储层致密化影响因素分析与有利成岩相带预测——以马岭油田长8油层组砂岩储层为例

发布时间：2018-11-13 16:39

【摘要】：马岭油田延长组长8油层组属典型的低孔、低渗致密砂岩储层,分析成岩因素对储层致密化的影响,并预测有利成岩相带发育区对寻找有利储层勘探区具有指导意义。通过岩心、铸体薄片、高压压汞、扫描电镜、X射线衍射等分析,研究了长8油层组储层岩石学、孔隙结构、物性特征,探讨了不同成岩作用因素对储层物性的影响,进而建立了成岩相划分标准,预测了有利成岩相带展布。结果表明:长8油层组为低孔、低渗储层,孔喉结构微观非均质性强;砂岩经历了中—强压实、中—强胶结和弱溶蚀成岩改造,压实、硅质胶结及碳酸盐胶结等作用共同促使了储层致密化,伊利石的存在造成了渗透率降低,绿泥石环边胶结、烃类侵位、长石及岩屑的溶蚀作用对储层发育均具有建设性作用,高岭石指示了次生孔隙的形成,但会对渗透率造成破坏;划分出6种成岩相,其中绿泥石-自生石英胶结相与溶蚀相等有利成岩相纵向上发育于长81、长82小层上部与中部,平面上呈透镜状、条带状,与水下分流河道、河口坝砂体具有较好的匹配关系,长81小层有利成岩相发育区规模远大于长82小层。
[Abstract]:Yanchang formation of Yanchang formation in Maling Oilfield is a typical low porosity and low permeability tight sandstone reservoir. The influence of diagenetic factors on reservoir densification is analyzed, and the prediction of favorable diagenetic facies development zone is of guiding significance in finding favorable reservoir exploration area. The petrology, pore structure and physical properties of Chang 8 formation reservoir are studied by means of core, casting sheet, high pressure mercury injection, scanning electron microscope and X-ray diffraction, and the effects of different diagenesis factors on reservoir physical properties are discussed. Furthermore, the criteria of diagenetic facies classification are established, and the distribution of favorable diagenetic facies belts is predicted. The results show that Chang 8 reservoir is low porosity, low permeability reservoir and strong microcosmic heterogeneity of pore throat structure. The sandstone has experienced medium-strong compaction, medium-strong cementation and weak dissolution diagenetic transformation, compaction, siliceous cementation and carbonate cementation, and so on. The existence of Illite has resulted in the decrease of permeability and the cementation of chlorite ring edge. Hydrocarbon emplacement, dissolution of feldspar and lithic debris have constructive effects on reservoir development, kaolinite indicates the formation of secondary pores, but it will destroy permeability. There are 6 diagenetic facies, in which chlorite-authigenic quartz cementation facies and dissolution are equal to favorable diagenetic facies developed longitudinally in Chang 81, upper and middle layers of Chang82 layer, in plane, lenticular and banded, which are similar to underwater distributary channel. Estuarine bar sand body has a good matching relationship, Chang81 small layer favorable diagenetic facies development area scale is much larger than Chang 82 small layer.
【作者单位】：油气藏地质及开发工程国家重点实验室·西南石油大学;西南石油大学地球科学与技术学院;中国石油长庆油田分公司第二采油厂;中国石油集团测井有限公司长庆事业部;
【基金】：国家重大科技专项“中国大型气田形成条件、富集规律及目标评价”(编号:2011ZX05007-004)资助
【分类号】：P618.13

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