二氧化碳驱替与埋存一体化数值模拟

Integrated Numerical Simulation of Carbon Dioxide Displacement and Sequestration

目前数值模拟无法同时计算CO_(2)在油、气、水相中的分配及水相中溶解CO_(2)对储层物性的影响。针对该问题,应用CO_(2)驱替与埋存一体化数值模拟,通过耦合油气两相闪蒸、CO_(2)在水中的溶解和溶蚀作用,同时模拟CO_(2)在油气水三相中的分配、溶解CO_(2)对储层物性的影响、CO_(2)驱油与埋存全过程。研究结果表明:CO_(2)溶于地层水后形成碳酸溶蚀岩石,导致储层渗透率增加,作用时间越长,溶蚀效果越明显;CO_(2)在水相中的溶解和溶蚀作用对累计产油量和CO_(2)埋存量均有影响,在研究CO_(2)驱替与埋存问题时需要同时考虑溶解和溶蚀作用,才能反映生产实际。对濮城油田沙一下储层进行数值模拟研究,证明了CO_(2)驱替与埋存一体化数值模拟方法准确。该研究对CO_(2)驱油与埋存项目的方案设计和CO_(2)埋存潜力评价具有借鉴和指导作用。

At present,numerical simulations cannot calculate the distribution of CO_(2) in oil,gas,and water and the effect of CO_(2) dissolved in water on the physical properties of the reservoir.In response to this problem,the innovative application of the integrated numerical simulation of CO_(2) displacement and sequestration can simulate the distribution of CO_(2) in oil,gas and water,the effect of dissolved CO_(2) on sequestration,and the whole process of CO_(2) displacement and sequestration on the basis of the coupled oil-gas flash evaporation and the solution and dissolution of CO_(2) in water.It was found in the study that CO_(2) dissolved in formation water developed into carbonic acid dissolved rock,leading to an increase in reservoir permeability,and the longer the action duration,the more obvious the dissolution effect;the solution and dissolution of CO_(2) in the water affected the cumulative oil production and CO_(2) sequestration.In the study of CO_(2) displacement and sequestration,it was necessary to consider both the solution and dissolution effects in order to reflect the actual production.The numerical simulation study was conducted in the Lower Sha 1 reservoir in Pucheng Oilfield,and proved that the integrated numerical simulation method of CO_(2) displacement and sequestration is accurate.This study can become certain reference and guidance for scheme design of CO_(2) displacement and sequestration project and the evaluation of CO_(2) sequestration potential.