Use these settings to configure the operation of the gas lift algorithm when the Gas Lift Control Mode is Injection Steps. The PID control mode is always pressure with flow override in this state. The pressure set point is controlled automatically by the program and the flow set point is configured via the Flow Rate Limit configuration parameter.
For each step that is enabled, the program will increase the pressure set point by the value in the Pressure Increment parameter once per minute. The pressure set point will be seeded with the current injection pressure when the first enabled step is entered.
If the actual pressure is greater than the Pressure Target for longer than the the Pressure Delay time then the system will move to the next step.
If the actual pressure does not exceed the Pressure Target within the Step Timeout, the system will halt and not continue to the next step. Gas will continue be injected, however the set point will no longer be incremented. PID control will continue as configured. Operator intervention is required to reset the algorithm when this occurs.
The sales valve is held open in this state and plunger control is interrupted. When all injection steps are complete, control will automatically be handed back to the plunger control loop. If plunger control is not enabled, nothing will happen, otherwise normal plunger control will start. If a timeout occurs, then the system will wait for operator intervention.
The Injection Steps injection mode will interrupt plunger control. The sales valve will be held open while in this state.
General Settings
These settings apply to all steps. When a step is entered, the Step Start Delay must expire before the system starts to examine whether the actual injection pressure exceeds the step's Pressure Target.
The actual injection pressure must exceed the Target Pressure for longer than the Step Complete Delay before moving on to the next step. This prevents a temporary pressure spike, or noise, from causing the system to inadvertently move to the next step.
Select the Enable Step option to enable this step. Steps that are not enabled will be skipped.
When a step is active, the pressure set point will automatically be increased by the Pressure Increment once per minute. If the actual pressure is greater than the Pressure Target for longer than the the Pressure Delay time then the system will move to the next step.
The Flow Rate Limit is used to override the pressure control PID. If the actual flow rate exceeds the Flow Rate Limit during the injection step then the PID will switch to flow control. The system will switch back to pressure control when the actual pressure falls below the pressure set point.
If the actual injection pressure does not exceed the Pressure Target sooner than the Step Timeout, then the system will halt and not move to the next step. Operator intervention will be required to exit this state.
