鄂尔多斯盆地西部盐池地区山1-盒8段储层特征研究

发布时间：2018-04-19 23:00

  本文选题：盐池地区 + 山1段—盒8段　； 参考：《西南石油大学》2015年博士论文

【摘要】：苏里格气田是中国近几年来发现的大型气田。但随着该气田的开发,盆地的后备油气资源接替区不足,而位于盆地西部的盐池地区与苏里格气田相邻,为新开辟的勘探区域。上古生界山西组山1段和石盒子组盒8段是盐池地区和苏里格地区的主力储层,在产能上存在一定差异,本文结合多个学科领域的理论体系,采用多种分析测试手段并统计,对比研究盐池地区上古生界山西组山1段以及下石盒子组盒8(上、下)段的沉积微相、储层岩石学、孔喉微观结构、成岩作用类型、储层物性和非均质性特征,最终探讨了储层物性主控因素,并进行储层综合评价。鄂尔多斯盆地西部盐池地区上古生界石盒子组和山西组物源来源一致,母岩主要为元古宇孔兹岩、TTG片麻岩,以及泥盆—石炭纪火山—岩浆活动产物。源区构造背景为活动大陆边缘、被动大陆边缘和大陆岛弧等同时存在的复杂构造背景。主要物源方向分盆地西北缘的阿拉善古陆和盆地北缘的阴山古陆西段两个方向,在盐池—姬塬一带形成混合物源区,文章首次定义了混合物源区的形态,即两头尖中间宽的“S”梭形。山1段发育曲流河三角洲沉积,具有完整的二元结构；盒8段发育辫状河三角洲沉积,以砂体叠置为特征。两个层段均呈北西—南东向展布。盐池地区砂岩储层主要分布于发育辫状河三角洲的盒8段,在发育曲流河三角洲的山1段也有砂岩分布,但发育层数明显比盒8段少。山1段、盒8段的岩石类型大致相同,颗粒总体分选中—好,磨圆次棱,但是仍然存在着一定的差别。盒8段的石英含量相比山1段更高,具有更高的成分成熟度和岩屑成熟度,抗压实作用更强,从而保留了一定的原生孔隙。储集空间以各种粒间孔、晶间孔、溶蚀孔等复合孔隙为主,裂缝发育较少或不发育。山1段储层成分成熟度较低,岩性主要为石英砂岩、岩屑石英砂岩,岩屑含量较高,填隙物含量较高,常见高岭石、水云母、碳酸盐、硅质；盒8段储层成分成熟度高,以石英砂岩、岩屑石英砂岩为主,岩屑含量较低,原生孔隙较发育,填隙物含量较高,以高岭石、水云母、硅质为主。结合物性资料判断,两个层段均属于特低孔、特低渗的孔隙型储层。对研究区内目的层段5块样品进行恒速压汞测试,结果显示样品均属中-大孔微细喉型,其中孔隙半径的大小及分布形态对渗透率贡献值较大。从CT扫描上看,样品中有微裂缝存在,但延伸较短。成岩作用分建设性成岩作用和破坏性成岩作用两种,主要类型有压实与压溶作用、胶结充填作用、交代蚀变作用和溶蚀作用等。成岩演化阶段主要为晚成岩的B期至C期。但处于不同层位、区域、岩性等条件下砂岩所遭受的成岩作用的强度不一致。其中石英砂岩表现出弱-中等压实、中等一强胶结、弱溶蚀的特征；而岩屑砂岩则表现为中一强度压实、中等一强胶结、较强溶蚀的特征,岩屑石英砂岩的成岩作用强度介于二者之间。综合考虑岩性、孔隙结构、物性等各种因素,对盐池地区山1、盒8段储层的成岩作用划分出4种类型的成岩相,列举了典型井纵向上的主要成岩相,并在研究区内勾画出成岩相平面展布图,为储层的综合评价提供依据。物源区母岩的性质决定着研究区储层的岩石类型及其成分成熟度,物源的构造背景和来源方向影响着沉积砂体的空间展布,从而影响着沉积相带的划分。沉积作用控制了储层的粒度、碎屑组分、砂体接触方式,进一步影响到未成岩—早期成岩作用的强弱,是控制储层物性的最主要因素。中—晚期的成岩作用则进一步强化了储层物性非均质性。因此,物源、沉积和成岩作用是评价研究区两个层位储层特征的主要参考因素。综合考虑储层的岩性、物性、孔隙结构、毛管压力曲线特征、成岩作用强度、成岩相类型及特征等方面因素,对研究区储层进行综合分类,由好到差分了四类储层,并对研究区山1段、盒8段储层进行了有利区筛选,绘制了研究区山1段、盒8下亚段及盒8上亚段的有利勘探区预测图。
[Abstract]:The Sulige gas field is a large gas field found in China in recent years. But with the development of the gas field, the reserve oil and gas resource replacement area of the basin is insufficient, while the Yanchi area, located in the west of the basin, is adjacent to the Sulige gas field. It is a newly opened exploration area. The 1 section of the upper Paleozoic Shanxi group mountain and the Shihezi box box 8 section are the salt pool area and the Sulige area. The main reservoir of the region has certain difference in capacity. In this paper, the sedimentary microfacies of the upper Paleozoic Shanxi group Shan 1 section and the Lower Shihezi Group 8 (upper and lower) section of the upper Paleozoic in the Yanchi area are compared with the theoretical system of many disciplines, and the reservoir petrology, pore throat microstructure, diagenesis type and reservoir type are compared. In the Western Ordos Basin, the upper Paleozoic Shihezi Formation in the Western Ordos Basin is the same as the source source of the Shanxi formation. The parent rock is mainly the Proterozoic oryds, TTG gneiss, and the Devonian Carboniferous volcanic magmatic products. The background is the complex tectonic setting of the active continental margin, the passive continental margin and the continental island arc. The main source direction is divided into two directions of the Alashan paleo land of the northwest margin of the basin and the western section of the Yinshan ancient land in the northern margin of the basin. The mixture source area is formed in the Yanchi Jiyuan area. The form of the mixture source area is first defined. The "S" shuttle shape in the middle of the two ends is wide. The 1 section of the River Delta is deposited in the 1 section of the mountain, with a complete two element structure; the 8 section of the braided river delta is developed in the box, and the sand body is stacked as the feature. The two layers are both northwestern and southward. The sandstone reservoirs in the salt pool area are mainly distributed in 8 sections of the braided river delta. The 1 section of the mountain of the River Delta also has sandstone distribution, but the number of development layers is obviously less than that of the box 8. The 1 section of the mountain is roughly the same type of rock in the 8 section of the box. The grain is generally selected - good and grinding round, but there is still a certain difference. The content of quartz in the 8 section of the box is higher than the 1 section of the mountain, and has a higher degree of maturity and cuttings maturity and anti compaction. The reservoir space is dominated by a variety of intergranular pores, intergranular pores, and dissolution pores, and the fractures are less developed or not developed. The reservoir composition of the 1 section of mountain is low, and the lithology is mainly quartz sandstone, lithic quartz sandstone, high content of rock debris, high content of fillings, common kaolinite and water cloud. Mother, carbonate and siliceous; the 8 section of the box has high maturity, mainly quartz sandstone, lithic quartzite, low content of cuttings, primary pore, high filling material, kaolinite, water mica and siliceous material. The two layers belong to ultra-low pore and ultra-low permeability pore type reservoir. 5 samples of the layer are tested at constant speed, and the results show that the samples belong to the medium pore microlarynx, and the size of the pore radius and the distribution pattern contribute to the permeability. From the CT scan, there are micro cracks in the samples, but the extension is short. The diagenesis is divided into two kinds, the constructive diagenesis and the destructive diagenesis. There are compaction and pressure dissolution, cementing filling, metasomatism and alteration and dissolution. The evolution stage of the diagenesis is mainly the B period of late diagenesis to C period, but the diagenesis of sandstone under the conditions of different beds, regions and lithology is not consistent. While lithic sandstone is characterized by medium strength compaction, medium strong cementation and strong dissolution, the diagenesis of lithic sandstone is between two. Lithology, pore structure and physical properties are considered comprehensively, and 4 types of diagenesis are divided into the diagenesis of the 1 and the 8 section of the reservoir in the Yanchi area. The main diagenetic facies in the longitudinal direction of the typical wells are enumerated, and the diagenetic map of the diagenetic facies is outlined in the study area, which provides the basis for the comprehensive evaluation of the reservoir. The nature of the parent rock in the source area determines the rock type and the maturity of the reservoir in the study area, and the tectonic setting and source direction of the source source affect the spatial distribution of the sedimentary sand body. It affects the division of sedimentary facies, which controls the granularity of the reservoir, detrital components, and the contact mode of sand body, which further affects the strength of the undiagenetic and early diagenesis, and is the most important factor in controlling the physical property of the reservoir. Rock interaction is the main reference factor to evaluate the reservoir characteristics of the two layers in the study area. Considering the lithology, physical property, pore structure, capillary pressure curve, diagenesis strength, diagenetic facies and characteristics, the reservoir is classified into four types of reservoirs, 1 sections of the study area, and the case of the 1 section of the study area. In the 8 section, the favorable area was screened, and the prediction map of favorable exploration area for the 1 segment of the mountain, the lower part of the box 8 and the upper part of the box 8 were plotted.

【学位授予单位】：西南石油大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P618.13
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本文编号：1775100