考虑约束条件的油藏生产优化

油藏生产优化是把对油藏生产体系的控制描述成一个最优化问题,通过求解最优化问题得到油藏生产的最优控制。首先利用数值方法得到目标函数的近似梯度,然后利用投影梯度方法将近似梯度投影到可行方向上,在可行方向上进行线性搜索,得到满足约束条件的最优解。通过计算案例,对两种近似梯度方法的优化效果与利用有限差分法得到的梯度的优化效果进行对比。优化得到的调控方案可以满足约束要求,并且能够有效改善注水开发效果,大幅度增加油田的经济效益。

Constrained reservoir production optimization

The control of a reservoir system was described as an optimal problem by using reservoir production optimization,and the best control strategy can be acquired.In order to deal with the constrained problems,first,the approximate gradient of object function was obtained by numerical method.Then,the approximate gradient was projected to feasible direction by projection gradient method.Finally,the constrained optimal solution was obtained by line searching on the feasible direction.The effects of two gradient-approximation methods were compared with that of real gradient calculated by finite differential method by calculating reservoir case.The acquired control strategy satisfies all of the constraints and improves the effect of waterflooding development and economic effect significantly.