鄂尔多斯盆地山庄地区长8_(2)段储层非均质性研究

Study on the Heterogeneity of Chang 8_(2)Reservoir in Shanzhuang Area of Ordos Basin

依据储层岩心观察资料、物性测试分析结果及测井数据,对鄂尔多斯盆地山庄地区长8_(2)段储层的层内、层间和平面非均质性进行精细研究。研究认为,层内非均质性在粒度颗粒大小、渗透率、夹层分布的影响下呈中等—强非均质性,垂向砂体韵律特征以复合韵律为主,局部地区表现出较强非均质性。与长8_(2)^(1)段相比,长8_(2)^(2)段的夹层频率、密度和变异系数、突进系数、级差及均质系数均较大,层内非均质性更为显著。受隔层广泛发育的影响,长8_(2)^(1)段的层间非均质性较强。平面上,长8_(2)^(2)段砂体的连通性更差,砂体宽度及物性变化较大,非均质性较强,其剩余油多分布在砂体两侧物性较差的部位。填隙物的后期发育使孔隙结构特征变得更为复杂,增强了储层的非均质性,进而影响了剩余油的分布。

Through the analysis of core observation data,physical property test analysis and logging data of Chang 8_(2)reservoir inShanzhuang area of Ordos Basin,the intra-layer,interlayer and planar heterogeneity of Chang 8_(2)reservoir is carefully studied.The results show that the intra-layer heterogeneity is medium-strong under the influence of particle size,permeability and mezzanine distribution,and the prosthesis characteristics of vertical sand are mainly composite prosody,and some local areas show strong heterogeneity.The interlayer frequency,density and variation coefficient,penetration coefficient,step difference and homogeneous coefficient of Chang 8_(2)^(2)are greater than that of Chang 8_(2)^(1),and the heterogeneity characteristics of intra-layer are more prominent.Affected by the extensive development of the septum,the heterogeneity between the Chang 8_(2)^(1)layers is strong.On the plane,the connectivity of the Chang 8_(2)^(2)sand body is worse,the width and physical properties of the sand body change greatly,and the heterogeneity is strong.The remaining oil is mostly distributed in the parts with poor physical properties on both sides of the sand body.The later development of the filler makes the pore structure characteristics more complex,enhances the heterogeneity of the reservoir,and then affects the distribution law of the remaining oil.