【作者】 党犇；

【导师】 周立发；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2003， 博士

【摘要】 鄂尔多斯盆地是一个多旋回叠合型盆地，其形成历史早、演化时间长。同时又是我国陆上第二大沉积盆地，油气资源非常丰富，油气勘探潜力很大。它已经成为我国未来油气勘探最重要的战略地区之一，其油气资源丰度及其探明程度直接影响着中国石油工业的发展，为了客观地总结鄂尔多斯盆地油气分布规律，有必要开展鄂尔多斯盆地构造沉积演化与天然气聚集研究。 本文以板块构造理论为基础；以含油气盆地整体、动态、综合分析研究为原则；以古亚洲、特提斯、滨太平洋三大构造域交切、叠合和复合，控制和影响着鄂尔多斯盆地在不同构造演化阶段的形成和发育为指导思想。采用野外地质调查与室内综合研究相结合，通过构造层序的划分及其相应盆地原型的确定、不同期次古构造应力场的分析、以297口探井数据为基础的相关构造图件的编制、奥陶系残余生烃坳陷及其迁移规律研究等的综合分析，开展了盆地基底以及盆地断裂系统、盆地及邻区构造与沉积演化、盆地原型及其形成的动力学背景、奥陶系产气层不同时期的古构造格局及其演化、不同期次构造应力场形成的不同世代盆地之间的叠置关系以及盆地改造与天然气藏的形成、重新分配和最终就位诸方面的研究。通过研究有以下成果及认识： 鄂尔多斯盆地及其周缘地区沉积盖层可划分为五大构造层序，盆地的形成和演化分为六大构造阶段：太古代至古元古代基底形成阶段、中新元古代克拉通内裂陷槽或坳拉槽演化阶段、震旦纪—早古生代华北陆表海盆演化阶段、晚古生代—早中生代华北克拉通坳陷演化阶段、中生代中晚期大鄂尔多斯内陆盆地演化阶段及独立鄂尔多斯盆地的形成、新生代周缘断陷盆地演化阶段。 盆地不同的构造沉积演化阶段受不同的构造动力体系控制。中新元古代为大陆裂谷集中发育阶段；古生代主要受控于古亚洲构造动力学体系；中生代主要受控于中特提斯—古太平洋构造动力体系的联合作用和影响，其中早期（T）主要受特提斯动力体系影响，晚期（J₃-K）主要受古太平洋动力体系影响；新生代主要受控于新特提斯—今太平洋构造动力体系的联合作用和影响。 将鄂尔多斯盆地的断裂构造造划分为盆地周缘断裂系统、盆地基底断裂系统、盆地盖层断裂系统和盆地盖层裂缝系统。盆地基底断裂最为发育，且主要发育NE向和EW向两个方向断裂，其中EW向断裂带和NE向的断裂带与油气关系最为密切。 裂缝系统以发育垂直裂缝为主，可形成于不同时期，常成对出现共同组成平 n中文摘要面X型共扼剪节理，现今的裂缝性质是喜山期最终作用的结果。裂缝的发育极大地改善了鄂尔多斯盆地低渗储层的储集性能，是控制油气最终就位和聚集的主要因素。 鄂尔多斯盆地中部气田地区存在一中部坳陷带一即乌审旗一靖边一安塞一甘泉坳陷带，该中部坳陷带并非沉积坳陷，而是加里东、早华力西运动构造改造后的残余地层分布坳陷带一即构造坳陷带.同时靖边一米脂地区又是马家沟组的一残余生烃坳陷，可视为中部坳陷带的一个次级构造单元，主生烃坳陷中心大致在陕参1井一带.中部坳陷带、残余生烃坳陷和中部气田分布范围的叠合，反映了它们之间内在的成生联系，表明中部气田的分布明显受控于中部坳陷带。 不同期次的盆地构造应力场研究表明:盆地区域主压应力场方向在加里东期呈NNE一SSw向和近sN向，主要是晚奥陶世以来秦岭洋盆向北俯冲并与华北板块碰撞的结果;印支期主要呈NW一SE向和NNE一SSW向、SN向，主要受中特提斯构造动力体系中羌塘地块与欧亚大陆碰撞拼贴产生的远程构造效应影响，西北缘呈NW一SE向为派生;燕山期主要呈NW一SB向，主要受古太平洋大陆板块与欧亚大陆板块碰撞远程构造效应影响，盆地西南缘呈NE一SW向;喜马拉雅期呈NNE一SSW向，主要受新特提斯构造动力体系和今太平洋构造动力体系联合作用影响，即今太平洋板块和印度板块与欧亚板块俯冲碰撞有关。 构造裂缝系统控制着奥陶系储集层的发育和天然气的聚集。强度较大的加里东期和燕山期构造应力场决定了盆地内裂缝系统的形成和演化，喜马拉雅期构造应力场决定了古生界天然气藏的最终就位空间，不同时期、不同性质、不同规模裂缝系统的交汇部位，通常都是天然气运移和聚集的主要场所，裂缝密集带及其相互交汇处通常又决定着天然气的高产部位。各时期构造应力场都程度不等的决定着天然气运移通道及其指向，决定着圈闭中天然气的聚集及其再分布。 鸟审旗一志丹南北一线为一构造转换枢纽带，是下古生界天然气主要聚集区。加里东一华力西期，它是整体西高东低构造背景上的一个次级开阔坳陷带;印支期基本构造面貌并未发生大的变化;燕山早中期，它作为一个独立完整的坳陷带存在;在燕山晚期区域构造反转，使东部抬升，西部下降，到早白全世末转变成为靖边一志丹料坡带.该构造转换枢纽带，在整个油气运聚史中，它是左右逢源、上下逢源，从而成为下古生界天然气聚集带并形成了世界级的中部大气田。更多还原

【Abstract】 Ordos Basin is a polycyclic superposition basin that is formed in an earlier geological history and has experienced a longer evolution. At the same time, it is the second largest sedimentary basin on land in China that possesses abundant oil and gas resources and has bright prospects in oil and gas exploration. It has been becoming one of the important tactical areas in oil and gas exploration in China. The amount of oil and gas resources and the degree up which it is proven will directly influence the Chinese petroleum industry. In order to summarize the rules of hydrocarbon accumulation and distribution in Ordos Basin objectively, it is necessary to research the tectonic sedimentary evolution and the accumulation of natural gas.The research base on the theories of plate tectonics, use the method that oil and gas basin is analyzed integrally, dynamically and comprehensively, and obey the principle that intersection, superposition and compound of the three tectonic domains (the paleo-Asian, the Tethyan and the circum-pacific) control and influence the formation and development of Ordos Basin in different tectonic stages. The investigation in the field was combined with research indoors. By classifying tectonic sequence, confirming corresponding prototype basin, analyzing paleo-tectonic stress fields in different periods, plotting correlative tectonic map based on 297 explore wells, and analyzing the traits of the remaining depressions producing hydrocarbon and their migration rules in the Ordovician, the author studied the basement of the basin; the fault system of the basin; the tectonic-sedimentary evolution of the basin and its circumference areas; the prototype basin and corresponding dynamics background; the paleo-tectonic pattern and its evolution in the layers of producing gas in different periods of Ordovician; the superposition relationship among the different period basins formed by different stress fields; the reformation of the basin and the formation, redistribution and final emplacement of the gas pools. Some conclusions are listed as follows:The plateform cover cap of Ordos Basin and its circumference areas can be divided into five tectonic sequences. The tectonic evolution of Ordos Basin can be classified in six stages: the basement formation phase (from Archeozoic to Paleoproterozoic); the aulacogen phase (from Mesoproterozoic to Neoproterozoic); the North China continental sea phase (from Sinian to early-Paleozoic); the north china intracratonic depression phase (from late-Paleozoic to early Mesozoic); large Ordos inland basin phase and the formation of independent Ordos Basin (Mid-Late Mesozoic); fault basin phase around the Ordos Basin (Cenozoic).The different evolution stages of tectonic sedimentary development were controlled by the different tectonic dynamic systems. The main continent rift developed in Mid-Late Proterozoic; the paleo-Asian tectonic dynamic system played an important role in the Paleozoic period; the combination of Tethys-paleopacific tectonic dynamic system influenced the basin in Mesozoic. During that period, the Tethyan dynamic system affected the basin in the early stage (T) while paleo-pacific dynamic system affected it in the latter stage (Js-K); the new Tethyan -circum pacific tectonic dynamic system dominated in Cenozoic period.The fault system of the Ordos Basin includes the basin-surroundings fault system, the basement fault system, the platform cover fault system, and the platform cover fracture system. The basement fault system was developed by two sets, the NE direction fault and the EW direction fault, which closely connect with the oil and gas accumulation.The fracture system was mainly made up of vertical fractures which were developed in different phases and showing themselves by plane X-conjugate joint systems. The current fracture character is the result of the Himalayan movement. The development of the fractures has obviously improved the character of reservoirs of Ordos Basin and controlled the accumulation of oil and gas.There更多还原