鄂尔多斯盆地南212井区长4+5^(2)储层的非均质性

Study on Heterogeneity of Chang 4+5^(2) Reservoir in N212 Wellblock of Ordos Basin

南泥湾油田延长组长4+5油层组砂体厚度,分布规模在纵、横向变化较大,不同小层储层孔隙结构、物性差异明显,导致储层非均质性强,增大了剩余油分布预测的难度。为了深入研究储层非均质性,高效开发储层剩余油,通过岩心观察、铸体薄片鉴定、物性测试实验及扫描电镜分析,对南212井区长4+5^(2)储层的长4+52-1和长4+5^(2-2)这2个小层非均质性进行详细研究。结果表明:长4+5^(2-1)小层的层间非均质性强于长4+5^(2-2),其平面非均质性弱于长4+5^(2-2),两个小层的层内非均质性整体差异不大,而长4+5^(2-1)的微观非均质性强于长4+5^(2-2)。

The sand body thickness and distribution scale of Chang 4+5 reservoir of Yanchang Formation in Nanniwan Oilfield vary greatly in vertical and horizontal directions, and the pore structure as well as petrophysical properties of different small layers are obviously distinguished, which results in strong reservoir heterogeneity, and further increases the prediction difficultyfor the distribution of remaining oil.Therefore, the intensive study of reservoir heterogeneity is of great significance for potential tapping of remaining oil and efficient development of the reservoir.The heterogeneity of two layers of Chang 4+5^(2) reservoir in Nan 212 well block was studied in detail by core observation, casting thin section identification, petrophysical property testing and scanning electron microscope analysis.The results show that the interlayer heterogeneity of Chang 4+5^(2-1)is stronger than that of Chang 4+5^(2-2),but the plane heterogeneity of Chang 4+5^(2-1)is weaker than that of Chang 4+5^(2-2).The overall heterogeneity of the two layers has little difference, while the microscopic heterogeneity of Chang 4+5^(2-1)is stronger than that of Chang 4+5^(2-2).