Well placement and control optimization for WAG/SAG processes using ensemble-based method
Well placement and control optimization for WAG/SAG processes using ensemble-based method
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DOI：
10.1016/j.compchemeng.2017.02.020
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
Yang Zhang;Ranran Lu;F. Forouzanfar;A. Reynolds
中科院分区：
文献类型：
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作者：
Yang Zhang;Ranran Lu;F. Forouzanfar;A. Reynolds
与CO2驱相比，水/表面活性剂溶液与CO2气交替注入（WAG/SAG）能较好地控制流度比，稳定驱替前缘，提高宏观波及系数。我们表明，WAG/SAG驱的性能可以显着改善，通过优化的位置和优化的速率或压力，以避免气/水窜，提高波及效率。为了最大化WAG/SAG过程的生命周期净现值（NPV），我们实施了最速上升算法结合单纯形随机梯度来寻找最佳井眼轨迹和控制。针对综合渠化油藏模型，研究了井位和控制联合优化的同时和顺序方法。井间距约束也包括在使用惩罚方法的优化过程中，以便保持威尔斯之间的距离大于指定的最小值。四个合成油藏问题进行了研究和优化，以说明该方法的可行性。
Compared to the CO2flooding, the alternative injection of water/surfactant solution and CO2gas (WAG/SAG) can provide good control over the mobility ratio, stabilize the displacement front and improve the macroscopic sweep efficiency of the flooding. We show that the performance of a WAG/SAG flood can be significantly improved by optimizing the locations and optimizing rates or pressure in order to avoid gas/water channelling and improve sweep efficiency. To maximize the life-cycle net present value (NPV) for a WAG/SAG process, we implemented a steepest ascent algorithm combined with a simplex stochastic gradient to find the optimal well trajectories and controls. Both simultaneous and sequential approaches for the joint optimization of well locations and controls are investigated for a synthetic channelized reservoir model. Well spacing constraints are also included in the optimization process using the penalty method in order to keep the distance between wells greater than a specified minimum value. Four synthetic reservoir problems are studied and optimized to illustrate the viability of the methodology.