Using fluid pill for heat transfer downhole

Patent metadata

Field	Value
Publication number	US-12410685-B2
Application number	US-202418403437-A
Country	US
Kind code	B2
Filing date	Jan 3, 2024
Priority date	Jan 3, 2024
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A method of cooling at least a portion of a downhole tool located within a drilled wellbore using a fluid pill configured to transfer heat away from a heat-generating segment of the downhole tool. The downhole tool may be a wireline logging tool. The fluid pill can comprise at least one fluid coolant and may include other additives that enable the fluid pill to transfer heat away from a heat-generating segment of the downhole tool even in the presence of one or more fluids present in the drilled wellbore. The fluid pill can be introduced into residual drilling mud in the wellbore, and the downhole tool may thereafter be operated with the heat-generating segment thereof in fluid contact with the fluid pill, whereby heat generated by the heat-generating segment is transferred away from the downhole tool and toward a wall of the wellbore by the fluid pill.

First claim

What is claimed is:

1. A downhole tool for use in a post-drilling operation, comprising:
a heat-generating segment;
a tool body positionable on a tool string for running the downhole tool into a drilled wellbore;
a first chamber and a second chamber separately defined within the tool body, each of the first chamber and the second chamber configured to releasably hold a fluid pill comprising one or more materials that enable the fluid pill to transfer heat from the heat-generating segment of the downhole tool to a wall of the wellbore;
at least one port in the tool body; and
a pump within the tool body, the pump in fluid communication with the first chamber, the second chamber, and the at least one port, and operatable to selectively expel a fluid pill from one or both of the first chamber and the second chamber through the at least one port and into the drilled wellbore.

2. The downhole tool of claim 1 , further comprising:
a first controllable valve fluidly coupling the first chamber to the pump and a second controllable valve fluidly coupling the second chamber to the pump; and
wherein the first controllable valve and the second controllable valve are operatable to place the pump in temporary fluid communication with one or both of the first chamber and the second chamber and to thereby cause an operation of the pump to selectively expel a fluid pill from one or both of the first chamber or the second chamber.

3. The downhole tool of claim 1 , wherein:
at least one of the ports in the first chamber and the second chamber is a two-way port; and
the pump is a reversible pump and is further operatable to selectively extract a fluid pill from the drilled wellbore into the first chamber or the second chamber through the at least one two-way port.

4. The downhole tool of claim 1 , wherein the downhole tool is a wireline logging tool and the heat generating segment includes at least one sensor for evaluating the drilled wellbore, a formation surrounding the drilled wellbore, or a fluid located within the drilled wellbore.

5. The downhole tool of claim 1 , further comprising a refillable tank located in the each chamber and configured to contain the fluid pill.

6. The downhole tool of claim 1 , wherein the pump is an electric pump or a spring-powered pump.

7. A system comprising:
a downhole tool for use in a post-drilling operation, comprising:
a heat-generating segment,
a tool body positionable on a tool string for running the downhole tool into a drilled wellbore, the tool body defining-a at least one chamber therein,
at least one port in the tool body, and
a pump located within the tool body and in fluid communication with the at least one port and the at least one chamber;

a fluid pill residing in the at least one chamber within the tool body, the fluid pill including one or more materials that enable the fluid pill to cool the downhole tool via a transfer of heat from the heat-generating segment of the downhole tool to a wall of the drilled wellbore; and
a controller communicatively coupled to the pump and configured to output commands to instruct the pump to expel the fluid pill from the at least one chamber through the at least one port in the tool body and into the drilled wellbore.

8. The system of claim 7 , wherein the fluid pill comprises one or more phase change materials.

9. The system of claim 8 , wherein:
the port in the tool body is a two-way port; and
the pump is operatable to extract a fluid pill from the drilled wellbore into the at least one chamber in the tool body through the two-way port.

10. The system of claim 7 , wherein the controller is located outside of the drilled wellbore and is communicatively coupled to the pump by a wireline.

11. The system of claim 7 , wherein the fluid pill includes at least one fluid coolant.

12. The system of claim 11 , wherein the fluid pill further includes one or more thermal conductivity-improving materials selected from the group consisting of carbon black, metals, ceramics, nanomaterials, and nanoparticles.

13. The system of claim 11 , wherein the fluid pill further includes one or more convection-improving thinning agents selected from the group consisting of polyacrylates, lignosulfonates, phosphates, surfactants, and polyimides.

14. The system of claim 7 , wherein the fluid pill has a composition selected from the group consisting of two or more types of separate fluids that are mixable once downhole at a target location to produce, via an endothermic chemical reaction, a transient temperature reduction in residual drilling mud present in the wellbore, and one or more additives that are reactive with well fluid already present in the wellbore to alter one or more properties of the well fluid.

15. The system of claim 7 , wherein:
the at least one chamber is a plurality of chambers, each of which contains a fluid pill; and
at least two of the fluid pills in the plurality of chambers have dissimilar compositions that are combinable in the drilled wellbore to cause a transient temperature reduction in residual drilling mud present in the drilled wellbore via an endothermic chemical reaction.

16. The system of claim 7 , wherein the downhole tool is a wireline logging tool and the heat generating segment includes at least one sensor for evaluating the drilled wellbore, a formation surrounding the drilled wellbore, or a fluid located within the drilled wellbore.

17. The system of claim 7 , wherein the fluid pill is an oil-based inert emulsion having an oil-to-water ratio of between 20:80 to 100:0.

18. The system of claim 7 , wherein the fluid pill is a water-based fluid comprising a brine selected from the group consisting of chloride brine, bromide brine, formate brine, and mixtures thereof.

19. The system of claim 3 , wherein the controller is programmed to instruct the pump to expel the fluid pill from the tool body after operation of the downhole tool for a pre-selected amount of time or based on a location of the at least one chamber in the tool body relative to a downhole location in the wellbore.

20. The system of claim 3 , wherein the fluid pill includes a single fluid containing one or more reactants that are maintained separately via a degradable coating or encapsulation material on at least one of the reactants.

Assignees

• Halliburton Energy Services Inc

Inventors

• Reding Christian
• Ball David Earl
• Hudson Marcus Ray
• Cernosek James
• Deville Jay

Classifications

• E21B47/0175

  Cooling arrangements · CPC title

• C09K5/16 Primary

  Materials undergoing chemical reactions when used · CPC title

• E21B36/001 Primary

  Cooling arrangements · CPC title