Hydrocarbon Well Performance Monitoring System

• US 20150142319A1
• Filed: 12/04/2014
• Published: 05/21/2015
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: James N. McCoy
• Original Assignee: James N. McCoy
• Inventors: McCoy, James N.
• Granted Patent: US 9,587,481 B2
• Time in Patent Office: Days
• US Class Current: 702/9
• CPC Class Codes: E21B 41/00 Equipment or details not covered by groups E21B15/00 - E21B40/00
• CPC Class Codes: E21B 43/127 Adaptations of walking-beam pump systems
• CPC Class Codes: E21B 47/008 Monitoring of down-hole pump systems, e.g. for the detection of "pumped-off" conditions
• CPC Class Codes: E21B 47/009 Monitoring of walking-beam pump systems
• CPC Class Codes: E21B 47/047 Liquid level measuring depth or liquid level using radioactive markers E21B47/053
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: E21B 47/13 by electromagnetic energy, e.g. radio frequency
• CPC Class Codes: E21B 49/00 Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
• CPC Class Codes: E21B 49/003 by analysing drilling variables or conditions E21B49/005 takes precedence; systems specially adapted for monitoring a plurality of drilling variables or conditions E21B44/00
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: G01L 5/0061 Force sensors associated with industrial machines or actuators for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21
• CPC Class Codes: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• CPC Class Codes: G01P 7/00 Measuring speed by integrating acceleration measuring travelled distance by double integration of acceleration G01C21/16

Abstract

A system and method for real-time data acquisition and presentation of force, position, load, pressures, and movement within a subterranean well pumping system, such as an oil well. Data is gathered using sensors attached to a surface level pump drive and wellhead system. Well structural data and well production data are combined therewith to generate a real-time display of down-hole well operation, including animated graphics of the pump operation, including pump movement, rod and tubing stretch, fluid movement, gas compression, system forces, and fluid pressures. Liquid levels are tested using an acoustic liquid level instrument, and incorporated to improve well performance analysis.

Claims

1. A method of real-time utilization of performance data by a processor, which is associated with a pump lifting well fluids of known physical properties above a liquid level in a casing of a subterranean well through a tube to a surface level, the pump having a chamber with a fluid inlet located below the liquid level that is gated by a stationary valve, and having a plunger slidably engaged with the chamber, the plunger having a known area and having a fluid outlet gated by a traveling valve that is coupled to deliver well fluids to the tube, the plunger reciprocated to vary the displacement of the chamber by a rod extending upward to a cyclical drive unit at the surface, the method comprising the steps of:

obtaining, in real time, a sequence of rod position data samples and rod load data samples corresponding to cyclical operation of said rod at the surface level;

calculating, in real time, a sequence of plunger position data points and plunger load data points corresponding to cyclical operation of the rod at the plunger level, and calculated in accordance with a set of structural data for the subterranean well;

determining a discharge pressure at the fluid outlet from the pump;

calculating, in real-time, a sequence of pump chamber pressure data points according to said sequence of plunger load data points, and

displaying, in real time, a portion of said sequence of plunger position data points, a portion of said sequence of plunger rod load data points, and a portion of said sequence of chamber pressure data points.

2. The method of claim 1, further comprises the steps of:

determining the liquid level in the casing of the subterranean well;

determining a density of liquid in the well fluids from the known physical properties;

determining a density of gas in the well fluids from the known physical properties;

determining a casing pressure at the surface level, and

calculating said inlet pressure based upon said density of liquid in a liquid column between the fluid inlet and the liquid level, and based upon said density of gas in a gas column between the liquid level and the surface level, and said casing pressure.

3. The method of claim 2, further comprising the steps of:

correcting said inlet pressure by adding said casing pressure.

4. The method of claim 3, and wherein:

said determining a casing pressure at the surface level step is accomplished in real-time, simultaneous with said calculating, in real-time, a sequence of pump chamber pressure data points according to said sequence of plunger load data points step.

5. The method of claim 2, and wherein;

said determining the liquid level in the casing of the subterranean well further comprises conducting an acoustic echo measurement simultaneously with said step of obtaining, in real time, a sequence of rod position data samples and rod load data samples.

6. The method of claim 1, and wherein said determining a discharge pressure step further comprises the steps of:

determining a density of liquid in the well fluids from the known physical properties;

determining a pump discharge level from the known physical properties, and

calculating said discharge pressure based upon the average liquid gradient of the density of liquid in a liquid column between said pump discharge level and the surface level, and the tubing pressure.

7. The method of claim 6, further comprising the steps of:

determining a tubing pressure at the surface level, and

offsetting said discharge pressure according to said tubing pressure.

8. The method of claim 7, and wherein:

said determining a tubing pressure at the surface level step is accomplished in real-time, simultaneous with said calculating, in real-time, a sequence of pump chamber pressure data points according to said sequence of plunger load data points step.

9. The method of claim 1, and wherein:

said calculating, in real-time, a sequence of pump chamber pressure data points step further includes calculation of said sequence of pump chamber pressure data points according to said fluid discharge pressure less the corresponding of said plunger load data points divided by the plunger area.

10. The method of claim 1, further comprising the steps of:

generating a graphical representation of the pump, including the chamber and the plunger;

animating the movement of the plunger according to said plunger position data points, and

displaying said pump chamber pressure values together with said animated movement of said pump.

11. The method of claim 1, further comprising the steps of:

segregating said sequence of polished rod position data samples and said sequence of polished rod load data samples into discrete data sets according to individual strokes of said cyclical drive unit;

delimiting said discrete data sets by identifying a position in a repetitive pattern in said sequence of polished rod position data samples;

storing in a machine readable file, said sequence of polished rod position data points and said sequence of polished rod load data points.

12. The method of claim 11, further comprising the steps of:

recalling said machine readable file, and

reproducing the data points recalled from said machine readable file in a graphical format.

13. The method of claim 1, further comprising the step of:

displaying, in real-time, said sequence of plunger position data samples and said sequence of plunger load data samples in a graphical format pump card, and

displaying a cursor, in real-time, on said graphical format pump card, indicating an instant corresponding pair of said sequence of plunger position data points and said sequence of plunger rod load data points.

14. A method of utilization of performance data by a processor, which is associated with a pump lifting well fluids from a subterranean well through a tube, the pump having a chamber with a fluid inlet that is gated by a stationary valve, and having a plunger slidably engaged with the chamber, the plunger having a fluid outlet gated by a traveling valve that is coupled to deliver well fluids to the tube, the plunger reciprocated to vary the displacement of the chamber by a rod cyclically driven from a surface level, the method comprising the steps of:

obtaining a sequence of rod position data samples and rod load data samples corresponding to cyclical operation of said rod at the surface level;

calculating a sequence of plunger position data points and plunger load data points corresponding to reciprocated movement of the rod at the plunger location;

calculating a sequence of chamber pressure data points having an inverses relationship with said sequence of plunger load data points, and

displaying said sequence of plunger position data points along a first axis of a graphical plot, and displaying said sequence of plunger load data points and said sequence of chamber pressure data points along a second axis of a graphical plot, thereby producing a unified graphical representation of the plunger load, plunger position, and chamber pressure of the pump during reciprocated movement of the plunger.

15. The method of claim 14, and further comprising the steps of:

establishing a plunger reference position in said sequence of plunger position data points at a first extreme value of plunger position in a reciprocated sequence, and

indicating said plunger reference position along said first axis.

16. The method of claim 14, further comprising the steps of:

determining a discharge pressure at the fluid outlet from the pump, and

generating a graphical representation of said discharge pressure on said unified graphical representation.

17. The method of claim 14, further comprising the steps of:

determining pump inlet pressure at the pump inlet, and

generating a graphical representation of said pump inlet pressure on said unified graphical representation.

18. A system of real-time utilization of performance data by a processor, which is associated with a pump lifting well fluids of known physical properties above a liquid level in a casing of a subterranean well through a tube to a surface level, the pump having a chamber with a fluid inlet located below the liquid level that is gated by a stationary valve, and having a plunger slidably engaged with the chamber, the plunger having a known area and having a fluid outlet gated by a traveling valve that is coupled to deliver well fluids to the tube, the plunger reciprocated to vary the displacement of the chamber by a rod extending upward to a cyclical drive unit at the surface, the system comprising:

a sensor assembly connected to the rod to obtain, in real time, a sequence of rod position data samples and rod load data samples corresponding to cyclical operation of said rod at the surface level;

said processor is programmed to calculate, in real time, a sequence of pump chamber pressure data points according to said sequence of plunger load data points, and according to a predetermined discharge pressure at the fluid outlet from the pump, and wherein

said processor is programmed to display on a display, in real time, a portion of said sequence of plunger position data points, a portion of said sequence of plunger rod load data points, and a portion of said sequence of chamber pressure data points.

19. The system of claim 18, further comprising:

a liquid level sensor coupled to provide a liquid level in the casing of the subterranean well to said processor;

a pressure sensor coupled to provide a casing pressure at the surface level to said processor, and wherein

a density of the liquid portion of the well fluids, and a density of the gas portion of the well fluids are predetermined from the known physical properties, and provided to said processor, and wherein

said processor is programmed to calculate said inlet pressure based upon said density of liquid in a liquid column between said fluid inlet and said liquid level, and based upon said density of gas in a gas column between said liquid level and said surface level, and said casing pressure.

20. The system of claim 19, and wherein:

said processor is programmed to correct said inlet pressure by adding said casing pressure thereto.

21. The system of claim 20, and wherein:

said processor is programmed to determine a casing pressure at the surface level in real-time, simultaneous with calculation of a sequence of pump chamber pressure data points according to said sequence of plunger load data points step.

22. The system of claim 19, and wherein;

said determination of said liquid level in the casing of the subterranean well is accomplished with an acoustic echo measurement device coupled to said processor, simultaneously with a sequence of rod position data samples and rod load data samples.

23. The system of claim 18, and wherein:

determination of said discharge pressure is accomplished with a predetermined density of liquid in the well fluids from the known physical properties and a predetermined pump discharge level from the known physical properties, and wherein

said processor is programmed to calculate said discharge pressure based upon the average liquid gradient of the density of liquid in a liquid column between said pump discharge level and the surface level, and said tubing pressure.

24. The system of claim 23, further comprising:

a pressure sensor coupled to said processor to provide a tubing pressure at the surface level, and wherein

said processor is programmed to offset said discharge pressure according to said tubing pressure.

25. The system of claim 24, and wherein:

measurement of said tubing pressure at the surface level is taken in real-time, simultaneous with calculation of a sequence of pump chamber pressure data points according to said sequence of plunger load data points.

26. The system of claim 18, and wherein:

calculation of said sequence of pump chamber pressure data points by said processor further includes calculation of said sequence of pump chamber pressure data points according to said fluid discharge pressure less the corresponding of said plunger load data points divided by the plunger area.

27. The system of claim 18, and wherein:

said processor is programmed to generate and display on said display, a graphical representation of the pump, including the chamber and the plunger, and wherein

said processor is programmed to animate the movement of the plunger according to said plunger position data points, and to display said pump chamber pressure values together with said animated movement of said pump.

28. The system of claim 18, and wherein:

said processor is programmed to segregate said sequence of polished rod position data samples and said sequence of polished rod load data samples into discrete data sets according to individual strokes of said cyclical drive unit, and wherein

said processor is programmed to delimit said discrete data sets by identification of a position in a repetitive pattern in said sequence of polished rod position data samples, and wherein

said processor is programmed to store in a memory, in a machine readable file, said sequence of polished rod position data points and said sequence of polished rod load data points.

29. The system of claim 28, and wherein:

said processor is programmed to recall said machine readable file, and reproduce on said display, said data points recalled from said machine readable file in a graphical format.

30. The system of claim 18, and wherein:

said processor is programmed to display in real time, on said display, said sequence of plunger position data samples and said sequence of plunger load data samples as a graphical format pump card, and wherein

said processor is programmed to display in real time, on said display, a cursor on said graphical format pump card, which indicates an instant corresponding pair of said sequence of plunger position data points and said sequence of plunger rod load data points.

31. A system of utilization of performance data by a processor, which is associated with a pump lifting well fluids from a subterranean well through a tube, the pump having a chamber with a fluid inlet that is gated by a stationary valve, and having a plunger slidably engaged with the chamber, the plunger having a fluid outlet gated by a traveling valve that is coupled to deliver well fluids to the tube, the plunger reciprocated to vary the displacement of the chamber by a rod cyclically driven from a surface level, the system comprising:

a sensor assembly connected to the rod to obtain, in real time, a sequence of rod position data samples and rod load data samples corresponding to cyclical operation of said rod at the surface level;

a processor interfaced to receive said sequence of rod position data samples and rod load data samples, and programmed to calculate, a sequence of plunger position data points and plunger load data points corresponding to reciprocated movement of the rod at the plunger location, and wherein

said processor is programmed to calculate a sequence of chamber pressure data points having an inverses relationship with said sequence of plunger load data points, and wherein

said processor is programmed to display, on a display, said sequence of plunger position data points along a first axis of a graphical plot, and display said sequence of plunger load data points and said sequence of chamber pressure data points along a second axis of said graphical plot, thereby producing a unified graphical representation of the plunger load, plunger position, and chamber pressure of the pump during reciprocated movement of the plunger.

32. The system of claim 31, and wherein:

said processor is programmed to establish a plunger reference position in said sequence of plunger position data points at a first extreme value of plunger position in a reciprocated sequence, and wherein

said processor is programmed to indicate, an said display, said plunger reference position along said first axis.

33. The system of claim 31, and wherein:

said processor is programmed to determine a discharge pressure at the fluid outlet from the pump, and wherein

said processor is programmed to generate a graphical representation of said discharge pressure on said unified graphical representation.

34. The system of claim 31, and wherein:

said processor is programmed determining pump inlet pressure at the pump inlet, and

generating a graphical representation of said pump inlet pressure on said unified graphical representation.