Abstract

In this paper, a new model is proposed for wax precipitation. Fugacity of the solid phase is calculated indirectly by considering the fugacity of the pure liquid phase. In this approach, crude oil is divided into five pseudo components using the SARA test results. Solubility parameters were calculated by SRK (Soave Modification of Redlich Kwong) equation of state, and the composition of components is calculated by employing Rachford Rice equation. Also, geneticalgorithm was used to improve the accuracy of results in WAT and wax weight. The average deviation of WAT (Wax Appearance Temperature) was 0.11 and 0.15% in the multi solid and solid solution models respectively, also the average deviation of the wax weight was 10.32 and 5.8% in the multi solid and solid solution models, respectively. The results showed that the solid solution model was more accurate in the prediction of wax precipitation in pipelines, as compared to the multi solid model. The optimized parameters in this solid solution model were more effective and had a dynamic influence. The multi solid and solid solution models had a remarkable accuracy with the experimental data. There was no logical explanation for asphaltene on wax precipitation and WAT. As a result, asphaltene was omitted in five crude oils in order to investigate the effect on the wax weight percentage and WAT. Results reveal that after omitting asphaltene, WAT and wax weight percentage were decreased.

中文翻译：

---

基于沥青质含量的管道蜡沉淀新实验与模型研究

摘要

本文提出了一种新的蜡沉淀模型。通过考虑纯液相的逸度间接计算固相的逸度。在这种方法中，使用SARA测试结果将原油分为五个假组分。溶解度参数通过状态的SRK（Redlich Kwong的Soave Modification）方程式进行计算，组分的组成采用Rachford Rice方程式进行计算。同样，遗传算法被用于提高WAT和蜡重的结果准确性。在多固溶体和固溶体模型中，WAT（蜡外观温度）的平均偏差分别为0.11和0.15％，在多固溶体和固溶体模型中，蜡重的平均偏差分别为10.32和5.8％。结果表明，与多固体模型相比，固溶模型在预测管道中蜡沉淀方面更为准确。该固溶模型中的优化参数更有效并具有动态影响。多固体和固体溶液模型的实验数据具有显着的准确性。没有关于沥青质对蜡沉淀和WAT的合乎逻辑的解释。结果，为了研究对蜡重量百分比和WAT的影响，在五种原油中省略了沥青质。结果表明，省略沥青质后，WAT和蜡的重量百分比降低了。多固体和固体溶液模型的实验数据具有显着的准确性。没有关于沥青质对蜡沉淀和WAT的合乎逻辑的解释。结果，为了研究对蜡重量百分比和WAT的影响，在五种原油中省略了沥青质。结果表明，省略沥青质后，WAT和蜡的重量百分比降低了。多固体和固体溶液模型的实验数据具有显着的准确性。没有关于沥青质对蜡沉淀和WAT的合乎逻辑的解释。结果，为了研究对蜡重量百分比和WAT的影响，在五种原油中省略了沥青质。结果表明，省略沥青质后，WAT和蜡的重量百分比降低了。