新疆三塘湖盆地牛圈湖区块中侏罗统西山窑组储层特征及储层控制因素

Reservoir Characteristics and Controlling Factors of the Middle Jurassic Xishanyao Formation in Niuquanhu Area,Santanghu Basin,Xinjiang

为了探讨新疆三塘湖盆地牛圈湖区块中侏罗统西山窑组储层特征及储层控制因素,在沉积相研究的基础上,利用铸体薄片、扫描电镜、X-衍射、微米级X-CT扫描、恒速压汞等先进实验对研究区砂岩储层的岩石学特征、储层储集空间类型、尺寸分布、几何形态进行了综合分析,最终探讨了研究区储层品质的控制因素。结果表明:研究区微米级储集空间发育,储层储集空间类型以残余粒间孔、凝灰质溶孔为主,几何形态主要呈条带型;沉积微相类型、成岩作用、微裂缝对储层的物性具有重要控制作用,通过对研究区储层孔隙演化的定量计算,压实过程孔隙度损失为20.31%,压实作用较强;早期、晚期胶结作用造成的孔隙度损失为11.54%;溶蚀作用使得储层孔隙度得到了一定程度的改善,孔隙度增加6.24%。孔隙演化分析计算得出现今储层孔隙度与常规物性分析所得出的西山窑组平均孔隙度结果符合较好,误差仅为1.1%;综合考虑研究区储层物性、沉积特征、微观孔隙结构等因素进行储层综合评价,评价结果表明:研究区以Ⅱ类、Ⅲ类储层为主。

Objectives： Analysis and discussion the reservoir characteristics of the Middle Jurassic Xishanyao Formation in Niuquanhu area,Santanghu basin,Xinjiang. And find the factors which controlling the physical property of reservoir.Methods：Based on the study of sedimentary facies,by using the casting thin sections,scanning electron microscope,X- ray diffraction, micrometer X-CT scanning, the constant speed mercury injection and other advanced experiment,the petrological characteristics,the reservoir space types,the size distribution and the geometry of the reservoir are analyzed,finally discussed the control factors of reservoir quality.Results：The residual intergranular pore and the tuffaceous pore are mainly storage space types of reservoir.The geometry shape of reservoir storage space is mainly belt type. The types of sedimentary micro facies,the diagenesis and the micro cracks play important roles in controlling the properties of the reservoir. Through the quantitative calculation of the reservoir pore evolution,the compaction effect is strong and compaction made reservoir porosity loss about 20. 31%; the early and later cementation caused a total loss of the porosity is 11.54%; the dissolution makes the porosity improved to a certain degree,porosity increased 6. 24%. The result of pore evolution calculation to the Xishanyao Formation is consistent with the result of the conventional property analysis,between the two results error is only 1. 1%.Conclusions：The Reservoir was evaluated by comprehensive consideration the factors of reservoir physical properties,sedimentary characteristics,and microscopic pore structure and so on. Evaluation results showed that the study area is based on the Ⅱ and Ⅲ class reservoirs.