硫酸钡结垢动力学瞬态模型研究

发布时间：2018-07-11 15:18

本文选题：硫酸钡结垢 + 地层损害　；参考：《西南石油大学学报(自然科学版)》2017年05期

【摘要】：注水是维持地层压力及提高原油采收率的最主要开发方式。当注入水与地层水混合后,由于注入水中的SO_4~(2-)与地层水中的Ba~(2+)的化学不相容性,将产生BaSO_4垢,堵塞储层的孔隙与喉道,造成严重的储层损害。为了定量预测硫酸钡结垢量,首先,在Bedrikovetsky经典动力学模型的基础上,详细推导了含扩散项的硫酸钡结垢动力学瞬态模型,对模型有限差分并利用第四和第五阶Runge-Kutta方程求出数值解,避免了国内外已有的模求解过程中做出岩芯入口端Ba~(2+)浓度与SO_4~(2-)浓度比远小于1的假设,提高了模型的适用性。然后,通过岩芯瞬态驱替实验测定岩芯出口端Ba~(2+)的浓度,利用浓度数据反演出模型中的两个重要系数——扩散系数和反应速率常数。最后,研究了低SO_4~(2-)浓度的注入水驱替不同PV时岩芯中硫酸钡结垢量的分布。结果表明:随着驱替体积增加,岩芯内的硫酸钡结垢量增大;沿岩芯长度方向上的结垢量呈先增大后减小趋势;岩芯内最大结垢量的位置向岩芯中部偏移。
[Abstract]:Water injection is the most important way to maintain formation pressure and improve oil recovery. When the injected water is mixed with formation water, due to the chemical incompatibility of SO4- ~ (2-) in injected water and Ba2 in formation water, BaSO4 scale will be produced, and the pore and throat of reservoir will be blocked, resulting in serious reservoir damage. In order to predict the barium sulfate scaling quantity quantitatively, firstly, based on Bedrikovetsky's classical kinetic model, the transient model of barium sulfate scaling dynamics with diffusion term was deduced in detail. The finite difference model and the fourth and fifth order Runge-Kutta equations are used to obtain the numerical solution, which avoids the assumption that the ratio of Ba ~ (2) concentration to so _ 4 ~ (2-) concentration at the inlet end of core is far less than 1, which improves the applicability of the model. Then, the concentration of Ba2 at the outlet end of the core is measured by the core transient displacement experiment. The diffusion coefficient and the reaction rate constant are two important coefficients in the model by using the concentration data. Finally, the distribution of barium sulfate scaling in cores with low so _ 4- ~ (2-) concentration in different PV cores was studied. The results show that with the increase of displacement volume, the barium sulfate scaling amount in the core increases, the scaling amount along the length of the core increases first and then decreases, and the position of the maximum scaling amount in the core shifts to the middle of the core.
【作者单位】：西南石油大学石油与天然气工程学院;西南石油大学理学院;
【分类号】：TE358.5

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