Characterization of fluids with drag reducing additives in a couette device

Patent metadata

Field	Value
Publication number	US-2016275221-A1
Application number	US-201315035072-A
Country	US
Kind code	A1
Filing date	Nov 7, 2013
Priority date	Nov 7, 2013
Publication date	Sep 22, 2016
Grant date	—

Abstract

A method is provided for characterizing fluid flow in a pipe where the fluid includes a drag reducing polymer of a particular type and particular concentration. A computational model is configured to model flow of a fluid in a pipe. The computational model utilizes an empirical parameter for a drag reducing polymer of the particular type and the particular concentration. The computational model can be used to derive information that characterizes the flow of the fluid in the pipe. The empirical parameter for the particular type and the particular concentration of the drag reducing polymer can be identified by solving another computational model that is configured to model turbulent Couette flow in a Couette device for a fluid that includes a drag reducing polymer of the particular type and the particular concentration. The empirical data needed for identification of the empirical parameter are obtained from Couette device experiments.

First claim

What is claimed is:

1 . A method of characterizing fluid flow in a pipe where the fluid includes a drag reducing polymer of a particular type and particular concentration, the method comprising:
i) providing a first computational model associated with a Couette device to model turbulent Couette flow of a fluid, wherein the first computation model includes an empirical parameter for the particular type and the particular concentration of the drag reducing polymer; ii) using the first computational model in conjunction with experimental data derived from operation of the Couette device with a fluid that includes a drag reducing polymer of the particular type and the particular concentration to solve for the empirical parameter; and iii) providing a second computational model that is configured to model flow of fluid in a pipe, wherein the second computational model is configured to utilize the empirical parameter as solved for in ii); and iv) using the second computational model to derive information that characterizes the flow of fluid in the pipe.

2 . A method according to claim 1 , wherein the second computational model includes a drag reduction parameter that is a function of the empirical parameter.

3 . A method according to claim 2 , wherein the drag reduction parameter is also a function of a dimensionless pipe radius R + .

4 . A method according to claim 3 , wherein the second computational model is configured to relate the drag reduction parameter to the empirical parameter by an equation of the form:
D * =1+α * R +
where
D * is the drag reduction parameter,
α * is the empirical parameter, and
R + is the dimensionless pipe radius.

5 . A method according to claim 2 , wherein the second computational model includes a friction factor that is a function of the drag reduction parameter, wherein the friction factor relates pressure loss due to friction along a given length of pipe to the mean flow velocity through the pipe.

6 . A method according to claim 5 , wherein the second computational model is configured to relate the friction factor to the drag reduction parameter by an equation of the form:

1

f
0.5

=

4


log
10



(

Re




f
0.5

)

+

8.2


D
*
2

-
8.6
-

12.2


log
10



D
*

where
f is the friction factor,
D * is the drag reduction parameter, and
Re is the Reynolds number of the flow in the pipe.

7 . A method according to claim 6 , wherein the second computational model is further configured to relate the Reynolds number Re to a dimensionless pipe radius R + .

8 . A method according to claim 6 , wherein the information derived in iv) includes a solution for the friction factor f for given flow conditions.

9 . A method according to claim 8 , wherein the information derived in iv) includes a pressure drop over a given length of pipe based on the solution for the friction factor f.

10 . A method according to claim 1 , wherein the second computational model is based upon a representation of the flow as two layers consisting of a viscous outer sublayer that surrounds a turbulent core.

11 . A method according to claim 1 , wherein:
the method is carried out for a number of different concentrations of a particular drag reducing polymer or over different drag reducing polymers to characterize the expected pipe flow for these different scenarios, and/or the method is carried out for a number of different flow conditions to characterize the expected pipe flow for these different scenarios.

12 . A method according to claim 1 , wherein the first computation model is based upon a representation of the turbulent Couette flow as three layers consisting of viscous outer and inner sublayers with a turbulent core therebetween.

13 . A method according to claim 1 , wherein the Couette device defines an annulus between first and second annular surfaces, and the first computational model includes a first drag reduction parameter associated with the first annular surface and a second drag reduction parameter associated with the second annular surface, wherein both the first and second drag reduction parameters are functions of the empirical parameter.

14 . A method according to claim 13 , wherein both the first and second drag reduction parameters are also functions of a dimensionless torque G applied to the Couette device.

15 . A method according to claim 14 , wherein:
the first and second annular surfaces of the Couette device are concentric with respect to one another about a common center, wherein the first annular surface is offset from the center by a first radius R and the second annular surface is offset from the center by a second radius r 0 , wherein R is greater than r 0 ; and the first computational model is configured to relate the first and second drag reduction parameters to the empirical parameter by equations of the following form:

D

o
*

=

1
+

α
*

2



(

1
-
η

)



G

2



π

D

i
*

=

1
+

Assignees

• Schlumberger Technology Corp

Inventors

• Barmatov Evgeny Borisovich
• Eskin Dmitry

Classifications

• G06F17/11

  for solving equations {, e.g. nonlinear equations, general mathematical optimization problems (optimization specially adapted for a specific administrative, business or logistic context G06Q10/04)} · CPC title

• G01N11/04 Primary

  through a restricted passage, e.g. tube, aperture · CPC title

• G01N2011/006

  Determining flow properties indirectly by measuring other parameters of the system · CPC title

• G01F1/28

  by drag-force, e.g. vane type or impact flowmeter · CPC title

• G06F2113/14

  Pipes · CPC title