Research On Optimization Methods In Oilfield Water Injection System Based On Artificial Fish Algorithm

The artificial intelligent that based on animal's behaviors can be used for the solving of optimization problems by animats'mode. The artificial fish algorithm is one of intelligent optimization algorithms which based on it. The algorithm just compares the values of object functions, so it has no special requirement for the problems. And the algorithm is insensitive to the initial values, has global search abilities for optimization and fast optimizing speed.The optimization problem of oilfield water system is to determine the open position and operation parameter of water injection stations under the instance that the service requires of the oilfield water system is given, in order to satisfy the requirement of the whole system and to cut down the power consumption. The optimization problem of oilfield water system is a non-linear optimization problem with mixed variant which has 0-1 integer variable and continuous variable. The problem has many variants, may be decades or hundreds, the number of equality constraint and non-equality constraint may be hundreds or more than thousands, so it is difficulty to solve the problem.The problem of the oilfield water system with mixed variant is difficult to solve. The article studies the optimization problem which is makes the flux of water injection stations as variant. We solve the problem with improved pattern search method and improved artificial fish algorithm, then compare and analyze the results.The article improves the artificial fish algorithm to solve the mixed variant optimization problem with 0-1 integer variable and continuous variable. The article design two algorithm, one of them is double-layer artificial fish algorithm that the fist layer artificial fish makes 0-1 integer variable the as variant and the second layer artificial fish makes continuous variable as variant. Another is one layer artificial algorithm which is makes 0-1 integer variable and continuous variable as variant. We solve the same problem of oilfield water system with two improved artificial fish algorithm, and then compare and analyze the two improved methods.The problem of oilfield water system has constraint conditions. The optimization algorithm will be exit without find the optimal solution because of the constraint conditions. The article uses the penalty function method transform the constraint optimization problem into non-constraint optimization problem, and then solves the non-constraint optimization problem with artificial fish algorithm.