基于核磁共振二维谱的稠油化学驱孔隙尺度动用规律

Experimental study on mechanisms of chemical flooding for heavy oil reservoirs at pore scale based on two-dimensional spectrum technology

为了研究稠油油藏化学冷采技术中复合驱的作用效果,借助二维核磁共振技术对比研究了DJ降黏剂和BHP聚表剂及其复合驱的提高采收率效果、油相流动能力变化及孔隙动用规律。研究表明:复合驱采收率比单一化学驱采收率高,2种药剂的协同作用明显;通过核磁共振测试得到的T2谱和扩散系数与相对幅度的关系,得出2种降黏剂均能不同程度地有效降低稠油黏度,增大油相的流动能力,并且大孔隙的动用程度明显高于小孔隙的动用程度,复合驱在大小孔隙中均有较好的提高稠油动用程度的效果。

In order to study the effect of compound flooding in chemical cold production technology of heavy oil reservoir,this paper makes a comparative study of two kinds of agents,DJ viscosity reducer and BHP polymeric surfactant,and their combination flooding to improve the recovery efficiency,change of flow capacity of oil phase and pore mobilization patterns by means of two-dimensional nuclear magnetic resonance technology.The results show that the recovery efficiency of combination flooding is higher than that of single chemical flooding,and the synergistic effect of the two chemicals is obvious.According to the relation between T2 spectrum or diffusion coefficient and relative amplitude obtained by nuclear magnetic resonance test,it is concluded that both kinds of viscosity reducers can effectively reduce viscous oil viscosity and increase the flow capacity of oil phase in varying degrees.Moreover,the production degree of macropore is obviously higher than that of micropore,and combination flooding has a better effect on improving the production degree of heavy oil in both large and small pores.