【作者】 郭顺；

【导师】 王震亮；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2011， 博士

【副题名】以川口油田川46井区延长组长4+5油藏为例

【摘要】 特低渗油藏的勘探、开发在我国油气生产中占有重要地位。但因其自身地质条件的特殊性,其渗流规律、开发方式、剩余油分布特征都有别于常规油藏,开展特低渗油藏精细描述与剩余油分布研究具有重要的理论与实际意义。位于鄂尔多斯盆地东南部的川口油田是典型的特低渗油田,地层平缓、构造简单、储层非均质性较强。该油田目前已进入开发的中后期,因开采前期一直利用自然能量采油,未对地层能量进行及时补充,导致存在地层亏空严重、单井产量低、产量递减快、含水上升快及剩余油分布规律不够明确等问题。本文以川口油田南部的川46井区长4+5油层组为解剖对象,通过开展油藏精细描述,研究剩余油分布规模。在沉积和储层研究基础上,划分流动单元类型,预测其平面分布,采用国际上的先进建模软件建立了储层孔隙度、渗透率和含油饱和度三维地质模型,通过油藏数值模拟方法预测剩余油分布,通过分析剩余油的宏观、微观控制因素,预测现今剩余油的分布规律,从而为特低渗油藏的高效开发奠定了较为坚实的地质理论基础。研究表明,储层微构造对特低渗透油藏的油水分异及剩余油的分布具有一定的控制作用,受沉积相分布和成岩作用影响,非均质性较强。划分出4类流动单元类型,其中,B类为该区的主要流动单元类型,主要沿河道方向展布,A、C类在区内分布相对较少,D类则主要是分布在分流间湾中,为渗流屏障。通过对解剖区的分析表明,以不同储层结构特征变差函数分析技术、根据测井资料解释泥质含量参数、应用协同克里格方法进行三维储层岩相建模技术、相控储层建模技术和储层地质特征的定量化及可视化技术,适用于低渗油藏描述及模拟,以此建立出了46井区长4+52-2小层的岩相、孔隙度渗透率及含油饱和度模型。经实际资料检验,所建立三维地质模型精度较高,能达到精细描述储层地质特征的要求。综合分析解剖区的储量分层动用和剩余油分布特征,因受井控及注采对应关系、储层非均质性及流动单元、砂体微构造及油层厚度、储层裂缝走向等因素的影响,长4+52-2储量动用程度平面上不同区域存在较大差异,尚有大量剩余油存在,预测出5个剩余油分布有利区。剩余油分布宏观上受沉积相、储层非均质性、流动单元和井网分布等因素控制,微观上还与孔隙结构的非均质性、水驱油过程中油水两相流动特征及流场的分布有关。更多还原

【Abstract】 The exploration and development of super-low permeability reservoirs occupies an important position in petroleum industry of China. As the special geological conditions, the characteristics of the vadose law, the development pattern and the remaining oil distribution are different from the conventional reservoir. Therefore, it has an important theoretical and practical significance on the fine description of super-low permeability reservoirs and the study of remaining oil distribution.Chuankou oilfield is located in the southeast of Ordos basin, characterised with a gentle and simple structure and a strong reservoir heterogeneity, is a typical super-low permeability oilfield. This oilfield is in middle and late periods, leds to the loss of formation energy, reducing of single-well production, depleting seriously of oil production, raising rapidly of water yield and the complexity of remaining oil distribution, because oil production was used to rely on natural energy in the early period, and formation energy didn’t complemented simultaneously.The distribution scale of remaining oil is researched by fine reservoir description in Chang4+5reservoirs of Chuan46block in southern Chuankou oilfield. Based on the deposition and reservoir analysis, the reservoir flow unit has been divided and its horizontal distribution has been forecasted. The three dimensional geological model of reservoir porosity, permeability and oil saturation was established by using the advanced international modeling software. The remaining oil distribution was forecasted by reservoir numerical simulation method. The current remaining oil distribution was predicted by way of analyzing the macroscopic and microscopic controlling factors of the remaining oil. Thus, these methods establish a solid theoretical foundation for highly effective development of super-low permeability reservoirs.It is showed that reservoir micro-structure plays a particular role in the controlling of oil-water differentiation and remaining oil distribution. There was strong heterogeneity in reservoirs as a result of sedimentary facies distribution and diagenesis. The flow units were divided into four types, in which type B flow unit was the main type in this area and distributed the region of the river channel, type A and C flow units were relatively less, type D flow unit was mainly distributed region of interdistributory bay and formed flow barrier.It is indicated from analysis on Chuan46block that the variation function analysis techniques of different reservoir structure feature, argillaceous content parameters by the log interpreting, the three dimensional reservoir lithofacies models by application of kriging technique, the quantitative and visualization technology of reservoir characteristics, are also suitable for low permeability reservoir description and simulation. Then the lithofacies, porosity and permeability and oil saturation model of Chang4+52-2of Chuan46block were established. The test result shows that requirement of correct statement reservoir characteristics can be achieved by this three dimensional geological models.The degree of reserves development in small layers and remaining oil distribution were researched synthetically in study area, the development degree in the plane of Chang4+52-2reserves is obviously different among different areas, because of influence of relations between well control and injection-production, reservoir heterogeneity and flow unit, sand body fine construction and reservoir thickness, reservoir fracture trend. There are still a lot of remaining oil, five favorable areas of remaining oil distribution are predicted. The distribution of remaining oil distribution is not only controlled by macroscopic factors, including sedimentary facies, reservoir heterogeneity, flow unit and well spacing distribution, but also controlled microscopicly by the heterogeneity of pore structure, flow characteristics of two phase flow and distribution of fluid field in process of water displacing oil.更多还原