The Logic Behind The Magic."Produce water treater vessel and injection pump"

The separated produced water from the hydrocyclone is routed to the Produced Water Treater Vessel to further enhance oil and water separation, The Primary function of treater vessel is to degas the produced water. As the pressure is reduced from the hydrocyclones, the gas bubles that are liberated rise within the water in the degasser and capture and separate the small, finely dispersed oil droplets. Larger oil droplets are removed by internal weir.

After treatment, produced water is re-injected back into reservoir via the Produced Water Injection Pumps. produced water treater process schematic is shown as following:

 Control loop description

Pressure Controller
The pressure controller maintains a constant pressure in PWT vessel by actuating control valve in separator gas outlet to regulate the inflow rate to PWT vessel and by actuating valve in HP flare to release excess pressure.

As the pressure falls below setpoint the controller shall open the control valves in separator gas outlet and close the control valves in HP flare to increase the pressure. The valve in separator gas outlet is fail closed type and the valve in HP flare is fail open type. The controller output shall be direct and control valve "OPDIR" is direct for the valve in separator gas outlet and reverse for the valve in HP flare.

Water Level Controller
 The controller maintains a constant water level in the Produced water treater vessel by actuating control valves downstream the PWT pumps.
The control valve is fail closed type. The controller output shall be direct and the control valve OPDIR shall be direct, As the liquid level falls bellow the setpoint the controller shall closed the control valve to increase the level.

Oil Level Controller
The controller maintains a constant oil level in the Produced water treater vessel by actuating control valves to reject oil vessel.
The control valve is fail closed type. The controller output shall be direct and the control valve OPDIR shall be direct, As the liquid level falls bellow the setpoint the controller shall closed the control valve to increase the level.

Flow Controller
The flow controller provide minimum flow control to protect each water injection pump by opening control valve to recycle flow to treater vessel. As the flow rate falls below the setpoint, the controller shall open the minimum recycle control valve to increase to flow rate. The control valve is fail open type. The controller output shall be reverse acting and the control valve OPDIR is reverse.