鄂尔多斯盆地长6砂质碎屑流储层特征

通过岩心观察及铸体薄片、扫描电镜、压汞、物性测试等资料,系统研究了鄂尔多斯盆地长6砂质碎屑流储层特征。研究表明,长6砂岩为块状砂岩和含漂浮泥砾砂岩,成分和结构成熟度低,目前处于中成岩阶段A亚期,强压实和胶结作用致使其成为低~特低孔隙度、超低渗透率储层;储集空间主要为剩余原生粒间孔和颗粒内溶蚀次生孔,具有孔喉半径小、连通性和渗流能力差的孔喉特征,较大孔喉是决定和改善储层渗透性的重要因素。块状砂岩物性最好,是目前超低渗油藏增储上产的首选层位。

Characteristics of sandy debris flow reservoirfrom Chang 6 formation in Ordos basin

Characteristics of sandy debris flow reservoir from Chang 6 formation in Ordos basin were studied systematically based on core observations, physical properties, casting thin-sections, scanning electron microscope observations, mercury injection analysis. The research shows the sandy debris flow reservoir is mainly composed of sandstones showing massive bedding and floating muddySgravel, has the characteristics of low compositional maturity and texture maturity, has already been in the first stage of the middle diagenetic phase, and belongs to low to extra-low porosity and super-low permeability becase of intense compaction and cementation. The main reservoir space types are the residual original intergranular pore and the intragranular secondary pore. The feature of reservoir pore throat structure is characterized by microscope throat, poor connectedness and weak percolation capacity. The coarse throat is the significant factor for improving permeability. Massive sandstone has the best physical properties and is at present the preferred target of increasing reserves and production on extra-low permeability reservoir.