Plunger Lift Lubricator with Mounted Pipe Connectors

Abstract

A plunger lift lubricator includes a tubular flow body having an internal lubricator bore, a top end, a bottom end, and a radial outlet in communication with lubricator bore; and a pipe connector circumferentially mounted on the tubular flow body about the radial outlet, the pipe connector having a vertical throughbore disposing the flow body, a pipe connector profile, and a horizontal passage extending between the vertical throughbore and the pipe connector profile. In accordance to some embodiments the flow body is formed of a single piece of material and the top end has a thread profile to connect a spring housing and the bottom end has a thread or a flange profile.

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 according to aspects of the disclosure includes a tubular flow body having an internal lubricator bore, a top end, a bottom end, and a radial outlet in communication with lubricator bore; and a pipe connector circumferentially mounted on the tubular flow body about the radial outlet, the pipe connector having a vertical throughbore disposing the flow body, a pipe connector profile, and a horizontal passage extending between the vertical throughbore and the pipe connector profile. In accordance to some embodiments the flow body is formed of a single piece of material and the top end has a thread profile to connect a spring housing and the bottom end has a thread or a flange profile.

An example of a method includes securing a pipe connector to a tubular flow body for use as a plunger lift lubricator, wherein the flow body comprises an internal lubricator bore, a top end, a bottom end, and a radial outlet in communication with lubricator bore, and the pipe connector comprising a vertical throughbore, a pipe connector profile and a horizontal passage extending between the vertical throughbore and the pipe connector profile, wherein the securing comprises positioning the flow body in the vertical throughbore with the radial outlet and horizontal passage located on the same horizontal plane and attaching the pipe connector to the flow body.

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 in accordance with one or more aspects of the disclosure.

FIGS. 4 and 8 illustrate single outlet lubricator flow bodies with circumferentially mounted outlet pipe connectors according to aspects of the disclosure.

FIGS. 5, 6-7 and 9 illustrate multiple outlet lubricator flow bodies with circumferentially mounted outlet pipe connectors according to aspects of the disclosure.

FIGS. 10 and 12 illustrate outlet pipe connectors circumferentially disposed about and secured on lubricator flow bodies according to aspects of the disclosure.

FIG. 11 illustrates an example of an internal locking element for securing a circumferentially mounted outlet pipe connector on a lubricator flow body.

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 12 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 provided with an associated outlet pipe connector 22 to fluidicly 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 connection.

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. 3-12, the plunger lift lubricator 10 includes a flow body 50 (conduit) having one or more radial production outlets 20, a spring housing 52 carrying the arrival spring 18, and an outlet pipe connector 22 circumferentially mounted on the flow body 50 at each of the outlets 20. The flow body 50 has an internal bore 54 and extends between a first end 56 and a second end 58. The spring housing 52 is connected to the top end of the flow body, shown as the first end 56, via threading to allow for removal of the spring housing when needed. The bottom end, shown as second end 58, is adapted to connect to the wellhead. In this example the bottom end is shown as a flange connection. In accordance to some embodiments, the lowermost end 58 of the flow body 50 is machined, forged or cast with a flange profile to avoid the weakness of welding a flange profile onto the flow body. Each of the flow bodies 50 illustrated in FIGS. 3-9 have a flange type profile at the lowermost end for connecting with the wellhead, however, a threaded connection may be utilized.

The flow body 50 includes one or more production outlets 20. Each outlet 20 includes an associated outlet pipe connector 22 mounted on and around the flow body 50 so as to connect surface piping 24 (FIG. 2) with the outlet 20 of the flow body. Each production outlet 20 may comprise one or more ports 60, e.g., cross-holes, (see, e.g. FIGS. 5, 6 and 9) formed circumferentially about the flow body 50 along a horizontal plane for fluid connection with the associated outlet pipe connector 22. The cross-holes 60 may have the same or a different diameter than the port identified as outlet 20.

The outlet pipe connector 22 includes a body 62 having a central vertical throughbore 64 in which the flow body 50 is disposed and a horizontal passage 66 extending between the vertical throughbore 64 and a pipe connector profile 68 comprising one of a threaded profile (FIGS. 3, 5, 9, 12) or a flanged profile (FIGS. 4, 6-8 and 10) for connecting to the surface production piping. The outlet pipe connector 22 may be forged, machined or cast thereby eliminating the welded connection of a thread or flange pipe connector profile 68.

In accordance to some embodiments, the outlet pipe connector 22 includes a catcher 26. In the non-limiting illustrated embodiments, the catcher 26 is aligned for example 180 degrees from the horizontal passage 66. In accordance to some embodiments as further described below, the catcher 26 may include an internal locking element to secure the outlet pipe connector 22 to the flow body as further described below.

The lubricator 10 can avoid welds or utilize welds to attach the outlet pipe connectors 22 to the flow body. Generally, when cracks appear in a welded joint, the potential is present for a catastrophic failure. However, in this instant design, the outlet pipe connector 22 (flange or threaded profile) is circumferentially mounted and secured on the vertical flow body 50 by design and should not break-off in a catastrophic manner, an innovative approach. By this novel and superior method of attaching the outlet pipe connectors, the hazards associated with stress cracking are reduced because of the way the outlet pipe connectors are circumferentially positioned on the flow body in the form of a hoop.

With reference in particular to FIGS. 3-9, the flow body 50 is machined, forged or cast as a one-piece unit including the connection profiles on the terminal ends 56, 58 from a single piece (billet) of material, exclusive of the one or more outlet pipe connectors 22. 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. 3-9 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, 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. In FIGS. 3 and 5 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 of the vertical flow body 50 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 (see, e.g., FIGS. 3, 5 and 9) may conform 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.

As previously described the flow body 50 includes one or more outlets 20, typically a single outlet or a dual outlet. An outlet pipe connector 22 is positioned at each of the outlets 20 to connect to the surface piping. The outlet 20 is formed in the flow body at a port section 82 which has an outer diameter substantially the same as the inside diameter of the vertical throughbore 64 of the outlet pipe connector 22. The outlet pipe connectors 22 are sealingly mounted on the flow body 50. For example, a seal 78 is positioned circumferentially about the flow body 50 at the port section 82 on each side (above and below) the outlet 20 to seal with the outlet pipe connector 22 in the vertical throughbore 64 as illustrated for example in FIG. 9.

The port section 82 may have an outside diameter that is different from other sections of the flow body. In FIGS. 3-8 the port sections 82 have a diameter that is greater than one or more sections of the flow body. In the dual outlet flow bodies 50 illustrated in FIGS. 5-7, the lower port section 82 has a larger outside diameter than the upper port section 82. In FIG. 9 the flow body 50 has a substantially constant outside diameter comprising the two port sections 82. The port section 82 may have an undercut (reduced diameter) section located along the horizontal plane of the outlet 20 which may be utilized for example to position the outlet pipe connector 22 on the flow body.

The outlet pipe connector 22 may be located and positioned on the flow body 50 in various manners. In FIGS. 3-7 and 9 the bottom side 84 of each of the outlet pipe connectors 22 are depicted as positioned on the port section 82 by a stop element 86. The stop element 86 may be formed as a shoulder such as in increased outside diameter portion of the flow body 50 as illustrated in FIGS. 3-7, by an element such as a ring or pin as shown at the lower outlet connector 22 in FIG. 9, and/or the end of a tubular sleeve 90 positioned about a portion of the flow body 50 to form a shoulder as shown for example at the top outlet connector 22 in FIG. 9. With reference to FIG. 9, the sleeve 90 provides a spacer between the upper and lower outlet pipe connectors 22 as well as provides at the top end a stop to position the top outlet port connector 22. With reference to FIG. 8, the outlet pipe connector 22 is not located or positioned at the port section 82 by a stop such as shoulder or lip. In FIG. 8, the outlet pipe connector is positioned and secured in place by an internal locking element 96 as further described below with reference to FIGS. 10-12. In some embodiments the internal locking element is incorporated in a catcher 26.

The outlet pipe connector 22 may be secured (i.e., attached) to the flow body in various manners. In a first example, not illustrated in the figures, the outlet pipe connector 22 may be welded to the flow body. In other embodiments the welded connection is eliminated for reasons discussed above. With reference to FIGS. 3-7, each of the port sections 82 includes a threaded portion 92 located at least on the upper side of the outlet pipe connector 22 opposite from the stop 86 to which a threaded external connector 94 (e.g., ring or collar) is connected to secure the outlet pipe connector 22 to the flow body 50 between the stop 86 and the connector 94 (e.g., external locking element). In FIG. 9, a single external connector 94 is utilized to secure two outlet pipe connectors 22 to the flow body. In FIG. 9, a second sleeve 91 is located about the flow body 50 above the upper outlet pipe connector and terminating at the threaded upper end 56. In this manner the external connector 94 can be threaded onto a portion of the threaded upper end 56. In some embodiments, threads can be formed for example above the each of the outlet pipe connectors or only above the top outlet pipe connector to attach the threaded connector 94. In some embodiments, the external connector 94 is a non-threaded element such as a snap ring.

By design, the securing or locking connector (external or internal) should not require extraordinary pressure-holding capabilities because the pressures within the various passageways of the lubricator are balanced within the seals 78 located above and below the radial outlet 20. The presence of pressure within the pipe connector 22 does not act to push the pipe connector upward or downward on the vertical flow body 50 as a result of the defined balance. As such, the threaded external connector may be replaced by a keeper ring or snap ring. An internal locking element 96 also may be used in place of or in addition to an external locking or securing connector.

With reference now to FIGS. 8 and 10-12 the outlet pipe connector 22 is secured to the flow body 50 with an internal locking element 96, e.g. in the form of a rod or sleeve, that is positioned in a portion of the pipe connector body 62 and the flow body 50. In the embodiments, illustrated in FIGS. 8 and 10-12 the internal locking element 96 is combined with a catcher 26, however, the internal locking element 96 may be utilized independent of a catcher. Outlet pipe connector 22 comprises a horizontal (radial) pathway 98 (e.g., connector pathway) extending perpendicular to the vertical throughbore 64 and through the body 62 from the outer surface 63 to the vertical throughbore 64. In the illustrated examples, the connector pathway 98 is located 180 degrees from the horizontal passage 66 of the outlet pipe connector 22 and is co-axial with the horizontal passage 66. In the illustrated embodiments the connector locking pathway 98 has a smaller diameter than the horizontal passage 66. A horizontal (radial) pathway 100 (e.g., body pathway) is formed in the flow body 50 perpendicular to lubricator bore 54 and on the same horizontal plane as the outlet 20. In some embodiments the body pathway 100 may be one of the outlet cross-holes 60 of the outlet 20. When the locking element 96 is utilized with the catcher 26 the body pathway 100 extends into the lubricator bore 54. If the locking element 96 is utilized independent of a catcher, the body pathway 100 may or may not fully extend into the lubricator bore 54.

With the outlet pipe connector 22 positioned at the outlet 20 the internal locking element 96 is positioned in the connector pathway 98 and the body pathway 100. The connector pathway 98 may then be sealed for example with an end piece 108 if the locking element is used independent of a catcher. The end piece 108 may be configured for example as a plug to be threadedly connected in the connector pathway.

When the internal locking element 96 is utilized in a catcher 26, the locking element 96 includes central bore 102, see FIG. 11, for disposing the catcher assembly. In the illustrated embodiments, the locking element 96 includes first outer diameter section 104 and a second outer diameter section 106. In the illustrated examples, the first outer diameter section 104 has a larger diameter than the second outer diameter section 106 and the first outer diameter section is located in the connector pathway 98 and the second outer diameter section 106 is disposed in the body pathway 100. With the locking element 96 positioned in the flow body and pipe connector, the catcher assembly can be positioned within the sleeve bore 102 and then the end piece 108 is secured to the outer surface 63 of the pipe connector body 62 securing the locking sleeve 96 in place and thereby securing the outlet pipe connector 22 with the flow body 50. The catcher assembly includes a pin 110 that is urged, for example by spring 112, into the bore 54 of the flow body 50 to capture the plunger. In the illustrated example the end piece 108 is secured to the body 62 by screws 114 eliminating a weld connection. In accordance to some embodiments, the end piece may be connected to the outlet pipe connector body by welding. As follows from the description above, a catcher 26 may be utilized that does not include the internal locking element 96. For example, in FIG. 6 an external locking element 94, such as a threaded ring or snap ring, secures the outlet connector 22 to the flow body and the catcher 26 includes a pin 110 and spring 112 but does not include an internal locking element 96. In accordance to some embodiments an actuator may be connected to the catcher to operate the pin 110.

When the internal locking element 96 is utilized an external connector may or may not be used to secure the outlet connector 22 to the flow body 50. For example, in FIG. 8 only an internal locking element 96 is utilized to secure the outlet pipe connector to the flow body 50. In FIG. 10, both an external locking element 94 and an internal locking element 96 are used to secure the outlet pipe connector 22 to the flow body 50.

The lubricator flow body 50 may be fabricated with one or more horizontally oriented pipe outlets 20. Two or more outlets 20 are utilized to reduce or remove the possibility of the plunger 14 (FIG. 2) 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 2.

Relative to a multiple outlet flow body, a single outlet flow body reduces the cost of manufacturing and the costs in the related surface piping. To remove or reduce the possibility of the traveling plunger blocking the flow path of the up-flowing fluid from within the wellbore, the single outlet 20 vertical flow body 50 may comprise an annular passage 118 that allows the wellbore fluid to bypass the plunger within the lubricator to pass through the outlet 20 into the surface piping as illustrated for example in FIGS. 3, 4 and 8.

FIGS. 3, 4 and 8 each illustrate single horizontal outlet flow bodies 50 with a perforated tubular liner 116 located in the lubricator bore 54 adjacent to the outlet 20. FIG. 10 also illustrates a liner 116 penetrated by the pin 110 of a catcher 26. The tubular liner 116 is positioned in the lubricator bore such that the annular passage 118 is formed between the liner 116 and the interior wall 120 of the flow body 50 defining the lubricator bore 54. With reference also to FIG. 2, when fluid is produced from the production string 12 it passes through the perforations 122 in the liner 116 and through outlet 20 and outlet pipe connector 22 to the surface piping 24.

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 tubular flow body having an internal lubricator bore, a top end, a bottom end, and a radial outlet in communication with lubricator bore; and

a pipe connector circumferentially mounted on the tubular flow body about the radial outlet, the pipe connector comprising a vertical throughbore disposing the flow body, a pipe connector profile, and a horizontal passage extending between the vertical throughbore and the pipe connector profile.

2. The plunger lift lubricator of claim 1, wherein flow body is formed of a single piece of material and the top end comprises a thread profile to connect a spring housing and the bottom end comprises one of a thread or a flange profile.

3. The plunger lift lubricator of claim 1, further comprising a first circumferential seal between the flow body and the pipe connector located above the radial outlet; and

a second and circumferential seal between the flow body and the pipe connector located above the radial outlet.

4. The plunger lift lubricator of claim 1, wherein the pipe connector is secured to the flow body without welding.

5. The plunger lift lubricator of claim 1, wherein the pipe connector is secured to the flow body with welding.

6. The plunger lift lubricator of claim 1, wherein the pipe connector is secured to the flow body with an internal locking element radially disposed in a connector pathway formed in the pipe connector and a body pathway formed in the flow body.

7. The plunger lift lubricator of claim 1, wherein the pipe connector is secured to the flow body by an external element.

8. The plunger lift lubricator of claim 1, wherein the pipe connector comprises a catcher having a pin member to selectively engage a plunger disposed in the lubricator bore.

9. The plunger lift lubricator of claim 1, comprising an external element securing the pipe connector to the flow body; and

the pipe connector comprising a catcher having a pin member to selectively engage a plunger disposed in the lubricator bore.

10. The plunger lift lubricator of claim 1, further comprising an internal locking element disposed in a connector pathway formed in the pipe connector and a body pathway formed in the flow body; and

the pipe connector comprising a catcher having a pin member to selectively engage a plunger disposed in the lubricator bore, wherein the internal locking element disposes the pin member.

11. The plunger lift lubricator of claim 1, further comprising a perforated liner disposed within the lubricator bore adjacent to the radial outlet; and

an annular gap defined between the perforated liner and the flow body.

12. The plunger lift lubricator of claim 11, wherein the pipe connector comprises a catcher having a pin member to selectively engage a plunger disposed in the lubricator bore.

13. The plunger lift lubricator of claim 1, wherein the flow body comprises only one radial outlet, and the plunger lift lubricator further comprises:

a perforated liner disposed within the lubricator bore adjacent to the radial outlet; and

an annular gap defined between the perforated liner and the flow body.

14. The plunger lift lubricator of claim 13, wherein the pipe connector comprises a catcher having a pin member to selectively engage a plunger disposed in the lubricator bore.

15. The plunger lift lubricator of claim 14, wherein the catcher comprises an internal locking element securing the pipe connector to the flow body, the internal locking element comprising a bore disposing the pin member.

16. A method, comprising:

securing a pipe connector to a tubular flow body for use as a plunger lift lubricator, wherein the flow body comprises an internal lubricator bore, a top end, a bottom end, and a radial outlet in communication with lubricator bore, and the pipe connector comprising a vertical throughbore, a pipe connector profile and a horizontal passage extending between the vertical throughbore and the pipe connector profile, wherein the securing comprises:

positioning the flow body in the vertical throughbore with the radial outlet and horizontal passage located on the same horizontal plane; and

attaching the pipe connector to the flow body.

17. The method of claim 16, wherein flow body is formed of a single piece of material and the top end comprises a thread profile to connect a spring housing and the bottom end comprises one of a thread or a flange profile.

18. The method of claim 16, further comprising providing a first circumferential seal between the flow body and the pipe connector located above the radial outlet; and

providing a second and circumferential seal between the flow body and the pipe connector located above the radial outlet.

19. The method of claim 18, wherein the attaching comprises positioning an internal locking element in a connector pathway formed in the pipe connector and a body pathway formed in the flow body.

20. The method of claim 19, further comprising connecting a catcher with the pipe connector having a pin member to selectively engage a plunger disposed in the lubricator bore, wherein the connecting comprises disposing the pin member in an internal bore of the internal locking member.