【作者】 刘春雷；

【导师】 李文厚；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2012， 博士

【摘要】 多年来的勘探及开发证明了鄂尔多斯盆地是中国天然气勘探最有潜力的盆地之一。针对上古生界气藏在盆地东部(研究区)认识程度非常低的现状,本论文采用地质与野外剖面观测、岩心观察描述与室内分析鉴定相结合,资料统计、单因素分析与综合作图相结合的研究思路,深入研究了鄂尔多斯盆地东部本溪组的沉积相类型及其空间分布规律,恢复了盆地东部本溪组的沉积演化历史,从宏观角度揭示了沉积相及砂体的平面分布、纵向演化特征。为研究区气藏的进一步勘探与开发提供重要的理论依据。依据研究区标志层、岩电特征、沉积旋回等对研究区目的气层组进行了对比,同时考虑地质分层及开发的实际情况,按其中、长期旋回,将本溪组划分为本1段(晋祠段)和本2段(湖田段及畔沟段)。系统总结出研究区的各类沉积相的相标志,为沉积相的识别和划分提供了有力的依据。结合沉积相纵向演化的基干剖面的分析,将研究区上古生界石炭系本溪组划分为障壁海岸及陆棚两大沉积体系,并进一步划分出砂坪、混合坪、泥坪、泥灰坪、泻湖泥、泥质陆棚七个沉积微相。本溪组障壁砂坝大体呈南北展布,砂坪呈北北西—南南东展布。研究区本溪组砂岩主要为石英砂岩,其次为岩屑质石英砂岩。主要的孔隙组合为粒间孔+晶间孔+溶孔型,成岩作用阶段普遍进入中成岩A—B期,局部达到晚成岩阶段。砂岩总体上属于特低孔特低渗型储层,储层物性主要受沉积作用和成岩作用的控制,研究区普遍发育的障壁岛及砂坪石英砂岩物性较好。综合分析研究区储层孔渗参数,将研究区储层划分为四类,并对各气层组储层的分类和平面展布进行研究。通过找砂体发育带及高孔、高渗带结合产能特征和测井资料对研究区各目的层段进行了叠合有利区的预测,为下一步勘探开发提供了地质依据。更多还原

【Abstract】 Exploration and development in recent years of the Erdos basin indicates that it is one of the important basins in china having the greatest potential in gas exploration. The Upper Paleozoic gas reservoirs in the eastern part of the basin (study area), however, is poorly understood. Based on outcrop observation, core observation and description plus geochemical analysis and identification, data statistics, univariative and comprehensive analysis of samples, we conducted detailed investigation on sedimentary facies analysis, spatial distribution, and evolutionary history of the sedimentology of the Benxi Formation in the eastern part of the Ordos Basin. This study reveals the horizontal distribution of sedimentary facies and sand body of the Benxi Formation from a macro perspective, which would offer an important theoretical basis for further exploration and development of the gas reservoirs in the study area.On the basis of marker beds, rock electric characteristics, and depositional cycles, gas reservoir-bearing strata in the study area are stratigraphically correlated. Considering the actual situation of geological stratification and development of the strata, the Benxi Formation is sub-divided into Ben1(an equivalent of the previous Jinci Member) and Ben2(equivalents of the previous Hutian+Pangou members) members, according to medium-to long-term cycles.A systematic summary of the signs of various types of sedimentary facies in the study area provides a strong basis for the identification and classification of sedimentary facies. Vertical evolution analysis at the representative section leads to the sedimentary sub-division of the Upper Paleozoic Carboniferous Benxi Formation as have deposited in two major depositional systems:barrier coast and continental shelf. These two depositional systems are further divided into seven sedimentary microfacies:the sand flat, mixed flat, mud flat, marl lime flat, lagoon mud, and muddy shelf. Sand barriers of the Benxi Formation lanes a north-south distribution, with the sand flat was spread in a NNW-SSE belt.Sandstone of the Benxi Formation is mainly composed of quartz sandstone, followed by lithic quartz sandstone. Pores are primarily intergranular+intergranular+dissolved types. The diagenetic history falls in an A-B phase, with some of them at the late stage. Sandstone generally is extra low porosity to low permeability reservoirs, and reservoir properties were controlled by the depositional and diagenetic processes. Barrier islands and sand flat quartz sandstone, occur commonly in the study area, generally have well reservoir properties.Reservoirs are divided into four categories. Classification and planar distribution of the gas reservoirs were investigated, on the basis of a comprehensive analysis of the reservoir porosity and permeability parameters in the study area. Reservoirs having higher exploration potential are predicted, based on the finds of sand body with high porosity and high permeability. This would be favorable for further exploration and development of gas reservoirs in the study area.更多还原