Method of determining a level of a fluid in a well

• US 8,662,168 B2
• Filed: 04/13/2010
• Issued: 03/04/2014
• Est. Priority Date: 02/23/2007
• Status: Expired due to Fees

• Current Assignee: Warren Michael Levy
• Original Assignee: Warren Michael Levy
• Inventors: Levy, Warren Michael
• Primary Examiner(s): Thompson, Kenneth L
• Application Number:
  US12/759,599
• Publication Number:
  US 20100259416A1
• Time in Patent Office: 1,421 Days
• Field of Search: 166/250.03, 166/66, 166/254.4, 166/250.01, 73/645.5, 732/90.R, 733/04.R, 731/525.5, 324/324, 324/341
• US Class Current: 166/250.03
• CPC Class Codes: E21B 47/047 Liquid level measuring depth or liquid level using radioactive markers E21B47/053
• CPC Class Codes: G01F 23/26 by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
• CPC Class Codes: G01F 23/263 by measuring variations in capacitance of capacitors
• CPC Class Codes: G01F 23/266 measuring circuits therefor
• CPC Class Codes: G01F 23/268 mounting arrangements of probes

Abstract

A sensor used to determine the height of one or more fluids in a fluid column and to determine a location of an interface or boundary between a plurality of fluids in a fluid column is disclosed. The sensor includes a plurality of sensing elements comprising a capacitor and other components, such as resistors and inductors. The sensor also includes an oscillator that alters a frequency of an electrical current applied to the sensor, from which the dielectric constant of the fluid in which each sensing element is disposed can be determined. Methods of using such a sensor to determine the relative heights of various fluids in a fluid column are disclosed. In particular, methods of using embodiments of the invention in a well, such as water and petroleum wells, are described.

Claims

1. A method of determining a location of an interface between a plurality of fluids, comprising:

disposing a plurality of sensing elements in a well bore, the well bore including a plurality of fluids therein;

coupling an electrical power supply configured to supply electrical power having a voltage and a current alternating at a frequency to the plurality of sensing elements;

coupling a frequency modulator to the electrical power supply, the frequency modulator configured to modulate the frequency of the current;

supplying a current at a first frequency to the plurality of sensing elements;

generating a first signal representative of an electrical characteristic of a first fluid of the plurality of fluids and a second fluid of the plurality of fluids;

supplying a current at a second frequency to the plurality of sensing elements;

generating a second signal representative of an electrical characteristic of the first fluid and the second fluid;

processing the first signal and the second signal to generate an interface signal representative of the location of an interface between the first fluid and the second fluid with a processor, and;

providing perceivable information to a user with an output device connected to the processor and configured to receive the interface signal, the perceivable information including a discernible indication of the location of the interface between the first fluid and the second fluid.

2. The method of claim 1, further comprising:

supplying a current at a third frequency to the plurality of sensing elements;

generating a third signal representative of an electrical characteristic of the first fluid, the second fluid, and a third fluid of the plurality of fluids;

processing the first signal, the second signal, and the third signal to generate an interface signal representative of the location of an interface between the second fluid and the third fluid, and;

providing a discernible indication of the location of the interface between the second and the third fluid with the output device.

3. The method of claim 1, further comprising selecting the plurality of sensing elements that include a dielectric for use in at least one of a selected pressure range and a selected temperature range present in a well bore.

4. The method of claim 3, wherein selecting the dielectric for use in at least one of a selected pressure range and a selected temperature range further comprises selecting a dielectric that exhibits a substantially predictable dielectric constant within the selected pressure range and the selected temperature range.

5. The method of claim 4, wherein selecting a dielectric that exhibits a substantially predictable dielectric constant further comprises selecting a dielectric that exhibits a substantially predictable dielectric constant within a smaller, selected pressure range within a range of approximately 14 pounds per square inch (psi) to approximately 30,000 psi and a smaller, selected temperature range within a range of approximately negative 100°

F. to approximately 600°

F.

6. The method of claim 3, wherein selecting the dielectric for use in at least one of a selected pressure range and a selected temperature range further comprises selecting a dielectric that exhibits a substantially constant dielectric constant within the selected pressure range and the selected temperature range.

7. The method of claim 6, wherein selecting a dielectric that exhibits a substantially constant dielectric constant further comprises selecting a dielectric that exhibits a substantially constant dielectric constant within a smaller, selected pressure range within a range of approximately 14 pounds per square inch (psi) to approximately 30,000 psi and a smaller, selected temperature range within a range of approximately negative 100°

F. to approximately 600°

F.

8. The method of claim 1, further comprising at least partially disposing at least a first sensing element of the plurality of sensing elements in the first fluid and at least partially disposing at least a second sensing element of the plurality of the sensing elements in the second fluid.

9. The method of claim 1, further comprising coupling the power supply and the frequency modulator to the plurality of sensing elements with an electrical conductor.

10. The method of claim 1 further comprising selecting the plurality of sensing elements, each of the plurality of sensing elements including an inner conductive element, a dielectric fixed to and at least partially covering the inner conductive element, and an outer conductive element spaced apart from the dialectic such that the dielectric and the outer conductive element are configured to define a volume configured to receive at least the first fluid.

11. The method of claim 1, further comprising generating a first signal representative of a dielectric constant of the first fluid and a second signal representative of a dielectric constant of the second fluid with the processor.

12. The method of claim 11, further comprising providing a discernible indication of the dielectric constant of the first fluid and the dielectric constant of the second fluid with the output device.

13. The method of claim 11, further comprising generating a first signal representative of the identity of the first fluid and a second signal representative of the identity of the second fluid with the processor.

14. The method of claim 13, further comprising providing a discernible indication of the identity of the first fluid and the identity of the second fluid with the output device.