Patent Application
20230107494
This invention relates generally to the field of oil and gas production, and more particularly to a gas lift system that incorporates an improved direct injection mechanism.
Gas lift is a technique in which gaseous fluids are injected into the tubing string to reduce the density of the produced fluids to allow the formation pressure to push the less dense mixture to the surface. In most applications, the gas is injected into the production tubing from the surrounding annulus between the tubing and the casing. The gaseous fluids can be injected into the annulus from the surface. A series of gas lift valves allow access from the annulus into the production tubing. The gas lift valves can be configured to automatically open when the pressure gradient between the annulus and the production tubing exceeds the closing force holding each gas lift valve in a closed position.
In most installations, each of the gas lift mandrels within the gas lift system is deployed above a packer or other zone isolation device to ensure that liquids and wellbore fluids do not interfere with the operation of the gas lift valve. Increasing the pressure in the annular space above the packer will force the gas lift valves to open, thereby injecting pressured gases into the production tubing.
To permit the unimpeded production of wellbore fluids through the production tubing, the gas lift valves are housed within “side pocket mandrels” that include a valve pocket that is laterally offset from the production tubing. Because the gas lift valves are contained in these laterally offset valve pockets, tools can be deployed and retrieved through the open primary passage of the side pocket mandrel. The predetermined position of the gas lift valves within the production tubing string controls the entry points for gas into the production string.
In other applications, a dedicated gas injection line is used to carry the pressurized gas from the surface to the gas lift mandrels. Unlike the conventional use of a pressurized annulus, the dedicated injection line can be configured to run through the packer to inject gas into the production tubing below the packer. Additionally, if the pressurized gas is contained within the dedicated injection line, there are fewer requirements for monitoring the pressure within the annulus.
However, existing gas lift systems that include a dedicated injection line suffer from several deficiencies. In particular, the injection line must be connected to the side pocket mandrels of the gas lift modules with a complicated bypass system that allows a portion of the injection gas to reach lower injection points. There is, therefore, a need for an improved gas lift system that overcomes these and other deficiencies in the prior art.
In one aspect, embodiments of the present disclosure are directed to a gas lift system for improving the recovery of petroleum fluids from a well to the surface through production tubing. In these embodiments, the gas lift system has a packer and a lower injection mandrel connected to the production tubing. The production tubing extends through the packer and the lower injection mandrel is located below the packer. The gas lift system also includes an injection line that carries pressurized gas from the surface to the lower injection mandrel and an injection line gas lift valve assembly connected to the injection line. The injection line gas lift valve assembly includes a seating module and a flow metering device removably captured within the seating module.
In another aspect, the present disclosure is directed to an embodiment in which the gas lift system includes a packer and a lower injection mandrel located below the packer. The production tubing extends through the packer to the lower injection mandrel located below the packer. The gas lift system further includes a gas lift module connected to the production tubing above the packer, where the gas lift module includes a side pocket mandrel. The gas lift system includes an injection line that carries pressurized gas from the surface to the lower injection mandrel and the side pocket mandrel of the gas lift module.
In yet another aspect, embodiments of the present invention are directed to a gas lift system for improving the recovery of petroleum fluids from a well to the surface through production tubing, where the gas lift system has a packer and a lower injection mandrel connected to the production tubing below the packer. The gas lift system further includes a gas lift module connected to the production tubing above the packer, and an injection line that carries pressurized gas from the surface to both the lower injection mandrel and the gas lift module. An upper injection line valve assembly is configured to provide a source of pressurized gas from the injection line to the gas lift module, while an injection line gas lift valve assembly is configured to provide a source of pressurized gas from the injection line to the lower injection mandrel.
As used herein, the term “petroleum” refers broadly to all mineral hydrocarbons, such as crude oil, gas and combinations of oil and gas. The term “fluid” refers generally to both gases and liquids, and “two-phase” or “multiphase” refers to a fluid that includes a mixture of gases and liquids. “Upstream” and “downstream” can be used as positional references based on the movement of a stream of fluids from an upstream position in the wellbore to a downstream position on the surface. Although embodiments of the present invention may be disclosed in connection with a conventional well that is substantially vertically oriented, it will be appreciated that embodiments may also find utility in horizontal, deviated or unconventional wells.
Turning to
The gas lift system 100 also includes an injection line 118 that extends from the surface through the wellhead 114 to a lower injection mandrel 120. The lower injection mandrel 120 can be positioned below the packer 116, within the packer 116, or above the packer 116. To accommodate the production tubing 112 and the injection line 118, the packer 116 is configured to provide two separated flow paths through the packer 116. One suitable device for use as the packer 116 is the Baker Hughes Parallel Head, which is available commercially from Baker Hughes Company of Houston, Tex. This type of parallel flow device is typically used for gas lift production operations.
The lower injection mandrel 120 is configured for connection to both the production tubing 112 and the injection line 118. The lower injection mandrel 120 includes an internal injection passage 121 that is joined to an internal production passage 123 that extends through the primary longitudinal axis of the lower injection mandrel 120. The internal production passage 123 is connected to the production tubing 112 or an intermediate conduit between the lower injection mandrel 120 and the production tubing 112. The internal injection passage 121 is laterally offset from the internal production passage 123 and is connected to the injection line 118.
The injection passage 121 transfers the pressurized gas from the injection line 118 to the wellbore fluid within the internal production passage 123. A sliding sleeve 122 or other flow control device can be located inside the lower injection mandrel 120 to selectively close or block the internal injection passage 121 from the internal production passage 123. When deployed, the sliding sleeve 122 prevents the exchange of fluids through the lower injection mandrel 122 by blocking wellbore fluids from entering the injection line 118 and also preventing pressurized gases in the injection line 118 from entering the production tubing 112.
The gas lift system 100 includes an injection line gas lift valve assembly 124 that is connected in line with the injection line 118. The injection line gas lift valve assembly 124 can be connected between adjacent sections of the injection line 118 above the packer 116 (
As illustrated in
The seating module 118 can be a landing nipple, latch or other setting assembly with an internal seal profile that matches the configuration of the flow metering device 128. This allows the flow metering device 128 to be securely and removably locked into position within the injection line 118 using standard, commercially available setting assemblies. Suitable seating modules 118 include the SureSet and Select brand setting assemblies available from Baker Hughes Company of Houston, Tex. The ability to use the standardized seating module 118 greatly facilitates the installation and removal of the flow metering device 128 and other components within the injection line gas lift valve assembly 124.
The injection line gas lift valve assembly 124 optionally includes a flow control device 130. The flow control device 130 can be a check valve (as depicted in
The injection line gas lift valve assembly 124 provides several advantages over prior art systems in which the injection line is connected directly to gas lift modules within internal gas lift valves housed inside pocket mandrels. Combining a standard gas lift valve or other flow metering device 128 with a conventional seating module 126 facilitates the installation and removal of the flow metering device 128 using conventional tools. Unlike typical gas lift systems, a kickover tool is not needed to retrieve a gas lift valve from a laterally offset side pocket mandrel. Additionally, the placement of the gas lift valve or other flow metering device 128 within the injection line gas lift valve assembly 124 rather than the conventional side pocket mandrel permits the use of larger gas lift valves, which are capable of larger throughput.
In operation, pressurized fluids or gases are injected from the surface through the injection line 118 and injection line gas lift valve assembly 124 to the lower injection mandrel 120. In accordance with well-established gas lift principles, when the pressure gradient across the flow metering device 128 exceeds a threshold value, the pressurized gases are admitted into the production tubing 112 through the injection line gas lift valve assembly 124 and lower injection mandrel 120. The pressurized gases combine with the produced fluids in the lower injection mandrel 120 to reduce the overall density of the fluid, which facilitates the recovery of the produced fluids from the well 102. The gas lift system 100 may find utility in recovering liquid and multiphase hydrocarbons, as well as in unloading water-based fluids from the well 102.
As depicted in
It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and functions of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to other systems without departing from the scope and spirit of the present invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/253,116 entitled, “Dual String Gas Injection System with Flow Control,” filed Oct. 6, 2021, the disclosure of which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63253116 | Oct 2021 | US |
