DEVELOPMENT OF A PID CONTROLLER FOR CONTINUOUS GAS-LIFT WELLS
Continuos Gas-Lift; Programmable Logic Controller; Control Algorithms; Computer Simulation.
Due to changes in operating conditions, a system operating by Continuous Gas-Lift (CGL) needs constant monitoring. It is in order to ensure the production of the well that electronic controllers have been developed for artificial lifting systems. It can be said that more than half of the industrial controllers in use today employ Proportional Integrative Derivative (PID) or modified PID control schemes. However, the use of conventional logic alone may not be enough, making it necessary to use other techniques, such as fuzzy logic, Programmable Logic Controller (PLC) or any alternative that suits the characteristics of the process and is operationally feasible. In large magnitude offshore wells, small errors in calculations can result in large changes in your production. This occurs because the PLC is becoming a familiar part of process controls in offshore installations, as they can be used with control systems that vary widely in their nature and complexity. The objective of this work is to develop a computational tool, which performs the monitoring and control of wells operating by CGL to optimize the production flow. This tool has control algorithms to carry out its activity, for which a dynamic CGL simulator was used in order to assist in the simulations. For validation purposes, the developed tool was tested with field data in computationally simulated wells. Through the tests carried out, it can be highlighted that the results obtained were satisfactory considering that there was an improvement in the flow rate of liquid produced and a reduction in the amount of injected gas.