Bulk modulus monitoring system

Patent metadata

Field	Value
Publication number	US-11111772-B2
Application number	US-201515749651-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Sep 29, 2015
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A monitoring system may include at least a strain gauge and a computing device for determining a bulk modulus of a fluid system of a pressure pump using strain measurements. The strain gauge may determine strain in a chamber of the pressure pump. The computing device may receive a strain signal generated by the strain gauge and may correlate the strain signal to pressure to determine a change in pressure during a period in which fluid is isolated in the chamber. The computing device may use the change in pressure during this period to determine a bulk modulus of the fluid system.

First claim

What is claimed is:

1. A monitoring system for a pump, comprising:
a strain gauge positionable on a fluid end of the pump to measure strain in a chamber of the pump and generate a strain signal representing the strain in the chamber, the strain signal being useable in determining actuation points for valves in the chamber; and
a computing device couplable to the strain gauge, the computing device including a processing device and a memory device, the memory device including instructions that are executable by the processing device for causing the processing device to:
receive, from memory, a predefined pressure value for an internal pressure of the chamber;
determine a change in the internal pressure in the chamber during an amount of time between the actuation points for the valves by correlating (i) a portion of the strain signal corresponding to the amount of time between the actuation points with (ii) the predefined pressure value; and
determine a bulk modulus of fluid isolated in the chamber during the amount of time between the actuation points for the valves based on the change in the internal pressure in the chamber.

2. The monitoring system of claim 1 , wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to determine the actuation points for the valves in the chamber by identifying discontinuities in the strain signal, wherein the valves include a first valve and a second valve, wherein the actuation points include a first point corresponding to a closing of the first valve and a second point corresponding to an opening of the second valve.

3. The monitoring system of claim 1 , wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to determine the predefined pressure value using finite element analysis of the pump.

4. The monitoring system of claim 1 , wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to determine an effective bulk modulus of the pump using (i) the change in the internal pressure in the chamber during the amount of time between the actuation points, (ii) a fluid volume in the chamber at one of the actuation points, and (iii) a change in the fluid volume during the amount of time between the actuation points, and
wherein the effective bulk modulus includes the bulk modulus of the fluid and a mechanical bulk modulus of non-fluid components of the pump.

5. The monitoring system of claim 4 , further comprising:
a position sensor positionable on a power end of the pump to sense a position of a member of a rotating assembly of the pump and generate a position signal representing the position of the member during operation of the pump, the position signal being usable in determining a movement of a displacement member in the chamber,
wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to determine the change in the fluid volume using a volume of the fluid in the chamber displaced by the movement of the displacement member during the amount of time between the actuation points for the valves.

6. The monitoring system of claim 5 , wherein the memory device comprises instructions executable by the processing device for causing the processing device to determine the movement of the displacement member by correlating the position of the member of the rotating assembly with a ratio representing a mechanical correlation of the displacement member to the member of the rotating assembly.

7. The monitoring system of claim 1 , wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to determine the bulk modulus of the fluid by:
determining a mechanical bulk modulus of non-fluid components of the pump by removing a first reciprocal of a known bulk modulus of a test fluid from a second reciprocal of an effective bulk modulus of the pump; and
removing a third reciprocal of the mechanical bulk modulus of the non-fluid components of the pump from the second reciprocal.

8. The monitoring system of claim 1 , wherein the strain gauge is positioned on an external surface of the fluid end of the pump to measure the strain in the chamber.

9. A pumping system, comprising:
a pump including a fluid end and a power end, the fluid end of the pump including a chamber having a first valve actuatable to a closed position at a first actuation point and a second valve actuatable to an open position at a second actuation point, an amount of time between the first actuation point and the second actuation point being detectable by a strain gauge; and
a computing device couplable to the pump, the computing device including a processing device and a memory device including instructions that are executable by the processing device for causing the processing device to:
determine the first actuation point and the second actuation point by identifying discontinuities in a strain signal received from the strain gauge and representing strain in the chamber;
receive, from memory, a predefined pressure value for an internal pressure of the chamber;
determine a change in the internal pressure in the chamber during the amount of time between the first actuation point and the second actuation point by correlating a portion of the strain signal to the predefined pressure value; and
determine a bulk modulus of fluid isolated in the chamber during the amount of time between the first actuation point and the second actuation point based on the change in the internal pressure in the chamber.

10. The pumping system of claim 9 , wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to receive the strain signal from the strain gauge.

11. The pumping system of claim 9 , wherein the predefined pressure value is determined using finite element analysis of the pump.

12. The pumping system of claim 9 , wherein the memory device further includes instructions that are executable by the processing device for causing the processing device to determine an effective bulk modulus of the pump using (i) the change in the internal pressure in the chamber during the amount of time between the first actuation point and the second actuation point, (ii) a fluid volume in the chamber at the first actuation point, and (iii) a change in the fluid volume during the amount of time between the first actuation point and the second actuation point, and wherein the effective bulk modulus includes the bulk modulus of the fluid and a mechanical bulk modulus of non-fluid components of the pump.

13. The pumping system of claim 12 , further comprising:
a position sensor positioned on the power end of the pump to sense a position of a crankshaft of the pump and generate a position signal representing the position of the crankshaft during operation of the pump,
wherein the fluid end of the pump further includes a plunger in the chamber that is mechanically coupled to the crankshaft, the position signal being usable in determining a movement of the plunger in the chamber, and
wherein the memory device comprises instructions executable by the processing device for causing the processing device to determine the change in the fluid volume using a volume of the fluid displaced in the chamber by the movement of the plunger during the amount of time between the first actuation point and the second actuation point.

14.

Assignees

• Halliburton Energy Services Inc

Inventors

• Beisel Joseph A

Classifications

• F04B1/053 Primary

  with actuating or actuated elements at the inner ends of the cylinders · CPC title

• F04B49/065

  and making use of computers · CPC title

• F04B9/045

  the means being eccentrics · CPC title

• F04B49/00

  Control {, e.g. of pump delivery, or pump pressure} of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 · CPC title

• F04B2201/0201

  Position of the piston · CPC title