鄂尔多斯北部十里加汗地区下石盒子组致密砂岩储层特征及主控因素

发布时间：2018-10-24 11:19

【摘要】：杭锦旗地区是中石化华北局重要的油气勘探区,是华北分公司近期天然气增储上产的重点目标区。但目前该地区致密砂岩储层的综合特征、主控因素和有效储层的分布等基础地质规律还有待进一步揭示。以鄂尔多斯盆地北部杭锦旗地区十里加汗区带为研究区,通过钻井、测井、地震和分析测试等资料的分析,对研究区二叠系下石盒子组发育的致密砂岩储层基本特征、储层成岩作用、有效储层划分与时空分布及储层的主控因素等进行了综合分析。研究揭示,下石盒子组不同层段储层岩石类型构成具有一定的差异性,其中盒1段岩石类型主要为含砾不等粒岩屑砂岩和岩屑石英砂岩,盒2段以细-中粒岩屑砂岩为主,而盒3段主要为粗-中粒岩屑砂岩和石英砂岩。不同层段岩矿特征具有明显的差异性,盒1段储集岩成分成熟度略高于盒2段和盒3段;而结构成熟度略低于盒2段和盒3段,主要表现在分选性和磨圆度差和石英含量等方面。盒1段、盒2段及盒3段储集岩长石含量低,不超过50%,其中盒3段长石含量相对最低;不同层段胶结特征差异明显,盒1段胶结类型多样,上部钙质胶结较强,下部略见粘土质胶结,主要成分是高岭石;盒2段以粘土矿物胶结为主,见少量钙质胶结;盒3段钙质和硅质胶结有所增强,见部分粘土质胶结。储层破坏性成岩作用主要包括胶结作用和压实作用,建设性成岩作用类型主要包括溶蚀作用、绿泥石早期衬垫、长石高岭石化以及破裂作用等。研究区下石盒子组储层总体致密,以低孔低渗为主,不同层段储层物性具有差异性,总体上,由盒3段、盒2段、盒1段储层物性总体变好。储层孔隙空间类型主要为粒间扩溶孔和溶蚀缝,可见粒间剩余孔、粒内溶孔、晶间溶孔、贴粒溶孔、铸膜孔和成岩缝等。不同层段孔隙类型具有一定差异性,总体上,盒1段以粒间溶孔和溶蚀缝为主,盒2以粒间溶孔和残余粒间孔为主,盒3以粒间溶孔和微裂缝为主。系统开展了储层的综合评价,划分出Ⅰ类、Ⅱ类和Ⅲ类三类有效储层类型,有效储层的钻遇率具有由盒1段向上总体降低的特点。各段有效储层主要以Ⅱ类为主,而相对优质的Ⅰ类储层由盒2段、盒3段、盒1段发育程度总体变好。综合研究揭示了有效储层的主控因素,提出了层序-古地貌-沉积宏观控制,岩性-成岩微观影响的有效储层主控因素。研究认为,横向上古地貌控制了储层的总体发育程度,地貌的低洼部位储层相对发育,垂向上有效储层具有明显的层序控制特征,三级层序的LST和HST储层相对较发育;岩性控制储层物性明显,粗粒砂岩和含砾砂岩物性最好;不同沉积环境条件下,河道砂体的形态和厚度控制储集物性明显,总体上,箱型河道砂体最为有利,辫状河道砂体要好于曲流河道砂体,曲流河内部的边滩和河道交汇区物性较好;在沉积背景基础上,后期的储层成岩作用和油气活动及构造破裂作用则对储层具有一定的辅助作用。综合分析认为箱型粗粒沉积、三级层序低位体系域和高位体系域是有利的有效储层发育部位。
[Abstract]:Hangjinqi area is an important oil and gas exploration area of SINOPEC oil and gas bureau, which is the key target area of recent natural gas enrichment in North China Branch. However, the comprehensive characteristics, main control factors and effective reservoir distribution of dense sandstone reservoirs in this area are also revealed. Based on the analysis of data such as drilling, logging, earthquake and analysis and analysis, the basic characteristics and diagenesis of the dense sandstone reservoir developed in the study area are studied by means of data analysis such as drilling, logging, earthquake and analysis and analysis. The effective reservoir division and the space-time distribution and the main control factors of the reservoir are comprehensively analyzed. The study revealed that the rock types in different layer sections of the lower stone box group have some difference, among which, the type of rock in the 1 section of the box is mainly composed of lithic debris sandstone and lithic quartz sandstone, and the 2 sections of the box are mainly composed of fine-medium grained lithic sandstone. The box 3 is mainly coarse-medium grained lithic sandstone and quartz sandstone. There is a significant difference in the characteristics of rock and ore in different layers, which is slightly higher than that of box 2 and box 3, while the maturity of structure is slightly lower than that of box 2 and box 3, mainly in the aspects of sorting and roundness difference and quartz content. 1 section of box, 2 sections of box and 3 sections of box 3, with low feldspar content, no more than 50%, of which the feldspar content of box 3 is relatively low; the cementing characteristics of different layer sections are obvious, the cementation type of section 1 is diverse, the upper calcareous cementation is strong, and the lower part is slightly seen in clay cementation. The main components are kaolinite; the two sections of the box are cemented with clay minerals; see a small amount of calcareous cementation; and the calcareous and siliceous cements of the box 3 are enhanced. See some clay cements. Destructive diagenesis of reservoir mainly includes cementation and compaction, and constructive diagenesis types mainly include dissolution, early stage liner, feldspar kaolinite and fracture. In the study area, the reservoir is compact, with low porosity and low permeability, and the physical properties of different layer sections are different. In general, the physical properties of the reservoirs in the section of box 3, box 2 and box 1 are generally changed. The pore space types of the reservoir are mainly intergranular expansion and dissolution pores, residual pores between the particles, dissolved pores in the grains, intergranular dissolved pores, patch dissolving holes, cast film holes and forming seams, and the like. The pore types of different layers have some difference. In general, the 1 section of the box is mainly composed of intergranular dissolved pores and dissolution joints, and the box 2 is mainly composed of intergranular dissolved pores and residual interparticle pores, and the box 3 is mainly composed of intergranular dissolved pores and micro cracks. The system has carried out the comprehensive evaluation of reservoir, divided into three types of effective reservoir types of class I, class II and class III, and the drilling meeting rate of effective reservoir has the characteristic of overall decreasing from the segment of box 1. The effective reservoir of each section is mainly composed of class II, while the relatively high quality type I reservoir is composed of 2 sections of box, 3 sections of box and 1 section of box 1. The comprehensive research reveals the main controlling factors of effective reservoir, and puts forward the effective reservoir main control factor of layer sequence-paleogeomorphology-deposit macro-control, lithology-diagenesis micro-influence. According to the study, the horizontal upper paleogeomorphology controls the overall development of the reservoir, the relative development of the reservoir in the reservoir area of the landform, the relative development of the vertical and upward effective reservoir, the relative development of the LST and the HST reservoirs in the tertiary layer sequence, and the obvious physical properties of the lithology control reservoir. The physical properties of coarse-grained sandstone and gravel-containing sandstone are the best; under different sedimentary environments, the shape and thickness of river sand bodies have obvious reservoir physical properties; in general, the box-type river sand bodies are most favorable, and the braided river sand bodies are better than curved river sand bodies. On the basis of sedimentary background, the diagenesis and oil and gas activities and tectonic fracture of the reservoir have a certain auxiliary effect on the reservoir. The comprehensive analysis shows that the box-type coarse grain deposition, the tertiary layer sequence low-order system domain and the high-level system domain are favorable effective reservoir development sites.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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