【作者】 刘佳庆；

【导师】 张小莉；

【作者基本信息】 西北大学 ， 固体地球物理， 2009， 硕士

【摘要】 低孔隙度、富含泥质、低渗透率、低含油饱和度的砂岩储集层,常伴随着相对或绝对油层电阻率低现象,使传统的油气测井评价方法解释精度下降,可能造成油气层漏失甚至误判。近年来油气资源需求量日益增加,系统研究低电阻率油层成因机理和识别评价方法,对油田勘探开发具有重要意义。鄂尔多斯盆地中生界油藏是国内典型的低孔低渗型油气藏,而盆地内三叠系延长组的多个含油层系均有低电阻率油层的发现,且分布广泛,成因复杂。由于低电阻率油层的常规测井响应特征复杂,给油层识别和评价带来很多困难。本论文以吴起胜利山油区长6油层组为研究对象,系统剖析其低阻特征典型的长61油层低电阻率的成因机理及主控因素。在大量收集胜利山区各井的录井资料、岩心分析数据、试油报告、生产数据、水分析数据、薄片、粒度及物性分析测试资料和原始测井曲线数据的基础上,精细分析研究区低电阻率油层的沉积背景、储层地质特征和试油试产特性,并与邻近区域正常油层的各种特征进行对比,找出低阻油层的分布特点和规律,结合压汞曲线、扫描电镜、x衍射、阳离子交换、油水分析等实验结果,总结出吴起胜利山区长6₁低电阻率油层的成因与储层孔隙结构复杂、黏土矿物的种类及含量、高放射性砂岩的影响、沉积微相的影响和少量铁质导电矿物的影响有关。在总结了胜利山区长6₁低阻油层主控因素的基础上,对该区典型井进行了四性关系研究。将储层地质特征、产液特征与测井响应特征有机结合,通过分析储层岩性、物性及含油性以及测井曲线响应特征,确定研究区长6₁油层的“四性”关系。用测井曲线中能够较灵敏地反映储层特征的参数建立测井定量解释模型,针对研究区岩石电导率与含油饱和度之间的关系不符合阿尔奇计算公式的特征,本论文选用部分灵敏参数或参数组合（必要时对部分参数做了放大差异处理）做交会图和重叠图,最终实现了较高精确度识别胜利山区长6₁低电阻率油层的目的。更多还原

【Abstract】 Sandstone reservoirs with low porosity, high clay, low permeability and low saturation are always in connection with low resistivity reservoirs. Because it is difficult to distinguish the features of logging response between oil layer and water layer in low resistivity reservoirs, the conventional logging interpretation methods on fluid identification are always causing poor application. These days, demand for hydrocarbon resources are increasing ,so, it is necessary to find out the contributing factors for low resistivity reservoirs and develop the proper logging recognition methods.Mesozoic reservoirs of Ordos Basin are featured as low porosity and low permeability. The low resistivity oil reservoirs can be found in Many sections of the upper Triassic Yanchang formation in Ordos Basin. As a kind of unconventional reservoirs, oil and gas layers with low resistivity are dominated by many factors directly or not. Conventional log usually leads to mis-perforation or stratum skip, and brings adverse effect to the oilfield development performance.This paper analyzed the characteristics of the 6th sections of the Triassic Yanchang formation in Wuqi shenglishan area .The aim is to find out the main causes of the low resistivity pay zone. Based on the detailed information of the basic geological character of the reservoir(sandstone distribution pattern, lithology character, physical characteristics, water characteristics , clay minerals , cementation material and its change in plane) and testing for oil , this paper focus on the differences of oil layers with low resistivity and normal resistive zone. By the data of core analysis ,log, scanning electronmicro scope , porosity and permeability analysis, X-diffraction, acoustic emission test and mercury injection test, the main causes of low resistivity reservoirs in Shenglishan area were defined: Complicated pore structures in low porosity and permeability reservoirs will affect the productivity and electric properties of reservoirs; The additional conductivity for clay minerals dues to their sorts , contents and the clay in the formation and the invasion influence of drilling mud on the oil pay resistivity; The affection of sandstone reservoirs with high natural gamma ray existed; The influence by micro-sedimentary facies; Some ferruginous conductive mineral. Based on the main causes of the low resistivity pay zone, compare the lithology character, physical characteristics, oiliness character and electric properties of reservoirs. The rule of them can be analyzed.According to actual conditions of region of interest, this paper calculate the total porosity ,clay content and several parameters of the model, these parameters were matching the core analysis data in Shenglishan low resistivity pay zone. As the Archie’s equation can not be used to compute Sw. cross plot, mathematics and comprehensive analyzing are put forward to identify oil layers qualitatively constrained by geological conditions, and the effects are satisfactory.更多还原