Comparison of SQP and AL algorithms for deterministic constrained production optimization of hydrocarbon reservoirs

The optimization of PUNQ reservoir model is considered in order to compare the performance and robustness of the AL and the SQP, where the gradients of the objective function and nonlinear constraints are estimated using the adjoint method. The computational results showed that with properly tuned parameters and good initial points, the AL could yield a slightly higher ultimate NPV in some cases. However, the SQP generally has better performance regarding efficiency, robustness and constraints handling. For example, under the SQP generated optimal well controls, the watercut of each producer would strictly obey the constraint, while the optimal well controls generated by AL would lead some minor valuations. Moreover, an SQP-AL algorithm is also proposed to solve the constrained production optimization problem by applying the AL search direction on the convergence of SQP. The results showed that the SQP-AL algorithm is able to achieve a higher NPV with slightly more iterations compared with the SQP method.