Method of attenuating annular pressure buildup using compressible particles

Patent metadata

Field	Value
Publication number	US-11814932-B2
Application number	US-202117221132-A
Country	US
Kind code	B2
Filing date	Apr 2, 2021
Priority date	Apr 7, 2020
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A method of attenuating annular pressure buildup within a wellbore. The method includes accessing a wellbore, with the wellbore having an annulus disposed between first and second strings of casing. The method also includes placing a column of cement around the second string of casing generally below the first string of casing. The method further includes pumping a fluid mixture into the annulus, forming a fluid column. The fluid mixture comprises a carrier fluid, and a plurality of compressible particles dispersed in the carrier fluid. Each of the compressible particles is fabricated to partially collapse in response to thermal expansion of the fluid mixture. The method also includes placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore. The method additionally includes at least partially sealing the annular region along at least one depth above the column of cement to inhibit vertical migration of the compressible particles.

First claim

We claim:

1. A method of attenuating annular pressure buildup within a wellbore, comprising:
accessing a wellbore, the wellbore comprising:
a first string of casing extending into a subsurface to a first depth; and
a second string of casing extending into the subsurface to a second depth that is greater than the first depth, wherein the first string of casing surrounds an upper portion of the second string of casing, forming an annular region;

pumping a fluid mixture into the annular region, forming a fluid column, wherein the fluid mixture comprises:
a carrier fluid; and
a plurality of compressible particles dispersed in the carrier fluid, wherein each of the compressible particles is fabricated to partially collapse in response to thermal expansion of fluid within the annular region during a production of hydrocarbon fluids, wherein at least some of the compressible particles have a density that is less than a density of the carrier fluid such that the compressible particles are biased to rise in the annular region; and

at least partially sealing the annular region along at least one depth above the first depth, thereby inhibiting migration of the compressible particles along the annular region, wherein at least partially sealing the annular region along at least one depth comprises securing at least one sealing joint in series along the second string of casing, wherein each of the at least one sealing joint comprises cups that are concave.

2. The method of claim 1 , further comprising:
pumping a column of cement into the annular region; and

allowing the column of cement to set around the second string of casing below the first depth, wherein the fluid mixture resides above the column of cement; and
wherein the compressible particles together have a reversible volumetric contraction of within the range of 10 to 25% when the fluid pressure acting on the particles is increased from 15 pounds per square inch (psi) to 10,000 psi.

3. The method of claim 1 , wherein each of the plurality of compressible particles comprises carbon fibers or carbon particles.

4. The method of claim 3 , wherein:
the carrier fluid comprises drilling fluid;
the fluid mixture further comprises weighting agent particles as part of the drilling fluid; and wherein the weighting agent particles each have a particle size that is about, but not less than, 150 times smaller than a size of the compressible particles.

5. The method of claim 3 , wherein:
each of the plurality of compressible particles comprises carbon particles; and
each of the carbon particles is coated with a polymeric rubber material.

6. The method of claim 5 , wherein:
the carrier fluid is brine or a thixotropic fluid; and
the polymeric rubber material is one or more of ethylene propylene rubber, hydrogenated nitrile butadiene rubber (HNBR), nitrile butadiene rubber (NBR), and fluoroelastomer (FKM).

7. The method of claim 1 , wherein:
the at least one sealing joint comprises at least two sealing joints; and
each of the cups is upwardly concave, downwardly concave, or some cups are upwardly concave while others are downwardly concave.

8. The method of claim 1 , wherein:
the carrier fluid is brine, an aqueous drilling fluid or a non-aqueous drilling fluid; and
each of the plurality of compressible particles comprises carbon particles;
at least some of the compressible particles have a specific gravity that is 1.5 to 2.0 times that of the carrier fluid; and
each of the carbon particles is coated with a polymeric rubber material.

9. The method of claim 1 , wherein the compressible particles have outer diameters that are between 40 micrometers (μm) and 1300 μm (in dry state).

10. The method of claim 1 , further comprising:
blending the compressible particles into the carrier fluid at a surface to form the fluid mixture, before pumping the fluid mixture into the annulus;
and wherein at least partially sealing the annular region comprises actuating a plurality of annular sealing devices.

11. The method of claim 10 , wherein:
the compressible particles comprise first compressible particles having a first density, and second compressible particles having a second density;
each of the compressible particles has a density at ambient conditions that is between 12.5 pounds per gallon (ppg) and 15.5 ppg; and
wherein the first compressible particles are biased to rise in the annular region after pumping, while the second compressible particles are biased to sink in the annular region after pumping.

12. A method of placing compressible particles within a wellbore, comprising:
running a first string of casing into a wellbore, the first string of casing extending into a subsurface to a first depth;
running a second string of casing into the wellbore, the second string of casing extending into the subsurface to a depth that is greater than the first depth, and wherein the first string of casing surrounds an upper portion of the second string of casing forming an annular region;
pumping a fluid mixture into the annular region, forming a fluid column, wherein the fluid mixture comprises:
a carrier fluid; and
a plurality of compressible particles dispersed in the carrier fluid;

at least partially sealing the annular region along at least one depth above the first depth, wherein at least partially sealing the annular region along at least one depth comprises securing at least one sealing joint in series along the second string of casing, wherein each of the at least one sealing joint comprises cups that are concave;
placing a column of cement around the second string of casing below the first depth; and
placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore over the annular region, wherein at least some of the compressible particles have a density that is less than a density of the carrier fluid such that the compressible particles are biased to rise in the trapped annulus;
and wherein:
the compressible particles comprises a plurality of carbonaceous particles, and
the carbonaceous particles are designed to absorb pressure in response to thermal expansion of wellbore fluids within the annular region during a production of hydrocarbon fluids from the wellbore.

13. The method of claim 12 , further comprising:
pumping a column of cement into the annular region;
allowing the column of cement to set around the second string of casing below the first depth, wherein the fluid mixture resides above the column of cement.

14. The method of claim 12 , wherein:
the carbonaceous particles are designed to have an optimum pressure performance comprising a maximum reversible volumetric expansion/contraction percentage at an upper end of the range of expected pressures within the trapped annulus during production; and
each of the plurality of compressible particles has a reversible volumetric expansion/contraction of within the range of 10 to 25% at pressures between 15 pounds per square inch (psi) and 10,000 psi.

15. The method of claim 14 , wherein:
the fluid mixture is pumped into the wellbore after the column of cement has been placed around the second string of casing; and
pumping the fluid mixture comprises pumping the fluid mixture down the annulus, through a reverse circulation sleeve residing along the second string of casing, and back up the second string of casing after the column of cement has set around the second string of casing.

16. The method of claim 14 , wherein:
a specific gravity of at least some of the compressible particles is within plus/minus 0.2 of a specifi

Assignees

• Exxonmobil Technology & Engineering Company

Inventors

• White Spencer A
• Petersen Thomas A
• Templeton-Barrett Elizabeth L
• Zeilinger Sabine C
• Ivan Catalin D
• Gordon Peter A
• Mayer Christian S

Classifications

• E21B41/0021 Primary

  Safety devices, e.g. for preventing small objects from falling into the borehole · CPC title

• E21B33/122

  Multiple string packers · CPC title

• F16F9/006

  characterised by the nature of the damping medium, e.g. biodegradable (variable viscosity damping adjustment F16F9/53) · CPC title

• F16L57/02

  against cracking or buckling · CPC title

• F16F2222/02

  temperature-related (F16F2228/002 takes precedence) · CPC title