A carbon dioxide flood has been implemented in the Conoco operated Maljamar Cooperative Unit (MCA) which features automated control and monitoring of the injection and well testing facilities. A programmable logic controller (PLC) was used to provide the functionality requirements. The injection system design required the PLC to perform continuous closed-loop control of the CO2 injection well rates and pressures. The well test system design required the PLC to monitor the gas and liquid volumes, control the liquid dump valves, and control the switching of the test header valves. The PLC also functions as a remote terminal unit, transmitting selected information via radio to the host computer for alarm notification, reporting, and database management functions.
This paper describes the instrumentation, PLC system hardware configuration, and programming that was used to perform CO2 injection control and well test monitoring at the MCA CO2 flood.