【作者】 刘锐娥；

【导师】 赵重远；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2004， 博士

【摘要】 本文针对鄂尔多斯盆地北部上古生界碎屑岩储层的特征，运用岩石物理模拟实验和地质理论分析相结合的方法，揭示了高效储层的成因机理及主控因素，建立了次生孔隙成因演化模式，预测的有利勘探目标直接指导了油田上古生界勘探方向的转移。研究成果及创新在于： 依据露头区基岩特征、探井基岩岩性特征、区域性不整合面、砂岩碎屑组分标型特征、区域大地构造背景分析，证实研究区物源方向主要来此北部，首次提出了东西部物源差异。 明确提出了鄂尔多斯盆地北部上古生界砂岩高效储层的主要储集空间为各种类型的溶蚀孔隙和残余粒间孔，明确提出易溶组分特别是蚀变凝灰质的溶蚀是形成苏里格气田盒8次生孔隙的主要成因。 提出了有机酸和无机酸的溶蚀机制差异，无机酸和凝灰质等易溶组分反应形成高岭石、石英，钾、钠离子被流体带出，产生孔隙；有机酸对凝灰质等易溶组分的溶蚀与无机酸不同，有机酸可使凝灰质中的Al³⁺形成络合物，被流体带走而产生孔隙，凝灰质的铸模孔可能与凝灰质在有机酸中的溶蚀有关。 在本区首次利用环境扫描电镜等先进技术开展了不同类型砂岩的酸溶模拟实验，通过实验证实在弱酸介质条件下，凝灰质石英砂岩溶蚀最为强烈，长石具有不明显的溶蚀，石英砂岩未发生溶蚀，且随酸度增加凝灰质砂岩溶蚀量加大。 首次提出了研究区次生孔隙的四种成因，即①构造微裂缝溶蚀型，②杂基裂隙化溶蚀型，③碳酸盐矿物埋藏溶蚀型和④铝硅质组分埋藏、交代、溶蚀型。建立了苏里格地区盒8段石英砂岩储层的次生孔隙演化模式。预测出榆林南、天环北两个有利勘探目标，西部前陆一个潜在勘探目标。 研究成果直接指导了油田分公司上古天然气勘探重点由神木地区向榆林地区的转移，并使榆林地区的勘探取得重大突破，获得一批高产工业气流井，形成2000×10⁸m³以上规模的富气区。同时通过研究提出的天环北、西部前陆也已引起油田公司高度重视。更多还原

【Abstract】 By the methods of combining the lab of rock physical simulation with geology theory analysis, the characteristics of the terrigenous clastic rock reservoir of upper Palaeozoic in the north of Ordos Basin have been studied. It reveals the forming mechanism and the key controlling factors of the effective reservoir and establishes the secondary pore evolution models in Ordos Basin. The predicted advantageous exploitation objects by this have changed the exploitation direction in upper Palaeozoic. The results and the creations in the paper are as follows:Based on the outcrop character, lithology character of exploitation well, the regional disconformity interface, the standard character of detrital composition in sandstone and the regional geotectonic background analysis, it is proved that the direction of source is coming from the north of the studied area, and points out the difference of source between the east and the west for the first time.The author bring forward clearly that all sorts of dissolution pores and the residual intergranular pores are the main space of the effective reservoir of upper Palaeozonic in the north of Ordos Basin. The easily-dissolved matters, especially the dissolved of the tuffaceous is the key to form the secondary pores of lower Shihezhi Formation upward in Sulige gas field.It is that the present paper points out the difference of dissolved mechanism between organic acid and inorganic acid. The interaction results of inorganic acid and tuffaceous sandstone produce Kaolinite and Quartz, K+ and Na+ are taken out by liquid and the pores be formed. As for the easily dissolved tuffaceous matters, the dissolution of organic acid is different from inorganic acid. The former can change Al+ of tuffaceous matters into complex compound, and are taken out by the liquid and formed the pores. The tuffaceous mold pores are probably related to the dissolution of tuffaceous matters into organic acid.Using ESEM2020 firstly, the acid dissolved simulation experiment of sorts of sandstone has been done in the field. Under the weak acid medium conditions, the tuffaceous sandstone is easily dissolved, but the feldspar is opposite. The pure sandstone is hardly dissolved, and the amount of dissolution will increases with the rise of the tuffaceous matters.The author put forward firstly four kinds of secondary pore origins, which are the structure microfissure-dissolved digenetic face, the matrix-supported digenetic face, the carbon-dissolved digenetic face, and the siallite-burial-cementing-replacing digenetic face. And it is been established of the secondary pore evolution models of lower Shihezi Formation upwardssandstone reservoirs in Sulige gas field. Two advantageous exploitation objects have been predicted in the south of Yulin and in the north of Tianhuan districts, and there is a potential exploitation object in the west of the foreland.The study in the paper directly lead to the transition of key exploitation from Shenmu district to Yulin , and it brings about great achievements, which gain a series of high-production gas well, with the scale of 2000 X 108m3gas field. Through the study, the north of Tianhuan and the west of foreland basin bring great attention for the oil field leaders.The study results directly lead to the exploitation direction change from Shenmu district to Yulin , and it brings about great achievements, which gain a series of high-production gas well, with the scale of 2000 X 108m3gas field. Through the study, the author provides that the north of Tianhuan and the west of foreland basin are the potential exploitation object. That has brought great attention for the oil field leaders.更多还原