考虑注采压差下SAGD产能预测模型

SAGD生产过程中除了重力泄油外，注采压差的存在也对产油有着显著的影响，因此在使用Butler方法进行产能预测及计算时易出现误差。考虑注采压差对SAGD开发效果的影响，建立了双水平井SAGD产能预测模型，并利用MATLAB编程语言对数学模型进行求解。研究结果表明：（1）双水平井SAGD数值模拟产能预测的结果反映了注采压差对SAGD开发效果具有一定的影响；（2）当SAGD开采过程存在一定注采压差时开发效果会更好，但这并不意味着注采压差越大越好，因为当注采压差大于汽窜临界压力值时会发生汽窜，从而对生产产生不利影响，因此注采压差存在一个最优值；（3）注采压差的存在会增加采油速度及减少蒸汽腔到达油层顶部的时间，随着注采压差的增大，采油速度增加幅度和蒸汽腔到达油层顶部的时间减少幅度都逐渐变缓。

SAGD Productivity Prediction Model Considering the Injector-Producer Pressure Difference

In addition to gravity drainage in the Steam Assisted Gravity Drainage (SAGD) production process, the existence of injector-producer pressure difference also significantly affects oil production. Therefore, using the Butler method for forecasting productivity can easily lead to errors. This study investigates the effect of injector-producer pressure difference on SAGD productivity. A double horizontal well is established as a prediction model of the SAGD productivity, and the mathematical model is solved. The following results were obtained:(1) The results of the SAGD numerical simulation calculation program show that the injector-producer pressure difference has a certain effect on the SAGD productivity. (2) The oil recovery effect will be better if there is a certain injector-producer pressure difference in the SAGD recovery process. However, a higher injector-producer pressure difference is not preferable. Because steam channeling has a negative impact on production when the injector-producer pressure difference is greater than the critical pressure value of steam channeling, there is an optimal value of injector-producer pressure difference. (3) The existence of the injector-producer pressure difference increases the oil recovery rate and reduces the time required by the steam to reach the top of the oil reservoir. With the increase in the injector-producer pressure difference, the rate of increase in the magnitude of oil recovery rate and the rate of decrease in the time required for the steam to reach the top of the reservoir decreases gradually.