Patent Application
20250116175
This invention relates generally to the field of oil and gas production, and more particularly to a gas lift system that incorporates an improved side pocket mandrel with delayed opening functionality.
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 annulus-to-tubing systems, pressurized gases are injected from the surface into the annulus, where the pressurized gases enter the tubing string through ports in the side pocket mandrel that communicate the injected gases through a gas lift valve inside the side pocket mandrel. Alternatively, in tubing-to-annulus systems, pressurized gases are injected into the tubing string and discharged into the annulus through the gas lift valve and ports, where the gases help to produce fluids out of the annulus. Thus, the gas lift valves allow access from the annulus into the production tubing or from the production tubing into the annulus. 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.
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 (or side pocket tube) that is laterally offset from the primary longitudinal axis extending through the production tubing. Ports extend through the valve pocket and side pocket mandrel to provide a fluid path between the annulus and the interior of the valve pocket. Because the gas lift valves are contained in these laterally offset valve pockets, tools can be deployed and retrieved through the open primary passage (central bore) 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. For illustration purposes,
When a well is first opened, the reservoir may have sufficient internal driving energy to produce a commercially adequate flow of the formation fluid to the surface. In time, however, that internal energy source may be dissipated long before the reservoir value is depleted. Production experience may anticipate such production developments by positioning side pocket mandrels in the production tube long before the actual need for gas lifted production. When the need for gas lifting arises, the only downhole operations required to begin gas lifting are the wireline placement of the gas lift valve elements in the respective side pockets. Compared to the enterprise of withdrawing and returning several miles of production tubing or coil tubing in a well, wireline procedures are minimal.
If the well operator needs to conduct an annular pressure test, the absence of a gas lift valve in the side pocket mandrel would allow pressurized gases to pass through the side pocket mandrel, thereby compromising the annular pressure test. Even if gas lift valves are present in the side pocket mandrel, the pressure used for the annular pressure test can exceed the opening pressure of the gas lift valve, which would also compromise the test if the gas lift valve opens during the annular pressure test.
Accordingly, as depicted in
In one aspect, embodiments of the present disclosure are directed to a side pocket mandrel for use in a gas lift system configured to improve the recovery of petroleum fluids from a well, where the gas lift system is surrounded by an annular space within the well. The side pocket mandrel includes a central bore extending through the side pocket mandrel, a side pocket tube laterally offset from the central bore, a port that extends from the side pocket tube to the annular space, and a single actuation valve installed on the port. The single actuation valve prevents the passage of the petroleum fluids from the annular space into the side pocket tube until an annulus pressure exceeds a high pressure threshold and then recedes below a low threshold pressure.
In another aspect, the present disclosure is directed to a side pocket mandrel for use in a gas lift system configured to improve the recovery of petroleum fluids from a well, where the gas lift system is surrounded by an annular space within the well. The side pocket mandrel includes a central bore extending through the side pocket mandrel, a side pocket tube laterally offset from the central bore, a port that extends from the side pocket tube to the annular space, and a single actuation valve installed on the port. The single actuation valve includes a valve body, an inner channel in the valve body, an outer channel in the valve body, a plunger that partially extends into the inner channel with the single actuation valve is in a closed state, and a biasing element that urges the plunger outward to dislocate the plunger from the inner channel.
In yet another aspect, the present disclosure is directed to a side pocket mandrel for use in a gas lift system configured to improve the recovery of petroleum fluids from a well, where the gas lift system is surrounded by an annular space within the well. The side pocket mandrel has a central bore extending through the side pocket mandrel, a side pocket tube laterally offset from the central bore, a port that extends from the side pocket tube to the annular space, and a single actuation valve installed on the port. The single actuation valve includes a valve body, an inner channel in the valve body, an outer channel in the valve body, a plunger that partially extends into the inner channel with the single actuation valve is in a closed state, and one or more holding mechanisms that control the position of the plunger with respect to the inner channel such that plunger prevents the passage of the petroleum fluids from the annular space into the side pocket tube until a high threshold pressure in the annular space is reached and then the pressure in the annular space is reduced so to a low threshold pressure.
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. The term “fluids” refers to gases, liquids, and mixtures of gases and liquids.
Turning to
Turing to
The side pocket mandrel 118 includes a valve pocket or side pocket tube 126 within the central portion 124. In
To delay the opening of the side pocket mandrel 118 and the activation of the gas lift valve 132, the side pocket mandrel 118 includes one or more single actuation valves 136, each connected to a corresponding annular port 134. The single actuation valve 136 can be threaded, welded, latched or otherwise connected to the annular port 134 of the side pocket mandrel 118. As explained below, each single actuation valve 136 is configured to switch between an initial state in which the single actuation valve 136 is closed and prevents the passage of fluid from the annular space 110 into the side pocket mandrel 118 to a final state in which the single actuation valve 136 is opened and thereby places the side pocket tube 126 and gas lift valve 132 in fluid communication with the annular space 110.
Unlike a rupture plate that fails open when exposed to a setpoint pressure, the single actuation valve 136 is configured to remain closed until the pressure in annular space 110 meets or exceeds a high threshold pressure and then decreases below a low threshold pressure that permits the single actuation valve 136 to open. In some embodiments, the single actuation valve 136 is irreversibly opened after the high and low pressure thresholds are sequentially met. The single actuation valve 136 enables the operator to conduct annulus pressure tests in which the pressure in the annular space 110 exceeds the opening pressure of the gas lift valve 132 without first installing a dummy valve in the side pocket mandrel 118 during the annular pressure test. Thus, as used herein, the term “high pressure threshold” refers to a pressure in the annular space 110 that is sufficient to place the single actuation valve 136 in an initial closed-but-activated state. The term “low pressure threshold” refers to a pressure in the annular space 110 that allows the single actuation valve 136 to switch to a final open state after the single actuation valve 136 has already been activated by pressures reaching the high pressure threshold. The pressure at the high pressure threshold is therefore necessarily greater than the pressure at the low pressure threshold.
Turning to
In contrast,
In each case, the single actuation valve 136 includes a holding mechanism that prevents the single actuation valve 136 from opening until the pressure in the annular space 110 meets or exceeds the high threshold pressure and thereafter falls below the low threshold pressure.
Turning to
Once the pressure in the annular space 110 is increased, such as during an annular pressure test, the increased fluid pressure forces the plunger 144 inward until the head 152 contacts the collar 158. The collar 158 includes a shoulder that prevents the collar 158 from being pushed into the outer channel 140. The inboard movement of the plunger forces the distal groove 150 and releasable lock 160 out of the lock recess 154 in the valve body 138. The releasable lock 160 is then permitted to expand away from the distal groove 150 and separates from the plunger 144. At this point, the external pressure in the annular space 110 is greater than the outward force applied by the biasing element 146, which keeps the head 152 of the plunger 144 at the innermost position within the exterior chamber 156. During this intermediate state, fluid cannot pass through the single actuation valve 136 because the plunger 144 and seals 162 remain inside the inner channel 142. That is, the pressure in the annular space 110 meets or exceeds a high threshold pressure required to press the plunger 144 into the onboard position which frees the releasable lock 160 from the plunger 144.
When the fluid pressure in the annular space 110 decreases to an extent that the inward force of the fluid pressure acting on the head 152 is less than the outward spring force applied by the biasing element 146, i.e., the annulus pressure falls below a low threshold pressure, the plunger 144 is urged outward by the biasing element 160 as depicted in
Turning to
In this embodiment, the single actuation valve 136 includes a stationary guide 164 that includes one or more J-slots 166 and one or more shear pin bores 168. The stationary guide 164 can be contained within a housing 176 that includes an exterior opening 178. The housing 176 can be configured to engage the valve body 138. Each J-slot 166 has an angular branch 166a that intersects a straight branch 166b at an apex 166c. The plunger 144 includes one or more guide pins 170 that are captured and configured for travel within a corresponding one of the J-slots 166. The plunger 144 also includes a shear pin 172, which is initially received in the shear pin bore 168 in the stationary guide 164. The plunger 144 further includes a flange 174 that extends radially from a central portion of the plunger 144. The flange 174 has an outer diameter that is nominally smaller than the diameter if the outer channel 170. The biasing element 146 can be a coiled spring that is captured within the outer channel 140 and configured to apply an outboard force against the flange 174.
The plunger 144 is retained in its initial position by the engagement between the shear pin 172 within the shear pin bore 168, as depicted in
When the pressure in the annular space 110 increases above a high threshold pressure during an annular pressure test or other pressure increasing event, the external force on the end of the plunger 144 forces the plunger 144 inward against the force of the biasing element 146. The inboard movement of the plunger breaks the shear pin 172, as depicted in
Thereafter, when the pressure in the annular space 110 is reduced below a low threshold pressure, the biasing element 146 forces the plunger 144 away from the side pocket mandrel 118 as permitted by the engagement between the guide pins 170 within the straight branches 166b of the J-slots 166. Once the plunger 144 has been dislocated from the inner channel 142, fluid can pass from the annular space 110 into the side pocket mandrel 118 through the lateral channels 148 and inner channel 142. The single actuation valve 136 is prevented from returning to a closed state by the configuration of the J-slot 166 and the force applied by the biasing element 146.
Turning to
In the embodiment depicted in
As depicted in
When the pressure in the annular space 110 is increased above a high threshold pressure during an annulus pressure test or other pressure increasing event, the inwardly directed force applied by the pressurized fluid on the head 152 overcomes the outwardly directed spring force applied by the biasing element 146 and the holding force applied by the shear pin 172. The shear pin 172 breaks and the plunger 144 shifts inboard until the head 152 contacts the collar 158, as depicted in
The plunger 144 will stay pressed against the collar 158 and valve body 138 until the pressure recedes within the annular space 110 below the low threshold pressure. Once the pressure in the annular space 110 falls below the low threshold pressure, the biasing element 146 pushes the plunger 144 outward such that the head 152 and collar 158 are retained in the outer chamber 180 and the plunger is displaced from the inner channel 142. Fluid from the annular space 110 can then pass into the side pocket mandrel 118 through the single actuation valve 136, as depicted in
Thus, in exemplary embodiments, the single actuation valve 136 provides a mechanism for delaying the opening of the side pocket mandrel 118. The single actuation valve 136 prevents the flow of fluid into the side pocket mandrel 118 until a holding mechanism is released by the sequential application of pressure in the annular space 110 that first exceeds a high threshold pressure and then recedes below a low threshold pressure, which shifts the single actuation valve 136 into an irreversible open state to permit the flow of fluid into the side pocket mandrel 118. The ability to hold the side pocket mandrel 118 in temporarily a closed state allows the operator to run an annular pressure test without installing a dummy valve in the side pocket mandrel 118 that would need to be removed and replaced with an unloading or operating gas lift valve 132 before production commences.
The holding mechanism can include one or more of the mechanisms disclosed herein, including the releasable lock 160 and lock recess 154, the shear pin 172 and shear pin bore 168, the J-slots 166 and the guide pins 170, and the compressible ring, the radial recess 186 and the intermediate chamber 182. Although the single actuation valve 136 is disclosed as being threaded or otherwise connected to the side pocket mandrel 118 as an external component, it will be appreciated that in some embodiments the single actuation valve 136 is manufactured or assembled as an integral part of the side pocket mandrel 118.
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.
