大庆油田北二西区剩余油成因分析

发布时间：2018-06-06 19:03

本文选题：沉积微相 + 储层结构　；参考：《长江大学》2015年硕士论文

【摘要】：油田进入后期高含水阶段,油水关系变的尤为复杂,剩余油零星分布。虽然剩余油的分布特征及其类型多种多样,但整体为局部相对富集。剩余油的形成是储层的非均质性引起的,因此,提高油田采收率,要从储层角度出发,解剖储层内部结构,刻画出导致剩余油形成的典型结构样式,进而指导其他地区的勘探应用。研究工区位于萨尔图油田西南地区,为三角洲平原和三角洲前缘沉积,纵向上共有萨尔图、葡萄花两套碎屑岩油层。工区自1964年主力油层投入开发以来,陆续经历了三次大的调整,共有6套井网,井网控制程度高,井网密度在100m左右。萨尔图油田已经进入开发中后期,“三高两低”的矛盾日益凸显,即综合含水率高、采油速度高、采出程度高、采收率低和储采比低。平面水淹面积大,剩余油分布复杂,开采的矛盾由层间转到了层内矛盾以及储层砂体内部结构之间的矛盾,开采程度高而采收率低的局面也对剩余油研究提出了更高的要求。控制剩余油形成最关键的因素在于储层,特别是连片分布的大型砂岩,非均质程度高,内部结构复杂。因此,从储层角度出发,刻画储层内部结构,进行井间剩余油研究；其次,通过注采对应关系分析平面剩余油分布；最后,综合储层内部结构以及平面剩余油分析,分析剩余油成因。具体采用以下思路进行本次研究：运用基础地质资料和测井资料,进行沉积微相的划分,为后期检查井以及剩余油成因分析奠定基础；再从统计学的角度出发,分析工区内4口相邻检查井不同砂体类型的综合水洗程度以及剩余油潜力砂体类型；最后根据注采受效关系刻画注入水运动趋势,揭示平面水淹关系,并从地质角度出发,运用储层内部结构解剖的方法,对剩余油成因加以研究分析,总结导致原油被屏蔽形成剩余油的结构样式。论文具体开展了以下工作：1.根据研究区提供的地质资料和测井资料,结合前人的研究成果以及沉积背景,对萨尔图、葡萄花油层进行了沉积微相分析,确定了7种主要沉积微相类型：分流河道微相、主体薄层砂微相、非主体薄层砂微相、分流间微相、水下分流河道微相、主体席状砂微相、非主体席状砂微相；弄清楚了砂体平面分布特征以及储层结构差异,为剩余油分布与形成分析提供了基础。2.对工区内相邻的4口检查井样品进行了统计,首先对4口井的样品进行砂体类型归类,共分为河道底部、河道中部、河道顶部、薄层表内、表内底部、表内中部、表内顶部、孤立表外、底部表外和顶部表外10种砂体类型；再根据检查井提供的精确的水洗结果,按不同砂体类型不同水洗特征和相同水洗特征不同砂体类型的分析方式,对每种砂体类型水洗特征比重做了详细的分析,并进行了剩余油潜力分析,包括砂体的类型以及存在的部位。3.通过工区内详细水淹解释数据以及井网开发史,根据油水井的相对位置以及射孔层段,采用“老井高淹,新井低淹”的思路对注采系统的受效区域以及注入水流线运动趋势进行刻画,绘制平面水淹分布图。4.以相邻的4口检查井精确的水洗资料为指导,对其进行砂体内部结构解剖,从地质角度出发,分析剩余油成因,最终总结了6种容易产生剩余油的典型结构屏蔽样式：①优势砂体末端屏蔽；②砂体异位屏蔽；③河道切叠处屏蔽；④曲流河点坝侧积体内夹层屏蔽；⑤砂体过渡带屏蔽；⑥优势通道附近屏蔽。总结了4种剩余油赋存样式：①结构屏蔽形成剩余油；②砂岩中泥纹控制的剩余油；③开发不完善形成剩余油；④非主力薄层溢岸砂内剩余油。综合之,论文结合工区资料和大量基础地质工作对萨尔图油田北二西区地质特征有了崭新认识。通过对检查井砂体类型以及水洗特征的统计分析,明确了该地区剩余油富集的砂体类型以及分布特征；再根据检查井解释结果,对水淹程度低的部位进行砂体内部结构解剖从而总结屏蔽产生剩余油的结构样式,并对剩余油赋存样式加以讨论,为油田下一步生产与调整提供了参考。
[Abstract]:In the late stage of high water cut, the relationship between oil and water becomes particularly complex and the remaining oil is scattered. Although the distribution characteristics and types of remaining oil are varied, the whole is partial relative enrichment. The formation of the remaining oil is caused by the heterogeneity of the reservoir. Therefore, to improve the recovery of oil fields, the reservoir should be dissected from the reservoir angle. It depicts the typical structural styles that lead to the formation of remaining oil, and then guides the exploration and application of other areas. The research area is located in the southwest of Saertu oilfield, which is a delta plain and delta front margin, with a total of two sets of clastic rocks in Saertu and grape flowers. After three great adjustments, there are 6 sets of well networks with high well net control and well network density of about 100m. The Saertu oilfield has already entered the middle and late stages of development. The contradiction of "three high and two low" has become increasingly prominent, that is, high comprehensive water content, high oil recovery speed, high recovery degree, low recovery yield and low production ratio. The surface water flooded area is large and the remaining oil distribution is complex. The contradiction between mining and mining is transferred from interlayer to inner contradiction and the contradiction between the inner structure of the reservoir sand body. The situation of high mining degree and low recovery yield also puts forward higher requirements for the study of remaining oil. The most critical factor in controlling the formation of residual oil lies in the reservoir, especially the large sandstone with continuous distribution, with high heterogeneity and internal knot. Therefore, from the reservoir angle, the internal structure of the reservoir is depicted and the residual oil in the well is studied. Secondly, the residual oil distribution in the plane is analyzed by the corresponding relationship between injection and production. Finally, the internal structure of the reservoir and the analysis of the remaining oil are analyzed to analyze the cause of the remaining oil. The data and logging data are divided in the sedimentary microfacies to lay the foundation for the later inspection well and the analysis of residual oil origin; then, from the statistical point of view, the comprehensive water washing degree and the potential sand body type of the remaining oil in 4 adjacent inspection wells in the industrial area are analyzed. Finally, the injection water transport is depicted according to the effect relationship of injection production. Dynamic trend, reveal the plane water flooding relationship, and from the geological point of view, use the method of the internal structure of the reservoir to study and analyze the cause of the remaining oil, summarize the structural style of the residual oil caused by the shielding of the crude oil. The following work is carried out in this paper: 1. according to the geological and logging data provided in the study area, it combines with the predecessors. On the basis of the research and sedimentary background, the sedimentary microfacies of Saertu, the grapevine oil layer were analyzed, and 7 types of main sedimentary microfacies were identified: the distributary channel microfacies, the main thin layer sand microfacies, the non main thin layer sand microfacies, the distributary microfacies, the underwater distributary channel microphase, the main sheet sand microphase and the non main sheet sand microfacies. The plane distribution characteristics of sand body and the difference of reservoir structure provide a basis for the analysis of the distribution and formation of residual oil and the analysis of 4 adjacent inspection wells in the industrial area. First, the samples of 4 wells are classified as the bottom of the river, the middle of the river, the top of the river channel, the thin sheet, the bottom of the surface, the middle part of the table, and the inside of the table. The top, outside the table, the bottom surface and the top surface are 10 kinds of sand body types. According to the accurate water washing results provided by the inspection wells, the water washing characteristics of each sand body type are analyzed in detail according to the different washing characteristics of different sand body types and the different sand body types of the same water washing characteristics, and the potential of the remaining oil is carried out. The analysis, including the type of sand body and the existing location.3. through the detailed water flooding interpretation data and the history of well network development, according to the relative position of the oil and water wells and the perforation layer, uses the idea of "old well flooding, new well low flooding" to depict the affected area of the injection production system and the movement trend of injection flow line, and draw flat water. The submergence map.4., guided by the accurate water washing data of 4 adjacent wells, carries out the internal structural anatomy of the sand body, analyzes the causes of the remaining oil from the geological point of view, and finally summarizes 6 typical structural shielding styles that are easy to produce residual oil: (1) the end screen of the dominant sand body; (2) the sand body ectopic shielding; 3. Masking; (4) the interlayer shielding in the side of the Quanda river point dam; (5) the shielding of the sand body transition zone; (6) shielding near the dominant channel. 4 remaining oil occurrence styles are summarized: (1) the residual oil is formed by the shielding of the structure; the remaining oil is controlled by the mud grain in the sandstone; (3) the remaining oil is formed by the imperfect development; (4) the residual oil in the non main thin layer of the overflow sand. According to the work area data and a large number of basic geological work, the paper has a new understanding of the geological characteristics of the north two west area of Saertu oilfield. Through the statistical analysis of the types of sand body and the characteristics of water washing, the types and distribution characteristics of the enriched sand body in this area are clearly defined, and the water flooded degree is low according to the interpretation results of the inspection wells. The structure of the internal structure of the sand body is carried out to summarize the structural style of the residual oil produced by shielding, and the remaining oil occurrence style is discussed, which provides a reference for the production and adjustment of the next oil field.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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