Abstract

Design of PID and Model Predictive Controller for Three Phase Flow (Crude Oil+Water+Air) through Helical Coil and Control Valve in Series

Author(s): Krishnamoorthy P and Bharanikumar R

Experimental model has been constructed in the laboratory to study the pressure drop characteristics for crude oil+water+gas flow through helical coils and control valve in series. This kind of three phase flow occurs in petroleum industries especially in oil rigs. When pumping crude oil from the oil well, it is coming out as a mixture of water and natural gas So the well pump has to pump out this three-phase mixture together. This crude oil+water+gas mixture creates three phase flow. This kind of three phase mixture is pumped by oil well pump and transported by pipes to the oil refinery for the further process. Often these pumps are repairing because of air-lock, holdup, and oil leakage in oil seal. So, transportation stops, this leads to heavy loss to the oil company. So, the pumping system has to be designed carefully with proper controller in the present work an experimental set up has been constructed to test the above three phase flow. Crude oil and water is mixed in a tank by an electric stirrer in a tank and air is injected by compressor, so these three-component flow via helical coil and control valve in series, pressure drop is measured across helical coil and control valve for different air flow rate and mixture flow rate. The pressure drop versus flow rate graph has been drawn by using the experimental data. Linearization method is used to obtain the second order equation for the above graph, using these equation proper MPC and PID controller is designed This controller will control the opening percentage of control valve, The MPC controller will control the three phases flow rate in the pipes by adjusting the valve and increase the crude oil flow rate. So, we can improve the extraction of crude oil rate from the oil rig and improve the efficiency rate of the oil rig system.