莺歌海盆地东方区黄流组储层微观孔喉特征及对物性的影响

Characteristics of Reservoir Microscopic Pores and Throats and Their Influence on Reservoir Physical Properties in Huangliu Formation of DF Area,Yinggehai Basin

通过恒速压汞实验,结合孔隙度和渗透率的测试,分析了莺歌海盆地东方区黄流组储层微观孔喉特征及其对储层物性的影响。结果表明:东方区黄流组储层以中孔、中—低渗为主,储层物性差异较大;储层孔隙半径分布相对集中,喉道半径及"孔喉比"非均质性较强;物性较差的储层小喉道所占比例较高,"孔喉比"较大,而物性较好的储层大喉道所占比例较高,"孔喉比"较小;喉道大小及其分布是影响储层渗透率大小的关键因素,储层的渗透性主要由所占比例较小的大喉道控制;受沉积作用的影响,莺歌海盆地东方区黄流组储层平均喉道半径小是低渗储层形成的主要原因。

Based on the constant speed mercury injection experiment,as well as the test data of porosity and permeability,characteristics of reservoir micro pores and throats and their influence on reservoir physical properties are analyzed in the Huangliu Formation of DF area,Yinggehai Basin. The results indicate that reservoir physical properties of the Huangliu Formation are mainly characterized by medium porosity and medium-low permeability,but with great differences in DF area. Besides,there is a relatively concentrated distribution of reservoir pore radius,while a strong inhomogeneous distribution of throat radius and the pore-throat ratio. For poor physical property reservoirs,small throats account for a higher percentage,and pore-throat ratio is also higher. On the contrary,for good physical property reservoirs,big throats account for a higher percentage,and pore-throat ratio is lower. The size of throat and its distribution are the key factors that affect the reservoir permeability,which is mainly controlled by large throats with lower percentage. Moreover,affected by sedimentation,small average throat radius of the reservoirs is the main reason for the formation of the low permeability reservoirs in the Huangliu Formation of DF area,Yinggehai Basin.