Select Port Chemical Injection Device and Method of Use

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority from earlier filed U.S. Provisional Patent Application No. 63/714,112 , filed Oct. 30, 2024, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a method and apparatus for controlling the flow of injected chemical inside an oil well or gas well. More specifically, the disclosed invention relates to a device and method for selectively injecting chemical into a production tubing string, annulus, or downhole pump.

2. Description of Related Art

Subsurface wells, used for extraction of fluid or gaseous media from a subsurface formation reservoir, typically contain a tubular pipe string extending to or through the reservoir. The tubular pipe string may be permanently set in place by anchors or cementing. Through the casing, additional tubular strings may be nested (e.g., a production tubing string). Nested tubing string may have an internal diameter or various staggered diameters sufficient to provide the desired pressure, velocity, and volume of media to the surface for collection. Tubing strings are most often comprised of lengths of metal pipe or “joints” of a certain diameter and wall thickness. The pipe is of nominal length and most often enlarged or “upset” on each end, as well as threaded externally for connection to a threaded coupling or collar. A collar is a larger diameter short piece of cylindrical metal of sufficient thickness and diameter to accommodate internal threads sized to fit the threaded ends of the tubing joints. The production tubing string comprises lengths of tubing joints connected with collars to achieve the desired depth of the production tubing string. An oil well or gas well relies on inflow and internal flow of petroleum products to and through the production tubing string. When natural reservoir inflow to a well is reduced or internal flow within well production tubing string is reduced, often the operator employs a wellbore treatment such as chemical injection. This is accomplished by pumping fluids such as acids, solvents, cleaners, or stimulation fluids from a surface storage supply into the well to improve well production.

Current methods include introducing treatment chemicals in various forms at the top surface of the well and releasing or pumping in volume in order to reach and treat a problem area. This method often proves wasteful and inefficient.

Other current methods involve the use of small flexible tubing strings placed within a well at specific depths for the direct delivery of treatment chemicals to predetermined locations within the wellbore. These “capillary strings” may be installed internally and/or externally in the production tubing string. Capillary strings convey the treatment chemical directly to the installed depth and may be terminated with various means.

A typical external production tubing string termination method utilizing a capillary string for chemical delivery includes the use of a side pocket mandrel. Side pocket mandrels are installed in the tubing string at a predetermined location along the length of the production tubing string and may serve as a termination point for the capillary tubing string. The side pocket connection or “lug” may be formed integral to a downhole tool or fixed to a length of tubing called a “tubing sub” by permanent means such as welding. Prior art side pocket lugs comprise connection means for connection of bottom hole tools, such as a chemical injection valve, which connect to the capillary tubing string. Current lugs are configured for pass through flow of fluids or chemicals into or outside of the production tubing string and into the media stream or reservoir. This fluid flow path must be selected at the time of manufacture of the side pocket lug before installation into the well. The current art requires a different piece of equipment for each type of installation, such that the particular equipment will allow for injecting chemical into either the production tubing string, the well annulus, or the downhole pump.

Many disadvantages of current devices and methods relate to the close proximity of an installed device, in the side pocket mandrel connection, with an interior wall of the well casing. Installed devices, such as a chemical injection valve, are often damaged during installation or removal of the production tubing string in the well. With current devices, a chemical injection valve is typically installed on top of the side pocket mandrel connection, leaving the chemical injection valve completely exposed within the well casing and production tubing string annulus. Ideally, the diameter of the installed chemical injection valve is smaller than the diameter of the side pocket mandrel lug. However, this smaller diameter reduces fluid flow capacity through the valve compared to the well operator's desired flow rate. Therefore, a larger diameter chemical injection valve often is installed to achieve the desired chemical flow rate. This increases the likelihood of an interference issue—the production tubing string may drift and collide with the interior surface of the well casing as it travels within the well during installation or removal, causing damage, fractures, or misalignment of the installed chemical injection valve connected to the side pocket mandrel lug. This results in leakage of chemicals or other inoperable conditions, increasing well servicing costs and lost well production.

In view of the foregoing, it is apparent that a need exists in the art for a select port chemical injection tubing device which overcomes, mitigates or solves the above problems in the art. It is a purpose of this invention to fulfill this and other needs in the art which will become more apparent to the skilled artisan once given the following disclosure.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to overcome the above-described drawbacks associated with current devices and methods used to inject chemicals into production tubing string at a selected depth, without obstructing production flow. To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, the present disclosure describes a select port chemical injection tubing device and method for injecting chemical or wellbore stimulation fluids directly into a wellbore production tubing string by means of production tubing, such as a tubing sub, incorporating an integral select port chemical injection valve cartridge lug.

The disclosed tubing sub comprises an integral select port chemical injection valve cartridge lug containing connection means for attachment of downhole tools such as a chemical injection valve. Interior cavities and passages for fluid flow and discharge are provided with communication to multiple discharge ports which may be deselected or plugged by means of pipe plugs (e.g., a threaded plug or any other member, such as a stopper, cap, etc., arranged and configured to permanently or temporarily seal off, close, or block an opening or port). The installer or operator can select the flow path or paths of treatment chemicals through the disclosed device via their selection of discharge ports to be isolated.

Further, the disclosed select port chemical injection tubing device with an integral injection valve cartridge lug comprises a unique chemical injection valve arranged and configured as a modular cartridge, herein referred to as a chemical injection valve cartridge, that provides many advantages over current designs. The injection valve cartridge eliminates potential failures due to possible collision or interference issues within a well annulus during removal or installation of the production tubing string into the well. The disclosed device incorporates integral guide and protection features in the cartridge lug, which is configured as a housing for the injection valve cartridge, to protect the injection valve cartridge from physical damage, thereby increasing reliability by decreasing the risk of damage to the injection valve cartridge. Additionally, the injection valve cartridge receptacle or cavity formed in the disclosed lug provides for increased flow capacity. The increased diameter and space of the cartridge receptacle allow for connection of larger internal injection valve components. Furthermore, the modular chemical injection valve cartridge design can be custom designed and configured with multiple features such as redundant check valves and as an integral point of injection anti-syphon valve. Finally, the valve cartridge design is arranged and configured for adjusting closed and cracking pressure by means of a pressure adjustment screw, shims, or spacers.

These, together with other objects of the invention, along with various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages, and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is described illustrative embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the present invention, and together with the description, serve to explain the principles of the invention. It is to be expressly understood that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. In the drawings:

FIG. 1 is a sectional side view of a select port chemical injection tubing sub constructed in accordance with the teachings of the present disclosure.

FIG. 2 is a side view of the device shown in FIG. 1.

FIG. 3 is a sectional side view of a select port chemical injection tubing sub and an enlarged sectional detail view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 4 is a side view of a select port chemical injection tubing sub constructed in accordance with the teachings of the present disclosure.

FIG. 5 is a top view of the device shown in FIG. 4.

FIG. 6 is a partial top view of a select port chemical injection tubing sub constructed in accordance with the teachings of the present disclosure.

FIG. 7 is an exploded sectional side view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 8 is a sectional side view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 9 is a sectional side view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 10 is a sectional side view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 11 is an exploded side view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 12 is an exploded side view of a chemical injection valve cartridge constructed in accordance with the teachings of the present disclosure.

FIG. 13 is an exploded sectional side view of a chemical injection valve cartridge constructed in accordance with the teachings of the present disclosure.

FIG. 14 is a sectional side view of a chemical injection valve cartridge constructed in accordance with the teachings of the present disclosure.

FIG. 15 is a front view of a front face of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 16 is a sectional side view of a lug with internal cartridge receptacle constructed in accordance with the teachings of the present disclosure.

FIG. 17 is a rear view of a rear face of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

FIG. 18 is a top view of a chemical injection valve cartridge lug constructed in accordance with the teachings of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Exemplary embodiments of select port chemical injection tubing devices in accordance with the present disclosure are discussed herein. Many other uses of the present invention will become obvious to one skilled in the art upon acquiring a thorough understanding of the present invention. Once given the below disclosures, many other features, modifications and variations will become apparent to the skilled artisan in view of the teachings set forth herein. Such other features, modifications and variations are, therefore, considered to be a part of this invention.

Turning to FIG. 1, the illustrated select port chemical injection tubing device 20 comprises a tubular member, such as the illustrated tubing sub 21, wherein the tubular member 21 comprises a tubing bore 22 having an inlet end 30 and an outlet end 29, said tubing bore being configured to receive reservoir fluids. The tubular member 21 further comprises one or more fluid inlet ports 32 formed through the tubing body for receiving injected fluids therethrough. The illustrated select port chemical injection tubing sub 20 further comprises a guide lug 25 arranged and configured to position, protect, and align a capillary line 24 along the outside of the tubing sub 21. A tubing connector 31 and double ferrule 34 and 35 (see FIG. 3) connect the capillary line 24 to a chemical injection valve cartridge 23. The ferrule may be a double ferrule as illustrated, comprising a back ferrule 34 and a front ferrule 35, or a single ferrule. The ferrule is used to create a high-pressure, leak-tight seal around the capillary tubing 24, and as illustrated, the double ferrule is part of the connection assembly between the capillary line 24 and the chemical injection valve cartridge 23. The illustrated select port chemical injection tubing sub 20 further comprises a chemical injection valve cartridge 23. The illustrated chemical injection valve cartridge 23 is received in a cavity or cartridge receptacle 54 (see FIG. 16) formed in a chemical injection valve cartridge lug 26. The chemical injection valve cartridge lug 26 comprises an internal cartridge receptacle 54. The chemical injection valve cartridge lug 26 is configured as a housing for a chemical injection valve cartridge 23.

FIG. 1 depicts a chemical injection valve cartridge assembly 23 installed in the cartridge receptacle 54. The disclosed chemical injection valve cartridge is arranged and configured such that the injection valve cartridge is releasably attachable, removable, and the cartridge is configured as a replaceable insert. The disclosed chemical injection valve cartridge can be removed and replaced without replacing the entire tubing sub with integral cartridge lug assembly. This arrangement allows the chemical injection valve cartridge assembly 23 to be custom designed and changed to a user's specifications.

As illustrated in FIG. 3, the chemical injection valve cartridge lug 26 comprises multiple fluid flow passages. The primary fluid flow passage 39 extends through the length of the injection valve cartridge lug 26. The primary fluid flow passage 39 directs injected fluid through the length of the lug and through any connected tubing or apparatus, such as to a downhole pump (not depicted). FIG. 1 depicts a tubing connector assembly 28 which may be configured for connection to tubing called a tail pipe. FIG. 8 shows the tubing connector assembly 28 disposed within an outlet discharge port 56. The tubing connector assembly 28 can connect the chemical injection valve cartridge lug 26 to a tail pipe (not shown), which tail pipe can connect directly to the inlet of a downhole pump or which tail pipe can deliver injected fluids indirectly to a downhole pump. This creates a primary fluid flow passage that allows injected fluids to flow through the injection valve cartridge lug 26 and through the tubing connector assembly 28 and into any connected tubing or apparatus, such as to a downhole pump. Alternatively, a plug member or sealing member 27, as illustrated in FIG. 1, can be inserted or installed into one or more discharge ports 38 and 56 to plug and seal off one or more discharge ports and change the fluid flow path of the injected fluid.

Turning to FIG. 3, the illustrated select port chemical injection tubing device 20 comprises a chemical injection valve cartridge lug 26 with an enlarged sectional detail view of an installed chemical injection valve cartridge 23 constructed in accordance with the teachings of the present disclosure. FIGS. 7 and 11 show exploded views of a chemical injection valve cartridge lug 26 and a chemical injection valve cartridge 23.

The injection valve cartridge lug 26 is arranged and configured for permanent fixation to a tubular member such as a tubing sub 21 or any other tubing (e.g., any section of pipe or joint used as part of a tubular string) as will be understood by those skilled in the art. The cartridge lug 26 may be permanently fixed to the tubing sub by welding it in place (see FIG. 6) or by any other means known to those skilled in the art. The injection valve cartridge lug 26 comprises one or more discharge ports 38 that intersect the primary fluid flow passage 39. In the attached drawings, three discharge ports 38 forming secondary fluid flow passages, in addition to the outlet discharge port 56 that forms part of the primary fluid flow passage, are shown. The present disclosure anticipates one or more discharge ports forming secondary fluid flow passages in the injection valve cartridge lug 26. As illustrated in the attached figures, the primary fluid flow passage 39, intersects the three discharge ports 38 creating bottom sections and top sections of the three discharge ports 38. The tubing 21 and the injection valve cartridge lug 26 each have apertures, and when the injection valve cartridge lug 26 is fixed to the tubing 21, the respective apertures are aligned, establishing a secondary fluid flow path into the tubing bore 22, as shown in the attached drawings. Specifically, the apertures in the tubing 21 are defined as fluid inlet ports 32 that allow fluid to flow into the tubing. Furthermore, the injection valve cartridge lug 26 has apertures on its top surface, as shown in FIGS. 5 and 6. The apertures in the injection valve cartridge lug 26 top surface create a fluid flow path into an annulus of a well. Thereby, the disclosed injection valve cartridge lug 26 is arranged and configured to provide three separate fluid flow paths into either the annulus, tubing bore, or through the outlet of the cartridge lug to a downhole apparatus, such as a downhole pump.

Turning to FIG. 8, a method and configuration for creating a primary fluid flow passage through the chemical injection valve cartridge lug 26 to a downhole apparatus, such as a downhole pump, is illustrated. In this drawing, six socket head pipe plugs 27 seal off the top sections and the bottom sections of the three discharge ports 38 of the cartridge lug 26. A primary fluid flow passage extends through the center of the lug from the inlet face 57 to the outlet face 58 of the cartridge lug 26. The primary fluid flow passage allows chemical to flow through the cartridge lug 26, through a tubing connector assembly 28, and through a tail pipe or any other connected tubing or apparatus, such as to a downhole pump.

In FIG. 9, the cartridge lug 26 is arranged for fluid flow into the annulus of a well. Here, three socket head pipe plugs 27 seal off the bottom sections of the three discharge ports 38 and the tubing fluid inlet ports 32. Additionally, one socket head pipe plug seals off the outlet discharge port 56 of the cartridge lug 26. This forces chemical to flow through the cartridge lug 26 and out of the top section of the discharge ports 38, establishing a fluid flow path into the the annulus of the well.

In FIG. 10, the cartridge lug 26 is arranged for fluid flow into the tubing bore 22. Here, three socket head pipe plugs seal off the top sections of the three discharge ports 38. Additionally, one socket head pipe plug seals off the outlet discharge port 56 of the cartridge lug 26. This forces chemical to flow through the cartridge lug 26 and through the tubing fluid inlet ports 32 and into the connected tubing bore 22 and directly into the production flow stream.

The drawings illustrate pipe plugs 27 configured as threaded socket head pipe plugs. Additionally, the drawings illustrate the chamber with receptacles configured to receive and releasably retain the pipe plugs 27. As will be understood by those skilled in the art, the pipe plug members 27 may be defined as a threaded plug or any other plug member, such as a stopper, cap, etc., arranged and configured to temporarily or permanently seal off, close, or block an opening or port. Likewise, the receptacles can be configured in any way to receive and retain—releasably, permanently, or temporarily—the plug members or sealing members. In other embodiments anticipated by the present disclosure, the flow-through chamber may be configured to only provide one fluid flow passage for injecting chemical into one of the following: production tubing string, annulus, or downhole pump. Alternatively, in other embodiments anticipated by the present disclosure, the flow-through chamber may be configured to provide two or more fluid flow passages for injecting chemical.

Turning to FIGS. 7-8 and 12-14, the chemical injection valve cartridge 23 comprises a cartridge housing 37 that connects to a cartridge retainer 51 to retain the cartridge components inside the chemical injection valve cartridge assembly 23. A sealing member 40, such as an O-ring, may be disposed around the cartridge housing 37, as depicted in FIG. 8. The illustrated chemical injection valve cartridge assembly 23 comprises a primary check valve and a secondary check valve. The disclosed check valves allow chemical to flow into the cartridge lug 26, while preventing backflow of well fluids into the capillary line 24. In the attached figures, the primary check valve and secondary check valve are depicted as ball-and-spring check valves, but other check valves known to those skilled in the art may be used (e.g., flapper check valve, wafer check valve, dart check valve, etc.). The illustrated secondary or backup check valve 41 is disposed inside the cartridge housing, which cartridge housing comprises a ball seat 59. A resilient member, such as a conical spring 42, holds the check ball 41 under tension against the ball seat 59 in the cartridge housing 37. The spring 42 is held in place by a spring cup or spring retainer 43. The spring retainer 43 comprises a non-circular slot 44 (e.g., an oval-shaped slot) arranged to prevent the check ball 41 from obstructing the chemical injection valve 23 in the event of a spring malfunction. Rather than designing the slot 44 as a circular aperture, which would allow the check ball to fall through and obstruct or plug the chemical injection valve 23 in the case of a spring failure, the disclosed spring retainer 43 may comprise a non-circular slot 44 configured to ensure that the check ball 41 does not obstruct or plug the chemical injection valve 23 if the spring 42 fails. A primary valve seat 46 is disposed against the spring retainer 43. FIG. 8 depicts a seal 45 that passes around the top circumference of the primary valve seat 46. Additionally, FIG. 7 depicts a seal, such as an O-ring 48 and two backup O-rings 47. The O-ring 48 and two backup O-rings 47 may pass around the middle circumference of the primary valve seat 46 (see FIG. 8). A primary check valve 49 is disposed against the primary valve seat 46. A ball stand 50 holds the check ball 49 in the correct position relative to the primary valve seat 46, limits movement of the check ball 49, and provides proper alignment and stability during operation of the injection valve 23. A cartridge retainer 51 connects with the cartridge housing 37 to retain all the components inside the chemical injection valve cartridge 23.

This chemical injection valve cartridge assembly 23 is a releasably attachable, removable, and replaceable cartridge. The cartridge assembly can be modified as needed and the cartridge assembly can be quickly installed or uninstalled in the cartridge receptacle 54 of the cartridge lug 26. The drawings illustrate threaded connections for installing and uninstalling the cartridge assembly. Other methods of connection known by those skilled in the art may be utilized to install and uninstall the cartridge assembly 23 in the cartridge receptacle 54 of the cartridge lug 26.

Additionally, as illustrated in FIG. 16, a spring receptacle 55 is formed in the cartridge lug 26. As depicted in FIG. 8, a spring 52 and shim spacers 53 are disposed in the spring receptacle 55. The shim spacers 53 provide a means of adjusting pressure. Shim spacers 53 may be added or deleted as needed to increase or decrease the set pressure.

It is important to note that the construction and arrangement of the elements of the invention provided herein are illustrative only. Although only a few exemplary embodiments of the present invention have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible in these embodiments (such as variations in orientation of the components of the system, sizes, structures, shapes and proportions of the various components, etc.) without materially departing from the novel teachings and advantages of the invention.

Many other uses of the present invention will become obvious to one skilled in the art upon acquiring a thorough understanding of the present invention. Once given the above disclosures, many other features, modifications and variations will become apparent to the skilled artisan in view of the teachings set forth herein. Such other features, modifications and variations are, therefore, considered to be a part of this invention, the scope of which is to be determined by the following claims.