Plunger Lift Lubricator

Abstract

A plunger lift lubricator including a lower lubricator section having an internal lubricator bore extending axially from a top thread profile to a bottom flange profile an outlet pipe connector comprising a body having a vertical throughbore forming a portion of the lubricator bore and a radial passage extending through a pipe connector profile to the vertical throughbore.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/205,310, filed Aug. 14, 2015, which is incorporated herein by reference in its entirety as if fully set forth herein.

BACKGROUND

This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.

Hydrocarbon producing gas wells generally produce liquids in addition to the flowing gas stream. These fluids, gas and liquids, are conducted to the surface by a string of production tubing that communicates the below ground formation to piping system at the surface. Removal of the liquid fraction of the fluid column is mandatory for maintaining the unrestricted production of gas from the production zone formation. Frequently, a beam pump unit is employed for this task. However, beam pumping units are expensive and suffer from high maintenance costs.

In the field of plunger lift, a plunger acts as an unattached free-traveling piston within the length of the production tubing for the purpose of lifting liquids from an active, gaseous hydrocarbon-bearing formation. In the life cycle of a plunger lift system, the plunger travels first downwardly to the bottom region of the tubing string adjacent to the formation then upwardly within the tubing string multiple times within the course of the day. The use of a plunger within the tubing conduit of a gas well will enable the upward flow of light-density gas to push toward the surface those heavier liquids within the tubing string.

The term wellhead lubricator can refer to the sealing and packing device atop the wellhead of a rod pumping unit where the polish rod enters the wellbore at the surface. In the field of plunger lift, a housing unit mounted atop a flowing gas well is also referred to as a lubricator. The plunger lift lubricators extant are occasionally made as a single outlet version in a T-shaped arrangement wherein production fluids flow into the T-shaped lubricator and thence into the surface piping. The upwardly traveling plunger moves into the uppermost portion of this T-shaped lubricator and held in this uppermost position by the up-flowing gas stream. When the moving gas stream is terminated by the subsequent closure of a valve within the surface piping downstream of the lubricator, the plunger falls into the wellbore by the force of gravity.

In a more common iteration, the common plunger lift lubricator is referred to as a “dual outlet,” meaning that the lubricator has two production passageways extending perpendicular from the main vertical section. An example of a common lubricator 300, having dual outlets, is illustrated in FIG. 1. The common lubricator 300 includes a metal vertical flow body 302 having an uppermost end 304 and a lowermost end 306, which are threaded (e.g., 2⅜ inch 8-round thread). A spring housing 308 is threaded connected at the uppermost end 304. The two outlets 310, 312 do not define a cross but instead are located one above the other along the length of the vertical flow body of the lubricator 300 and are separated vertically by the approximate length of a common plunger (piston). The purpose of the dual outlet arrangement is to avoid flow restrictions as the plunger enters into and remains in the lubricator vertical section. A single outlet lubricator is subject to flow restrictions, should the plunger come to rest across the opening of the single outlet.

The lowermost end of the common lubricator, made from metallic tubing, presents a seal-tight threaded arrangement for attachment to the wellhead. In a common alternate version, the lowermost end of the common lubricator is first attached, by threading or welding, to a flange which is subsequently bolted to the mating flange of the uppermost valve in the wellhead. All common flanges are purchased as pre-threaded or as prepared for welded attachment. Welded connections are capable of holding 10,000 psi.

In general, the uppermost section of the common wellhead assembly (e.g., tree) that exists below these common lubricators presents a flange style connection as the preferred version within the industry because of the reliability and pressure holding capabilities of flange connections. Flange to flange connections are capable of holding 10,000 psi.

The outlet pipe connections 311, 313 oriented horizontally and attached to the vertical section of the common lubricator are made by the use of seal-tight threaded connections (2″ NPT) or with the aid of the welding process. The connections, whether threaded or flanged, joining the lowermost section of these common lubricators to the uppermost end of the wellhead tree are made using seal-tight threaded components or with the aid of the welding process to join the metallic tubing to the flange on the lowermost end of the common lubricator.

The one or more threaded (2″ NPT) connectors 311, 313 (thread-o-lets) of the common lubricator 300 that are provided at the respective one or more outlets 310, 312 are attached to the vertical section by welding 315. This threaded adaptor 311, 313, welded to the vertical section, permits threaded piping to be connected. All appropriate passageways 310, 312 are first drilled into the vertical section prior to the welding process. In another common iteration, one or more horizontally oriented flanged style outlet connectors may be used and are welded to the vertical section of the common lubricator and later joined to the surface pipe facility by mating to these flanged connections.

For the purpose of inspecting or removing the plunger, a catcher device 316 is installed with the lubricator 300 to catch and hold the plunger in its uppermost position within the lubricator. This device is most commonly a spring-loaded pin that passes horizontally through the external wall of the lubricator and acts to pin the plunger against the opposite wall. The rounded end of the pin that makes contact with the plunger does not damage, nor is damaged, by impact with the plunger.

Limitations of the common plunger lift lubricators extant include the use of the various threaded connections. The commonly used threaded pipe, National Pipe Thread (“NPT”), specifications describe a V-shape thread with a pressure containment rating of 5,000 psi (2″ NPT), whereas the wellhead tree is commonly rated at 10,000 psi. Dissimilar ratings invite mistakes with potential for failure. A pressure-caused failure can occur when a fracking operation is being conducted on a nearby wellbore and the fractures migrate through the hydrocarbon-containing source-rock to a wellbore that has been completed by underrated surface equipment, including a lubricator with NPT, V-shaped threads.

Another limitation related to the use of a common lubricator involves failures related to misalignment in the several components of the piping arrangement leading away from the wellhead and lubricator assembly. The equipment and components that make up the totality of the wellhead and surface facilities is supplied by a variety of vendors. This variety of equipment is typically installed by third parties without complete knowledge of any limitations that should signal against alignment by force. Forced alignment procedures can be the source of failures in piping systems under cold stress. By its nature, threaded pipe is rigid and unforgiving with regard to misalignment. The exposed threaded section of threaded pipe represents the weakest point along the length of the pressure-containing pipe and the most common location for stress cracking and failure.

Further limitations are related to the use of welded connections. The welding process creates a heat affected zone (“HAZ”) adjacent to the weld. The improper heating and cooling of this heat affected zone creates internal stress within the material.

With or without the heat of the welding process, the materials of these pressure containing lubricators are aggravated by a cold environment. Steel, when subject to temperatures for example below zero-degrees Fahrenheit, becomes brittle. It is common for lubricators used in cold climates to experience stress-inducing temperature swings from 100 to −20 degrees Fahrenheit in a matter of minutes, multiple times a day, from the intermittent flow of very warm production fluids in the presence of sub-zero wind and blowing snow.

SUMMARY

A plunger lift lubricator including a lower lubricator section having an internal lubricator bore extending axially from a top thread profile to a bottom flange profile an outlet pipe connector comprising a body having a vertical throughbore forming a portion of the lubricator bore and a radial passage extending through a pipe connector profile to the vertical throughbore. In accordance to aspects of the disclosure the lower lubricator section does not have any welds. In some embodiments the lower lubricator section is formed of a single piece of material including the top thread profile, the bottom flange profile, and the outlet pipe connector and the pipe connector profile.

In some embodiments the lower lubricator section includes the outlet pipe connector formed of a single piece of material with the vertical throughbore extending between a top surface and a bottom surface, a flow body formed of a single piece of material having a vertical throughbore forming a portion of the lubricator bore and extending from the bottom flange profile to a top flange profile that is connected to the bottom surface of the outlet pipe connector and an adaptor formed of a single piece of material having a vertical throughbore forming a portion of the lubricator bore extending from the top thread profile to a bottom flange profile that is connected to the top surface of the outlet pipe connector.

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 illustrates a prior art common plunger lift lubricator.

FIG. 2 illustrates a plunger lift well system incorporating a lubricator in accordance with one or more aspects of the disclosure.

FIG. 3 illustrates a plunger lift lubricator having a lower lubricator section that is constructed of a single piece of material including the top and bottom connection profiles and one or more outlet pipe connectors in accordance with aspects of the disclosure.

FIG. 4 illustrates a single piece lower lubricator section including the top and bottom connection profiles and more than one outlet pipe connector according to aspects of the disclosure.

FIGS. 5 and 6 illustrate a single piece lower lubricator section including the top and bottom connection profiles and a single outlet pipe connector according to aspects of the disclosure.

FIG. 7 illustrates a plunger lift lubricator having a lower lubricator section that is constructed of multiple elements interconnected without welding in accordance with one or more aspects of the disclosure.

FIGS. 8 and 9 illustrate an example of a multiple element lower lubricator section according to aspects of the disclosure including a bore liner.

FIG. 10 illustrates an example of a plunger catcher in accordance to one or more aspects of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

As used herein, the terms connect, connection, connected, in connection with, and connecting may be used to mean in direct connection with or in connection with via one or more elements. Similarly, the terms couple, coupling, coupled, coupled together, and coupled with may be used to mean directly coupled together or coupled together via one or more elements. Terms such as up, down, top and bottom and other like terms indicating relative positions to a given point or element are may be utilized to more clearly describe some elements. Commonly, these terms relate to a reference point such as the surface from which drilling operations are initiated.

With reference generally to FIGS. 2 to 10 example embodiments of lubricators for use in plunger lift systems are described. FIG. 2 illustrates a well system 5 incorporating a plunger lift system 7 in accordance to one or more aspects of the disclosure. Plunger lift system 7 includes a lubricator 10 in accordance to one or more aspects of the disclosure positioned at the top of a production string 12 (tubing string) to cushion the arrival of a plunger 14 (i.e., piston) that cyclically travels a length of the production string 12. Plunger 14 may be a bypass or a solid plunger. The depicted plunger 14 is illustrated as a bypass type of plunger having an internal passage that is selectively blocked by a valve element 16 (e.g., ball, dart, etc.).

The lubricator 10 is a special piping arrangement installed for plunger lift to capture the cycling plunger 14 at the top of the well. In accordance to embodiments the lubricator 10 includes an arrival spring 18 (mechanical or gas), which cushions the arrival of a plunger within the lubricator 10, and one or more radial fluid outlets 20 each formed in an associated outlet pipe connector 22 to connect the lubricator to the surface production pipe 24. The lubricator 10 may include one or more catchers 26 adapted to selectively hold the plunger 14 within the lubricator. In accordance to some embodiments the catcher may be arranged with an outlet pipe connector.

The well system 5 includes a borehole 28 extending from a surface 30 of the earth to a producing formation 32. Wellbore 28 may be lined with a casing 34 including perforations 36 proximate the producing formation. The surface end of the casing is closed at the surface by a wellhead generally denoted by the numeral 38 having a valve 40 located below or upstream of the lubricator toward the producing formation. The production string 12 extends down the wellbore inside of the casing. A bumper spring 42 is positioned at the lower end of the tubing string 12 to stop the downward travel of the plunger 14.

Formation fluid 44 enters the casing through the perforations and into the tubing string for example through a standing valve 46. The free travelling plunger 14 is lifted from the bottom of the well to the surface when the lifting gas energy below the plunger is greater than the liquid load 48 and gas pressure above the plunger. In a plunger lift system operation, the well is shut-in by closing for example a flow control valve 25 for a period of time during which sufficient formation pressure is developed within the casing to move the plunger 14 and the liquid slug 48 that is above the plunger upward to the surface when the flow control valve is opened.

With reference in particular to FIGS. 2-10, the plunger lift lubricator 10 generally includes a lower vertical lubricator section 11 forming a vertical bore 54 and extending between a top end 56 connected to a spring housing 52 carrying the arrival spring 18 and a bottom end 58 to be connected to a wellhead. The lower vertical section comprises a flow body 50 and a radial outlet 20 formed in a pipe connector 22. According to aspects of the disclosure the lower lubricator section 11 does not include welded connections. FIGS. 3-6 illustrate a lower lubricator section 11 that is constructed, via forging or machining, as a single piece including the top and bottom connection profiles 56, 58 and the one or more outlet pipe connectors 22. FIGS. 7-9 illustrate embodiments of a lower lubricator section 11 formed of interconnected elements without welding. FIG. 10 illustrates a non-limiting example of a catcher 26.

Referring first to FIGS. 3-6, the spring housing 52 is connected to the top end 56 of the flow body via threading to allow for removal of the spring housing when needed. The bottom end 58 is adapted to connect to the wellhead. Each of the flow bodies 50 illustrated in FIGS. 3-6 have a flange type profile at the lowermost end 58 for connecting with the wellhead, however, a threaded connection may be utilized. In accordance to some embodiments, the lowermost end 58 is machined, forged, or cast with the flange profile to avoid the weakness of welding a flange profile onto the flow body.

The flow body 50 includes one or more radial production outlets 20. Each outlet 20 is formed through an outlet pipe connector 22 which is formed as a single unit with the flow body 50 in FIGS. 3-6. The pipe connector 22 forms a horizontal passage 66 extending from the radial outlet 20 and lubricator bore 54 through a pipe connector profile 68 for connecting to the surface production piping 24 (FIG. 2). In FIGS. 3 and 4 the pipe connector profile 68 is a thread profile. In accordance to some embodiments, the thread profile 68 is an Acme thread profile, such as a 14.5 degree thread profile. In FIGS. 5 and 6 the connector profile 68 is a flange profile. The outlet pipe connector 22 is forged, machined or cast with the flow body 50 eliminating the welded connection of a thread or flange connector profile 68.

In accordance to some embodiments, the outlet pipe connector 22 includes a catcher 26 for example as described below with particular reference to FIG. 10. In the non-limiting illustrated embodiments, the catcher 26 is aligned for example 180 degrees from the horizontal passage 66.

With reference in particular to FIGS. 3-6, the flow body 50 is machined, forged or cast as a one-piece unit including the outlet pipe connector(s) 22 and the connection profiles on the terminal ends 56, 58 from a single piece (billet) of material. The flow body 50 may be constructed for example of an alloy compound including but not limited to carbon, stainless steel, or other corrosion resistant materials. In accordance to an embodiment a billet of material receives a stress-relieving heat-treatment from the supplying mill at the time of manufacture and carries a Rockwell hardness rating of 22 or less (Rc22). Above 22Rc, steel will not pass the Charpy impact test and is deemed unsuitable for cold service.

The lubricator bore 54 may include one or more internal diameters. For example, in FIGS. 3-6 the lubricator bore 54 comprises a top passage 70 portion proximate to the top end 56 having a different diameter than a lower passage 72 portion extending below the top passage portion. In the illustrated embodiments, the top passage 70 has a larger diameter than the lower passage 72. With reference to FIG. 3, the lower end 74 of the spring housing 52 is positioned inside the top passage 70 and an internally threaded collar 76, which is rotationally attached to the spring housing 52, connects with the external threads on the top end 56 of the flow body 50. A seal (e.g., O-ring) 78 is disposed with the lower end 74 of the spring housing to seal the connection with the flow body and lubricator bore. The addition of seal 78 provides for additional sealing capability in particular in the event that the spring housing 52 and flow body 50 are misaligned during connection. A striker element 80 may be disposed with the arrival spring 18 and located at least partially within the top passage 70 portion of the flow body. The illustrated striker element 80 is a striker block for use for example with a plunger having a male fish neck profile. The striker element 80 can take various forms. In some embodiments the striker element 80 will include a rod to extend into the internal passage of the plunger to move the valve element to the open position.

In the illustrated embodiments the uppermost end 56 is defined by a thread profile without the aid of the welding process. The thread profile of the uppermost end 56 conforms to a 14.5 degree Acme profile in at least one embodiment, representing a strong, pressure resistant design, unlike the common V-thread. In accordance to some embodiments, the thread profile of the outlet pipe connector profile 68 conforms to a 14.5 degree profile to maintain the integrity of the seal by withstanding the pressure induced stress.

Square threads have a zero-degree thread flank angle and induce less friction than a 14.5 degree Acme profile and therefore may be preferred for maximal applied axial force to engage the sealing element into a leak-tight joint. However, the square thread profile is subject to loosening, especially in the presence of the type of vibration that occurs periodically within a flowing fluid stream that is intermittently pressurized with gas then liquid. In accordance with an embodiment a square thread may be utilized with an anti-rotation, thread locking device to secure a non-locking, square thread.

Common 60 degree V-threads, whether straight or tapered, induce undue friction during the tightening process because the vector of the thread angle directs 30% of the force generated during the tightening process in a direction perpendicular to the preferred axis. Consequently, the common, 60 degree V-thread may not impart sufficient axial force to engage the mating surfaces of the surface piping into the concave surface of the lubricator outlet profile. The common V-thread is defined by its seal-tight thread. In profile, the thread is tapered along its length which causes the male profile to wedge into the female profile as the threads are tightened. For the pressurized fluid to escape it must migrate the length of the spiral path of the thread engagement, a task made difficult by the presence of the sealant compound. The Acme thread taught herein is a straight thread in profile wherein the spiral profile maintains a constant diameter along its length. Sealing does not take place within the thread itself The seal occurs when the engagement of the thread acts to bias two mating surfaces into a sealing contact. These two surfaces are each defined by a radius shape, one concave and the other convex, hence, the allowance for a slight misalignment. The 14.5 degree thread profile carries a greater sheer resistance because the profile of the thread is wider at its base when compared to a square thread profile.

Acme threads (14.5 degree) are considerably stronger against the forces of thrust versus V-thread. At 14.5 degrees, the Acme thread flank profile combines the correct balance of thread-locking friction with the ultimate holding power of the material's yield strength. This combination resists the axial movement generated by the force of the internal pressure as well as resistance to rotational creep.

Referring now to FIGS. 7-9, the lubricator 10 includes a lower lubricator section 11 formed of multiple elements that are interconnected without welding. In the illustrated embodiments, the vertical lubricator bore 54 of the lower lubricator section 11 is formed of a flow body 50 having the bottom connector profile 58, one or more outlet pipe connectors 22, and an adaptor 60 carrying the top connector profile 56 for connection with a spring housing 52. In the illustrated embodiments the lower lubricator elements 50, 22, 60 are interconnected at non-threaded flanges. In FIG. 7 a portion of the lubricator bore 54 adjacent to the radial outlet 20 is shown with an enlarged diameter relative to the bore 54 at the bottom end 58 to dispose a liner as illustrated in FIGS. 8 and 9. Although all of the single outlet lubricators are shown as including a liner as further described below, the single outlet lubricators do not require a liner.

The outlet pipe connector 22 comprises a body 62 formed of a single piece of material such as an alloy compound including but not limited to carbon, stainless steel, or other corrosion resistant materials. In accordance to an embodiment a billet of material receives a stress-relieving heat-treatment from the supplying mill at the time of manufacture and carries a Rockwell hardness rating of 22 or less (Rc22). Above 22Rc, steel will not pass the Charpy impact test and is deemed unsuitable for cold service. In the illustrated examples the outlet pipe connector is formed from a square shaped raw material and may retain the square shape when completed.

The outlet pipe connector 22 comprises a vertical throughbore 64 forming part of the lubricator bore 54 and extending between top and bottom surfaces 82, 84 or flange profiles. A horizontal passage 66 extends radially from vertical throughbore 64 to a surface pipe connection profile 68 for connection with the surface piping 24 (FIG. 2). The surface pipe connection profile 68 may be a threaded or flange type of profile. In accordance to embodiments the flange profiles 68, 82, 84 may be the planar or substantially planar outer surface of the outlet pipe connector 22. In the illustrated examples, the flange profiles of the outlet pipe connector 22 may include threaded sockets 90 for receive threaded elements (e.g., studs or bolts) 92 or may comprise threaded elements 92 on which the flange profiles of the respective adaptor 60, flow body 50 and surface piping can be attached. In accordance to some embodiments, the outlet pipe connector 22 includes a catcher 26 for example as described below with particular reference to FIG. 10. In the non-limiting illustrated embodiments, the catcher 26 is aligned for example 180 degrees from the horizontal passage 66.

The flow body 50 is made as a one-piece unit, machined, forged or cast from a single piece of material, along a single vertical axis of a material such as used to form the outlet pipe connector 22. The lower end 58 of the flow body 50 is formed with a connection profile adapted for connecting with a wellhead. In the illustrated examples the lower end profile 58 is a flange profile. The flow body 50 has a top flange-type connection profile 86 for connection with the bottom flange-type connection profile 84 of the outlet pipe connector 22. The flow body 50 has a vertical throughbore 65 forming part of the lubricator bore 54 and extending from the bottom end 58 to the top end 86.

Adaptor 60 is made as a one-piece unit, machined, forged or cast from a single piece of material, of a material such as used to form the outlet pipe connector 22 and flow body 50. Adaptor 60 has a vertical throughbore 67 extending from the top end 56 to the bottom flange-type connection profile 88 connected to the top flange connection profile 82 of the outlet pipe connector 22. In accordance to some embodiments, the top threaded profile 56 and or a threaded connector profile 68 conforms to a 14.5 degree Acme profile in at least one embodiment, representing a strong, pressure resistant design, unlike the common V-thread.

With reference to FIGS. 2-10, the lower lubricator section 11 may include one or more horizontally oriented pipe outlets 20. Two or more outlets 20 are traditionally utilized to reduce or remove the possibility of the plunger 14 from blocking the flow path of the produced fluid from the production string through the lubricator and into the surface piping. If the plunger blocks a first horizontal outlet 20 the wellbore fluid can be produced from one or more of the additional vertically spaced horizontal outlets 20.

Relative to a multiple outlet lubricator, a single outlet reduces the cost of manufacturing and the costs in the related surface piping. To remove or reduce the possibility of the traveling plunger 14 blocking the flow path of the up-flowing fluid from within the wellbore, the single outlet 20 lubricator may comprise an annular passageway 94 that allows the wellbore fluid to bypass the plunger 14 within the lubricator to pass through the outlet 20 into the surface piping as illustrated for example in FIGS. 3, 6, and 8-10. In accordance to embodiments, the annular passage 94 is formed between a perforated liner 96 disposed in the lubricator bore 54 adjacent to the outlet 20 and the inner wall 98 forming the lubricator bore. The perforated liner 96 includes openings 100 to allow fluid to pass radially through the liner. In accordance to some embodiments, an opening 100 may be sized and positioned to pass a pin element of a catcher 26, see e.g. FIG. 10.

FIG. 10 illustrates an example of a catcher 26 which may be utilized with a lubricator section 11. Catcher 26 includes an element 102, such as pin, adapted to selectively engage a plunger 14 (e.g., FIG. 8) when it is located in the lubricator bore 54. In the illustrated example the pin 102 is biased by a spring 104. In accordance to some embodiments the catcher 26 is automated and operated by an actuator. Pin 102 is moveably disposed in a radial passage 106 formed for example through the outlet pipe connector 22 and extending from the outer surface 63 to the lubricator bore 54. In accordance to some embodiments, the pin passage 106 is located about 180 degrees from the horizontal outlet passage 66. An end piece 108 is connected with the body 62 of the outlet pipe connector 22 over the pin passage 106. In the illustrated example, the end piece 108 is connected with a non-welded fastener 110, e.g., a screw, to avoid a welded connection. The end piece may be connected via welding in some embodiments.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the disclosure. Those skilled in the art should appreciate that they may readily use the disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the disclosure. The scope of the invention should be determined only by the language of the claims that follow. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open group. The terms “a,” “an” and other singular terms are intended to include the plural forms thereof unless specifically excluded.

Claims

1. A plunger lift lubricator, comprising:

a lower lubricator section having an internal lubricator bore extending axially from a top thread profile to a bottom flange profile; and

an outlet pipe connector comprising a body having a vertical throughbore forming a portion of the lubricator bore and a radial passage extending through a pipe connector profile to the vertical throughbore.

2. The plunger lift lubricator of claim 1, wherein the outlet pipe connector comprises a liner disposed in the lubricator bore; and

an annular passage between the liner and an inner wall of the lubricator bore.

3. The plunger lift lubricator of claim 1, wherein the top thread profile conforms to a 14.5 degree Acme profile.

4. The plunger lift lubricator of claim 1, wherein the pipe connector profile of the outlet pipe connector is a thread profile that conforms to a 14.5 degree Acme profile.

5. The plunger lift lubricator of claim 1, wherein the top thread profile conforms to a 14.5 degree Acme profile; and

the pipe connector profile of the outlet pipe connector is a thread profile that conforms to a 14.5 degree Acme profile.

6. The plunger lift lubricator of claim 1, comprising a spring housing threadedly connected to the top thread profile.

7. The plunger lift lubricator of claim 1, further comprising a spring housing haying a lower end disposed within a top passage of the top thread profile; and

a connector attached to the housing and threadedly connected to the top thread profile.

8. The plunger lift lubricator of claim 7, wherein the outlet pipe connector comprises a liner disposed in the lubricator bore; and

an annular passage between the liner and an inner wall of the lubricator bore.

9. The plunger lift lubricator of claim 7, wherein the pipe connector profile of the outlet pipe connector is a flange profile.

10. The plunger lift lubricator of claim 7, wherein the outlet pipe connector comprises a liner disposed in the lubricator bore; and

an annular passage between the liner and an inner wall of the lubricator bore.

11. The plunger lift lubricator of claim 1, wherein the lower lubricator section is formed of a single piece of material including the top thread profile, the bottom flange profile, and the outlet pipe connector and the pipe connector profile.

12. The plunger lift lubricator of claim 11, wherein the outlet pipe connector comprises a liner disposed in the lubricator bore; and

an annular passage between the liner and an inner wall of the lubricator bore.

13. The plunger lift lubricator of claim 11, where the pipe connector profile is flange profile.

14. The plunger lift lubricator of claim 11, further comprising a spring housing having a lower end disposed within a top passage of the top thread profile; and

a connector attached to the housing and threadedly connected to the top thread profile.

15. The plunger lift lubricator of claim 14, wherein the outlet pipe connector comprises a liner disposed in the lubricator bore; and

an annular passage between the liner and an inner wall of the lubricator bore.

16. The plunger lift lubricator of claim 1, wherein the lower lubricator section comprises:

the outlet pipe connector formed of a single piece of material, wherein the vertical throughbore extends between a top surface and a bottom surface;

a flow body formed of a single piece of material having a vertical throughbore forming a portion of the lubricator bore and extending from the bottom flange profile to a top flange profile that is connected to the bottom surface of the outlet pipe connector; and

an adaptor formed of a single piece of material having a vertical throughbore forming a portion of the lubricator bore extending from the top thread profile to a bottom flange profile that is connected to the top surface of the outlet pipe connector.

17. The plunger lift lubricator of claim 16, wherein the outlet pipe connector comprises a liner disposed in the lubricator bore; and

an annular passage between the liner and an inner wall of the lubricator bore.

18. The plunger lift lubricator of claim 16, further comprising a spring housing having a lower end disposed within a top passage of the top thread profile; and

a connector attached to the housing and threadedly connected to the top thread profile.

19. The plunger lift lubricator of claim 16, wherein the pipe connector profile of the outlet pipe connector is a flange profile.

20. The plunger lift lubricator of claim 16, wherein the pipe connector profile of the outlet pipe connector is a thread profile.