Application of process control loop benchmarking to an oil production platform

A complex system usually comprises numerous loops that are controlled by local SISO controllers. The decision to retune or replace any one of these controllers should be based on an investigation as to whether a change will improve the performance. Such a procedure is referred to as benchmarking. With a benchmarking tool, the engineer can justify a proposed retuning of the controller, since it provides a measure for the quality of control achieved. In this paper, first, the basic theory on minimum variance control is presented. Then, the results that are arising from this theory, and directly applicable to benchmarking, are given. Finally, application of the given ideas to an industrial example, namely a Separation Vessel in an Oil Platform, is described.