麻黄山西区块长6、长8油组油藏储层特征研究

发布时间：2018-03-11 13:53

  本文选题：沉积微相　切入点：岩石学特征　出处：《长江大学》2015年硕士论文　论文类型：学位论文

【摘要】：麻黄山西区块地处鄂尔多斯盆地天环向斜中段的西部地区,研究区的西部为西缘冲断带中段一马家滩段与天环向斜中段连接过渡的部位。其构造作用在受断裂作用影响下的二级断块背斜带对油气运移聚集起主要控制作用,局部以背斜、断块及鼻状构造为主要的地质构造。研究区目的层段为长6、长8油组,平面控制面积120.8km2,累计埋深2400-2900米,完钻探井44口,均有良好油气显示。延长组长6、长8油组以岩性油藏为主,储层砂体主要为三角洲类型,具有埋藏深、隐蔽性强的特点；麻黄山西区块长6、长8油组储层为典型的低孔-特低孔、超低渗-特低渗储层。在以石油地质理论为指导,本文根据宏微观相结合的研究思路,研究了麻黄山西区块长6、长8油组储层的岩石学特征、沉积微相、成岩作用、物性及非均质性特征,并对研究区的储层进行分类与储层评价标准,确定和指出了有利的优选目标区,为油田更好的指导下一步的油气勘探工作。在岩心观察和测井资料综合解释的基础上,采用的原理是旋回一厚度对比及高分辨率层序地层划分与对比,运用不同成因砂体对比模式及空间接触关系处理方式,对全区44口井长6、长8油组沉积期的小层划分与对比,将长6划分为3个砂组9个小层,长8划分为2砂组6个小层；建立了地层单元等时地层格架。利用碎屑颗粒组分石英、长石、岩屑含量、地震均方根振幅属性图、砂组砂岩厚度等平面图展布特征及砂组砂体百分含量图等多因素综合分析,对研究区物源进行了多元综合分析,发现长6、长8油组的沉积物源主要是来自研究区西北方向。结合区域沉积背景资料,通过对测井、粒度的分析,对比岩心的观察、描述及对取心井资料的认识,对研究区沉积微相类型及沉积演化规律进行了研究,可以认为研究区长6、长8油组沉积期为三角洲前缘环境。主要发育的微相有水下分流河道、席状砂、远砂坝、河口坝、间湾。长6油组砂岩成份主要有岩屑质长石砂岩、长石质石英砂岩,有少量长石岩屑砂岩；长8油组砂岩成份主要有岩屑砂岩、岩屑质石英砂岩,有少量长石砂岩、长石质岩屑砂岩。成分成熟度偏低,分选中等-好,磨圆度以次棱-次圆状为主；交接类型占主导的是孔隙式胶结,其次为孔隙-基底式胶结。长6油组填隙物主要为碳酸盐类,长8油组填隙物主要为碳酸盐类和粘土矿物。本区的主要孔隙类型有原生粒间孔、粒间溶孔、长石溶孔、岩屑溶孔、微裂缝等5种孔隙类型,其中以粒间孔隙为主。喉道类型可划分为微喉道、片状、弯片状喉道三种,主要为弯片状、微喉道,储层渗透性很差。综合发现,两个油组储层均表现为低孔-特低孔、超低渗-特低渗储层。研究区长6、长8油组储层总体处于中成岩A阶段。通过一系列的成岩相研究可看出,本研究区发育斑状粒间溶孔成岩相、碳酸盐胶结成岩相、泥质胶结成岩相、致密压实成岩相。通过收集的试油资料,对比对应储层成岩相相关性进行分析,发现斑状粒间溶孔成岩相与油气有着很好的对应关系,可以看出建设性成岩作用对储层的物性变好有较好的改造作用,因而可以知道该类储层含油气较好。沉积作用和成岩作用是研究区储层物性的主控因素。储层致密化的主要原因是由于碎屑颗粒中长石、岩屑等不稳定组分及杂基含量较高,通过压实作用及胶结作用使原生孔隙大大降低,由于成岩期溶蚀作用不强,次生孔隙不发育,导致储层致密化。针对储层的特征和性质,选用孔隙度、砂岩厚度、渗透率及泥质含量等4个参数建立评价标准,运用灰色系统理论及聚类分析方法,对储层进行评价,将研究区的储层类型划分为Ⅰ类、Ⅱ类、Ⅲ类、Ⅳ类。根据在平面上的展布储层类型的特征并结合沉积相图,发现Ⅰ类、Ⅱ类储层主要集中在水下分流河道微相中,其次在河口坝、远砂坝微相中。远砂坝中主要发育Ⅱ类、Ⅲ类储层。河口坝中主要发育Ⅱ类储层,有少部分Ⅲ类储层。在席状砂、远砂坝中以Ⅲ类、Ⅳ类储层交互为主。在上述分析的基础上,通过有效砂厚、储量丰度、储层类型相及构造部位等图叠合,结合油气分布规律研究、储层分类的评价标准,对研究区目的层段的有利区进行了预测,优选出5个有利成藏区块。
[Abstract]:The Shanxi block is located in Ordos basin ephedra Tianhuan syncline middle western region, the western region of the thrust belt in the western margin of a middle Majiatan section and Tianhuan Syncline area. The middle connecting structure in by fracture under the effect of two faulted anticline belt on the migration and accumulation of oil and gas has main control in effect, local anticline, faulted nose structure and geological structure. The main target layer in the study area is 6, 8 oil group, plane control area of 120.8km2, total depth of 2400-2900 meters, drilled 44 exploratory wells, have good oil and gas shows. Yanchang Formation Chang 6, Chang 8 oil group the lithologic oil reservoir, reservoir sand bodies are mainly delta type, with burial depth, concealed features; ephedra block of Shanxi Chang 6, Chang 8 oil reservoir is typical of low porosity, low permeability and extra low permeability reservoir. In petroleum geology theory this paper, based on the macro Study on the idea of microcosmic study, ephedra Shanxi block long 6, long 8 reservoir petrology, sedimentary facies, diagenesis, physical property and heterogeneity, and the reservoir of the study area classification and reservoir evaluation standard, determine and points out the favorable target selection for the oil area, to better guide the next exploration work. Based on the core observation and logging comprehensive interpretation, the principle is a cycle thickness correlation and high resolution sequence stratigraphic division and correlation, the contact relation between different sand contrast mode and space approach, 44 of the region's export well Chang 6, Chang 8 oil formation during the deposition of thin layer division and contrast, 6 will be divided into 3 sand groups 9 small layer 8 is divided into 2 sand groups 6 layers; established stratigraphic isochronous stratigraphic framework. The detrital quartz, feldspar group, debris content the earthquake. The root mean square amplitude attribute graph, multi factor comprehensive analysis of sand group sandstone thickness plane graph distribution characteristics and sand formation sand body content on the map, the research area source of multivariate analysis, found 6, sediment source of Chang 8 oil group is mainly from the northwest study area. Combined with the regional sedimentary background based on the data, logging, granularity analysis, comparative observation of core, description and understanding of coring data, sedimentary microfacies and sedimentary evolution in the study area were studied. The study area can be 6, the delta front environment of Chang 8 oil formation. The main microfacies are developed the underwater distributary channel, sand sheet, far sand dam, mouth bar, interdistributary bay. Chang 6 oil sandstone composition are mainly lithic feldspar sandstone, feldspathic quartz sandstone, with a small amount of feldspar lithic sandstone; sandstones of Chang 8 oil ingredients are mainly lithic sandstone, lithic quartz sand 宀，

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