核磁共振技术采油机理

Oil recovery mechanism using nuclear magnetic resonance technology

在深入研究新疆克拉玛依油田八区下乌尔禾组砾岩油藏储层特征的基础上,应用核磁共振技术研究采油机理。在实验室内对同一岩样分别进行水驱油实验和渗吸实验,研究不同开采方式下油水分布、采出程度及孔隙动用特征。结果表明:小孔隙占总的孔隙体积的50%以上,中孔隙和大孔隙各占20%以上,水驱采油主要发生在大孔隙和中空隙中,小空隙所做贡献很小。渗吸采油时,小孔隙内的油是采出程度得主要贡献,与水驱采油的情况明显不同。但渗吸总体采出程度比较低,渗吸速度较慢。因此水驱采油是该地区低渗透砾岩储层采油的主要技术,渗吸作用可以有效动用小孔隙,是水驱采油的补充。

For Wuerheensis group conglomerate oil reservoir in eight block of Karamaica Oil Field in Xinjiang,there is no positive effect infilling time and again or strengthening water injection.And the development mechanism is not very clear.After study on reservoir characterization,some researches are carried out on the oil recovery mechanism using nuclear magnetic resonance technology.Water/oil displacement and imbibition researches are made respectively for the same rock sample,studying water/oil distribution,degree of reserve recovery and pore producing characteristics under different producing method.Researches show that fine pores account for 50 percent of the total pore volume,and mesopores and macropores account for more than 20 percent respectively.Waterflood production mainly occurs in mesopores and macropores,and fine pores almost have no contribution.Differently,Imbibition displacement mainly occurs in fine pores,and as imbibition velocity is slow,the general degree of reserve recovery is lower.So for this low-permeability conglomerate oil reservoir,water/oil displacement is the major producing method,and imbibition displacement is the supplementary method as it can produce oil in fine pores.