摘要
针对鄂尔多斯盆地长73亚段纹层型页岩油层产油贡献来源不清,油产量主控因素不明等问题,运用岩石力学与渗流力学理论,按照地质工程一体化的理念,对纹层型页岩油层的储集性、渗流性、含油性、流体可动性、可压性进行分析。结果表明:页理不具有特殊的储集和渗流意义,含油性从不是制约页岩油勘探的主要问题;所谓的吸附烃、游离烃、滞留烃等,仅反映了因组分的差异而导致动力黏度存在差异,不能完全反映地层条件下烃类流体的可动性;地层的整体渗流能力、岩石的弹性模量、岩石的抗拉强度和地应力场共同决定了地层的可压性,压裂易于形成垂向裂缝–水平渗流的渗流场,难以形成平行纹层方向的水平向裂缝–垂直渗流的渗流场;油层厚度、孔隙度、含油饱和度、渗透率以及含油面积等宏观因素是决定勘探目标选择成效的关键;上述认识为该类型页岩油勘探部署提供了新的思路。
Aiming at problems such as unclear sources of oil production contribution and unclear of oil production main controlling factors from the laminated shale reservoir of the Chang 73 sub segment in the Ordos Basin, Using the theory of rock mechanics and seepage mechanics, According to the idea of reengineering integration, The reservoir property, percolation property, oil bearing property, fluid mobility and compressibility of laminated shale reservoir are analyzed. Oil content is never the main problem restricting shale oil exploration. The so-called adsorbed hydrocarbon, free hydrocarbon and retained hydrocarbon only reflect the difference in dynamic viscosity caused by the difference in composition, and cannot fully reflect the mobility of hydrocarbon fluid under formation conditions. The overall permeability of the formation, The elastic modulus of rock,the tensile strength and geostress field of the rock together determine the compressibility of the formation. Fracturing is prone to forming a vertical crack horizontal seepage flow field, but it is difficult to form a horizontal crack vertical seepage flow field parallel to the layering direction;The reservoir thickness, porosity, oil saturation,permeability and oil bearing area are the key factors to determine the effectiveness of exploration target selection. The above understanding provides a new idea for the exploration and deployment of this type of shale oil.
