陕西直罗油田长_2油层组储层特征

直罗油田主力产层为三叠系延长组长2油层组，储层以三角洲分支河道砂体为主，岩性主要为长石细砂岩，大量的自生矿物对原生孔隙产生了很大程度的破坏。较强的成岩后生作用使得储层以粒间溶孔及原生粒间余孔为主要储集空间。储层孔隙结构表现为以小孔隙、小喉道为主要特征，非均质性较强。物性分布主要与其在砂体中的分布部位有关。

OIL RESERVOIRS IN THE LAYER NO. 2 OF THE YANCHANG FORMATION IN THE ZHILUO OIL FIELD, SHAANXI

The oil reservior beds occuring in the layer No. 2 of the Triassic Yangchang Formationare the dominant oil production horizons in the Zhiluo oil field. The reservior beds are mainlycomposed of delta distributary channel sand bodies with fine-arkose as main rocks. Becausemost of primary intergranular spaces had been destroyed by plenty of authigenic minerals,the main reservior spaces concentrated among intergranular pores and some remaining poresof the primary intergranular spaces resulted from intensive lithogenesis. The smaller poresand throat - like channels, with intensified nonhomogeneity, are the major characteristicpore structures in the oil reserviors and the distributions of their physical properties are related to the locations of the reserviors in sand bodies.