【作者】 李仲东；

【导师】 施泽进；

【作者基本信息】 成都理工大学 ， 矿产普查与勘探， 2006， 博士

【摘要】 含油气盆地异常压力是一种全球性的重要地质现象。越来越多的研究表明，异常压力的形成与油气运移、聚集、成藏等关键作用有着密切的关系，日益受到人们的重视。针对鄂尔多斯盆地上古生界普遍低压异常、储层致密、构造简单，而含气层分散、天然气聚集机理复杂、成藏规律难以把握的特点，论文通过对研究区200多口井地层压力资料的详细研究，系统地分析了塔巴庙、杭锦旗、苏里格庙、榆林等地区地层压力分布规律；分析了压力封存箱的成藏规律；建立了研究区气藏运聚、成藏模式。取得的主要成果如下： （1） 通过压力成因的定量计算和综合分析表明：①“欠压实”作用是压力封存箱内非烃源岩现今高压形成的最主要因素；②生烃作用是烃源岩形成古高压异常的主要因素；③水热作用具有双重性；④构造抬升剥蚀及后期调整期的地温下降、砂岩“回弹”是引起储层古高压下降的主要原因，目前上古压力封存箱是一个高低压相间共存系统。研究发现砂岩声波传播时间、电阻率与深度有较强的规律性，纵向上具分段性，分别反映砂岩的胶结成岩过程的正常压实、建设性与破坏性成岩作用消长发育及次生孔隙的保存与发育的不同阶段。压力封存箱的封隔作用有效地保护了砂岩的次生孔隙，同时在成藏过程中，酸性水对压力封存箱内部砂岩次生孔隙的形成十分有利。 （2） 通过对研究区沉积埋藏史、成烃史、成岩史、地热史的系统研究，结合砂泥岩的压实特征、压力成因演化历史恢复、包裹体分析、地层剥蚀厚度等资料的综合分析，提出了三个关键成压成藏阶段，特别强调了K₂期构造抬升阶段对上古生界气藏形成的重要性，建立了上古生界压力封存箱气藏成藏演化模式。把成烃动力学、流体运动学、成藏动力学与成盆的全过程相联系，揭示了油气从成烃到成藏的内涵，丰富了含油气系统理论，为正确划分成藏阶段、认识气藏成藏的主控制因素提供了科学依据。 （3） 首次通过对鄂尔多斯盆地北部上古生界压力封存箱的形状和内幕结构研究认为：①各地区压力封存箱的形状不同，最大过剩压力出现的层位不同，控制了主力气层的分布；②封存箱的内幕结构可划分出三种类型，代表了不同的含气性，Ⅰ类产气性最好，Ⅱ类产气性一般，Ⅲ类含气性差；③箱内砂泥岩的不同配置关系，反映了不同的含气组合。该成果为研究压力封存箱内天然气分布及富集规律奠定了理论基础，对稳定的克拉通叠合盆地压力封存箱的油气聚集机理、更多还原

【Abstract】 The abnormal pressure in Petroliferous basin is an universal important geological phenomenon. It is indicated through more and more studies that abnormal overpressure had close relation with hydrocarbon migration and accumulation, which is paid much more attention by geologists. Aiming at the characteristics of universal low abnormal pressure, tight reservoirs, simple tectonics, dispersed gassy beds, complicated mechanism of gas accumulation in upper Paleozoic of Ordos Basin, the distribution pattern of formation pressure in the areas of Tabamiao, Hangjinqi, Sugelimiao and Yulin area etc. is analyzed through the research of pressure data from more than 200 wells in the areas, the rule of hydrocarbon pooling in the compartments is also analyzed, and hydrocarbon migration-accumulation and pooling models are established.Main cognitions and research results are as follows:(1) through quantitative calculation of pressure and synthetical analyse It is indicate through quantitative calculation of pressure and synthetical analyse that: ①under-compaction is the main factor of high pressure on non-source rocks in the compartments at present; ②hydrocarbon generation is the main factor forming ancient high pressure in the source rocks; ③hydrothermal condition has dualism; ④geotemperature falling in tectonic uplift-denudation and the later period and sandstone "springback" are the main factors resulting ancient high pressure dropping in the reservoirs.At present, the pressure compartment is a coexistence system of alternate high and low pressure in upper Paleozoic. It is discovered through the research that there is a better regularity between the acoustic wave traveltime, electrical resistivity of the sandstone and burial depth. The segmentations vertically reflect that different stages, such as the normal, the constructive and destructive diagenesis periods. Pressure compartment protected effectively the development of secondary porosity in the sandstones. At the time of hydrocarbon pooling process, acidic water is very favorable to the development of secondary porosity in the sandstones in the pressure compartment.(2) Three key phases of pressure and hydrocarbon pooling are put forward through the detailed analysis about sedimentary burial history, hydrocarbon-generating history, diagenesis history, geothermal history and combining with the synthetic analysis on compacting characteristic of the sandstone and mudstone, reconstruction history of pressure origin and evolution, inclusion analysis, denuded thickness et. al. The importance of tectonic uplift to gas pooling in upper更多还原