鄂尔多斯盆地西峰油田三叠系延长组长6—8段储层砂岩成岩作用研究

鄂尔多斯盆地西峰油田的储集岩—三叠系延长组长 6— 8段砂岩是典型的低孔低渗储集岩 ,具有粒径细、成分成熟度低、磨圆度较差、分选性较好的特点。运用薄片鉴定、粘土矿物、稳定同位素分析及物性分析等资料 ,研究了延长组长 6— 8段的成岩作用特征 ,分析了它们对储层物性的影响状况 ,确定了储层砂岩的成岩作用阶段 ,指出西峰油田优质储层的发育取决于储集砂岩中粘土膜形成作用。

海相碳酸盐岩储层实验分析技术进展及应用

中国石油集团碳酸盐岩储层重点实验室经过近10年的建设和发展,初步形成了岩石组分与结构分析、储层地球化学实验分析、孔隙形成与分布模拟实验、储层地质建模和基于储层地质模型的地震储层预测5项技术系列,为碳酸盐岩沉积储层研究提供了一站式解决方案。本文重点阐述了岩石组分与结构分析和储层地球化学实验分析2项技术系列的技术内涵、技术进展及应用。岩石组分与结构分析主要从不同角度开展岩石结构和矿物成分分析,是碳酸盐岩沉积储层研究最基础的工作,为深化沉积储层认识提供了手段。储层地球化学实验分析主要包括同位素和元素地球化学检测,在碳酸盐岩储层成因与分布规律研究中得到广泛的应用,其中碳酸盐矿物激光原位U-Pb同位素定年、团簇同位素、激光原位碳氧稳定同位素在线取样测定和微量-稀土元素激光面扫描成像等技术是近几年开发的核心技术,也体现了储层地球化学实验分析技术从全岩溶液法到激光原位法再到激光面扫描成像的技术发展趋势。

天然气同位素特征及作用

利用天然气同位素组成在油气扩散和对流中的差异、碳氢同位素组成与原来所作断块图的对比、天然气在储层内混合的同位素组成平衡原理和天然气成因与同位素变化之间的制约关系等特征，能有效地判识砂体连通性划分储集流体单元；可确定油气水界面和压力系统，使断块划分更加准确，进一步完善断块图，进行油藏精细描述；能确定不同源岩层所作的贡献，进而对混层开采进行配产，并能为下伏油藏的存在提供快速的判识。

Reservoir geochemistry of the Tazhong Oilfield in the Tarim Basin, China, Part II. Migration, accumulation and mixing of crude oils

Measurements of the absolute and relative concentrations of nitrogen-containing compounds in crude oils from different reservoir strata (Ordovician, Silurian and Carboniferous) in the Tazhong region of the Tarim Basin, Xinjiang, China, showed that even though there are quite a number of factors affecting the distributional and compositional characteristics of neutral nitrogen-containing compounds in crude oils, the distributional and compositional characteristics of crude oils whose source conditions are approximate to one another are influenced mainly by the migration and fractionation effects in the process of formation of oil reservoirs. In addition, crude oils in the Tazhong region show obvious migration-fractionation effects in the vertical direction. Carboniferous crude oils are characterized by high migration parameters and low compound concentrations, just in contrast to Ordovician crude oils. This indicates that crude oils from shallow-level oil reservoirs were derived from those of deep-level oil reservoirs via faults, unconformable contact or carrier beds. Crude oils from the Tazhong region show some migration-fractionation effects in the lateral direction, but mixing of crude oils derived from different hydrocarbon source rocks in the process of formation of oil reservoirs made it more complicated the migration and accumulation of crude oils, as well as the formation of oil reservoirs.