Fluid inflow

Patent metadata

Field	Value
Publication number	US-10422677-B2
Application number	US-201515307562-A
Country	US
Kind code	B2
Filing date	May 8, 2015
Priority date	May 8, 2014
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

Methods and apparatus for determining fluid inflow to a well are described. In one example, a method comprise determining a first fluid flow velocity profile from slug tracking and determining a second fluid flow velocity profile from an estimate of fluid inflow at each of a plurality of perforations in a well. The first and second fluid flow velocity profiles are combined to provide a combined velocity profile. An indication of fluid inflow at least one perforation is derived from the combined velocity profile.

First claim

The invention claimed is:

1. A method of determining an indication of fluid inflow in a well, the method comprising:
determining a first fluid flow velocity profile based on slug tracking; determining a second fluid flow velocity profile from an estimate of fluid inflow at each of a plurality of perforations in the well;
combining the first and second fluid flow velocity profiles to provide a combined velocity profile;
deriving, from the combined velocity profile, an indication of fluid inflow at at least one perforation.

2. A method according to claim 1 in which at least one of the first and second fluid flow velocity profiles are smoothed fluid flow velocity profiles.

3. A method according to claim 2 in which combining the first and second fluid flow velocity profiles to provide a combined velocity profile comprises determining a function in which the first velocity profile and a smoothed second velocity profile are coupled, and using the function to act on the second velocity profile.

4. A method according to claim 3 in which a coupling parameter is determined, the coupling parameter determining the degree of coupling between the first and second fluid flow velocity profiles.

5. A method according to claim 1 in which determining the first fluid flow velocity profile comprises determining a flow signal due to a slug as the slug moves though a well.

6. A method according to claim 5 in which determining the flow signal comprises monitoring the signal energy in a frequency band and tracking a feature having a characteristic energy as it moves through the well.

7. A method according to claim 1 in which determining the estimate of fluid inflow comprises determining a signal energy in a frequency band, and relating the signal energy to fluid inflow.

8. A method according to claim 1 in which determining the second fluid flow velocity profile comprises:
determining a flow signal at a perforation;
relating the flow signal to an estimated fluid inflow; and
determining, from the estimated fluid inflow, an estimated fluid flow velocity profile.

9. A method according to claim 8 in which determining the second fluid flow velocity profile comprises:
monitoring the temperature at a plurality of locations within the section of the well, the locations comprising (a) a first set of locations, at or near a perforation; and (b) a second set of locations at which the temperature is substantially independent of temperature effects of the inflow of gas at a perforation;
determining an indication of temperature excursions at the locations;
obtaining an indication of the inflow of fluids to the well by relating the indications of temperature excursions from the second set of locations to liquid inflow and relating the indications of temperature excursions from the first set of locations to liquid and gas inflow.

10. A method according to claim 9 in which the second set of locations comprise locations between the perforations.

11. A method according to claim 9 in which the inflow of liquid is estimated by considering the indication of temperature excursions at each of the second set of locations as being proportional to:

d
⁢

⁢

T

s
⁢

⁢
l
⁢

⁢
u
⁢

⁢
g

×

∑
1
n

⁢

W

perf
⁢

⁢
n

,

where dT slug is the temperature difference between liquid rising in the well at that location and the equilibrium temperature at that point, n is the nth perforation in the section of the well, and

∑
1
n

⁢

W

perf
⁢

⁢
n

is the total amount of liquid in the well passing that location.

12. A method according to claim 9 in which the inflow of liquid and gas are estimated by considering the indication of temperature excursions at each of the first set of locations as being proportional to:

[

d
⁢

⁢

T

perf
⁢

⁢
n

+

d
⁢

⁢

T

s
⁢

⁢
l
⁢

⁢
u
⁢

⁢
g

]

×

∑
1
n

⁢

W

perf
⁢

⁢
n

,

where n is the nth perforation in the section of the well, dT perf n is the temperature difference from an equilibrium temperature due to the inflow of gas a

Assignees

• Optasense Holdings Ltd

Inventors

• Crickmore Roger
• Ridge Andrew

Classifications

• E21B47/07 Primary

  Temperature · CPC title

• E21B47/135

  using light waves, e.g. infrared or ultraviolet waves · CPC title

• G01F1/696 Primary

  Circuits therefor, e.g. constant-current flow meters · CPC title

• G01F1/661

  using light · CPC title

• G01F1/704

  using marked regions or existing inhomogeneities within the fluid stream, e.g. statistically occurring variations in a fluid parameter (G01F1/76, G01F25/00 take precedence) · CPC title