硫酸钡结垢对岩心渗透率影响模型研究

发布时间：2018-03-18 04:19

  本文选题：硫酸钡结垢　切入点：动力学模型　出处：《科学技术与工程》2017年31期 　论文类型：期刊论文

【摘要】：油田注水过程中,含SO_4~(2-)的注入水与含Ba~(2+)地层水不配伍将导致硫酸钡垢产生,堵塞地层孔喉,造成严重的渗透率下降。建立合理的数学模型,精确地预测岩心渗透率的变化,对于选择合理的注水方案具有重要意义。首先研究了Bedrikovetsky化学动力学模型,在此基础上优化了模型的求解方法,避免了国内外已有的硫酸钡结垢动力学模型的求解方法中做出的岩心入口端Ba~(2+)与SO_4~(2-)浓度比远小于1的假设;其次,改进了模型中的三个重要参数——扩散系数、反应速率常数和地层损害系数的求取方法;最后,针对来自长庆油田的两块岩心求模型参数,对模型有限差分并在0≤T≤T_f范围内利用Runge-Kutta方法求数值解,得出了驱替至不同孔隙体积倍数时岩心中无因次Ba~(2+)浓度分布、硫酸钡结垢量分布及岩心渗透率比值的变化。结果表明:岩心中有少量的硫酸钡垢生成时,渗透率便迅速下降。随着驱替孔隙体积倍数增加,岩心中Ba~(2+)含量减小;SO_4~(2-)含量增加;岩心中结垢量增大;岩心的渗透率降低。
[Abstract]:In the process of oil field water injection, the incompatibility of injected water with Ba~(2) will lead to barium sulfate scale, block formation pore and throat, and cause serious permeability decline. A reasonable mathematical model is established to accurately predict the change of core permeability. It is of great significance to select a reasonable water injection scheme. Firstly, the chemical kinetic model of Bedrikovetsky is studied, and the solution method of the model is optimized. It avoids the assumption that the concentration ratio of Ba~(2) to so _ 4N _ 2) is far less than 1 in the solution of barium sulfate scaling dynamic model, and then improves the diffusion coefficient of three important parameters in the model. The method of calculating reaction rate constant and formation damage coefficient is given. Finally, for the two cores from Changqing Oilfield, the model parameters are obtained by using the Runge-Kutta method in the range of 0 鈮，

本文编号：1627963