Automatic system profiling for a well system

1. A method for sensing a pre-charge of a pressurized storage tank, comprising:

activating a well pump in fluid communication with the pressurized storage tank to initiate a filling operation;

monitoring a change of fluid pressure of the pressurized storage tank during the filling operation;

detecting a step change in the fluid pressure of the pressurized storage tank, wherein the step change is detected when a rate of change of the fluid pressure exceeds a predetermined rate;

recording a pressure value at an upper end of the step change as the pre-charge of the pressurized storage tank;

deactivating the pump and disabling pressure-based control of the pump;

monitoring a rate of change of fluid pressure of the pressurized storage tank while the pressurized storage tank is emptying;

detecting when the rate of change of fluid pressure falls below a threshold; and

recording a pressure value when the threshold is met as a remaining pre-charge of the pressurized storage tank.

2. The method of claim 1 , further comprising comparing the remaining pre-charge against the pre-charge of the pressurized storage tank to measure pre-charge degradation of the pressurized storage tank.

3. The method of claim 1 , wherein the pressurized storage tank remains coupled to a plumbing system during the pressure monitoring.

4. The method of claim 1 , further comprising configuring pressure settings for a normal operation of the pump based on the pre-charge.

5. The method of claim 4 , wherein the pressure settings specify a cut-in pressure and a cut-out pressure for the pump.

6. The method of claim 5 , wherein the cut-in pressure is 2 psig above the pre-charge and the cut-out pressure is 22 psig above the pre-charge.

7. A controller for a well system, comprising:

a processor;

an interface for operatively coupling the processor to a pump; and

a computer-readable storing computer-executable instructions, that when executed by the processor, configure the processor to:

activate the pump via the interface to initiate a filling operation of a pressurized storage tank in fluid communication with the pump;

receive pressure readings from a pressure sensor during the filling operation, the pressure sensor is configured to measure a fluid pressure of the pressurized storage tank;

detect a step change in the fluid pressure of the pressurized storage tank, wherein the step change is detected when a rate of change of the fluid pressure exceeds a predetermined rate; and

record a pressure value at an upper end of the step change as a pre-charge of the pressurized storage tank.

8. The controller of claim 7 , the computer-executable instructions further configure the processor to:

disable pressure-based control of the pump and deactivate the pump;

receive pressure readings from the pressure sensor while the pressurized storage tank is emptying;

detect when a rate of decrease of the fluid pressure fall below a threshold; and

record a pressure value as a remaining pre-charge value of the pressurized storage tank when the threshold is reached.

9. The controller of claim 8 , the computer-executable instructions further configure the processor to compare the remaining pre-charge value of the pressurized storage tank to the pre-charge of the pressurized storage tank to measure pre-charge degradation of the pressurized storage tank.

10. The controller of claim 7 , wherein the computer-executable instructions further configure the processor to establish system settings based on the pre-charge of the pressurized storage tank.

11. The controller of claim 10 , wherein the system settings include a pressure cycle range within which the controller maintains the fluid pressure of the pressurized storage tank.

12. The controller of claim 11 , wherein the pressure cycle range is 2 psig above the pre-charge of the pressurized storage tank to 22 psig above the pre-charge of the pressurized storage tank.

13. A system, comprising:

a tank configured to store a fluid and provide the fluid under pressure to a plumbing system; and

a controller configured to control operation of a pump to supply the fluid to one of the tank or the plumbing system, wherein the controller is operatively coupled to the pump and a pressure sensor that provides a pressure reading for the system,

wherein the controller is configured to:

activate the pump to initiate a filling operation;

obtain pressure readings from the pressure sensor to monitor a change of pressure during the filling operation;

detect a step change in the monitored pressure, wherein the step change is detected when a rate of change of the pressure exceeds a predetermined rate; and

record a pressure value at an upper end of the step change as an initial pre-charge of the tank.

14. The system of claim 13 , wherein the controller is further configured to:

disable pressure-based control of the pump;

monitor a rate of change of pressure with the pressure sensor while the tank is emptying;

detect when the rate of change of pressure while the tank is emptying falls below a threshold; and

record a pressure value when the threshold is reached as a remaining pre-charge of the tank.

15. The system of claim 14 , wherein the controller is further configured to compare the remaining pre-charge of the tank with the initial pre-charge of the tank to measure pre-charge degradation of the tank.

16. The system of claim 13 , wherein the controller is further configured to establish pressure setpoints for pressure-based pump control based on the initial pre-charge of the tank.

17. The system of claim 16 , wherein the pressure setpoints include a cut-in pressure and a cut-out pressure for the pump.

18. The system of claim 17 , wherein the controller sets the cut-in pressure to be 2 psig above the initial pre-charge of the tank and sets the cut-out pressure to be 22 psig above the initial pre-charge of the tank.