【作者】 翟志伟；

【导师】 施尚明；

【作者基本信息】 东北石油大学 ， 油气田地质工程， 2011， 博士

【副题名】以大庆油田北二东层系重组试验区为例

【摘要】 河流相储层是我国陆相油田中最普遍的油气储集层类型,占现有开发油田储层的半数以上,而曲流河亚相在河流相储层中又占据了相当大的比例,因此点坝砂体作为曲流河中最重要的储层,其研究意义对进入高含水后期的大庆长垣北二东重组试验区十分重大。密井网区丰富的测井曲线、砂岩解释、水淹状况等资料为准确识别地下点坝砂体提供了真实可靠的支持数据。为研究特高含水期进一步提高水驱采收率的调整对策提供技术支持和保证。本文利用河流沉积学、油气田开发地质学、油气储层评价技术等方法和理论,对研究区萨葡高油层的8个油层组110个沉积单元进行了校正和调整,达到了单一成因砂体级别的划分和对比,实现了全区各级沉积单元的统一闭合。在此基础上选取35个具代表性的小层对其沉积微相进行划分,重点对曲流河亚相和三角洲分流平原亚相的P12等小层的砂体分布形态、废弃河道的发育情况进行研究,建立了一套利用沉积微相划分、废弃河道识别,结合单井垂向沉积韵律识别点坝侧积体的综合方法,共识别4个小层内点坝砂体10处。对于点坝砂体内部建筑结构,主要对侧积夹层的发育状况、类型以及产状等特征进行了研究和预测。通过分析侧积夹层的成因及影响因素,确定试验区内主要发育泥质侧积层和少量的钙质侧积层,并利用Leeder河流满岸深度和满岸宽度的经验公式,以及河流宽深比与侧积夹层倾角的拟合公式,确定侧积夹层的倾向、倾角、间距、单一侧积体宽度等产状参数,并对试验区典型点坝砂体内部建筑结构进行详细解剖,分析侧积层空间建筑结构形态,明确了侧积夹层在平面的展布特征。试验区点坝砂体内部剩余油分布由于受到沉积微相类型、储层非均质性及其内部侧积夹层和废弃河道分布的影响,形成了不同类型油层动用程度差异较大、薄差层动用程度较差的特点,通过分析重点沉积单元层内渗透率变化特征以及侧积夹层对点坝内部流体渗流特征的影响机制,确定了河道砂顶部、油层物性差、低渗透带遮挡、层间干扰及注采不完善等五种剩余油分布类型,并通过分析检查取芯井和相对较新井的水淹资料,研究主力油层中剩余油分布的垂向特征,指出点坝砂体顶部由于侧积夹层和废弃河道的侧向遮挡作用形成剩余油分布的有利区带,应该作为挖潜的重点目标,是提高最终采收率的有效措施。更多还原

【Abstract】 Fluvial facies reservoir is the most common oil and gas reservoir types in continental oilfield, accounting for half of the current development of reservoir the types of existing development oilfield reservoir, and over half of fluvial facies reservoir is occupied by meandering fluvial facies, so as the most important reservoir, the research significance of point bar into late high water stage in Beierdong re-test area of DaQing Chang Yuan is very significant. Rich logging curves, sandstone interpretation, water flooded condition and so on in dense well network area provides a true and reliable supporting data for accurately identifying point bar underground and provide technical support and assurance for the study of improving the water flooding recovery ratio.8 oil layers and 110 sedimentary unit were corrected and adjusted in the use of River Sedimentology, Oil and Gas Field Development Geology, Oil and Gas Reservoir Evaluation Technology and other methods and theories, reached a single cause sand body division and contrast, realizing the unity of sedimentary unit closed at various levels. sedimentary facies of 35 small layer are divided on this basis, on the emphasis of the sand body distribution patterns of PI2 and the development of abandoned channel in the meandering river subfacies and delta distributary’s plain subfacies conducted a study, building a set of comprehensive method which can identify point bar lateral accretion by using microfacies, abandoned channel identification and combining with single well vertical sedimentary rhythm, identified a total of 10 point bar in 4 small layers.For the interior building structure of point bar sand body, mainly research and forecast the development condition, type and characteristics of the lateral accretion layer, By analyzing the causes and influencing factors of lateral accretion, determined that shale lateral accretion and a small amount of calcium lateral accretion are mainly developed in the experimental area,and use the empirical formula of Leeder river bankfull depth and bankfull width and the fitting formula of the river breadth and depth ratio and lateral accretion dip angle to determine the tendency, dip angle, spacing of lateral accretion, and carried on a detailed anatomy for the typical point bar’s interior building structures in the test area, analyzed the space structure form of lateral accretion, cleared the distribution characteristics of lateral accretion in the plane. The residual oil distribution in point bar formed different types of higher level of oil use, poor use of thin and poor layer due to the sedimentary facies type, reservoir heterogeneity and its internal lateral accretion and distribution of abandoned channels, the top of the river sand, poor reservoir properties, low permeability zone block, layer interference and imperfect injection and five types of remaining oil distribution are determined by analyzing the inner permeability changes of sedimentary unit in characteristics and the influence mechanism of point bar internal fluid by lateral accretion, and through the analysis and inspection of flood data of core wells and relatively new wells, study the vertical distribution characteristics of remaining oil in the major reservoirs, point that the favorable zones of remaining oil’s distribution is formed by the lateral shelter affection of lateral accretion and abandoned channel, this should be the important goal of tapping and an effective measure to improve the ultimate recovery.更多还原