新疆石油地质 ›› 2025, Vol. 46 ›› Issue (3): 360-366.doi: 10.7657/XJPG20250313

• 油藏工程 • 上一篇    下一篇

CO2溶解度实验及预测模型

杨宏楠1(), 乐平1(), 范伟2a, 张维2b, 汪周华1, 李丹宸2a   

  1. 1.西南石油大学 油气藏地质及开发工程全国重点实验室,成都 610500
    2.中国石油 长庆油田分公司 a.勘探开发研究院,西安 710018;b.第四采油厂,银川 718500
  • 收稿日期:2024-12-05 修回日期:2024-12-19 出版日期:2025-06-01 发布日期:2025-06-13
  • 通讯作者: 乐平(1983-),男,湖北随州人,教授,博士,油气藏工程及数值模拟,(Tel)13088040285(Email)yuepingaa@126.com
  • 作者简介:杨宏楠(1994-),男,天津人,博士研究生,注气提高采收率,(Tel)18328068988(Email)yanghongnan2020@163.com
  • 基金资助:
    国家自然科学基金(U24B200683);四川省自然科学基金(2024NSFSC2012)

CO2 Solubility Experiments and Prediction Model

YANG Hongnan1(), YUE Ping1(), FAN Wei2a, ZHANG Wei2b, WANG Zhouhua1, LI Danchen2a   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2. PetroChina Changqing Oilfield Company, a.Research Institute of Exploration and Development, Xi’an, Shaanxi 710018, China;b.No.4 Oil Production Plant, Yinchuan, Ningxia 718500, China
  • Received:2024-12-05 Revised:2024-12-19 Online:2025-06-01 Published:2025-06-13

摘要:

CO2溶解度是影响低渗、致密油藏注CO2提高采收率和深盐水层CO2埋存效果的重要参数。基于高温高压可视化相态反应釜的CO2溶解实验明确了地层温度和压力、地层水矿化度和多相流体饱和度变化对原油-地层水体系中CO2溶解度的影响,并通过拟合实验结果建立地层温度及压力下原油-地层水体系CO2溶解度预测模型。结果表明:原油-地层水体系中,CO2溶解度受压力和流体类型影响较大,压力和含油饱和度越高,越有利于CO2溶解,地层水矿化度和温度均能小幅度影响CO2在地层水中的溶解度;CO2在原油中的溶解呈现出多阶段溶解特征,并随含油饱和度的增大大幅增加;随着油水两相体系中含水饱和度的增大,CO2溶解度迅速降低,且伴随温度的升高,CO2溶解度小幅降低。基于CO2溶解度实验拟合得到CO2溶解度预测模型,油水两相体系中的CO2溶解度可分别采用CO2在原油、地层水中的溶解度对油水两相饱和度加权得到,模型计算结果与实验结果一致性较高。

关键词: CO2溶解度, 原油-地层水体系, 地层水矿化度, 含油饱和度, 预测模型

Abstract:

CO2 solubility is a critical parameter impacting the effects of CO2 injection for enhanced oil recovery (EOR) in low-permeability/tight reservoirs and CO2 storage in deep saline aquifers. By using a high-temperature, high-pressure visualized phase reactor, CO2 dissolution experiments were conducted to investigate the influences of formation temperature/pressure, formation water salinity, and multiphase fluid saturation on solubility of CO2 in crude oil-formation water systems. A prediction model for CO2 solubility in crude oil-formation water systems under formation temperature and formation pressure was developed by fitting experimental data. The results show that in crude oil-formation water systems, CO2 solubility is strongly influenced by pressure and fluid type, and higher pressure and oil saturation can promote CO2 dissolution. Both formation water salinity and temperature have minor impacts on solubility of CO2 in formation water. CO2 dissolution in crude oil exhibits multistage behaviors, and the CO2 solubility increases significantly with the increase of oil saturation. Moreover, CO2 solubility declines rapidly with increasing water saturation in oil-water systems and decreases slightly with increasing temperature. The solubility prediction model, derived from the fitting of experimental data, calculates CO2 solubility in two-phase systems via saturation-weighted contributions of the solubility in oil and water phases and the results show high consistency with the experimental results.

Key words: CO2 solubility, crude oil-formation water system, formation water salinity, oil saturation, prediction model

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