大港油田中南部上古生界沉积相分析及储层研究

发布时间：2019-06-28 19:21

【摘要】：大港油田发现至今已40余载,黄骅坳陷已进入勘探的中晚期阶段,勘探难度逐渐增大,油气聚集区日趋复杂使大港探区勘探工作谋求二次创业。上世纪90年代末,大港先后找到了以上古生界煤系地层为油气源的潜山带,表明上古生界油气藏具有较大的勘探潜力。通过岩心、测井资料、扫描电镜、普通薄片、铸体薄片、压汞法、X衍射等实验室分析技术,对黄骅坳陷进行沉积相分析和储层研究,为后期勘探部署提供科学依据。黄骅坳陷石炭-二叠纪地层从下至上分为本溪组、太原组,山西组、下石盒子组、上石盒子组和石千峰组。黄骅坳陷石炭-二叠纪地层主要发育的砂体类型是：河流相砂体主要发育于上石盒子组、下石盒子组和石千峰组；山西组主要发育三角洲砂体；潮坪-o_湖相砂体和渴湖-障壁岛相砂体主要发育于本溪组和太原组。黄骅坳陷石炭-二叠纪有利储层的砂体类型是河流相砂体和三角洲相砂体。通过研究黄骅坳陷上古生界砂岩储集层表明上古生界储层主要以长石砂岩和岩屑质长石砂岩为主,但垂向上差异明显,广义石英砂岩(包括岩屑质石英砂岩和长石质石英砂岩)基本分布于下石盒子组和上石盒子组；储层内石英含量自下而上呈现明显增加的趋势,而岩屑含量则表现为自下而上降低的趋势。砂岩成分成熟度及结构成熟度都有逐渐降低的趋势。整体上,储层内孔渗均相对较好的层段是河道砂体的下石盒子组,也是进一步勘探的重点区域。其次是太原组,上石盒子组相对较差。从数据上来看,山西组地层表现出极差的孔渗性能,属于非渗透层。成岩作用对研究区砂岩储集物性影响表现得非常明显,在制约储层储集物性的诸多因素中,压实作用基本决定了砂岩储集性能的好坏,压实作用在储层物性改造过程中起了一个负面的作用,导致储层的原生孔隙损失量较大。在砂体埋深的中后期,胶结作用逐渐取代压实作用成为破坏砂体储集性能的主力军,粘土岩胶结物、碳酸盐胶结物、硅质胶结物是使砂岩储集层孔隙度和渗透率降低的主要原因。溶蚀作用(酸性溶蚀和碱性溶蚀)产生了大量的次生孔隙,极大地改善了储层物性,对油气储集空间的形成起到积极的作用。黄骅坳陷上古生界砂岩储集空间整体上都是次生形成的,各段均未见原生孔隙留存,以次生粒间溶孔、粒内溶孔及铸模孔为主,仅山西组层段内裂缝相对发育。次生孔隙的形成极大地改善了储层物性。整体上,上石盒子组的排驱压力较小,喉道分选系数偏小,表现出来的孔喉连通性较好；下石盒子和太原组排驱压力中等,分选系数偏小,孔喉连通性略低于上石盒子组；山西组排驱压力最大,分选系数最高,孔喉连通性相对最差。黄骅坳陷上古生界储层总体上以特低孔-超低渗、低孔-超低渗物性特征为主。储层的储集物性受多方面因素影响,沉积环境及沉积相决定了砂岩储集层的原始条件,成岩作用成为了沉积后研究区储层物性的主控因素。黄骅坳陷最有利的储层砂体是下石盒子组和上石盒子组的河流相砂体,储集物性较好,是本区上古生界最有前景的储层。
[Abstract]:Since the discovery of Dagang oil field has been over 40 years, the Huangyan depression has entered the middle and late stage of the exploration, the exploration difficulty is gradually increased, and the oil and gas accumulation area is becoming more and more complex to make the exploration work in the Dagang exploration area to seek for a second start-up. In the late 1990s, Dagang has successively found the above-Paleozoic coal measures strata as the buried hill zone of oil and gas source, which indicates that the upper Paleozoic oil and gas reservoir has great exploration potential. The sedimentary facies analysis and reservoir research were carried out in Huangyan depression by using the laboratory analysis techniques such as core, logging data, scanning electron microscope, ordinary sheet, casting sheet, mercury-pressing method and X-ray diffraction, so as to provide scientific basis for later exploration and deployment. The Carboniferous-Permian strata in the Huangbu depression are divided into Benxi Formation, Taiyuan Formation, Shanxi Formation, Lower Stone Box Group, Shangshi Box Group and Shiqianfeng Group from bottom to top. The main development of the Carboniferous-Permian strata in the Huangbu depression is that the fluvial facies sand body is mainly developed in the upper stone box group, the lower stone box group and the stone thousand peak group, and the Shanxi Formation mainly develops the delta sand body; The sandbodies of the tidal flat-o _ lake facies and the thirsty-barrier island are mainly developed in the Benxi and Taiyuan Formation. The sand body type of the Carboniferous-Permian favorable reservoir in the Huangyan depression is the fluvial facies sand body and the delta facies sand body. Based on the study of the Upper Paleozoic sandstone reservoir in the Upper Paleozoic, the upper Paleozoic reservoir is mainly composed of the feldspar sandstone and the lithic feldspar sandstone, but the vertical difference is obvious. The generalized quartz sandstone (including the rock-rock and the long-stony quartz sandstone) is mainly distributed in the lower-stone box group and the upper-stone box group, and the quartz content in the reservoir shows a significant increase from the bottom to the bottom, and the content of the rock fragments shows a tendency to lower from the bottom to the bottom. The maturity of the sandstone and the maturity of the structure are gradually decreasing. In the whole, the relatively good layer segment of the inner hole of the reservoir is the lower stone box group of the channel sand body and the key area for further exploration. The second is Taiyuan Formation, the upper stone box group is relatively poor. On the basis of data, the formation of Shanxi Formation shows very poor permeability and belongs to the non-permeable layer. The influence of diagenesis on the reservoir physical property of the study area is very obvious, and in many factors which restrict the reservoir physical property, the compaction effect basically determines the reservoir property of the sandstone, and the compaction effect plays a negative role in the reservoir physical property modification process. Resulting in a large amount of pore loss in the reservoir. In the middle and late stage of the burial depth of the sand body, the effect of the cementation gradually replaces the compaction, which is the main force to destroy the reservoir performance of the sand body, and the clay-rock cement, the carbonate cement and the siliceous cement are the main reasons for reducing the porosity and the permeability of the sandstone reservoir. The dissolution (acid corrosion and alkaline corrosion) has produced a large number of secondary pores, which greatly improves the reservoir physical property and plays an active role in the formation of the reservoir space of the oil and gas. The reservoir space of the Upper Palaeozoic Sandstone in the Huangyan depression is formed in the whole, and the remaining sections are not found in the primary pores, and the secondary-particle-soluble, intragranular and mold-shaped pores are the main ones, and only the fractures in the Shanxi Formation are relatively developed. The formation of secondary pores greatly improves reservoir physical properties. As a whole, the drainage pressure of the upper stone box group is small, the separation coefficient of the throat is small, and the connectivity of the well throat is good; the lower stone box and the Taiyuan group have the middle discharge pressure, the separation coefficient is small, the connectivity of the pore throat is lower than the upper stone box group, and the discharge pressure of the Shanxi group is the most, The separation coefficient is the highest, and the pore-throat connectivity is the worst. The upper Paleozoic reservoir in the Huangbu depression is mainly characterized by the characteristics of ultra-low porosity, low porosity and ultra-low permeability. The reservoir properties of the reservoir are influenced by many factors, and the sedimentary environment and the sedimentary facies determine the original condition of the sandstone reservoir, and the diagenesis has become the main control factor of the reservoir physical property in the post-sedimentary study area. The most favorable reservoir sand body in the Huangyan depression is the river facies sand body of the lower stone box group and the upper stone box group, and the reservoir physical property is good, which is the most promising reservoir in the upper Paleozoic in the area.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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