大庆油田三元复合驱液与储层岩心反应性研究

Study on the reaction of alkali/surfactant/polymer and reservoir cores in Daqing Oilfield

关键词:  大庆油田  三元复合驱  储层岩心  动力学方程  反应机理  技术建议 

Key words:  Daqing Oilfield  ASP  reservoir core  kinetics equation  reaction mechanism  technical proposal

摘要:

三元复合驱技术能够显著提高石油的采收率,但在生产过程中,三元复合注入液易与储层岩心反应并结垢,造成井下堵塞,采收率降低。因此,研究了三元复合驱液在储层中的溶、运、堵规律。采用X射线衍射(XRD)、傅里叶转换红外光谱(FT-IR)、偏光显微镜(PM)、环境扫描电镜(ESEM) 及X射线能谱仪(EDS)测试手段,分析了大庆油田储层岩心与三元复合驱液作用的反应过程,并通过反应动力学计算得到了相应的Si、Al溶出动力学方程。结果 显示,南五区、杏树岗、喇嘛甸岩心碱溶50天后,分别生成钠长石、黝方石、铵长石,Si溶出量约为Al的3～4倍,Al的动力学方程为幂函数形式。建议将强碱物质NaOH改为钾或钙性碱物质。 

Abstract:

The alkali/surfactant/polymer (ASP) flooding technology can significantly enhance oil recovery, but the ASP injection fluid can easily react with reservoir cores, resulting in scaling, plugging and the recovery rate reducing. So it is necessary to study dissolution, transportation and plugging rules of ASP in reservoir. In this paper, the reaction process of ASP and reservoir cores in Daqing Oilfield was analyzed by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), polarizing microscope(PM), environmental scanning electron micoscope(ESEM) and energy dispersive spectroscopy(EDS). The study on reaction kinetics was conducted and the dissolution kinetics equations of Si and Al were calculated. The results show that albite, nosean, buddingtonite are respectively formed in Nanwuqu, Xingshugang, and Lamadian cores after 50 days. The dissolved amount of Si is three to four times than that of Al and the kinetics equations of Al are in the power function form. The replacement of NaOH with KOH or Ca(OH)₂ is advised.