溶气原油CO2溶解度预测模型

Prediction model of carbon dioxide solubility in crude oil

关键词:  CO₂驱油  集输管道  溶气原油  溶解度

Key words:  carbon dioxide flooding  gathering and transportation pipeline  dissolved gas crude oil  solubility

摘要:

目的 解决目前气体溶解度模型难以应用于溶气（CO₂）原油等问题。方法 利用自行设计建设的可承压搅拌釜装置研究了集输温度和压力对CO₂溶解度的影响规律，利用亨利定律对实验规律进行了分析，并建立了适用于集输环境下的CO₂溶解度计算模型。结果 该模型创造性地引入了与实际压力和常压比值相关的4个参数，消除了已有模型的量纲问题。经过实验及文献数据验证，发现新的CO₂溶解度模型计算值与实验值相对误差最大为32.5%，与3种经典预测模型计算误差动辄超过50%相比有了明显改善，且绝对误差可以控制在2 L/L（以原油计）以内。结论 基于该模型预测效果的显著提升，可以有效应用于溶气原油工业集输过程，对保障原油输运具有重要工程意义。

Abstract:

Objective The aim is to solve the problem that the original gas solubility models are difficult to be applied to dissolved gas (carbon dioxide) crude oil. Methods The influence of temperature and pressure on carbon dioxide solubility in the gathering and transportation environment was studied using a self-manufactured pressure-bearable stirring tank, and the experimental law was analyzed by Henry's law. At the same time, a new calculation model of carbon dioxide solubility in crude oil was established by using experimental data. Results The new model creatively introduced four parameters related to the ratio of actual pressure and atmospheric pressure, eliminating the dimensional problem of the existing models. Through the verification of experimental and literature data, it was found that the maximum relative error between the calculated value and the measured value was less than 32.5%, which was significantly improved compared with the three classical prediction models, which often exceeded 50%. The absolute error could be controlled within 2 L/L (CO₂ based) crude oil. Conclusion Based on the remarkable improvement of the prediction effect of the model, it can be effectively applied to the gathering and transportation process of dissolved gas crude oil industry, and has important engineering significance for ensuring crude oil transportation.