永8断块沙二段5-8砂层组储层构型研究

发布时间：2018-02-03 10:35

本文关键词： 胜利油田永8断块辫状河三角洲前缘储层构型流体渗流　出处：《中国石油大学(华东)》2015年硕士论文　论文类型：学位论文

【摘要】：陆相断陷盆地的三角洲砂体是最主要的油气储集体,其中辫状河三角洲占有很大的比例。目前国内对该类储层的油气开发很多已经进入高含水期,储层构型研究是精细刻画储层内部渗流通道和隔夹层的分布的有效方法。目前国内外对辫状河三角洲构型的研究并不多,本文以胜利油田永8断块沙二下亚段辫状河三角洲前缘厚层砂体为研究对象,充分利用岩心、测井、地震和开发资料,参考Miall河流相构型界面分级方案,在高分辨率层序地层学理论指导下,在沉积旋回控制下,对应开发层系,在标志层控制下识别6级构型界面,在6级构型界面约束下,采用相控旋回、砂体平对、部分砂体斜对的方法,进行5级、4级构型界面划分,将主力层段沙二下亚段划分为6级界面限制的多期三角洲前缘叠置体、5级界面限制的三角洲前缘复合沉积体和4级界面限制的单一三角洲前缘沉积体,并对每一级构型单元及构型界面分别成等厚图,分析砂岩、泥岩分布规律。通过岩心精细观察与描述,在单一三角洲前缘沉积体中识别出水下分流河道、河道周缘溢岸砂体、河口坝主体、河口坝周缘、分流间湾等构型单元,并与测井曲线对应,总结各类型构型单元测井响应特征,指导各种辫状河三角洲前缘构型单元的测井识别。通过Google Earth图像,测量并计算辫状河三角洲分流河道河道长度、河谷长度、河道宽度、河道弯曲度等参数,得到辫状河三角洲分流河道均比较顺直,且河道宽度往往较小,一般不大于300m的结论,而前人研究成果表明,辫状河三角洲河口坝规模往往较大,长宽均可达数千米。在上述辫状河三角洲地质知识库的指导下,综合利用曲线形态差异、砂体横向厚度变化、砂体间泥质沉积、隔夹层数目差异等进行砂体边界与叠置关系划分,确定了辫状河三角洲前缘单一沉积体的平面和剖面的构型样式。依据上述方法,对永8断块沙二下亚段30套单砂体进行构型单元划分,揭示了单一沉积体各构型单元逐层进积的基本过程,明确了该区辫状河三角洲具有河窄坝宽、河薄坝厚、河顺坝横的特点。统计研究区30套单砂体内各构型单元的规模,主要为分流河道和河口坝的宽度、厚度、宽厚比等,统计结果表明,研究区沙二段辫状河三角洲前缘主要构型单元分流河道、河口坝在宽度、厚度之间的相关性不甚明显,但分流河道与其对应的河口坝在规模上相关性较好,河口坝厚度与分流河道厚度之比在1.25~2.5间,主要分布于1.25~2之间,约占80%,河口坝宽度与河道宽度的比值范围在2.23~8.95之间,变化范围大,在3~6之间的约占75%,这与浅水辫状河三角洲的沉积环境有关。综合分析构型单元分布、储层非均质性、优势渗流通道、隔夹层等因素对流体渗流及剩余油分布的影响,并针对不同储层类型提出提高采收率的开发方案。
[Abstract]:The delta sand body in continental faulted basin is the most important oil and gas reservoir, among which braided river delta accounts for a large proportion. At present, many oil and gas development of this kind of reservoirs in China has entered a high water-cut period. The study of reservoir configuration is an effective method to describe the distribution of percolation channel and intercalation in the reservoir. At present, there are few researches on braided river delta configuration at home and abroad. This paper takes the braided river delta front thick sand body in Sha2 submember of Yong8 fault block in Shengli Oilfield as the research object, and makes full use of core, logging, seismic and development data. Referring to the classification scheme of Miall river facies and configuration interface, under the guidance of high-resolution sequence stratigraphy theory, under the control of sedimentary cycle, corresponding to the development layer system, the 6-level tectonic interface is identified under the control of the marker layer. Under the constraint of 6 order configuration interface, the interface of 5 grade and 4 grade configuration is divided by the method of phase controlled cycle, sand body flat pair and partial sand body skew pair. The lower sub-member of the main formation is divided into six order interfacial limited multi-stage delta front superimposed delta front composite sedimentary body and a single delta front sedimentary body with 4 level interface limitation. The distribution law of sandstone and mudstone is analyzed and the underwater distributary channel is identified in single delta front sedimentary body by careful observation and description of core. This paper summarizes the logging response characteristics of various types of configuration units, such as sandbody, main body of estuarine dam, periphery of estuarine dam, intertidal bay of distributary and so on, corresponding to well logging curve. Through Google Earth image, the length of distributary channel, length of river valley and width of channel in braided river delta are measured and calculated. The results show that the braided delta distributary channel is straight, and the channel width is usually smaller, generally less than 300m, and the previous research results show that the channel curvature is not more than 300m. The size of the braided river delta estuarine dam is usually large and the length and width can reach several kilometers. Under the guidance of the geological knowledge base of the braided river delta, the variation of transverse thickness of sand body can be comprehensively utilized. The relationship between the boundary of sand body and the superposition is divided, and the plane and profile of the single sedimentary body in the front edge of braided river delta are determined. According to the above method, the structure of the single sedimentary body in the front edge of braided river delta is determined. The structural units of 30 sets of single sand bodies in the lower sub-member of Shaer 2 of Yong8 fault block are divided, the basic process of stratified precession of each tectonic unit of the single sedimentary body is revealed, and it is clear that the braided river delta in this area has narrow river dam width. The size of each configuration unit in 30 sets of single sand body in the statistical study area is mainly the width, thickness, width ratio of distributary channel and estuarine dam, etc. The statistical results show that. In the study area, the correlation between width and thickness of estuarine dam is not obvious, but the correlation between distributary channel and its corresponding estuary dam is good in scale. The ratio of the thickness of the estuarine dam to the thickness of the distributary channel is between 1. 25 and 2. 5, mainly distributed between 1. 25 and 2, accounting for about 80%. The ratio of the width of the estuarine dam to the width of the channel is between 2.23 and 8.95, and the range of variation is large, accounting for about 75% in the range of 3 ~ (6). This is related to the sedimentary environment of the shallow water braided river delta. The effects of such factors as the distribution of tectonic units, reservoir heterogeneity, dominant percolation channels and intercalation on the fluid seepage and remaining oil distribution are comprehensively analyzed. According to different reservoir types, the development plan of improving oil recovery is put forward.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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