【作者】 付金华；

【导师】 刘池阳；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2004， 博士

【摘要】 针对鄂尔多斯盆地上古生界低孔、低渗、低丰度、大面积分布的隐蔽性气藏的特点，在综合前人研究成果和已有勘探资料的基础上，综合运用了沉积学、流体化学、石油地质学等最新理论和进展，立足全盆地区域地质大背景，以上古生界沉积特征与后期演变为基础，以典型气藏解剖为手段，以天然气运聚成藏为线索，以高渗储层成因与天然气富集规律为重点，系统分析和研究了盆地上古生界大面积岩性气藏成藏地质条件、成藏模式，高效储层形成机理、天然气分布规律及有利勘探目标的选择。 在地层划分和沉积体系研究基础上，采用T.A.Cross倡导的高分辨率层序地层学理论体系及研究方法，根据基准面升降旋回特点及等时对比原则、综合利用露头、钻井、地震和测井资料，将本溪组至下石盒子组的地层划分为3个长期旋回和14个中期旋回、中期旋回内又各包含若干短期旋回。 利用包体测温、自生石英的氧同位素测定、方解石胶结物的电子探针和同位素分析等先进分析测试技术，结合水岩反映理论，建立了煤系地层的成岩模式和相应的时间温度模型和孔隙演化模式，为高效储层的寻找提供了依据。 以有效烃源岩评价为起点，以油气的运移聚集为枢纽，以天然气成藏和分布为目标，提出了源内式、近源式和远源式三种天然气成藏组合模式。通过典型气田的解剖，总结了不同天然气成藏组合油气成藏的主要特点及分布模式。 鄂尔多斯盆地上古生界天然气富集的主要控制因素是：①构造热事件主导了上古生界天然气的生成。盆地晚中生代存在一次明显的构造热事件，导致上古生界天然气的生成表现为一个相对集中的事件，主要在晚侏罗世至早白垩世末期完成，该期生气速率达到0.2×10~8m~3／km~2·Ma以上；②提出了上古生界天然气近距离运聚成藏模式。天然气生气强度控制了气田的分布，平面上，气田主要分布在生气强度大于20×10~8m~3／km~2的地区；纵向上，太原、山西组气源层内部及其附近成为天然气聚集的主要层位；③三角洲的沉积环境及沉积作用对油气的富集具有明显的控制作用，三角洲平原分流河道及三角洲前缘水下分流河道砂体为主的沉积区是天然气富集的主要区域；④高效储层是天然气富集的主要场所。高效储层主要控制因素包括古地形条件、构造演化和沉积相带、砂体的沉积特征、成岩作用、火山物质的溶蚀作用、裂缝的改善作用。其中，同沉积火山物质在成岩后期的溶蚀是形成以次生孔隙为主高效储层的关键因素，烃类早期进入有利于形成以原生孔隙为主的高效储层。 在成藏主控因素分析的基础上，指出盆地中部陕北斜坡大型岩性气藏分布区仍是目前天然气勘探的主攻方向，西部的西缘逆冲带和天环坳陷是构造气藏勘探的重要领域，北部伊盟隆起和南部渭北隆起是天然气勘探的战略接替区。更多还原

【Abstract】 Aiming at the subtle gas reservoirs characteristic of low pore, low permeability, low abundance and large area’s distribution of the upper Paleozoic in Ordos basin, in the way of studying typical gas reservoirs, in the clue of the gas migration and on the emphasis of high permeability reservoir generation and accumulation regulation, the paper is based on the existing research data , combined with the new theory and progress of the sedimentology, fluid chemistry, petroleum geology, etc, and analyzes systematically geological condition, accumulation model, high beneficial reservoir formation mechanics, distribution regulation of the lithological reservoirs , and points the valid exploration.On the basis of stratigraphic classification and depositional system study, the high resolution sequence stratigraphy theory and way, initiated by T.A.Cross, is adopted in this paper. According to datum lever jacking cycle , isochronous correlation principle and the data of outcrop, drilling, seismic and logging, the strata from Benxi formation to later Shihezi formation is divided into three long cycles and fourteen middle cycles ,and middle cycles are been divided into many short cycles.Using the advanced analysis technology, such as inclusion measuring temperature, calcite cement’s electronic probe and isotope analysis, and the water-core reaction theory, the paper sets up the diagenetic model of coal measures strata, time-temperature model and pore evolutionary model, and provides the basis for seeking the high efficient reservoirs.With the studying of valid hydrocarbon source rock evaluation, oil and gas migration, accumulation, and distribution, the paper puts forward three types of gas accumulation combination: inside source type, near source type and far source type, and explains the main characteristic and distribution models of different gas reservoirs.The main controlling factors about upper Paleozoic gas accumulation in Ordos basin are listed in the following:(1) Structural thermal event mainly control the gas forming of upper Paleozoic. It is the later Mesozoic that formed a clear structural thermal event, and resulted in the course of later Jurassic and early Cretaceous, whose gas generation rate is over 0.2 108m3/km2- Ma.(2) Putting the upper Paleozoic gas proximal migration and accumulation models. Gas field’s distribution is controlled by gas generation intensity, and it distributed at the region that gas generation intensity large than 20 108m3/km2 from plane, at the same time, the main gas accumulation horizon is inside or near of Taiyuan formation and Shanxi formation.(3) Deltaic sedimentary environment and sedimentation mainly contribute to oil and gas’s accumulation, and the main accumulation regions are distributary channel sandstones of deltaic plain, and underwater distributary channel sandstones of deltaic front.(4) High efficient reservoir is the main place of gas accumulation. Its main controlling factors include ancient landform condition, structural evolution, sedimentary facies, sedimentary characteristic of sandstones, diagenesis, corrosion of volcanics and betterment of fracture. Amongthem, later diagenesis corrosion of consedimental volcanics is the key factor of high efficient reservoir, which is in the major of secondary pore.Basing on the analyzing the main controlling factors of forming gas reservoirs, it is pointed that the large lithological gas reservoirs distribution region of Shanbei slope in the middle of basin, is still the main exploration region at present, the west reverse faults and Tianhuan depression of structural pool are the important exploration region, the strategy reserve region is the North Yimeng uplift and South Weibei uplift.更多还原