Welding method for eccentric working barrel

Abstract

In one aspect, embodiments of the present disclosure relate to a method for manufacturing an eccentric working barrel involving welding an upper swage and a lower swage to a central body of an eccentric working barrel. In some embodiments, the method includes the steps of providing a first side of the welded joint and a second side of the welded joint, where the first side and the second side are either the central body or the swage. The method continues with the step of approaching the first side and the second side such that the first side and the second side are in contact. Importantly, the first side and the second side are placed together without forming a root gap between the first side and the second side. Next, the first side and the second side are welded together to form a welded joint between the swage and the central body.

Description

[0001] Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63 / 417,685, filed Oct. 19, 2022, and entitled "Welding Process for Side Pocket Mandrel", the disclosure of which is hereby incorporated herein by reference. Technical Field

[0003] The present invention generally relates to the field of oil and gas production and, more particularly, to an improved method for manufacturing a side pocket mandrel for a gas lift system. Background Art

[0004] Gas lift is a technique of injecting a gaseous fluid into a tubing string to reduce the density of the produced fluid so that formation pressure can push the lower density mixture to the surface. In an annulus-to-tubing system, pressurized gas is injected from the surface into the annulus, where the pressurized gas enters the tubing string through a series of gas lift valves. Alternatively, in a tubing-to-annulus system, pressurized gas is injected into the tubing string and discharged into the annulus, where the gas helps to produce the fluid leaving the annulus. A series of gas lift valves allows entry into or out of the production tubing from 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 the closed position.

[0005] To allow for unobstructed production of wellbore fluid through the production tubing, the gas lift valves are housed within a "side pocket mandrel" that includes a valve pocket (or eccentric tube) that is laterally offset from the production tubing. Since the gas lift valves are housed in these laterally offset valve pockets, tools can be deployed and retrieved through the open main passage (central orifice) of the side pocket mandrel. The gas lift valves control the entry point of gas into the production column at a predetermined location within the production tubing string.

[0006] The side pocket mandrel typically has a central body that is large enough in cross-sectional area to include an internal valve pocket that is laterally offset from a central orifice that is coaxially aligned with the production tubing. The cross-sectional shape of the central body can be annular or elliptical. Upper and lower upset portions connect the central body to adjacent joints of the production tubing.

[0007] The upper and lower forging sections are typically joined to the central body by welding methods. Standard welding methods for eccentric working cylinders require the use of conventional fillet weld shoulders and root gaps between the forging sections and the central body. These welds require a gas-shielded "root pass" and several subsequent filler passes to fill the body thickness. In many cases, the root pass is made by gas metal arc welding (GMAW) methods, followed by multiple flux-cored welding arc (FCAW) filler passes. Conventional welding methods are complex and time-consuming. In some cases, the welding process takes one to two hours to complete. Accordingly, there is a need for an improved method for joining the upper and lower forging section segments to the central body of an eccentric working cylinder. The present disclosure addresses these and other deficiencies in the prior art. Summary of the Invention

[0008] In one aspect, embodiments of the present disclosure relate to a method of manufacturing an eccentric working cylinder that involves welding an upper forging section and a lower forging section to a central body of the eccentric working cylinder. In some embodiments, the method includes the steps of providing a first side of a weld joint and a second side of the weld joint, where the first side and the second side are either the central body or a forging section. The method proceeds with the step of bringing the first side and the second side closer together such that the first side and the second side contact. Importantly, the first side and the second side are brought together without forming a root gap between the first side and the second side. Next, the first side and the second side are welded together to form a weld joint between the forging section and the central body. Eliminating the root gap and not requiring a shielding gas reduces the time required to successfully join the upper and lower forging sections to the central body, while improving the consistency and quality of the resulting weld joint.

[0009] In other embodiments, the present disclosure relates to a two-component assembly that includes a forging section and a central portion that are configured to be joined together at a weld joint. The two-component assembly includes a first side and a second side, where the first side is either the forging section or the central portion, and if the first side is the central portion, then the second side is the forging section, and where if the first side is the forging section, then the second side is the central portion.

[0010] In other embodiments, the present disclosure relates to a method for forming a welded joint between a swage section and a central body of an eccentric working barrel. In these embodiments, the method includes the steps of: providing a first side of the welded joint, wherein the first side is the central body; providing a second side of the welded joint, wherein the second side is the swage section; and bringing the first side and the second side into proximity such that the first side and the second side contact without a root gap. The method proceeds with the steps of: performing a root pass weld between the first side and the second side; and then performing one or more filler welds on top of the root pass weld to complete the welded joint between the swage section and the central body. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic view of a gas lift system deployed in a wellbore constructed in accordance with an exemplary embodiment.

[0012] Figure 2A and Figure 2B depict side and cross-sectional views of an exemplary eccentric working barrel constructed in accordance with the embodiments disclosed herein.

[0013] Figures 3A to 3D depicts a cross-sectional view of a swage-to-body joint constructed and welded in accordance with a first embodiment.

[0014] Figures 4A to 4D depicts a cross-sectional view of a swage-to-body joint constructed and welded in accordance with a second embodiment.

[0015] Figures 5A to 5D depicts a cross-sectional view of a swage-to-body joint constructed and welded in accordance with a third embodiment.

[0016] Figures 6A to 6D depicts a cross-sectional view of a swage-to-body joint constructed and welded in accordance with a fourth embodiment. DETAILED DESCRIPTION

[0017] As used herein, the term "petroleum" broadly refers to all mineral hydrocarbons such as crude oil, natural gas, and combinations of oil and gas. The term "fluid" generally refers to both gases and liquids, and "two-phase" or "multiphase" refers to a fluid that includes a mixture of gas and liquid. "Upstream" and "downstream" may be used as position references based on the movement of fluid flow 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 should be understood that the embodiments may also have utility in horizontal, deviated, or unconventional wells.

[0018] Turning Figure 1, which shows a gas lift system 100 disposed in well 102. Well 102 includes a casing 104 and a series of perforations 106 that allow wellbore fluid from the production geological formation 108 to enter well 102 through the casing 104. An annular space 110 is formed between the gas lift system 100 and the casing 104. The gas lift system 100 is connected to a production tubing 112 that transports the produced wellbore fluid from the formation 108 through the gas lift system 100 to the wellhead 114 on the surface. In Figure 1 the depicted embodiment, a packer 116 or other zone isolation device has been placed between the perforations 106 and the gas lift system 100. It should be understood that Figure 1 this is intended to provide only the background for the deployment of the gas lift system 100 and should not be construed as a restrictive representation of the various embodiments in which the gas lift system 100 can be deployed.

[0019] The gas lift system 100 also includes one or more eccentric work barrels 118 that are in line with the production tubing 112 above the packer 116. Turning to Figure 2A and Figure 2B , which show a side view and a cross-sectional view of an eccentric work barrel 118 constructed according to an exemplary embodiment, respectively. The eccentric work barrel 118 generally includes an upper swage section 120 and a lower swage section 122 on opposite sides of the eccentric work barrel 118. As used herein and in the appended claims, the independent term "swage section" refers to either the upper swage section 120 or the lower swage section 122. The eccentric work barrel 118 includes an enlarged central body 124 between the upper swage section 120 and the lower swage section 122. As shown, the upper swage section 120 and the lower swage section 122 provide a transition to a smaller diameter from the enlarged central body 124 to the adjacent production tubing 112. In some embodiments, the cross-sectional shape of the central body 124 is circular or elliptical.

[0020] The central body 124 has a larger diameter to accommodate an eccentric tube 126 in an offset position, which is configured to hold a gas lift valve 128. The eccentric tube 126 is laterally offset from a central orifice that extends collinearly along the central longitudinal axis of the production tubing 112. It should be understood that the eccentric tube 126 includes a latch mechanism 130 that is designed to releasably hold the gas lift valve 128 or another downhole tool. Ports 132 extend through the outer wall of the central body 124 into the eccentric tube 126 to provide a path for fluid to move between the annular space 110 and the interior of the eccentric tube 126. A guide sleeve 134 may be located near or within the upper swage section 120 to facilitate engagement and use of a kickover tool that is designed to install and remove the gas lift valve 128 in the eccentric tube 126.

[0021] The upper forging part 120 and the lower forging part 122 are connected to the central body 124 of the eccentric working cylinder 118 through a welded joint 136. The welded joint 136 is designed to achieve a structural sealed connection between the upper forging part 120 and the lower forging part 122 and the central body 124 of the eccentric working cylinder 118. FIGS. 3 to 6 illustrate various methods for constructing the welded joint 136. In each case, the welded joint 136 includes a first side 138 and a second side 140, where the first side 138 and the second side 140 can each be either the upper forging part 120 or the lower forging part 122, or the central body 124. Thus, the first side 138 and the second side 140 together provide a two-component assembly that can be connected together through the welded joint 136 to form the eccentric working cylinder 118. The first side 138 and the second side 140 are tubular with an interior and an exterior. It should also be understood that a single eccentric working cylinder 118 can include a combination of different forms of the welded joint 136. For example, the eccentric working cylinder 118 can include a welded joint 136 between the upper forging part 120 and the central body 124 in a first embodiment and a welded joint 136 between the lower forging part 122 and the central body 124 in a second embodiment.

[0022] Figures 3A to 3D A first method of welding the upper forging part 120 and the lower forging part 122 to the central body 124 is illustrated. In this embodiment, the first side 138 of the welded joint 136 includes a lower lip portion 142, and the second side 140 includes a mating recess 144 and a nose portion 146. The first side 138 includes a first inclined surface 148 leading to the outer side of the lip portion 142. The second side 140 includes a second inclined surface 150 that transitions into the nose portion 146. When the first side 138 and the second side 140 are connected, the intersection of the first inclined surface 148 and the second inclined surface 150 forms an internal angle between approximately 45° and 90°, with an optimal angle of approximately 60°. The first inclined surface 148 and the second inclined surface 150 may not directly contact each other, such that a smaller portion of the lip portion 142 is exposed between the first inclined surface 148 and the second inclined surface 150.

[0023] As Figure 3B and Figure 3C illustrated, the lip portion 142 is captured within the recess 144 such that the nose portion 146 extends over a portion of the outer side of the lip portion 142. As Figure 3APreferably, the nose portion 146 on the central body 124 is configured to extend above the outside of the lip portion 142. This achieves a structural connection between the upper forging portion 120 or the lower forging portion 122 and the central body 124, which helps to align these components before performing the welding operation. In addition, since the weld joint 136 does not include a typical root gap, it is not necessary to place a shielding gas inside the eccentric working cylinder 118 and then discharge it from the eccentric working cylinder.

[0024] Once the central body 124 has been placed in alignment with the upper forging portion 120 or the lower forging portion 122, a first "root" weld bead can be made to secure the nose portion 146 to the lip portion 142. In some embodiments, a welding flux paste can be added to the weld joint 136 to prevent oxidation. If external clamps are not used, a tack weld can be used to secure the central body 124 to the upper forging portion 120 or the lower forging portion 122. Once the parts are secured, a flux-cored arc welding (FCAW) method can be used to make the root pass (RP). The root pass can be made with a welding machine at 26+ volts and between 160 and 240 amperes. After the root pass has been completed, the weld can be cleaned with a wire brush to remove slag and impurities. After the root pass has been cleaned, one or more filler passes (FP) can be made to fill the space between the first bevel 148 and the second bevel 150, as Figure 3D illustrated. By using this method and with the novel configuration of the first side 138 and the second side 140 of the weld joint 136, the entire welding process can take less than thirty (30) minutes, which represents a significant time savings compared to conventional welding methods.

[0025] Turning to Figures 4A to 4D , which shows a second method for welding the upper forging portion 120 and the lower forging portion 122 to the central body 124. In this embodiment, the first side 138 includes a tongue portion 152 instead of the lip portion 142, and the second bevel 150 does not include the recess 144 or the nose portion 146. The tongue portion 152 includes an angled face 154 that mates with the inner portion of the second bevel 150. Since the tongue portion 152 mates with the second bevel 150 to form a solid backing on the inside of the weld joint 136, it is not necessary to use an internal back purge gas.

[0026] Once the first side 138 and the second side 140 have been fixed together using a jig or tack welding, a flux-cored arc welding (FCAW) method can be used to make the root pass (RP). The root pass can be made with a welding machine at 26+ volts and between 160 amps and 240 amps. After the root pass has been completed, the weld can be cleaned with a wire brush to remove slag and surface impurities. After the root pass has been cleaned, one or more filler passes (FP) can be made to fill the space between the first bevel 148 and the second bevel 150, as Figure 4D illustrated. By using this method and adopting the novel configuration of the first side 138 and the second side 140 of the weld joint 136, the entire welding process can take less than thirty (30) minutes, which represents a significant time savings compared to conventional welding methods.

[0027] Go to Figures 5A to 5D , which shows a third method for welding the upper forging part 120 and the lower forging part 122 to the central body 124. In this embodiment, the first side 138 and the second side 140 are configured for a butt joint connection, where the first side 138 includes a first adjacent surface 156 and the second side 140 includes a second adjacent surface 158. The first adjacent surface 156 includes a first external notch 160, and the second adjacent surface includes a corresponding second external notch 162. When the first side 138 and the second side 140 are brought closer so that the first adjacent surface 156 and the second adjacent surface 158 are in close contact, the first external notch 160 and the second external notch 162 form an external V-shaped groove 164. Thus, assembling the first side 138 and the second side 140 together without a root gap eliminates the need for back purge gas. A flux paste can be used on the adjacent surfaces to reduce oxidation.

[0028] Once the first side 138 and the second side 140 have been placed in contact, a single welding pass (SP) can be used to form the weld joint 136. In an exemplary embodiment, a constricted plasma arc welding (PAW) method using a suitable inert shielding gas such as argon or helium is used to make the single pass. In some applications, the welding machine can operate at 500 amps to 700 amps and at over 30 volts. By this method, the weld joint 136 can be completed in less than 3 minutes without using filler metal.

[0029] Go to Figures 6A to 6D, which shows a fourth method and a fifth method for welding the upper forging portion 120 and the lower forging portion 122 to the central body 124. In these embodiments, the first side 138 and the second side 140 are configured for butt joint connection, wherein the first abutting surface 156 and the second abutting surface 158 do not include a first external notch 160 and a second external notch 162 respectively. The first side 138 and the second side 140 are brought close together such that the first abutting surface 156 is pressed against the second abutting surface 158 through a tight butt joint that does not include a notch or a root gap. In some embodiments, the active flux 166 can be placed on the first abutting surface 156 and the second abutting surface 158, as well as on the exposed outer surfaces and the abutting surfaces 156, 158 of the first side 138 and the second side 140 (as Figure 6B and Figure 6C depicted).

[0030] Once the first side 138 and the second side 140 have been placed in contact, whether or not the active flux 166 is used, a single pass weld (SP) can be used to form the weld joint 136. In an exemplary embodiment, a single pass is made using a constricted plasma arc welding method (PAW) utilizing a suitable inert shielding gas such as argon or helium. In some applications, the welder can operate at over 700 amperes and over 30 volts. By this method, the weld joint 136 can be completed in less than 3 minutes without the use of filler metal.

[0031] Accordingly, the embodiments of the present disclosure depict various methods for welding the upper forging portion 120 and the lower forging portion 122 to the central body 124 of the eccentric working barrel 118. The embodiments include welding methods and structural features on the first side 138 and the second side 140 that do not require the conventional use of a root gap and an internal shielding gas. Eliminating the root gap and not requiring a shielding gas shortens the time required to successfully join the upper forging portion 120 and the lower forging portion 122 to the central body 124, while improving the consistency and quality of the weld joint 136.

[0032] It should be understood that although many features and advantages of various embodiments of the present invention have been set forth in the foregoing description, as well as details of the structure and function of various embodiments of the present invention, the present disclosure is illustrative only, and to the greatest extent indicated by the broad general meaning of the terms expressed in the appended claims, detailed changes can be made, particularly in the structure and arrangement of parts within the principles of the present invention. Those skilled in the art should understand that the teachings of the present invention can be applied to other systems without departing from the scope and essence of the present invention.

Claims

1. A method for forming a welded joint between a forging section and a central body of an eccentric working cylinder, the method comprising the steps of: providing a first side of the welded joint, wherein the first side is either the central body or the forging section; providing a second side of the welded joint, wherein the second side is either the central body or the forging section and is different from the first side; bringing the first side and the second side closer together such that the first side and the second side come into contact without a root gap; and welding the first side and the second side together to form the welded joint between the forging section and the central body.

2. The method according to claim 1, wherein the step of providing the first side of the welded joint comprises providing a first side that comprises: a lip; and a first inclined surface.

3. The method according to claim 2, wherein the step of providing the second side of the welded joint comprises providing a second side that comprises: a second inclined surface; a recess configured to cooperate and engage with the lip; and a nose formed by the intersection of the recess and the second inclined surface.

4. The method according to claim 3, wherein the step of welding the first side and the second side together to form the welded joint comprises: forming a root pass at the intersection of the lip, the first inclined surface and the second inclined surface; and forming one or more filler passes above the root pass between the first inclined surface and the second inclined surface.

5. The method according to claim 1, wherein the step of providing the first side of the welded joint comprises providing a first side that comprises: a tongue having an angled surface; and a first inclined surface.

6. The method according to claim 5, wherein the step of providing the second side of the welded joint comprises providing a second side that includes a second inclined surface configured to mate and engage with the angled surface of the tongue.

7. The method according to claim 6, wherein the step of welding the first side and the second side together to form the welded joint comprises: forming a root pass at the intersection of the tongue, the first inclined surface and the second inclined surface; and forming one or more filler passes above the root pass between the first inclined surface and the second inclined surface.

8. The method according to claim 1, wherein the step of providing the first side of the welded joint comprises providing a first side that comprises: a first adjacent surface; and a first external notch located in the first adjacent surface.

9. The method according to claim 8, wherein the step of providing the second side of the welded joint comprises providing a second side that comprises: a second adjacent surface; and a second external notch located in the second adjacent surface.

10. The method according to claim 9, wherein the step of welding the first side and the second side together to form the welded joint comprises: Assemble the first side and the second side together such that the first abutting surface is in close contact with the second abutting surface, and the first outer notch and the second outer notch form a V-shaped groove between the first side and the second side; and Form a single weld bead within the V-shaped groove.

11. The method according to claim 1, wherein the step of providing the first side of the welded joint comprises providing a first side that includes a first abutting surface.

12. The method according to claim 11, wherein the step of providing the second side of the welded joint comprises providing a second side that includes a second abutting surface.

13. The method according to claim 12, wherein the step of welding the first side and the second side together to form the welded joint comprises: Assemble the first side and the second side together such that the first abutting surface is in close contact with the second abutting surface; and Form a single weld bead at the intersection between the first side and the second side.

14. The method according to claim 13, the method further comprising the step of applying an active flux paste to the intersection of the first side and the second side prior to the step of forming the single weld bead at the intersection between the first side and the second side.

15. A two-component assembly, the two-component assembly comprising a swaged portion and a central portion, the swaged portion and the central portion being configured to be connected together with a welded joint, wherein the two-component assembly comprises: A first side, wherein the first side is either the swaged portion or the central portion; and A second side, wherein if the first side is the central portion, the second side is the swaged portion, and wherein if the first side is the swaged portion, the second side is the central portion.

16. The two-component assembly according to claim 15, wherein the first side comprises: A lip; and A first inclined surface that extends away from the lip.

17. The two-component assembly according to claim 16, wherein the second side comprises: A nose; A second inclined surface that extends away from the nose; and A recess located inside the nose, the recess being configured to receive the lip of the first side such that the nose rests on a portion of the lip, and the first inclined surface and the second inclined surface extend away from each other.

18. The two-component assembly according to claim 15, wherein the first side comprises: A tongue, the tongue including an angled surface; and A first inclined surface that extends away from the tongue.

19. The two-component assembly according to claim 18, wherein the second side includes a second inclined surface that mates with the angled surface of the tongue of the first side.

20. A method for forming a welded joint between a swaged portion and a central body of an eccentric working cylinder, the method comprises the following steps: Provide a first side of the welded joint, wherein the first side is the central body; Provide a second side of the welded joint, wherein the second side is the swaged portion; Bring the first side and the second side closer to each other such that the first side and the second side contact each other without a root gap; and Perform root pass welding between the first side and the second side; and Perform one or more filler weldings on the top of the root pass welded portion to complete the welded joint between the swaged portion and the central body.

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