岩呈指状交互的区域。膏盐岩层的溶解及油气充注、超压裂缝的疏导控制了储层硬石膏的发育。硫酸盐热还原反应(TSR)及局部硬石膏胶结物的溶解,有利于提高储层物性。但是,研究区沙三段地层温度为TSR的最低反应温度,且低SCCS值的区域较为局限,其改善作用比较微弱。相反,当斑块状胶结的硬石膏含量超过5%时,与储层孔隙度、渗透率呈明显的负相关。
[Abstract]:Based on the observation and description of core, the identification of thin section of casting body, the observation of scanning electron microscope, the analysis of physical properties and the statistics of formation water data, the development characteristics and formation mechanism of anhydrite in the reservoir of the third member of Shahejie formation in the northern part of Dongpu sag are studied in this paper. Distribution and its relationship with reservoir physical properties are studied. The results show that the reservoir anhydrite in the northern part of Dongpu depression is mainly plaques cemented, and the development depth is 2700-4400m, which is in the middle diagenetic A- middle diagenetic stage B. The formation fluid environment of anhydrite precipitation is mainly the supersaturation of CaSO4. The formation water calcium sulfate saturation coefficient (SCCS) in anhydrite reservoirs is more than 140. Its material sources mainly include: paleo-sedimentary water, gypsum salt dissolution, cation alternate adsorption, dissolution of feldspar and carbonate cement and plagioclase albite, etc. The distribution of anhydrite reservoir is mainly related to the distribution of gypsum rock. Longitudinally, the more developed anhydrite reservoirs are mostly distributed in the upper part of the gypsum rock layer, the lower part or between the gypsum rock, and in the plane, the relatively developed anhydrite cementation reservoir mainly distributes at the edge of the gypsum rock stratum. An area that interacts with gypsum rock in the form of a finger. The development of anhydrite is controlled by the dissolution of gypsum rock, the filling of oil and gas, and the grooming of overpressure fracture. Sulfate thermal reduction reaction (TSR) and dissolution of local anhydrite cement are beneficial to improve reservoir physical properties. However, the formation temperature of the third member of the study area is the lowest reaction temperature of TSR, and the area with low SCCS value is relatively limited, and the improvement effect is weak. On the contrary, when the anhydrite content of plaque cemented is more than 5, it is negatively correlated with reservoir porosity and permeability.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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