苏里格中区T34-S470区块马五段储层特征研究

发布时间：2019-06-07 19:25

【摘要】：T34-S470井区位于鄂尔多斯盆地陕北斜坡西北部,面积约500km2。下奥陶统马家沟组马五段为该区重要产气层。马五段储层地质特征的详细研究对该地区进一步勘探与开发具有重要意义。该区域马五段属陆表海台地环境,潮坪相十分发育。研究区马五12与马五13、马五14孔隙度、渗透率、含气性均较好,且平均值相当;马五11、马五22孔隙度、渗透率、含气饱和度较差,属于典型的低孔低渗型碳酸盐岩储层。马五段储层的主要成岩作用类型有白云石化作用、压实作用、压溶作用、溶蚀作用、去膏化作用、去白云石化作用等。成岩作用特征可概括为:白云石化为储层发育奠定了良好的基础。溶蚀作用有利于储层的发育。储集空间包括孔、洞、缝三大类和十几个类型,其中未充填或充填程度的溶蚀孔(洞)、缝和晶间孔是研究区最主要的储集空间类型。研究区马五1-马五4亚段的半充填-全充填裂缝超过80%,半充填-全充填的水平缝、垂直缝和斜交缝也超过75%。充填物以方解石为主,方解石的半充填-全充填影响了裂缝在改善本区储层渗透性及促进天然气运移方面的作用。综合孔隙度、渗透率、测井含气饱和度、压汞曲线类型、有效厚度和无阻流量等指标,进行了储层分类评价,将储层进行了分类:I类储层、II类储层、III类储层和IV类储层,I类储层分布于马五13小层,共有5块分布区域,面积较小。II类储层在马五13、马五22、马五12小层均有不同程度的分布。其中五13小层II类储层的面积最大,马五22小层次之,马五12小层仅有3处零星分布。因此应将下一步勘探工作的重点放在马五13小层和马五22小层的II类储层发育区。
[Abstract]:The T34-S470 well area is located in the northwest of northern Shaanxi slope of Ordos Basin, with an area of about 500km2. Ma5 member of Majiagou formation of Lower Ordovician is an important gas producing layer in this area. The detailed study of reservoir geological characteristics of Ma 5 member is of great significance for further exploration and development in this area. The Ma-5 member of this area belongs to the platform environment on the surface of the continent, and the tidal flat phase is very developed. The porosity, permeability and gas content of Ma 5 12 and Ma 5 13 and Ma 5 14 in the study area are good, and the average value is the same, and the porosity, permeability and gas saturation of Ma 5 11 and Ma 5 22 are poor, so they belong to the typical low porosity and low permeability carbonate reservoirs. The main diagenetic types of Ma5 member reservoir are dolomitization, compaction, pressure dissolution, degypsum, dedolomization and so on. The diagenetic characteristics can be summarized as follows: dolomitization has laid a good foundation for reservoir development. Dissolution is beneficial to the development of reservoir. Reservoir space includes hole, fracture and more than ten types, among which dissolution hole (cave), fracture and intergranular hole are the most important types of reservoir space in the study area, among which the dissolution hole (cave) without filling or filling degree is the most important type of reservoir space in the study area. In the study area, the semi-filling-full filling cracks in the Ma-51-Ma-5 4 subsection are more than 80%, and the semi-filling-fully filled horizontal joints, vertical joints and oblique joints are also more than 75%. Calcite is the main filling material. The semi-filling-full filling of calcite affects the role of fractures in improving reservoir permeability and promoting natural gas migration in this area. Based on the indexes of porosity, permeability, logging gas saturation, mercury injection curve type, effective thickness and unobstructed flow rate, the reservoirs are classified and evaluated, and the reservoirs are classified as type I reservoirs, II reservoirs, III reservoirs and IV reservoirs. Class I reservoirs are distributed in Ma 513 small layer, with a total of 5 distribution areas, with a small area. Type II reservoirs are distributed in Ma Wu 13, Ma 5 22 and Ma 5 12 small beds to varying degrees. Among them, the area of small layer II reservoir is the largest, the area of Ma 522 small layer is the largest, and there are only three sporadic distribution of Ma Wu 12 small layer. Therefore, the next exploration work should focus on the II reservoir development area of Ma 513 small layer and Ma Wu 22 small layer.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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