Cavitation avoidance system

Patent metadata

Field	Value
Publication number	US-11028845-B2
Application number	US-201616321964-A
Country	US
Kind code	B2
Filing date	Sep 13, 2016
Priority date	Sep 13, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A monitoring system for a plurality of pressure pumps may include, for each pump, a strain gauge, a position sensor and a pressure transducer. A strain gauge may be positionable on each pump to generate a strain measurement corresponding to strain in each pump. A position sensor may be positionable on each pump to generate a position measurement corresponding to a position of a rotating member corresponding of each pump. A pressure transducer is positionable on each pump to generate a boost pressure measurement that is usable with the strain measurement and the position measurement to determine a cavitation threshold for each pump.

First claim

What is claimed is:

1. A monitoring system, comprising:
a plurality of strain gauges positioned on a plurality of pressure pumps to generate strain measurements for chambers of the plurality of pressure pumps;
a plurality of position sensors positioned on the plurality of pressure pumps to generate position measurements for rotating members of the plurality of pressure pumps;
a plurality of pressure transducers positioned on the plurality of pressure pumps to generate boost pressure measurements associated with fluid ends of the plurality of pressure pumps; and
a computing device including a processor and a memory, the memory including instructions that are executable by the processor for causing the processor to:
determine a cavitation threshold of each pump of the plurality of pressure pumps based on the strain measurements, the position measurements, and the boost pressure measurements;
identify a first pump of the plurality of pressure pumps operating beyond the cavitation threshold;
transmit a first control signal for causing a pump rate of the first pump to be adjusted in a first direction;
identify a second pump of the of the plurality of pressure pumps based on the boost pressure measurement of the second pump, wherein the boost pressure measurement of the second pump indicates that the second pump is farthest below the cavitation threshold as compared to a remainder of the pressure pumps in the plurality of pressure pumps; and
transmit a second control signal for causing a pump rate of the second pump to be adjusted in an opposing direction that is opposite to the first direction, to maintain a total flow rate through the plurality of pressure pumps.

2. The monitoring system of claim 1 , further comprising the computing device being communicatively coupled to the plurality of strain gauges, the plurality of position sensors, and the plurality of pressure transducers.

3. The monitoring system of claim 2 , wherein the memory further includes instructions that are executable by the processor to cause the processor to determine the adjustment to be made to the pump rate of the second pump.

4. The monitoring system of claim 1 , wherein the memory further includes instructions that are executable by the processor to cause the processor to:
subsequent to transmitting the first control signal and determining an undesirable change in response to adjusting the first pump rate in the first direction to an adjusted pump rate, transmit a third control signal configured for causing the adjusted pump rate of the first pump to be adjusted in the opposing direction that is opposite to the first direction.

5. The monitoring system of claim 1 , wherein the memory further includes instructions that are executable by the processor to cause the processor to determine the cavitation threshold for a respective pump of the plurality of pressure pumps by:
determining actuation points for a valve of a chamber of the pump using the strain measurement for the chamber of the pump;
determining a position of a displacement member mechanically coupled to the rotating member of the pump using the position measurement for the rotating member of the pump;
determining actuation delays corresponding to the valve by correlating the actuation points of the valve and the position of the displacement member;
determining a minimum boost pressure of the pump at an inlet to the chamber of the pump based on the boost pressure measurement of the fluid end of the pump; and
determining a cavitation boost pressure corresponding to the minimum boost pressure when cavitation is present in the pump using the actuation delays.

6. The monitoring system of claim 5 , wherein the memory further includes instructions that are executable by the processor for causing the processor to determine the cavitation boost pressure of the respective pump by:
comparing the actuation delays to additional actuation delays corresponding to additional pumps of the plurality of pressure pumps;
determining a point of cavitation in the pump by identifying deviations in the actuation delays for the pump from a trend of the additional actuation delays of the additional pumps; and
comparing the point of cavitation to the minimum boost pressure to determine the minimum boost pressure of the pump at the point of cavitation.

7. The monitoring system of claim 5 , wherein a pressure transducer of the plurality of pressure transducers includes an enveloping filter to determine the minimum boost pressure of the respective pump by tracing lower peaks of a pressure signal corresponding to the boost pressure measurement for the pump.

8. The monitoring system of claim 1 , wherein the plurality of pressure pumps are positioned in parallel between an intake manifold and an outlet manifold, wherein the outlet manifold is fluidly couplable to a wellbore to inject fluid from the plurality of pressure pumps into the wellbore to fracture a subterranean formation positioned adjacent to the wellbore.

9. A method, comprising:
determining, by one or more processors, actuation delays for one or more valves in each pump of a plurality of pressure pumps using strain measurements of strain in the plurality of pressure pumps and position measurements for rotating members of the plurality of pressure pumps;
determining, by the one or more processors, minimum boost pressures for the plurality of pressure pumps;
determining, by the one or more processors, a cavitation threshold for each pump of the plurality of pressure pumps using the actuation delays and the minimum boost pressures;
identifying, by the one or more processors, a pump of the plurality of pressure pumps having a boost pressure beyond the cavitation threshold determined for the pump; and
adjusting, by the one or more processors, a pump rate of the pump.

10. The method of claim 9 , wherein determining the actuation delays for the one or more valves of the plurality of pressure pumps includes, for a respective pump of the plurality of pressure pumps:
receiving, from a position sensor, a position signal representing the position measurement for the pump;
receiving, from a strain gauge, a strain signal representing the strain measurement for a chamber of the pump;
determining a position of a displacement member mechanically coupled to the rotating member of the pump using the position signal;
determining actuation points of a valve of the chamber; and
correlating the position of the displacement member and the actuation points of the valve to determine the actuation delays for the pump.

11. The method of claim 9 , wherein determining the minimum boost pressure for a respective pump of the plurality of pressure pumps includes tracing low peaks of a pressure signal generated by a pressure transducer coupled to an inlet of a chamber of the pump.

12. The method of claim 9 , wherein determining the cavitation threshold for each pump includes, for a respective pump of the plurality of pressure pumps:
comparing the actuation delays of the pump with additional actuation delays for additional pumps of the plurality of pressure pumps;
determining a point of cavitation in the pump based on the actuation delays; and
determining the minimum boost pressure for the pump at the point of cavitation.

13. The method of claim 9 , further comprising:
adjusting, by the one or more processors, the pump rate of the pump in a first direction;
maintaining, by the one or more processors, a total pump rate of the plurality of pressure pumps; and
determining, by the one or more processors, a change in the boost pressure for the pump in response to adjusting the pump rate to an adjus

Assignees

• Halliburton Energy Services Inc

Inventors

• Beisel Joseph A

Classifications

• E21B43/2607

  Surface equipment specially adapted for fracturing operations · CPC title

• F04B2201/0201

  Position of the piston · CPC title

• F04B1/00 Primary

  Multi-cylinder machines or pumps characterised by number or arrangement of cylinders (machines or pumps with pistons coacting within one cylinder F04B3/00) · CPC title

• F15B21/047

  Preventing foaming, churning or cavitation · CPC title

• F04B2205/03

  Pressure in the compression chamber · CPC title