【作者】 吕瑞文；

【导师】 孙卫；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2010， 硕士

【摘要】 本文通过粒度分析、图象孔隙、铸体薄片、扫描电镜、高压压汞、恒速压汞、油水相渗、微观砂岩模型水驱油、核磁共振、X衍射等实验方法和技术,对吴起油田薛岔区块长6储层进行系统研究,着重分析该区低渗储层的孔隙结构和渗流特征,并探讨沉积作用和成岩作用对该区储层孔隙结构、渗流特征的影响,取得了以下认识：(1)薛岔区块长6储层孔隙、喉道类型多样。孔隙以粒间孔、长石溶孔为主,孔隙组合以溶孔—粒间孔型、微孔型为主,喉道类型以弯片状、片状喉道为主。微孔类型所占比例较大,溶蚀孔相对发育薄弱,是造成研究区储层渗透率较低的原因之一；孔隙连通性差,孔喉配位数低是造成渗透率低的另一原因。(2)喉道是决定低渗透储层渗流能力的关键因素,其中相对粗大的喉道仅占少部分,但对渗透率贡献较大。在进汞初期,总体压力曲线主要与孔隙压力曲线一致,随着进汞压力的不断增加,总体压力曲线的变化趋势主要取决于喉道压力曲线的形态。(3)对储层物性影响较大的孔隙结构参数主要有最大连通喉道半径、中值喉道半径、主流喉道半径、排驱压力、中值压力和均值。喉道半径越大、均值越小,储层岩石的孔隙结构越好,物性越好。(4)真实砂岩微观模型研究表明,岩性、物性、孔隙结构的差异,造成了含油饱和度、驱替样式、残余油类型的不同。研究区长6储层可动流体饱和度、可动流体孔隙度、含油饱和度、驱油效率等参数较低且非均质性强。微观孔隙结构是影响储层可动流体饱和度、可动流体孔隙度、含油饱和度、驱油效率的主要因素。(5)研究区长6储层物性呈明显的相控特点,水下天然堤物性最差,河口坝次之,水下分流河道最好。碎屑颗粒成分成熟度低、结构成熟度中等,与沉积微相共同影响储层物性。机械压实作用和钙质胶结作用导致研究区原生粒间孔损失殆尽,长石、岩屑的溶蚀是次生孔隙发育的主要原因。更多还原

【Abstract】 With the the techniques of grain size analysis, pore image, casting section, SEM, high pressure mercury penetration, rate-controlled mercury penetration, relative permeability, water/oil displacement experiment, NMR, and x-ray diffraction analysis, the thesis makes a thorough research, focusing on reservior’s pore structure and Infiltrating Characteristic of Chang-6 Reservoir in Xuecha Area, and the impact of sediment and diagenesis on pore structure character. The conclusions go as following:(1) The types of reservoir pore and throat are various in Xuecha Area. The main reason of low permeability reservoir in the region of interest is that micro-pores are more than dissolution pores, another reason is that pore connectivity is poor. Low coordination number of pore-throat also can make the low permeability reservoir.(2) Throats is the key factor for the ability of flow in low permeability reservoir, Even though there are a little wider throats,they have made great contributions to the permeability. At the beginning of mercury injection, the total pressure curve and pore preesure cure are consistent. With the increasing of mercury injected pressure,the trend of total pressure curve depends on the form of the throat preesure cure.(3) The parameters which make more effect on reservoir in the region of interest are as following:principal stream throat radius, maximum throat radius, medium radius and mean value,. The wiser the throat radius sizes and the smaller the mean value get, the better the reservoir’s pore structure and the physical property.(4) The results of oil/water displacement experiments demonstrate that different models because of the diversity in lithology, physical property and pore structure display differently in the process of oil saturation, displacement, residual oil type.The parameters of the reservoir in the region of interest are not only low, but also have serious heterogeneity. The micro-pore structure is the crucial factor affecting these parameters.(5) The physical property is obviously controlled by the sedimentary facies, underwater distributary channel’s physical property is better than underwater natural barrier s.Although under the same diagenetic histories, the intensity of diagenesis function is differert. Therefore, there are different porosity evolution histories, which are embodied the discrepancies of pore struetures and reservoir properties.更多还原