  To improve the dynamic response performance of wave code communication in
intelligent layered water injection of oilfield, this paper proposes an output
optimal fusion control method based on MPC-PID. Firstly, depending on the well
structure and the flow-pressure characteristics of the layer, the steady-state
model between the differential pressure and flow of the whole well and
different layer sections is established for layered water injection, and the
corresponding wave code amplitude at the steady-state operating point of
different layer sections is solved, the numerical calculation verifies that the
increase of the nozzle opening in a single layer section will drive the
pressure and flow curve of the whole well downward. Secondly, combining the
dynamic response characteristics and steady-state model of the whole-well water
distribution equipment, a dynamic model of layered intelligent water injection
is established, and the generation process of the wave code is defined;
Finally, the MPC-PID optimal fusion control algorithm structure is designed to
derive the fusion control law that minimizes the cost function under fixed
weights, , and the optimal weights are calculated by combining the internal
model structure of controller, so the optimization performance of each
algorithm in the optimal fusion control is balanced. By analyzing the control
simulation results, the fast response characteristics of the fusion control
method are verified. Meanwhile, the simulation comparison experiments of fast
wave code communication under different methods are conducted with the actual
working conditions, the results show that the fusion control method has both
fast tracking control capability and strong robustness, which effectively
enhances the efficiency of wave code communication and shortens the wave code
operation time.
