高含水水平井注CO₂酸岩反应数学模型

Mathematical Model of Acid Rock Reaction in the Process of CO₂ Huff and Puff Stimulation of Horizontal Wells in High Water Cut

摘要: 高含水水平井进行CO₂吞吐时，就酸液在井筒径向上对储层的改造作用建立数学模型，机理性研究CO₂吞吐对储层的影响以及注入速度、注入量、焖井时间、吞吐次数、地层压力和地层温度对改造作用的影响，采用塔河9区实际油田参数后的结果表明，吞吐过程中酸液的有效作用距离很短，小于0.2 m；随着注入速度的增加，酸液作用距离增加，储层改造的程度下降；随着注入量、地层温度和地层压力的增加，改造程度增加；焖井时间对储层改造的影响很小；随着吞吐次数的增加，储层改造的程度越大，但是每阶段吞吐改造的程度变小。

Abstract: Mathematical model of corrosion of CO₂ on the wellbore radial in the process of CO₂ huff and puff of horizontal wells in high water cut is established to study the effect CO₂stimulation to the reservoir and the effect of injection rate, injection, soaking time, time of huff and puff, pressure of reservoir and temperature of reservoir to corrosion. Simulation results show that the effective distance of acid is short, which is less than 0.2 m; with the increase of injection rate, acid range increases, the degree of reservoir reconstruction decreases; as the injection, formation temperature and formation pressure increase, modification extent increase; soak time will have little impact on the reservoir reconstruction; with the increase of throughput times, the degree of reservoir re-construction become greater, but the degree of each stage and reformation decreases.