为准确评价延长油田长7致密油储层流体可动用性,利用核磁共振结合高速离心对延长油田长7致密油储层T2截止值进行标定,对可动流体百分数和不同级别大小孔隙中流体控制量进行深入分析.对比了中国典型致密油区的可动流体百分数分布特征.通过CT、高压压汞、恒速压汞,从微观孔隙结构角度详细分析了流体可动用性的内在控制因素.研究表明:延长油田长7致密油储层饱和水状态T2图谱可分为4类,T2截止值介于1.7~11 ms之间.可动流体主要来自亚微米空间,储层60%以上的流体控制于纳米级空间.0.05×10 -3μm2以下储层可动流体百分数低于30%,储层难以动用.延长致密油可动用性好于大庆和大港致密油储层.储层致密是影响储层流体可动用性的关键因素.
For the movable fluids of Chang 7 tight reservoir in Yanchang Oilfield being better estimated, With NMR and centrifugation,the T2cut off was gotten and the movable fluids were analyzed.The movable fluids varia-tion characteristics of the typical tight oil fields in China were contrasted.And the essential influencing factors were analyzed in detail by using the CT, mercury injection with high pressure and mercury injection with constant rate technology.The results indicate that there are 4 types of T2curves,the value of T2cut off is 1.7~11 ms.Movable fluids are mainly contributed by the sub-microscale space.Over 60%is storage in nanoscale space for fluid in tight reservoirs.The percent of movable fluids is lower than 30%for reservoirs with permeability lower than 0.05×10 -3 μm2.Therefore,the reservoirs are very difficult to be developed.The movable fluids percentage of Yanchang tight reservoir is bigger than that of Daqing and Dagang tight reservoirs.The key factor influencing movable fluids is that the reservoir is too tight.