Downhole gas separators and methods of separating a gas from a liquid within a hydrocarbon well

Patent metadata

Field	Value
Publication number	US-10450848-B2
Application number	US-201615245858-A
Country	US
Kind code	B2
Filing date	Aug 24, 2016
Priority date	Nov 12, 2015
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

Downhole gas separators, artificial lift systems including the downhole gas separators, hydrocarbon wells including the artificial lift systems, and methods of separating a gas from a liquid hydrocarbon within a hydrocarbon well. The downhole gas separators include an elongate outer housing that defines an enclosed volume, a fluid inlet port, and a gas outlet port. The downhole gas separators further include an elongate dip tube that extends within the enclosed volume, and the gas outlet port is configured to selectively provide fluid communication between the enclosed volume and an external region.

First claim

The invention claimed is:

1. A downhole gas separator for an artificial lift system, the separator comprising:
an elongate outer housing including an enclosed first housing end region and a second housing end region that is spaced apart from the first housing end region, wherein the outer housing at least partially defines an enclosed volume, and further wherein the second housing end region is configured to operatively couple the separator to a reciprocating pump of the artificial lift system;
an elongate dip tube having a first tube end and a second tube end, wherein the dip tube extends within the enclosed volume to define a separator annulus between the dip tube and the outer housing, wherein the first tube end is proximal the first housing end region relative to the second tube end and is configured to receive a fluid from the enclosed volume, and further wherein the second tube end is configured to provide the fluid to the reciprocating pump;
a fluid inlet port extending through the outer housing and configured to provide fluid communication between the enclosed volume and an external region that is external to the enclosed volume; and
a gas outlet port extending through the outer housing and configured to selectively provide fluid communication between the enclosed volume and the external region, wherein the gas outlet port is closer to the first housing end region than the fluid inlet port.

2. The separator of claim 1 , wherein the gas outlet port further includes a flow-regulating device configured to selectively regulate fluid flow through the gas outlet port and also to selectively regulate fluid flow within the separator annulus, wherein the flow-regulating device includes a first orientation, in which the flow-regulating device restricts fluid flow through the gas outlet port and permits fluid flow through the separator annulus, and a second orientation, in which the flow-regulating device permits fluid flow through the gas outlet port and restricts fluid flow through the separator annulus.

3. The separator of claim 2 , wherein the reciprocating pump is configured to repeatedly perform an intake stroke and a subsequent exhaust stroke, and further wherein the flow-regulating device is configured to:
(i) be in the first orientation during at least a portion of each intake stroke; and
(ii) be in the second orientation during at least a portion of each exhaust stroke.

4. The separator of claim 2 , wherein, when in the first orientation, the flow-regulating device forms a first fluid seal across the gas outlet port.

5. The separator of claim 2 , wherein, when in the second orientation, the flow-regulating device:
(i) forms a second fluid seal between the outer housing and the dip tube; and
(ii) restricts fluid flow within the separator annulus and between the fluid inlet port and the gas outlet port.

6. The separator of claim 5 , wherein the second fluid seal permits fluid flow within the separation annulus and between the first tube end and the gas outlet port.

7. The separator of claim 2 , wherein the flow-regulating device is a passive flow-regulating device configured to automatically transition between the first orientation and the second orientation responsive to a fluid flow within the separator annulus.

8. The separator of claim 7 , wherein the flow-regulating device is biased to the second orientation and is configured to transition to the first orientation responsive to the fluid flow within the separator annulus, and further wherein the flow-regulating device includes a biasing mechanism configured to provide the bias.

9. The separator of claim 2 , wherein the flow-regulating device is an active flow-regulating device configured to transition between the first orientation and the second orientation responsive to receipt of a transition signal.

10. The separator of claim 1 , wherein the flow-regulating device is a flapper valve.

11. The separator of claim 1 , wherein the separator defines a fluid inlet port flow distance, which is measured within the separator annulus and between the fluid inlet port and the first tube end, wherein the separator further defines a gas outlet port flow distance, which is measured within the separator annulus and between the gas outlet port and the first tube end, and further wherein the gas outlet port flow distance is less than the fluid inlet port flow distance.

12. The separator of claim 1 , wherein the fluid inlet port and the gas outlet port are sized such that an inlet port resistance to fluid flow from the external region to the first tube end, via the fluid inlet port, is less than 50% of an outlet port resistance to fluid flow from the external region to the first tube end, via the gas outlet port.

13. The separator of claim 1 , wherein the separator is configured to be oriented vertically within a vertical wellbore.

14. An artificial lift system for a hydrocarbon well, the artificial lift system comprising:
a reciprocating pump;
a drive assembly for the reciprocating pump;
wherein the drive assembly includes at least one of an electric motor, an internal combustion engine, and a hydraulic pump; and
the separator of claim 1 .

15. The system of claim 14 , wherein the reciprocating pump includes a rod pump.

16. A method of separating a gas from a liquid hydrocarbon within a hydrocarbon well utilizing the artificial lift system of claim 14 , the method comprising:
powering the reciprocating pump to provide artificial lift to a reservoir fluid that is present within a subterranean formation and that includes the gas and the liquid hydrocarbon, wherein the reciprocating pump includes an intake stroke and an exhaust stroke;
during the intake stroke of the reciprocating pump, restricting fluid flow through the gas outlet port of the separator while permitting fluid flow through the separator annulus of the separator to permit the liquid hydrocarbon to enter the first tube end of the dip tube via the separator annulus;
during the exhaust stroke of the reciprocating pump, permitting fluid flow through the gas outlet port of the separator while restricting fluid flow through the separator annulus of the separator to permit the gas to exit the separator annulus via the gas outlet port; and
producing the fluid from the subterranean formation.

Assignees

• Wang Jason Y
• Troshko Andrey A
• Buechler Scott R
• Romer Michael C
• Exxonmobil Upstream Res Co

Inventors

• Wang Jason Y
• Troshko Andrey A
• Buechler Scott R
• Romer Michael C

Classifications

• E21B4/04

  Electric drives (E21B4/12 takes precedence) · CPC title

• C10G2300/1033

  Oil well production fluids · CPC title

• B01D19/0042

  modifying the liquid flow (B01D19/0021 takes precedence) · CPC title

• B01D19/0063

  Regulation, control including valves and floats (for construction and details of valves F16K) · CPC title

• E21B2034/005

  Fixed Constructions · mapped topic