鄂尔多斯盆地延安地区长7段陆相页岩气储层三维地质建模研究

Three-dimensional Geological Modeling of Continental Shale Gas Reservoirs in Chang 7 Member,Yan′an Area,Ordos Basin

以鄂尔多斯盆地延安地区长7段陆相页岩气储层为研究对象,采用petrel 2018建模软件,综合应用确定性建模与随机建模相结合、等时建模和沉积相控建模等建模原则,建立长7段陆相页岩气储层三维构造模型及GR、孔隙度、TOC、吸附气和抗压强度三维属性模型。依据三维地质模型,推导长7段页岩的TOC值、孔隙度值、吸附气量、抗压强度的井间数据,刻画各属性的平面展布特征。结果表明,页岩TOC值分布在0.5%~4.5%之间,TOC高值区位于研究区西南部;页岩孔隙度值分布在2.0%~5.0%之间,孔隙度高值区位于研究区中部;页岩吸附气量分布在0.4~3.5m^(3)/t之间,吸附气量高值区位于研究区西南部;抗压强度分布在80~250MPa之间,抗压强度高值区位于研究区东北部。对三维地质模型进行抽稀验证,实钻数据与模型数据趋势基本一致,该三维地质模型可靠性较高。

Taking the continental shale gas reservoirs of the 7th member of Yanchang Formation in Yan'an area of Ordos Basin as the research object,three-dimensional structural model and three-dimensional attribute model of GR,porosity,TOC,adsorbed gas and compressive strength of the continental shale gas reservoirs in Chang7 Member are established based on modeling principles of the combination of deterministic modeling and stochastic modeling,isochronous modeling and sedimentary facies control modeling by using petrel 2018modeling software.Based on the established three-dimensional geological model,the cross well data of TOC,porosity,adsorbed gas volume and compressive strength of Chang 7 shale in the study area are derived,and the plane distribution characteristics of each attribute are described.The results show that the TOC value of shale distributes between 0.5%-4.5%,and the high TOC value area is located in the southwest of the study area;the porosity of shale is 2.0%-5.0%,and the high porosity area is located in the middle of the study area;the adsorbed gas volume in shale is 0.4-3.5m^(3)/t,and the high value area of adsorbed gas volume is located in the southwest of the study area;the compressive strength of shale is 80-250MPa,and the high compressive strength area is located in the northeast of the study area.The 3D geological model is verified by sampling,and the trend of actual drilling data is basically consistent with that of model data.The 3D ge-ological model has high reliability.