Managing equivalent circulating density during a wellbore operation

Patent metadata

Field	Value
Publication number	US-11466523-B2
Application number	US-201616078623-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	May 20, 2016
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

The equivalent circulating density (“ECD”) in a wellbore may be managed during a wellbore operation using ECD models that take into account the rheology of the wellbore fluid and the rotational speed of tubulars in the wellbore. For example, a method may include rotating a rotating tubular in a stationary conduit while flowing a fluid through an annulus between the rotating tubular and the stationary conduit; calculating an equivalent circulating density (“ECD”) of the fluid where a calculated viscosity of the fluid is based on an ECD model ?_eff=f(? ?_eff)*h(Re), wherein ?_eff is the viscosity of the fluid, ? ?_eff is an effective shear rate of the fluid, and Re is a Reynold's number for the fluid for the rotational speed of the rotating tubular; and changing an operational parameter of the wellbore operation to maintain or change the ECD of the fluid.

First claim

The invention claimed is:

1. A method comprising:
flowing a fluid through an annulus between a rotating tubular and a stationary conduit for a wellbore operation in a wellbore;
determining a critical rotational speed of the rotating tubular, above which a formation of toroidal vortices in the fluid occurs;
calculating a viscosity of the fluid for an operating rotational speed of the rotating tubular based on an equivalent circulating density (“ECD”) model,
wherein the ECD model is based, at least in part, on an effective shear rate of the fluid,
wherein the ECD model is based, at least in part, on a ratio of Reynold's numbers at the operating rotational speed and the critical rotational speed when the rotational speed of the rotating tubular is greater than or equal to the critical rotational speed;
calculating an ECD of the fluid based on the viscosity of the fluid; and
based on the ECD of the fluid, adjusting one or more operation parameters for the wellbore operation to control the ECD of the fluid.

2. The method of claim 1 , wherein the ECD model is μ eff =ƒ({dot over (γ)} eff ) when Re<Re crit and

μ
eff

=

f
⁡

(

γ
.

eff

)

⁡

[

1
+

α
⁡

[

(

Re

Re
crit

)

β

-
1

]

]

when Re≥Re crit , wherein μ eff is the viscosity of the fluid, {dot over (γ)} eff is the effective shear rate of the fluid, Re is the Reynold's number for the fluid at the operating rotational speed of the rotating tubular, Re crit is a critical Reynold's number for the fluid at the critical rotational speed, and α and β are experimentally determined factors for the fluid.

3. The method of claim 2 , wherein ƒ({dot over (γ)} eff ) is calculated based on assuming the fluid is one of a Power-law fluid, a Bingham plastic fluid, a Herschel-Bulkley fluid, a generalized Herschel-Bulkley fluid, and a Casson fluid.

4. The method of claim 1 , wherein adjusting the one or more operation parameters for the wellbore operation to control the ECD of the fluid comprises maintaining the ECD of the fluid between a fracture gradient and a pore-pressure gradient of a formation surrounding the wellbore.

5. The method of claim 1 , wherein the fluid is a cement slurry and the stationary conduit is a casing.

6. The method of claim 1 , wherein the fluid is a drilling fluid, the rotating tubular is a drill string, and the stationary conduit is one of the wellbore and a casing positioned in the wellbore.

7. A method comprising:
modeling a wellbore operation that comprises:
rotating a tubular in a stationary conduit of a wellbore at an operating rotational speed;
flowing a fluid through an annulus between the rotating tubular and the stationary conduit;
calculating a viscosity of the fluid for the operating rotational speed of the rotating tubular based on an equivalent circulating density (“ECD”) model, wherein the ECD model is based, at least in part, on an effective shear rate of the fluid, wherein, at operating rotational speeds less than a critical rotational speed, an operating Reynold's number for the fluid is less than a critical Reynold's number for the fluid and wherein, at operating rotational speeds greater than or equal to the critical rotational speed, the ECD model is based, at least in part, on a ratio of Reynold's numbers at the operating rotational speed and the critical rotational speed of the rotating tubular;

calculating an equivalent circulating density (“ECD”) of the fluid based on the viscosity of the fluid; and
determining, using the ECD model, wellbore operation parameters that maintain the ECD of the fluid between a fracture gradient and a pore-pressure gradient of a formation.

8. The method of claim 7 , wherein the wellbore operation parameters comprise at least one of the operating rotational speed of the rotating tubular, a flow rate of the fluid, a yield stress of the fluid, the viscosity of the fluid, and a formulation of the fluid.

9. The method of claim 7 , wherein the ECD model is μ eff =ƒ({dot over (γ)} eff ) when Re<Re crit and

μ
eff

=

f
⁡

(

γ
.

eff

)

⁡

[

1
+

α
⁡

[

(

Re

Re
crit

)

β

-
1

]

]

when Re≥Re crit , wherein μ eff is the viscosity of the fluid, {dot over (γ)} eff is the effective shear rate of the fluid, Re is the operating Reynold's number for the fluid at the operating rotational speed of the rotating tubular, Re crit is the critical Reynold's number for the fluid, and α and β are experimentally determined factors for the fluid.

10. The method of claim 9 , wherein ƒ({dot over (γ)} eff ) is calculated based on assuming the fluid is one of a Power-law fluid, a Bingham plastic fluid, a Herschel-Bulkley fluid, a generalized Herschel-Bulkley fluid, and a Casson fluid.

11. The method of claim 7 , wherein the fluid is a cement slurry.

12. The method of claim 7 , wherein the stationary conduit is one of a casing positioned in th

Assignees

• Halliburton Energy Services Inc

Inventors

• Singh John Paul Bir
• Kulkarni Sandeep D
• Lopes Pereira Vitor
• Yerubandi Krishna Babu

Classifications

• E21B21/082 Primary

  Dual gradient systems, i.e. using two hydrostatic gradients or drilling fluid densities · CPC title

• E21B33/14

  for cementing casings into boreholes · CPC title

• E21B19/00

  Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables · CPC title

• E21B47/06

  Measuring temperature or pressure · CPC title

• E21B21/08 Primary

  Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10) · CPC title