Plunger Lift

The PLC Shift Plunger Lift application lets you optimize production from your gas wells. Key features include:

 

 

Wells with and without a plunger can be controlled. Use the 'Plunger Exists' parameter in the 'Plunger Configuration' group choose whether the well has a plunger. When the plunger does not exist, after the sales valve is opened, the application starts evaluation shut in conditions to decide when to close the sales valve. When the plunger exists, the application waits for plunger arrival instead.

 

Use the settings in the 'Flow Conditions' group to decide when to open the sales valve and allow the well to flow. All the enabled flow conditions must be met for the sales valve to be opened. After all flow conditions are met, the application will either go to the 'Waiting for Plunger Arrival' state or the 'After Flow Delay State', depending on whether a plunger is installed or not.

 

Use the settings in the 'Shut In Conditions' group to decide when to close the sales valve and shut the well in. The well is shut in when any enabled shut in condition is met. After a shut in condition is met, the application will enter the 'After Shut In Delay' state.

 

Use protection settings to protect the well from adverse operating conditions. Once a protection setting is triggered, the sales valve will be closed and control will stop. Set the 'Exit Protection' control parameter in the 'Plunger Control' group to 'true' to exit protection mode.

 

The PLC Shift Plunger Lift application features automatic optimization. Condition set points are adjusted automatically to try and force the plunger to arrival normally, instead of early or late. Optimization requires a plunger to be installled, and for arrival times to be configured correctly for the well. Use the 'Enable Optimization' parameter in the 'Plunger Configuration' group to enable optimization.

 

When the plunger arrives early, at the end of the plunger cycle, setpoints for the conditions that are enabled are adjusted so that the plunger will arrive later in the next cycle. When the plunger arrives late, setpoints for the conditions that are enabled are adjusted so that the plunger will arrive earlier in the next cycle.

 

The size of the adjustment depends on how dar away the actual arrival time was from the ideal arrival time. The greater the distance, the greater the adjustment. Normally, only the condition that triggered opening or closing the sales valve is adjusted.

 

Use settings in the 'Flow Conditions Optimization' and 'Shut In Conditions Optimization' configuration groups to set limits on the maximum allowable automatic adjustment for any given parameter. Setting to range to 0 will disable automatic adjustment for a parameter, even if the parameter is enabled and optimization is enabled.

 

Use th e 'Reset Optimization' control parameter in the 'Plunger Control' group to reset optimized values back to the configured setpoints. View all optimized setpoints in the 'Optimized Values' status group.

 

The PLC Shift Plunger Lift program has features that allow it to be used with gas lift applications. Integration with the PLC Shift Gas Lift application is very easy, but any gas lift application can be used.

 

Integration with gas lift applications happens via tags. User Defined output tags in the 'Gas Lift Coordination' group are used to tell the gas lift application the state of the plunger lift application. The gas lift application uses these tags to determine where in the plunger cycle the plunger lift application is, and whether or not to inject gas.

 

For example, the 'Plunger is Late' tag is set when the plunger has not arrived before the 'Late Arrival Time' expires. The gas lift application can use this information to increase the amount of gas that's injected in an effort to make sure that the plunger arrives.

 

Tags from the plunger lift application are synchronized with the PLC, and the PLC can either contain a basic gas lift application, or use the PLC Shift Gas Lift application. When the PLC Shift Gas Lift application is used, output tags from the plunger lift application must be mapped to input tags in the gas lift application. This is a modular approach that gives the PLC programmer complete control over how the system works. Values of the mapped tags can be adjusted as desired in the PLC to account for site specific or customer specific requirements.

 

View the application's diagnostic for detailed troubleshooting information. See the 'Log Files' section for more details.