【作者】 束青林；

【导师】 夏斌； 姜在兴；

【作者基本信息】 中国科学院研究生院（广州地球化学研究所） ， 构造地质学， 2005， 博士

【摘要】 针对孤岛油田馆陶组河流相油藏地质特征,从储层地质模型研究入手,利用沉积学、储层地质学、油藏工程学理论和测井约束反演、数值模拟、矿场测井和动态检测等技术系统总结了河流相储层结构模式,精细描述了河流相储层结构特征,总结了河流相储层剩余油分布规律与控制模式,结合孤岛油田地质特征提出了不同剩余油分布模式控制下的提高剩余油采收率的各种措施。取得了如下研究进展和创新性认识: 1.系统总结了曲流河、辫状河、网状河的沉积特征、微相特征、河道及各种漫溢相的结构特征,探讨了储层的层次性和不同河型砂体的连通性、渗流差异性,认为曲流河中点坝构成地下水动力系统意义上的“半连通体”,辫状河心滩砂体形成局部通而不畅乃至连而不通的“泛连通体",网状河储集体为“网连通体”。 2.采用小波分频叠后高分辨和去噪处理技术和测井曲线重构技术进行高精度储层反演,精细描述了储层的外部形态和空间分布。提出单成因砂体概念、识别和对比方法,探讨了废弃河道的成因及其在储层描述和油藏注采关系中的意义。以单成因砂体研究为基础,进行了河流相储层建筑结构和流动单元的划分。 3.不同河型储层中夹层成因、形态、规模、产状各具特征。曲流河和网状河砂体中多发育垂向加积和侧积作用形成的2种夹层;辫状河砂体内发育心滩落淤层、河道顶部泥质薄层和砂体内部泥质纹层3种加积成因的夹层。结合孤岛油田地质情况,总结了该区夹层的物性特征、测井响应,总结出该区边滩和心滩砂体内夹层分布模式。 4.建立了河流相储层剩余分布的3种模式:纵向相变控制模式、平面相变控制模式、砂体内部控制模式。统计表明,主力层水淹程度高,但可采储量高于非主力层,仍是剩余油分布的主体;同一油层中,平面相变导致了剩余油的形成,主流相与侧缘相物性差异越大,侧缘相剩余油饱和度越高,富集区越大。在砂体内部,剩余油分布主要受韵律性、大孔道和夹层分布的影响。 5.根据该区正韵律厚油层中夹层的分布特征和实际注采情况,建立了注水井钻遇夹层、采油井钻遇夹层、夹层在油水井之间3种类型12种注采模式,研究了不同注采模式下的剩余油分布规律及层内夹层对剩余油的控制作用。夹层平行层面、注水井钻遇夹层且注水井只在夹层以上射孔时,剩余油最发育:夹层位于油水井之间时,剩余油最不发育。夹层斜交层面时,夹层与注采井的关系以及射孔方式控制了剩余油的差异分布。 6.针对不同的剩余油分布模式,提出了相应的提高采收率的方向和措施。根据中一区Ng5~3正韵律厚油层地质特征和特高含水期顶部剩余油富集规律,提出了实施水平井挖潜的原则,优化了水平井位置、水平段长度、生产压差和提液时机等参数。矿场实施水平井16口,在综合含水已达93.7%,采出程度高达45.3%的背景下,水平井初期产油量达18-33.5t/d,是周围直井的3-4倍,综合含水只有38.8%。更多还原

【Abstract】 Targeting the fluvial reservoir characteristics of Guantao formation in Gudao oil field, and based on the research of reservoir geological model, the fluvial reservoir architecture and modes are systematically generalized by means of study on sedimentology, reservoir geology, reservoir enginerring and logging-constrained seismic conversion, numerical simulatiom, field logging and dynamic monitoring. Therefore the characteristics of fluvial reservoir are revealed and the remaining oil in the fluvial reservoir, with respect to distribution rule and controlling factors, is generalized. Accordingly, based on the work above, the approaches, taking into account of the geological characteristics of Gudao oil field, some different residual oil distribution modes, to enhance the recovery ratio, are proposed, and therefore of certain research significance and innovative suggestions as follows:1. Systematic generalization on the sedimentary characteristics, micro-facies features and over-bank deposits properties, and the discussion on hiberarchy of reservoir and correlated connectivity and permeability difference of different sandbody deposited in specific fluvial type. And, it is thought herein that the point bar in the meandering river acts as the semi-conductive medium, and the channel bar in the brained river as "pan-connective body" which is locally less permeable even connected, and blocked even connected; and the sandstone in the netted river as net-like connective body.2. The technologies, mainly post-stack wavelet separating frequency and noise elimination, and logging curve reconstruction, are adopted in the high resolution conversion of reservoir to elaborate the external shape and distribution, and the concept of single original sandstones, the accordant identification and correlation method are subsequently proposed. Moreover, the genesis of abandoned river channel and the relevant significance in the reservoir description and development are further inferred. In addition, the fluvial reservoir structure and fluid unit are further classified based on the study of uni-geneis sandstone.3. The genesis, shape, scale and occurrence of interlayer are all specific to each river types. Generally, there are 2 kinds of interlayers formed respectively by vertical aggradation and lateral deposition in meandering river and netted river, and 3 interlayers formed by falling silt in channel bar, muddy lamina in the top of channel deposition and muddy lamina in sandstone respectively. Two interlayer distribution modes, i.e. point bar interlayer and channel bar interlayer, are generalized according to the geological property and logging reponse ofinterlayers and fluvial reservoir characteristic in Gudao oil field.4. Three distribution modes, vertical facies change controlling mode, lateral facies change controlling mode and sandstone interior change controlling mode, of remaining oil in fluvial reservoir are presented. It is demonstrated by statistics that, though high in water-cut, the main production layers are still of more recoverable reserve compared that of other layers, hi one layer, the lateral facies changes account for the formation of remaining oil, therefore, the higher discrepancy of reservoir property between main stream facie and lateral facies, the more saturated of remaining oil in lateral facie, and larger in accumulation zone accordingly, hi the inner part of sand-reservoir, the distribution of remaining oil varies as a function of rhythmicity, large pore and interlayer distribution.5. Based on the distribution characteristic of interlayer in thick positive rhythm oil layers and field injection-production situation, twelve injection-production modes of three types, that is, interlayer drilled by water wells, by oil wells, and existed between water well and oil well, are suggested. The remaining oil distribution rule under different injection-production modes and the controlling effect of interlayer on the remaining oil are studied. The results show that the influence of the interlayers on the remaining oil is dependent on the thickness, spread scale and vertical position of the interlayer. When interlayer parallels sandstone layer, the remaining oil is poorest if interlayer lay between water well and oil well, and is richest only if water well drilled interlayer and the upper part on the interlayer was shot in water well. When interlayer is not parallel to sandstone layer, the distribution of remaining oil was controlled by the relationship between interlayer and injection-production well and shoot mode.6. Targeting the different mode of residual oil distribution, the corresponding methods and approaches for enhancing the recovery ratio are proposed. According to the geologic characters of the Ng53 with thick positive-thythm oil layers, and top remaining oil enrichment rule during extra-high water cut period in Zhong 1 area of Gudao, the principle of developing the potential by horizontal well is proposed. The parameters, which include the position of the horizontal well, length of horizontal section, producing pressure differential, timing of liquid lifting and so on, are optimized. Field application achieved good results in 16 horizontal wells. Under the background of composite water cut is up to 93.7% and recovery factor up to 45.3%, initial oil production rate of horizontal well is up to 18-33.5 t/d, 3-4 times more than the vertical wells around; and composite water cut is only 38.8%, 30-50% lower than the vertical wells around.更多还原