Methods and Systems for Determining Process Variables Using Location of Center of Gravity

• US 20110138892A1
• Filed: 12/10/2009
• Published: 06/16/2011
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Weightman, Glenn H., Crain, Steve, Lucas, Bruce C., McConnell, Rebecca
• Granted Patent: US 8,511,150 B2
• Time in Patent Office: Days
• US Class Current: 73/65.01
• CPC Class Codes: G01F 22/00 Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for
• CPC Class Codes: G01F 23/20 by measurement of weight, e.g. to determine the level of stored liquefied gas
• CPC Class Codes: G01F 23/804 containing circuits handling parameters other than liquid level
• CPC Class Codes: G01G 19/08 for incorporation in vehicles

Abstract

Methods and systems for using force measurements to determine the amount of material in a container and/or the rate at which material is discharged from a container are disclosed. A container for storing a desired material is positioned so that the center of gravity of the container shifts horizontally with changes in level of the material in the container. A plurality of load sensors are symmetrically arranged at a base of the container and are used to monitor the amount of materials in the container.

Claims

1. A method of monitoring materials in a container comprising the steps of:

placing the container in a desired position;

wherein when the container is placed in the desired position, a change in level of materials in the container changes position of center of gravity of the materials in the container along the horizontal axis;

determining location of center of gravity of the materials in the container; and

determining level of materials in the container;

wherein the level of materials in the container is determined using position of the center of gravity of the materials in the container and container geometry.

2. The method of claim 1, further comprising determining volume of the materials in the container;

wherein the volume of the materials in the container is determined using the level of materials in the container and container geometry.

3. The method of claim 2, further comprising determining density of the materials in the container, wherein determining the density of the materials in the container comprises:

determining the mass of the materials in the container and dividing the mass of the materials in the container by the volume of the materials in the container.

4. The method of claim 3, further comprising determining the volumetric flow rate of the materials in the container, wherein the volumetric flow rate is determined using the density and rate of change of mass of the materials in the container.

5. A method of monitoring materials in a container comprising:

placing the container at an angle to vertical;

wherein the container rests on a first load sensor and a second load sensor;

wherein the first load sensor and the second load sensor are separated by a predetermined distance;

determining mass of the materials in the container using the readings of the first load sensor and the second load sensor;

determining location of center of gravity of the container using a ratio of force at the first load sensor and force at the second load sensor;

determining level of materials in the container using the location of the center of gravity and the angle of the container from vertical; and

determining volume of materials in the container using the level of materials in the container and container geometry.

6. The method of claim 5, further comprising determining density of materials in the container by dividing the mass of the materials in the container by the volume of the materials in the container.

7. The method of claim 5, wherein the load sensor is selected from the group consisting of a hydraulic load cell, a scale, a load pin, a dual shear beam load cell, a strain gauge, an electronic load cell and a pressure transducer.

8. The method of claim 5, wherein the angle of the container from vertical is measured with an incline sensor.

9. A method of monitoring the amount of materials in a container comprising:

placing the container on an angled platform resting on a first load sensor and a second load sensor;

wherein the first load sensor and the second load sensor are separated by a predetermined distance;

locating center of gravity of the container at a first point in time;

changing the amount of materials in the container;

locating center of gravity of the container at a second point in time;

determining the change in the level of materials in the container between the first point in time and the second point in time; and

determining the volume of materials removed from the container.

10. The method of claim 9, wherein the materials comprise a fluid used in oil field operations.

11. The method of claim 9, further comprising:

determining a first mass of the materials in the container based on readings of the first load sensor and the second load sensor at the first point in time;

determining a second mass of the materials in the container based on readings of the first load sensor and the second load sensor at the second point in time;

determining a differential mass, wherein the differential mass comprises difference between the first mass and the second mass; and

determining density of the materials in the container using the change in volume of the materials in the container and the differential mass of the materials in the container.

12. The method of claim 11, further comprising determining the total volume of the materials in the container at the second point in time using the density of the materials in the container and the second mass of the materials in the container.

13. The method of claim 12, further comprising determining the mass flow rate of the materials in the container.

14. The method of claim 13, wherein determining the mass flow rate of the materials in the container comprises dividing the differential mass of the materials in the container by a change in time;

wherein the change in time represents the difference between the first point in time and the second point in time.

15. The method of claim 14, further comprising determining the volumetric flow rate of the materials in the container.

16. The method of claim 15, wherein determining the volumetric flow rate of the materials in the container comprises dividing the mass flow rate of the materials in the container by the density of the materials in the container.

17. A system for monitoring material storage comprising:

a container for storing a material;

wherein center of gravity of the container shifts horizontally with changes in level of the material in the container; and

a plurality of load sensors coupled to the container;

wherein the plurality of load sensors are symmetrically arranged at a base of the container.

18. The system of claim 17, wherein the load sensors are load cells.

19. The system of claim 17, further comprising an information handling system coupled to one or more of the plurality of load sensors.

20. The system of claim 19, wherein the information handling system displays a real time reading of the one or more of the plurality of load sensors.

21. The system of claim 19, wherein the information handling system processes the readings of the load sensors to determine information selected from the group consisting of a mass of the material in the container, a volume of the material in the container and the density of the material in the container.

22. The system of claim 21, wherein the information handling system displays information selected from the group consisting of the mass of the material in the container, the volume of the material in the container and the density of the material in the container in real time.

23. The system of claim 17, wherein the container is placed at an angle from vertical.

24. The system of claim 23, further comprising an incline sensor for measuring the angle of the container from vertical.

25. A method of monitoring materials in a container comprising:

placing the container on a first load sensor and a second load sensor;

wherein the container is positioned at an angle to vertical;

determining a relationship between readings of force at the first load sensor and the second load sensor and level of materials in the container;

placing a desirable material in the container;

monitoring amount of the desirable material in the container using the readings of force at the first load sensor and the second load sensor.

26. The method of claim 25, wherein determining the relationship between readings of force at the first load sensor and the second load sensor and the level of materials in the container comprises:

placing a test material in the container;

changing the level of the test material in the container;

monitoring the change in readings of force at the first load sensor and the second load sensor against the change in the level of the test material in the container.

27. The method of claim 25, wherein the desirable material is homogeneous.