涠西南凹陷流沙港组成岩相与有效储层研究

在岩石薄片、粘土X 衍射、镜质体反射率研究基础上，划分流沙港组砂岩于早成岩B 至中成岩B 阶段，通过成岩参数定量分析，区分8 种成岩相，厘定了压实是主要成岩作用。研究区中深层存在差异孔隙演化，岩石类型与成岩差异对孔隙演化起控制作用。根据地层测试、岩类孔渗关系综合确定常规有效储层渗透率下限为5 mD。采用经验公式法作为基本孔隙演化模型，孔隙预测误差为0.2%2.8%。建立以孔隙度、渗透率、岩石类型、压力、产能多因素约束的精细度储层分类。中等—好储层类型与三角洲水下分流河道和中等压实成岩相有关。同深度背景条件下，湖底扇浊流储层性质比三角洲滩坝差。

Study on the Diagenetic Facies and Effective Clastic Reservoirs in Liushagang Formation of Weixinan Sag

Based on thin-section，clay X-ray diffraction and vitrinite reflectance，diagenetic stage of Liushagang Formationis determined to be early B to middle B. According to quantitative analysis of diagenetic parameters，eight diagenetic faciesare determined the main diagenesis among which is comparison. different pore evolution exists middle-deep interval，whichis mainly controlled by rock types and diagenetic difference. Formation test and pore-permeability relationship are applied todraw a conclusion that lower limit of permeability is 5 mD. Empirical formula is used as basic pore evolution model and theerror of porosity prediction is 0.2% to 2.8%. The division of clastic reservoir types is found by porosity，permeability，rocktype，pressure and production capability. The better to best reservoir types are related to delta front underwater channels andmoderate compaction facies. The reservoir property of basin-lake fan is poorer than delta sandbar at the same depth.