三维水平井轨道设计最优控制模型改进的进化规划方法

针对三维水平井井眼轨道设计问题 ,建立了一个非线性最优控制模型。该模型以设计轨道总长度最短为性能指标 ,以非线性动力系统为约束条件 ,通过对非线性动力系统积分 ,将最优控制模型转化为一个非线性规划问题求解。为了求非线性规划问题的全局最优解 ,在附加一个目标函数小于当前目标函数值的约束条件下 ,用改进的进化规划方法寻找新的可行点策略 ,提出了一种新算法。将非线性最优控制模型及算法应用到实际水平井轨道设计中 ,数值结果证明了该模型及算法的正确性和有效性

An improved evolutionary programming method of nonlinear optimal control for designing three-dimensional trajectory of horizontal wells

A nonlinear optimal control model for designing three-dimensional trajectory of horizontal well was established. In the model, the objective function is to minimize the total length of the trajectory, and a nonlinear dynamical system was taken as the constraint condition for designing three-dimensional trajectory of horizontal well. This optimal control model was translated into the nonlinear programming problem through integration of the nonlinear dynamical system. In order to obtain the global optimal solution of the nonlinear programming problem, a new algorithm was proposed on the basis of a strategy of searching for a new feasible point by using an improved evolutionary programming method under a new constraint that forces the value of the objective function to be lower than the current value of the objective function. The new algorithm and model have been applied to practical design of horizontal wells. The numerical results illustrated the accuracy and efficiency of the algorithm and model.