鄂尔多斯盆地富县探区三叠系延长组长8致密油层综合研究

发布时间：2018-03-10 21:35

  本文选题：鄂尔多斯盆地　切入点：富县探区　出处：《西北大学》2016年博士论文　论文类型：学位论文

【摘要】：综合岩心观察、薄片分析、扫描电镜、高压压汞、微米CT等分析测试资料,系统研究了鄂尔多斯盆地富县探区延长组长8致密储层沉积类型、储层特征、储层成岩作用及致密化过程,详细分析了生油层特征及致密油特征,并指出下一步勘探方向及有利区。取得以下主要认识与结论：富县探区延长组长8储层的物源来自于北东方向,其沉积相主要为三角洲前缘亚相中的水下分流河道微相和分流间湾微相；长82时期主要为水下分流河道砂体和水下分流间湾砂体,长81时期逐渐演变为水下分流河道砂体与泥岩互层,垂向上具有湖侵砂退的旋回特征。长8储层砂岩碎屑成分具有“高长石端元、较低石英端元”的特点,填隙物主要为方解石和伊利石。储层孔隙度平均为8.0%,渗透率平均为0.26mD,为典型的致密砂岩储层,孔隙主要发育粒间孔隙、原生粒间孔和粒内、粒间溶孔及长石溶孔。孔隙结构特征复杂且分布不均,主要以亚微米级孔喉和少量的纳米级孔喉系统为主。长8储层成岩作用强烈,普遍已进入中成岩阶段A期,其成岩作用主要有压实作用、胶结作用和溶蚀作用等。泥质岩屑、黑云母碎屑等塑性组分是砂岩致密化的基础,强烈的压实作用及碳酸盐矿物胶结作用是砂岩致密化的关键,长石和一些易溶岩屑形成的次生孔隙改善了储层的物性,致使一部分致密砂岩形成致密油储层。储层物性受埋深、岩性、沉积相、碳酸盐胶结物的共同影响。据此,结合高压压汞参数将长8储层分为4种类型：Ⅰ类为优质储层,Ⅱ类为中等储层,Ⅲ类为差储层,Ⅳ类为非储层。其中Ⅱ类储层为油储量、产量的主要贡献者。地化参数表明,研究区长8致密油层广覆式分布成熟优质生油层,生油层与储层共生,无明显圈闭界限。油气聚集带主要分布在水下分流河道的砂体厚度大、储层孔隙结构好的区带,据此预测Ⅰ类“甜点区”4个,Ⅱ类“甜点区”7个。
[Abstract]:Based on core observation, thin slice analysis, scanning electron microscope, high pressure mercury injection, micron CT and other data, the sedimentary types and reservoir characteristics of Chang 8 dense reservoir in Fuxian exploration area, Ordos Basin, are systematically studied. The diagenesis and densification process of reservoir are analyzed in detail. It also points out the next exploration direction and favorable area. The main conclusions are as follows: the material source of Yanchang No. 8 reservoir in Fuxian exploration area comes from the north-eastern direction, The sedimentary facies are mainly subaqueous distributary channel microfacies and interdistributary bay microfacies in delta front facies, while in Chang82 period, they are mainly underwater distributary channel sand body and underwater distributary bay sand body. The Chang 81 period gradually evolved into an underwater distributary channel sand body and mudstone interbedded, with vertical transgressive sand regressive cycle characteristics. The sandstone clastic composition of Chang 8 reservoir has the characteristics of "high feldspar end member, lower quartz end member". The porosity of reservoir is 8. 0 and the average permeability is 0. 26 mD. it is a typical tight sandstone reservoir with intergranular pores, primary intergranular pores and intragranular pores, and the porosity is mainly composed of calcite and Illite. Intergranular dissolution pore and feldspar dissolution pore. The pore structure is complex and unevenly distributed, mainly composed of sub-micron pore throat and a small amount of nanometer pore throat system. The diagenesis of Chang 8 reservoir is so strong that it has generally entered the stage A of middle diagenesis. Its diagenesis mainly includes compaction, cementation and dissolution, etc. The plastic components such as shaly and biotite are the basis of sandstone densification, and strong compaction and carbonate mineral cementation are the key to the densification of sandstone. The secondary pores formed by feldspar and some easily soluble lithic cuttings improve the physical properties of the reservoir and result in the formation of dense oil reservoirs in part of the compact sandstone. The physical properties of the reservoir are affected jointly by the buried depth, lithology, sedimentary facies and carbonate cementation. The Chang 8 reservoir can be classified into four types according to high pressure mercury pressure parameters: type 鈪，

本文编号：1595163