CN107849905B

CN107849905B - Pipe connector

Info

Publication number: CN107849905B
Application number: CN201680033627.4A
Authority: CN
Inventors: 克林特·罗格·萨巴捷
Original assignee: 925599 Alberta Ltd
Current assignee: 925599; 925599 Alberta Ltd
Priority date: 2015-04-10
Filing date: 2016-04-11
Publication date: 2020-08-28
Anticipated expiration: 2036-04-11
Also published as: WO2016161526A1; HK1250764A1; CA2982000C; AU2016244745A1; AU2021202556A1; CO2017011479A2; MX2017012976A; CN107849905A; CA2982000A1; MX2022016242A; SA517390136B1; AU2021202556B2

Abstract

A pipe connector. The connector includes a body having opposing connection portions for connecting two tubes. The protective portion extends along at least a portion of the inner surface intermediate the connecting portions. The protective portion comprises a protective material that wears less than the stem as compared to the body. The connector has an inner diameter along at least a portion of the protective portion that is equal to or narrower than an inner diameter of other portions of the connector so that the post preferentially contacts the protective material rather than other portions of the body. The connector may include an extended gripping portion for gripping with power tongs, and may further include a reinforcing portion for enhancing the resistance of the pipe connector to deformation when threadedly connected with a pipe section with the connector.

Description

Pipe connector

Cross Reference to Related Applications

This application claims priority from U.S. provisional patent application No.62/146,073 filed on day 4/10 in 2015 and U.S. conventional patent application No.15/014,941 filed on day 2/3 in 2016, both of which are incorporated herein by reference.

Technical Field

The present disclosure generally relates to the assembly of pipe segments for producing fluids from a well.

Background

Subterranean reservoirs of fluids (e.g., hydrocarbons, water, etc.) are typically produced by drilling a well into the reservoir and pumping the fluid out of the reservoir through a pipeline. A string used to produce fluids from a reservoir may be assembled from individual pipe sections. The sections are typically threaded with male threaded ends at both ends and are connected at both ends by connectors with female threaded ends. The produced fluid may be conveyed uphole through the tubing string using manual lifting methods including the use of a rod string, such as a progressive cavity pump. In some cases, the string wears more severely at the connections between the sections of the production tubing than elsewhere in the production string. Rod wear can lead to rod string breakage. To continue production after the string breaks, the uphole portion of the string must be pulled up and the downhole portion of the string must be retrieved from the production string. Pulling up the production string and fishing up the broken rod results in lost time and additional costs.

Disclosure of Invention

Disclosed herein is a pipe connector for a production string, the production string comprising a stem string for artificial lift; methods of using and making the tube connector are also disclosed. When using a rotary rod production method, such as a progressive cavity pump, the rod string may be forced against the inner surface of the production string, for example in a deviated portion of the well. Rotation of the stem against the connector can cause rod wear as the stem is forced against the female connector at the junction of the male threaded end (typically on a production tubing section) and the female threaded end (typically on the connector). Rod wear can result in the rod string breaking. To continue production after the string breaks, the uphole portion of the string may be pulled up and the downhole portion of the string fished out of the production string. These and other corrective measures complicate and increase the production costs of the well. Thus, reducing rod wear at the connector is mitigated.

The tube connectors disclosed herein include a protective portion on the inner surface of the tube connector between the internally threaded ends or other connection portions of the tube connector. The protective portion includes a protective material that is softer and has a low coefficient of friction with the stem relative to the grade of steel or other material typically used to manufacture production tubing connectors. As a result, the protective portion wears less against the post than would be the case with steel surfaces found on other portions of the connector. The connector has an inner diameter along the protective portion that is equal to or narrower than elsewhere between the internally threaded ends. As a result, the post will contact the protective portion in preference to other portions of the connector. The pipe connector disclosed herein may reduce rod wear compared to previous pipe connectors because the stem preferentially contacts the protective portion and the protective portion wears less than the steel body of the previous pipe connector.

The pipe connectors disclosed herein may include a gripping portion to facilitate use of the connector with power tongs. The clamping portion may extend between the connection portions of the connectors. The gripping portion facilitates gripping of the tube connector with a powered jaw to establish or break a connection between the tubes. The gripping surface extends along an outer surface of the gripping portion along a portion of the tubing connector that is unthreaded on an inner diameter of the tubing connector. The gripping surface on the outer surface may be coextensive with the protective portion on the inner surface. The gripping portion is at least as long as a jaw that may be used on a power tong when making or breaking a connection between the connector and a pipe section. The power tong grips a gripping surface on the pipe connector and the gripping force on the pipe connector required to apply a make-up torque is concentrated in the gripping portion, thereby avoiding direct application of force to the portion of the body having the thread on the inner surface and reducing the likelihood of thread damage at a given torque value compared to gripping the outer surface of an internally threaded end connection.

The pipe connector disclosed herein may include the gripping portion having a wall thickness along at least a portion of a length of the gripping portion sufficient to provide a reinforced portion of the pipe connector. The reinforcement portion may provide deformation resistance of the pipe connector. In an example application of the pipe connector comprising the protective portion, the gripping surface and the reinforcement portion, an increase in the torque required to twist the connector is observed, so that the connection is established at a greater torque value at the same number of revolutions. This increase in the torque-to-torque ratio may be due to the resistance to deformation provided by the reinforcing portion. The reinforcement portion may include a torque stop to facilitate torquing the connection to full establishment. The reinforcement portion facilitates establishing a connection between pipe sections or other pipe segments at greater torque values without requiring the connection portion to have any particular thread configuration. The connection portion may include interference fit threads that match commonly used american petroleum institute ("API") standard interference fit threads (e.g., 8-start threads used on production tubing, etc.) to allow a connection between pipe segments having a threaded configuration to be established with a greater torque value using the pipe connector than was the case with previous API pipe connectors. Using a pipe connector that includes the protective portion, the gripping surface, the reinforcing portion, and API interference fit threads can facilitate establishing a connection at torque values above an optimal API specification value, and in some examples, at or above an API maximum specification torque value for a used pipe outside diameter and steel grade, and reduce the likelihood of thread damage. The effective position of the clamping surface is used for clamping by the power tongs. The length of the gripping surface also facilitates the inclusion of the reinforcement portion between the connection portions by distributing additional mass along the length, thereby providing the reinforcement portion with reduced protrusion of the connector body wall into the flow path through the connector body. The length of the gripping surface increases the contribution to increasing the mass of the body along a given wall thickness of the stiffened portion. The length of the gripping surface also provides additional inner surface length for the protective portion, which can help mitigate bar wear damage.

In a first aspect, the present disclosure provides a pipe connector. The connector includes a body having opposing connection portions for connecting two tubes. The protective portion extends along at least a portion of the inner surface intermediate the connecting portions. The protective portion includes a protective material that wears less from the post than the body. The connector has an inner diameter along at least a portion of the protective portion that is equal to or narrower than the inner diameter of other portions of the connector so that the post preferentially contacts the protective material rather than other portions of the body. The connector may include an extended gripping portion for gripping by a power tong and may further include a reinforcing portion for increasing the resistance of the pipe connector to deformation when a pipe section is threaded with the connector.

In another aspect, the present disclosure provides a connector comprising: a body extending between a first end and a second end; a first connecting portion proximate the first end for connecting a first tube; a second connecting portion for connecting a second pipe adjacent to the second end; and a protective portion extending along at least a portion of an inner surface of the body intermediate the first connection portion and the second connection portion, the protective portion comprising a protective material that is less abrasive to the stem than the body. The body and the protective material have a protective portion inner diameter along at least a portion of the protective portion that is equal to or narrower than an inner diameter of other portions of the body.

In some embodiments, the protective portion comprises a sleeve formed of the protective material secured within the body. In some embodiments, the connector includes a groove defined in the inner surface along the protective portion, and wherein the sleeve is secured within the body by seating within the groove; in some embodiments, the sleeve comprises a split sleeve. In some embodiments, the sleeve is secured against a stop intermediate the protective portion and the first connection portion; in some embodiments, the sleeve is secured against the stop by a compression ring intermediate the protective portion and the second connecting portion. In some embodiments, the protective material comprises polyethylene having a shore D hardness of about 65 and a dynamic coefficient of friction of about 0.10. In some embodiments, the protective material comprises nylon having a shore D hardness between about 75 and about 85 and a dynamic coefficient of friction of about 0.20.

In some embodiments, the protective portion comprises a layer of protective material bonded to the inner surface. In some embodiments, the protective material comprises a thermosetting resin; in some embodiments, the thermosetting resin comprises a zirconium frit epoxy powder coating having a pencil hardness (H scale) rating of 6H. In some embodiments, the protective material comprises an extrusion cured coating. In some embodiments, the protective material comprises a metal alloy coating; in some embodiments, the metallic alloy coating comprises a coating having a rockwell C hardness between about 45 and about 55, a wear resistance between about 12 and about 16 taber wear index, and a dynamic coefficient of friction of about 0.15.

In some embodiments, the first connection portion includes a first internally threaded end having threads on the inner surface for connection with the first pipe and the second connection portion includes a second internally threaded end having threads on the inner surface for connection with a second pipe. In some embodiments, the connector includes a gripping surface extending along an outer surface of the body intermediate the first and second connection portions for a gripping length at least as long as a jaw length of a pair of power tongs used to connect the connector with a production tubular.

In some embodiments, the clamping surface comprises a concave clamping surface; the body having a first outer diameter along the first and second connection portions and a second outer diameter along the recessed gripping surface; and the first outer diameter is greater than the second outer diameter. In some embodiments, a first outer diameter transition point between the first outer diameter and the second outer diameter is located intermediate the first end and the recessed gripping surface; and a second outer diameter transition point between the first outer diameter and the second outer diameter is located intermediate the second end and the recessed gripping surface. In some embodiments, the first outer diameter transition point is located on a portion of the outer surface that is coextensive with the first connection portion on the inner surface; said second outer diameter transition point is located on a portion of said outer surface coextensive with said second connection portion on said inner surface; and a portion of the body having the second outer diameter extends axially outwardly from the jaw gripping portion into each of the first and second connection portions; in some embodiments, the first outer diameter transition point is located on a portion of the outer surface axially inward along the body from the first connection portion; the second outer diameter transition point is located on a portion of the outer surface axially inward along the body from the second connection portion; and a portion of the body having the first outer diameter extends axially inwardly along the body from each of the first and second connection portions.

In some embodiments, the threads comprise interference fit threads, and the connector further comprises a reinforcing portion of the body intermediate the first and second connection portions for resisting deformation of the body when a connection is established with the connector. In some embodiments, the reinforcing portion comprises: a first torque stop defined on the inner surface adjacent the first connection portion for abutting the first pipe when the first pipe is connected with the first connection portion; and a second torque stop defined on the inner surface proximate the second connection portion for abutting the second tube when the second tube is connected with the second connection portion.

In some embodiments, the reinforcement portion further includes a reinforcement member extending between the first torque stop and the second torque stop. In some embodiments, the protective portion extends along the inner surface substantially and along substantially the entire length of the stiffening member; in some embodiments, the inner diameter of the body is substantially constant along the reinforcement member between the first torque stop and the second torque stop; in some embodiments, the stiffening member extends along the body and substantially along the entire length of the clamping portion. In some embodiments, the stiffening member extends along the body and substantially along the entire length of the clamping portion.

In some embodiments, the first connection portion includes a first internally threaded end having threads on the inner surface for connection with the first pipe and the second connection portion includes a second internally threaded end having threads on the inner surface for connection with a second pipe. In some embodiments, the connector includes a gripping surface extending along an outer surface of the body intermediate the first and second connection portions for a gripping length at least as long as a jaw length of a pair of power tongs used to connect the connector with a production tubular. In some embodiments, the gripping length is about 3.5 inches and the connector has an outer diameter of 4.5 inches along the first and second connection portions; in some embodiments, the gripping length is about two inches longer than the jaw length; the gripping length is about twice as long as the jaw length.

In some embodiments, the first connection portion includes a first internally threaded end having threads on the inner surface for connection with the first pipe and the second connection portion includes a second internally threaded end having threads on the inner surface for connection with a second pipe. In some embodiments, the connector includes a gripping surface extending along an outer surface of the body intermediate the first and second connection portions for a gripping length at least as long as a jaw length of a pair of power tongs used to connect the connector with a production tubular. In some embodiments, the gripping length is about 3.25 inches; the connector has an outer diameter of about 4.5 inches along the first and second connection portions; and the first and second pipes each comprise an API interference fit threaded production pipe section of 3.5 inch od. In some embodiments, the body is made of J-55 grade steel. In some embodiments, the reinforced portion comprises a portion of the body having a wall thickness of about 0.625 inches. In some embodiments, the protective portion inner diameter is at least 0.025 inches narrower than the inner diameter of the other portion of the body. In some embodiments, the protective portion inner diameter is about 2.5 inches; in some embodiments, the protective portion extends along the inner surface for a length of about 2.0 inches.

In some embodiments, the first pipe and the second pipe each comprise a production tubing section.

In some embodiments, the first tube and the second tube each have an outer diameter of 3.5 inches.

In some embodiments, the tube has an outer diameter of 2.375, 2.875, 3.5, 4.5, 5.5, or 7.0 inches.

In some embodiments, the protective portion inner diameter is equal to or narrower than the inner diameter of the production tubing for which the connector is designed.

In some embodiments, the protective portion inner diameter is substantially equal to an inner diameter of a production tubing for which the connector is used.

In another aspect, the present disclosure provides a method of manufacturing a connector, comprising: providing a connector comprising a body having an inner surface portion intermediate opposing connection portions; and securing a protective material to the inner surface portion to provide a protective portion along at least a portion of the inner surface portion. The protective material is less abrasive to the pole than the body. The body and the protective material have a protective portion inner diameter along at least a portion of the protective portion that is equal to or narrower than an inner diameter of other portions of the body.

In some embodiments, securing the protective material to the inner surface portion includes applying a protective coating to the inner surface portion.

In some embodiments, securing the protective material to the inner surface portion includes securing the sleeve within a groove defined in the inner surface portion.

In some embodiments, securing the protective material to the inner surface portion includes securing the sleeve against a stop.

In some embodiments, the protective portion inner diameter is equal to or narrower than the inner diameter of the production tubing for which the connector is used.

In another aspect, the present disclosure provides a connector for connecting a first pipe with a second pipe using a power tong having a tong length, the connector comprising: a body extending between a first end and a second end; a first connection portion proximate the first end and including threads on an inner surface of the connector for connecting a first pipe; a second connection portion proximate the second end and including threads on the inner surface for connecting to a second pipe; a protective portion extending along at least a portion of the inner surface intermediate the first connection portion and the second connection portion, the protective portion comprising a protective material that is less abrasive to the stem than the body; and a gripping surface extending along an outer surface of the body intermediate the first and second connection portions, the gripping surface extending along the outer surface for a gripping length at least as long as the jaw length. The body and the protective material have a protective portion inner diameter along at least a portion of the protective portion that is equal to or narrower than an inner diameter of other portions of the connector.

In some embodiments, the clamping surface comprises a concave clamping surface; the body having a first outer diameter along the first and second connection portions and a second outer diameter along the recessed gripping surface; and the first outer diameter is greater than the second outer diameter.

In some embodiments, the connector includes a reinforcing portion of the body intermediate the first and second connection portions for resisting deformation of the body when connection is established with the connector. In some embodiments, the reinforcing portion comprises: a first torque stop defined on the inner surface adjacent the first connection portion for abutting the first pipe when the first pipe is connected with the first connection portion; and a second torque stop defined on the inner surface proximate the second connection portion for abutting the second tube when the second tube is connected with the second connection portion.

In some embodiments, the connector includes a reinforcing portion of the body intermediate the first and second connection portions for resisting deformation of the body when connection is established with the connector. In some embodiments, the gripping length is about 3.25 inches; the connector has an outer diameter of about 4.5 inches along the first and second connection portions; and the first and second pipes each comprise an API interference fit threaded production pipe section of 3.5 inch od. In some embodiments, the body is made of J-55 grade steel. In some embodiments, the reinforced portion comprises a portion of the body having a wall thickness of about 0.625 inches. In some embodiments, the inner diameter of the body and the protective material is about 0.025 inches narrower than the inner diameter of the rest of the body. In some embodiments, the protective portion extends along the inner surface for a length of about 2.0 inches.

In some embodiments, the first and second pipes comprise production tubing and the API interference fit threads comprise 8-o-ring threads.

In some embodiments, the first and second pipes comprise production tubing and the API interference fit threads comprise 10-stab threads.

In another aspect, the present disclosure provides a method of connecting a first pipe and a second pipe, comprising: a connector is provided. The connector includes: a protective portion extending along at least a portion of an inner surface of a body of the connector intermediate a pair of interference fit threaded connection portions, the protective portion comprising a protective material that is less abrasive to a post than the body; a clamping surface on an outer surface of the body and intermediate the pair of connection portions; and a reinforcing portion of the main body, intermediate the pair of connecting portions, for resisting deformation of the connector when connection is established with the connector. The body and the protective material have a protective portion inner diameter along at least a portion of the protective portion that is equal to or narrower than an inner diameter of other portions of the connector. The method further comprises: clamping the clamping surface and the first pipe with a powered jaw; rotating the connector relative to the first pipe with the power tong to connect the connector to the first pipe at a torque value; gripping the gripping surface and gripping the second pipe with the power tong; and rotating the second pipe relative to the connector with the power tong to connect the connector to the second pipe at the torque value.

In some embodiments, the connector further comprises a pair of torque stops proximate the connecting portion, each torque stop for abutting a nose of a tube threaded into the connecting portion proximate the torque stop. In some embodiments, abutting the nose indicates that the torque value has been reached.

In some embodiments, the connection portion is threaded with API interference fit threads. In some embodiments, the torque value exceeds the API optimum value for a connector for a pipe having an outer diameter equal to the reference outer diameter value for the first and second pipes, at the same grade of steel. In some embodiments, for a connector for a pipe having an outer diameter equal to the reference outer diameter value, the torque value exceeds the API maximum value at the same grade of steel.

In some embodiments, the connection portion is threaded with API interference fit threads. In some embodiments, the gripping length is about 3.25 inches; the connector has an outer diameter of about 4.5 inches along the first and second connection portions; and the first and second pipes each comprise an API interference fit threaded production pipe section of 3.5 inch od. In some embodiments, the body is made of J-55 grade steel. In some embodiments, the reinforced portion comprises a portion of the body having a wall thickness of about 0.625 inches. In some embodiments, the torque value exceeds an API maximum value for a connector for a pipe having an outer diameter equal to the reference outer diameter value. In some embodiments, the torque value is at least 3000 foot pounds. In some embodiments, the torque value is about 3600 foot pounds. In some embodiments, the protective portion inner diameter is at least 0.025 inches narrower than the inner diameter of the other portion of the body.

In some embodiments, the protective portion comprises a sleeve formed of the protective material secured within the body.

In some embodiments, the protective portion comprises a sleeve formed of a protective material secured within the body. In some embodiments, the connector includes a groove defined in the inner surface along the protective portion, wherein the sleeve is secured within the body by seating within the groove; in some embodiments, the sleeve comprises a split sleeve. In some embodiments, the sleeve is secured against a stop intermediate the protective portion and the first connection portion; in some embodiments, the sleeve is secured against the stop by a compression ring intermediate the protective portion and the second connecting portion. In some embodiments, the protective material comprises polyethylene having a shore D hardness of about 65 and a dynamic coefficient of friction of about 0.10. In some embodiments, the protective material comprises nylon having a shore D hardness between about 75 and about 85 and a dynamic coefficient of friction of about 0.20.

Other aspects and features of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.

Drawings

Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying figures in which features sharing a reference numeral having a common last two digits of the reference numeral correspond to similar features in multiple figures (e.g.,

bodies

12, 112, 212, 312, 412, 512, 612, 712, 812, 912, 1012, 1112, 1212, etc.).

FIG. 1 is a cross-sectional view of a production string having sections of production tubing joined with a previous connector;

FIG. 2 is a cross-sectional view of a connector as described herein;

FIG. 3 is a cross-sectional view of a production string having sections of production tubing joined by the connector of FIG. 2;

FIG. 4 is a cross-sectional view of a production string having sections of production tubing joined by a connector having a protective coating;

FIG. 5 is a cross-sectional view of a production string having production tubing sections connected with a connector having a protective sleeve;

FIG. 6 is a cross-sectional view of a production string having production tubing sections joined with a connector having a protective sleeve secured with a ring;

FIG. 7 is a cross-sectional detail view of a stop defined in the body of the connector of FIG. 6;

FIG. 8 is a cross-sectional view of a coupling having gripping surfaces that is coupled to a pipe section using a pair of power tongs;

FIG. 9 is a cross-sectional view of a production string having sections of production tubing joined by a connector having a gripping surface and a protective coating;

FIG. 10 is a cross-sectional view of a production string having production tubing sections connected with a connector having a gripping surface and a protective sleeve;

FIG. 11 is a cross-sectional view of a production string having production tubing sections connected with a connector having a gripping surface and a protective sleeve secured with a ring;

FIG. 12 is a cross-sectional view of a production string having production tubing sections joined with a connector having a recessed gripping surface and a protective sleeve secured with a ring;

FIG. 13 is a cross-sectional view of a connector having a gripping surface and a reinforcing portion;

FIG. 14 is a cross-sectional view of the coupling of FIG. 13 connected to a pipe section and being torqued above an API optimum with a power tong;

fig. 15 is a cross-sectional view of a connector having a recessed gripping surface, a reinforcing portion and a protective sleeve secured with a ring;

FIG. 16 is a cross-sectional view of the coupling of FIG. 15 connected to a pipe section and being torqued above an API optimum with a power tong;

FIG. 17 is a cross-sectional view of a production string and a string positioned within the production string, the production string including production tubing sections connected with the connector of FIG. 15;

FIG. 18 is a cross-sectional view of a connector having a concave gripping surface and a reinforcing portion;

FIG. 19 is a cross-sectional view of a connector having a concave gripping surface and a reinforcing portion;

FIG. 20 is a graph of applied torque as a function of number of revolutions for a prior connector applying different values of torque and a connector having a reinforcement portion as described herein;

FIG. 21 is a graph of applied torque as a function of number of revolutions for a pipe connector as described herein having a reinforced portion clamped at a clamping surface and applied different values of torque;

FIG. 22 is a graph of applied torque as a function of number of revolutions for a pipe connector as described herein having a reinforcement portion that is clamped at the internally threaded end and applied with different values of torque; and

figure 23 is a graph of torque applied versus number of revolutions for a standard API collar clamped and applied with different values of torque.

Detailed Description

In general, the present disclosure provides a connector, such as a pipe connector, for connecting pipe segments, such as sections of production pipe. The connector disclosed herein includes a protective portion extending between two threaded connection portions along a portion of an inner surface of the connector. The protective portion comprises a protective material that wears less for the rotating stem that is forced against the protective portion than if the stem were forced against various grades of steel or other materials that are typically used to make the connector. The connector has an inner diameter along the protective portion selected to contact the string in preference to other portions of the connector when the string is forced against the production string. As a result, the connector disclosed herein may reduce rod wear in a production string relative to a production string assembled using a previous unprotected portion connector.

In addition to the protective portion, the connector may include a clip holding portion extending on an outer surface of the connector in the middle of the connecting portions at both ends of the body. The body provides a jaw gripping surface along an outer surface of the jaw gripping portion to facilitate gripping of the connector with the power jaw. The protective portion extends along an inner surface of the body and the clamping portion extends along an outer surface of the body. The protective portion and the gripping portion may be at least partially coextensive along the length of the body. For a given connector, the length of the jaw gripping portion may be selected with reference to the outside diameter of the pipe for which the given connector is to be used and the length of the power tong teeth to be used on the power tong that grips the connector. The length of the jaw gripping portion may be at least as long as the desired jaw length. The expected jaw length may be the maximum jaw length of a power tong used by the connector and a pipe having an outer diameter for which the well pipe connector is designed.

In addition to the protective portion, the connector may include an extended jaw gripping portion and a reinforcing portion of the body, both intermediate the two threaded connection portions. The protective portion extends along an inner surface of the body, the clamping portion extends along an outer surface of the body, and the reinforcing portion is defined by a wall thickness and a length of the body. A combination of two or more of the protective portion, the clamping portion, and the reinforcing portion may be at least partially coextensive along a length of the body. The reinforcing portion, which may include a torque stop or another radial extension into a flow passage defined within the connector, increases the strength and resistance to deformation of the body proximate and in some examples at the threaded connection. The torque required to screw the externally threaded end into one of the two threaded connection parts per revolution is increased relative to previous connectors having the same threads. The increase in torque per revolution compared to previous connectors facilitates the connection of pipes having commonly used thread configurations with greater torque. The length of the jaw gripping portion facilitates providing the stiffening portion without increasing the wall thickness of the connector body to the point where the flow passage lacks sufficient cross-sectional area for a selected fluid flow rate. The protective portion and the reinforcing portion may be sized such that the flow path along the protective portion is equal to or narrower than other portions of the connector or a tube to be connected with the connector without unduly restricting fluid flow through the connector. The reinforcing portion may include a torque stop to facilitate torquing the connection to full establishment. When the connection is fully made, a discernible torque increase occurs without further rotation, thereby mitigating inadvertent or over-tightening of the connector beyond full make-up.

Previous connector

FIG. 1 shows a cross-section of a production string 60, the production string 60 including a first tubing section 40 and a second tubing section 42 connected using a previous tubing section connector P01. A string 62 is included in the production string 60 to provide manual lift for producing fluids through the production string 60. The stem 62 includes a damaged portion 64 where rod wear (sometimes referred to as "scuffing") has compromised the stem 62. The damaged portion 64 corresponds to the location of the connector P01 where rod wear is more likely to occur than in the production tubing itself, at the location of the connector P01. In some cases, the stem 62 will break at the damaged portion 64. After the string 62 is broken, the uphole portion of the string 62 may be pulled from the production string 60 and the downhole portion of the string 62 may be fished out of the production string. Pulling the uphole portion of broken string 62 out and fishing out the downhole portion of broken string 62 are both time consuming and expensive. The space P02 between the first externally threaded end 44 of the first conduit section 40 and the second externally threaded end 46 of the second conduit section may be susceptible to the accumulation of particles and other debris between the connector P01 and the post 62. Rod wear may particularly result in damage to the rod string 62 at the space P02. While the stem 62 is shown with a damaged portion 64 resulting from rubbing, other types of stem wear may be caused in a rotating stem, and other types of stem wear may be caused in a reciprocating stem.

Protective connector

Fig. 2 shows a cross-section of the connector 10. The connector 10 has a body 12 extending between a first end 14 and a second end 16. The inner surface 18 of the body 12 includes threads extending from the first end 14 along the first connection portion 15 of the body 12 and threads extending from the second end 16 along the second connection portion 17 of the body 12. The thread may be any suitable thread, such as an interference fit thread. The threads may be American Petroleum institute ("API") standard interference fit threads compatible with commonly used production pipe sections and other tubulars. The outer surface 21 of the body 12 defines an internally threaded end along each of the first and

second connection portions

15, 17 of the body 12. The body 12 includes a protective portion 70 extending along at least a portion of the inner surface 18 between the first connection portion 15 and the second connection portion 17. The protective portion 70 includes a protective material 72 secured with the inner surface 18. The guard portion 70 defines a guard portion inner diameter 71 of the connector 10. The guard portion inner diameter 71 comprises an inner diameter of the body 12 that is further narrowed due to the thickness of the guard material 72.

FIG. 3 shows a cross-section of the connector 10 connected to a first tubing section 40 and a second tubing section 42 in a production string 60. The first connection portion 15 is connected to a first pipe connection portion 45 of the first pipe section 40 immediately adjacent the first externally threaded end 44 of the first pipe section 40. The first connection portion 15 has a sufficient axial depth to connect with the first pipe connection portion 45. The second connection portion 17 is connected to a second pipe connection portion 47 of the second pipe section 42 proximate to the second externally threaded end 46 of the second pipe section 42. The second connection portion 15 has a sufficient axial depth to be connected with the second pipe connection portion 47.

The protective material 72 is softer than the various grades of steel or other materials typically used to make production tubing connectors. The protective material 72 is also softer than the grades of steel or other materials typically used to make the sections, connectors, continuous rods, or other components of the pole 62. As shown in the examples of the protective material 72 provided below, the protective material 72 may be selected to be sufficiently soft such that rotation or translation of the stem 62 against the protective material 72 is less damaging to the stem 62 than rotation or translation of the stem 62 when forced against the body 12. The protective material 72 may also be selected to be sufficiently wear resistant to extend the life of the connector 10 and the reduction in rod wear provided by the connector 10. The protective material 72 may also be selected to have a low coefficient of friction with the stem 62 relative to various grades of steel or other materials typically used to manufacture production tubing connectors. The low coefficient of friction is selected to allow the stem 62 to rotate relatively freely when forced against the protective material 72. As a result, the protective material 72 is less abrasive or otherwise damaged to the stem 62 when the stem 62 is forced against the protective material 72 than various grades of steel or other materials typically used to make production tubing connectors.

Body 12 and protective material 72 may be equal to or narrower than the inner diameter of body 12 elsewhere between connecting

portions

15, 17 or at different portions of body 12 along protective portion inner diameter 71 of protective portion 70. The protective portion inner diameter 71 may be equal to the production tubing inner diameter 41 of the production tubing sections 40, 42 (as shown in FIG. 3). The guard portion inner diameter 71 may be equal to or narrower than the production tubing inner diameter 41, examples of connectors having narrower inner diameters at the guard portion being shown in fig. 6, 7. Since the guard portion inner diameter 71 is equal to or narrower than elsewhere along the inner surface between the

connection portions

15, 17, when the stem string 62 is forced against the production string 60, the stem string 62 may contact the connector 10 at the guard portion 70 in preference to contacting the connector 10 at other features of the connector 10.

Where the

pipe sections

40, 42 include an externally upset ("EUE") connection, the production pipe inner diameter 41 may be larger proximate the externally threaded ends 44, 46 of the

pipe sections

40, 42. In the figures provided herein, the pipe sections are shown schematically as having a constant inner diameter for simplicity. However, in the case of the EUE conduit section, the narrower protection portion inner diameter 71 as compared to the inner diameters of the

conduit sections

40, 42 along the first and second

conduit connecting portions

45, 47 is also narrower than the inner diameters of the

conduit sections

40, 42 outside the EUE portion because the EUE conduit section will have a larger inner diameter outside the first and second

conduit connecting portions

45, 47.

In the event that the protective section inner diameter 71 is equal to or less than the inner diameter elsewhere in the production string 60, the stem string 62 preferentially contacts the protective section 70, or the protective section 70 and other portions of the connector 10, as the stem string 62 is forced against the production string 60. The protective material 72 is less abrasive than the steel body or bodies 12 of previous pipe connectors. As a result, the connector 10 can reduce rod wear as compared to previous pipe connectors.

The guard portion 70 differs from the other portions of the inner surface 18 in that: its hardness, coefficient of friction with the stem 62, or other features that mitigate fretting of the stem 62 when rotated with the stem 62 forced against the protective portion 70, a particular example being that a given connector may be provided by selecting an appropriate protective material 72. The guard portion 70 also differs from the other portions of the inner surface 18 in that: the body 12 and the protective material 72 have a protective portion inner diameter 71 along the protective portion 70 that is equal to or narrower than the inner diameter of the body 12 at other locations in the connector 10. The protective portion 70 may include any suitable protective material 72 and may be prepared and secured to the body 12 by any suitable method.

FIG. 4 shows the connector 110 connected to

production tubing sections

140, 142 in a production string 160. The protective portion 170 includes a protective coating 173 of protective material 172 on the body 112. The protective coating 173 is permanently secured to the body 112 by chemical bonding. Any suitable protective material 172 may be used for the protective coating 173, such as a thermosetting resin, an extrusion cured coating, a metal alloy coating, or other coating. An example of a thermosetting resin is the zaro 100 coating supplied by zaerocor Tubulars, which is a zirconium fusion bonded epoxy powder coating having a pencil hardness (H scale) rating of 6H and a low coefficient of friction.

The extrusion cured coating may include a phenolic based coating, a nylon based coating, or a novolac based coating, which may be applied as a powder or a liquid to form a coating;or modified examples of these coatings. These coatings are described inwww.nov.comSold on-line as "Tube-Kote Production coatings" including TK-2 liquid phenol, TK-7 liquid modified phenol, TK-15 powder modified novolac, TK-69 liquid epoxy modified phenol, TK-70 powder epoxy, TK-70XT powder epoxy, TK-99 powder nylon, TK-216 powder epoxy, TK-236 powder epoxy novolac, TK-505 powder epoxy, TK-800 powder modified epoxy, TK-805 powder phenolic novolac, or TK-900 powder modified novolac.

The metallic alloy coating may include a MAC-100 corrosion resistant coating having sliding wear capability inwww.pcscanada.caSold on-line, having a hardness of 49 rockwell C, a wear resistance with a taber abrasion index of 12-16, and a dynamic coefficient of friction of about 0.15, a tensile strength of 800MPa and an elastic modulus of 170 GPa.

FIG. 5 shows connector 210 connected to

production tubing sections

240, 242 in a production string 260. The guard portion 270 includes a sleeve 274, the sleeve 274 being secured within the slot 219 defined in the body 212. The sleeve 274 may include a split 275 to facilitate securing the sleeve 274 within the groove 219. Any suitable protective material 272 may be used for the sleeve 274, such as high density polyethylene, ultra high molecular weight polyethylene, or nylon. The sleeve 274 may be made of ultra high molecular weight polyethylene having a shore D hardness of about 65 and a dynamic coefficient of friction of about 0.10. The sleeve 274 may be made of nylon having a hardness between about 75 shore D and 85 shore D and a dynamic coefficient of friction of about 0.20. The protective portion inner diameter 271 of the sleeve 274 is approximately equal to the inner diameter of the

production tubing sections

240, 242 along the

tubing connection portions

245, 247 to provide preferential contact between the sleeve 274 and the stem passing through the connector 210.

Fig. 6 and 7 show connector 310 connected to

production tubing sections

340, 342 in a production tubing string 360. The sleeve 376 may be secured within the body 312 against the stop 311. Sleeve 376 may be secured between stop 311 and compression ring 378. The compression ring 378 may be secured against the sleeve 376 with the outer surface 379 of the compression ring 378 flush with the stop 313 as shown to provide a flush surface for the externally threaded end 344 in the connecting portion 317. The sleeve 376 may be made of a protective material 372 similar to the protective material 272 used in the sleeve 274. The protective section inner diameter 371 of the sleeve 376 is narrower than the inner diameter of the

production tubing sections

340, 342 along the

tubing connection sections

345, 347 to provide preferential contact between the sleeve 376 and the stem passing through the connector 310.

For example, connector 310 may be designed for a 3.5"API EUE production pipe having a weight of 9.30 lbs/ft, an inner diameter of 2.992" along

pipe connection portions

345 and 347, and a through diameter of 2.867 ". A connector 310 designed for such tubing may have a protective portion inner diameter 371 of the sleeve 376 of a value of 2.967", which would provide a 0.025" reduction in the protective portion inner diameter 371 of the sleeve 376 relative to the tubing inner diameter 341 while remaining 0.100 "higher than the gauge of the

production tubing section

340, 342.

Extended protective connector

FIG. 8 shows the connector 410 connected to

production tubing sections

440, 442 in a production tubing string 460. Connector 410 includes a jaw gripping portion 420. Connector 410 and second production tubing section 442 are being gripped by power tong 450. The jaw gripping portion 420 extends along the outer surface of the body 412 and is not coextensive with either of the

connection portions

415, 415 on the inner surface 418.

A jaw gripping surface 426 is defined on an outer surface 421 of the body 412 along the jaw gripping portion 420. The jaw gripping portion 420 may be gripped by the power tong 450 with less loss to the connector 410 than if either of the

connection portions

415, 417 were gripped, particularly if the gripped threaded

connection portions

415, 417 were connected to a threaded pipe connection portion of a pipe section (such as the first pipe connection portion 445 of the first pipe section 440 or the second pipe connection portion 447 of the second pipe section 442).

A first clamp transition point 428 separates the clamp gripping portion 420 from the first connection portion 415. A second clamp transition point 429 separates the clamp gripping portion 420 from the second connection portion 417. The

clamp transition points

428, 429 each define the boundaries of the clamp gripping portion 420. In connector 410, jaw clamping portion 420 is adjacent to

connection portions

415, 417, and clamp

transition points

428, 429 each define a boundary between jaw clamping surface 420 and one of the two

clamp transition points

428, 429.

The

clamp transition points

428, 429 are characteristic of the inner surface 418 in that there are no threads on the inner surface 418 within the confines of the clamp gripping portion 420 defined by the

clamp transition points

428, 429. The

grip transition points

428, 429 are also features of the outer surface 421 in that the jaw gripping surface 426 is defined along the outer surface 421 within the confines of the jaw gripping portion 420 defined by the

grip transition points

428, 429.

A pair of power tongs 450, shown in fig. 8, is being used to connect the first pipe section 440 with the second pipe section 442 using the connector 410. The power tong 450 includes a main tong 452 and a back-up tong 454. The active tong 452 includes active tong teeth 456 for contacting a pipe or connector to be gripped and rotated. The back clamp 454 includes back clamp teeth 458 for contacting a pipe or connector that is held stationary relative to the pipe or connector being rotated by the active clamp 452. The first pipe connection portion 445 of the first pipe section 440 engages the first connection portion 415, the first connection portion 415 being on the abrasive side of the connector 410 relative to the power tong 450. The second pipe connection portion 447 of the second pipe section 442 engages a second connection portion 417, the second connection portion 417 being on the site side of the connector 410 when connected with the power tong 450.

Where a power tong 450 is used to make or break a connection between the connector 410 and the second pipe section 442, a driving tong 452 grips the second pipe section 442 and a back-up tong 454 grips the gripping portion 420 of the connector 410 (as shown in figure 8). Back-up clamp 454 holds connector 410 stationary relative to second pipe section 442 to make or break a connection between connector 410 and second pipe section 442 while active clamp 452 is used to rotate second pipe section 442 relative to connector 410.

Where the power tong 450 is used to make or break a connection between the connector 410 and the first pipe section 440 (not shown), the active tong 452 grips the gripping portion 420 of the connector 440 and the back-up tong 454 grips the first pipe section 440. The back-up clamp 454 holds the first pipe section 440 stationary relative to the connector 410 while the active clamp 452 is used to rotate the connector 410 relative to the first pipe section 440 to make or break a connection between the connector 410 and the first pipe section 440.

Where power tong 450 is used to break a connection between connector 410 and second pipe section 442 or to break a connection between connector 410 and first pipe section 440, clamping portion 420 may also provide a hammered surface to assist in breaking the connection without hammering an outer surface of body 412 that is coextensive with either of

connection portions

415, 417.

The jaw gripping portion 420 extends along an outer surface 421 defining a jaw gripping surface 426 for a gripping length at least as long as the

jaws

456, 458 on a power tong 450 that will be used to rotate the connector 410 or

pipe sections

440, 442 to make or break a connection between one of the

pipe sections

440, 442 and the connector 410. The length of the

jaws

456, 458 is selected with reference to the outer diameter of the connector 410 and the outer diameter of the well tubing that the connector 410 is to be used with, the torque required to establish the connection, and the application of the well tubing. As a result, the gripping length of the jaw gripping portion 420, which is selected with reference to the length of the

jaws

456, 458, is also selected indirectly with reference to these factors. For example, for a power tong 450 that can be used with a pipe having an outside diameter between about 3.5 "and about 5.5", the back tong teeth 458 may have a tong length of about 1.5 "and the active tong teeth 456 may have a tong length of about 3.0". The clamping portion 420 will be at least 3.0 "long for such a power tong 450, and may be about 5" to allow for a one inch margin on each side of the

power tong teeth

456 or 458 located in the center of the clamping portion 420. Where the connector 410 is designed for smaller or larger outer diameter tubulars, the gripping portion 420 will be correspondingly smaller or larger to accommodate the smaller or larger jaw size of the power tong 450 that will be used on such smaller or larger outer diameter tubulars or other tubulars.

As with the connector without the clip portion 420, the protective portion 470 may include any suitable protective material 472 and may be prepared and secured to the body 412 by any suitable method as described above with respect to fig. 4-7. The additional length of the guard portion 470 may improve the mitigation of post damage relative to the short connectors shown in fig. 2-7.

Fig. 9 shows connector 510 where protective portion 570 includes protective coating 573.

Fig. 10 shows the connector 610 wherein the protective portion 670 includes a sleeve 674, the sleeve 674 being secured within a slot 619 defined in the body 612.

Fig. 11 shows a connector 710 in which a sleeve 776 is secured between the stop 711 and a compression ring 778. Because the body 712 has a greater length than the body 310, the sleeve 776 and the compression ring 778 may be more easily manufactured and secured to the connector 710 than the connector 310. As a result, the sleeve 776 and compression ring 778 may be larger, easier to handle, simpler to manufacture to specification, and simpler to assemble with the body 712 than the smaller sleeve 376 and compression ring 378 for the smaller body 312.

Concave clamping portion

Fig. 12 shows a connector 810 in which a female jaw gripping portion 822 in a body 812 is defined by the absence of connecting

portions

815, 817 and by the change in outer diameter of the body 812. Body 812 has a first outer diameter 835 along connecting

portions

815, 817 and a second outer diameter 837 along recessed jaw holding portion 822. The first outer diameter 835 is larger than the second outer diameter 837. The change in outer diameter of body 812 intermediate first end 814 and female jaw gripping surface 822 is due to a first taper in the profile of the outer diameter of body 812 at first outer diameter transition point 823. The change in outer diameter of the body 812 intermediate the second end 816 and the concave jaw gripping surface 822 is due to a second taper in the profile of the outer diameter of the body 812 at a second outer diameter transition point 824 of the body 812. In the connector 810, a first outer diameter transition point 823 is at the portion of the body 812 that includes the first pinch transition point 828. Similarly, the second outer diameter transition point 824 is at a portion of the main body 812 that includes the second clamp transition point 829. The change in outer diameter at outer

diameter transition points

823, 824 may be achieved by a taper or other feature (e.g., step, etc.) in the profile of body 812 as shown in connector 810.

In the illustrated connector 810, the positions of the outer

diameter transition points

823, 824 along the main body 812 each coincide with the positions of the

grip transition points

828, 829 along the main body 812. As shown in fig. 18, 19, the outer diameter transition point may be located on a portion of the body other than the gripping transition point, or may be located on a portion of the body that limits the length of the gripping surface to a length less than the axial spacing between the connection portions. Where the change in the outer diameter of the body is at a portion of the body other than the transition point, the connecting portion provides sufficient axial depth to engage the externally threaded portion of the pipe section, while the recessed gripping portion does not engage the pipe section, and the recessed gripping portion provides sufficient axial length for the power tong to grip surfaces with the active and back jaws.

The change in outer diameter may be on a portion of the body 812 other than the

pinch transition points

828, 829, such as in the connector 1110 shown in fig. 18, 19. In the case of no threads on inner surface 818 and in the case of jaw clamping surface 826 on outer surface 821, clamping

transition points

828, 829 each define the boundaries of female clamping portion 822, respectively. In contrast, outer

diameter transition points

823, 824 each define a boundary between different outer diameter values of body 812. The axial spacing between the outer diameter transition points may be greater than the axial spacing between the gripping surface transition points, such as in the connector 1110 of fig. 18. In this case, the outer diameter transition point is within the connecting portion and the clamping surface has a shorter length than the portion of the body having the reduced diameter. Conversely, the outer diameter transition points may be separated by a smaller axial distance than the length of the space between the connection portions, such as in connector 1210 of fig. 19. In this case, the outer diameter transition point and the clamping surface transition point coincide, as shown in fig. 19, because the jaw clamping portion is defined by a jaw clamping surface on the outer surface (except for the lack of threads on the inner surface), which has sufficient length in reduced diameter to be clamped by the power jaws, and this sufficient length is only available between the outer diameter transition points.

The recessed gripping portion 822 and corresponding jaw gripping surface 426 provide a location for gripping with the jaws that is easily located, visually or by feel, and the operator can be confident that there is no threading on the inner surface 818. The recessed nature of the female clamping portion 822 facilitates a quick determination of the location of the female clamping portion 822 relative to the clamping portion 720 of the connector 710. Positioning of the recessed clamp portion 822 may be facilitated both by the visual differentiation provided by the change in outer diameter between the first outer diameter 835 and the second outer diameter 837 and by the use of power tongs to position the change in outer diameter while translating the active tong or back-up tong along the connector 810 until the operator feels the change in outer diameter. The facilitated positioning of the female clamping portion in turn facilitates gripping of the female clamping portion 822 of the connector 810 with the power tong.

Reinforced connector

Fig. 13 shows a connector 910 having a body 912 including a reinforced portion 930.

FIG. 14 shows the connector 910 connected to

production tubing sections

940, 942 in a production tubing string 960. The connector 910 and the second production tubing section 942 are being gripped by the power tong 950.

The reinforcing portion 930 extends along a reinforcing length 936 of the body 912 intermediate the connecting

portions

915, 917. The reinforcement portion 930 extends axially generally between the first clamp transition point 928 and the second clamp transition point 929. On inner surface 918, reinforced portion 930 extends between a first torque stop 932 proximate first transition point 928 and a second torque stop 934 proximate second transition point 929. The body 912 has a wall thickness 938 along the reinforced length 936. Wall thickness 938 is any thickness about body 912 that does not include protective portion 970, and protective portion 970 is made from protective material 972 rather than the harder steel or other material used to make body 912 (although the thickness of protective material 972 falls within protective portion inner diameter 971). Wall thickness 938 is selected to provide strength and resistance to deformation to body 912. Without being bound by theory of task, the increased torque to torque ratio of the connection with the connecting

portions

915, 917 relative to that observed in previous connectors may be provided by the reinforcing portion 930. By providing some level of control over the make-up torque and the torque to revolution ratio of the

connection sections

915, 917 without changing the thread configuration, the reinforcement section 930 facilitates the use of the connector 910 to connect pipe sections having a common thread configuration to be established with a greater torque than with previous connectors.

Increasing the length 936 of the reinforced section 930, increasing the wall thickness 938 of the body 912 along the reinforced section 930, or making the body 912 from a stronger grade of steel will increase the strength and resistance to deformation of the body 912. The increase in strength and resistance to deformation, in turn, facilitates the connection of

pipe sections

940, 942 with connector 910 at higher torque values for the same number of revolutions, while reducing the likelihood of

pipe sections

940, 942 or connector 910 snagging or other failure. The clamping surface 920 provides a low risk location on the body 912 for applying the greater clamping force required to apply the higher torque values made possible by the reinforcement 930.

The connector 910 may also include a reinforcing portion extending along a smaller extent of the body 912 between the connecting

portions

915, 917. In this case, the reinforcement portion would still be designed to contribute sufficient strength and resistance to deformation to the body 912 to allow the connection to be established at a particular torque value. The reinforced section 930 has a sufficient length 936 such that the wall thickness 938 does not have to extend into the flow channel within the connector to such an extent that the flow channel is narrower than the tube for which the connector 910 is to be used. The reinforcement portion may also extend outwardly from the outer surface 921 of the connector body 912 and provide additional strength and resistance to deformation to the body 912. However, adding reinforcement to the outer surface 921 of the connector body 912 also increases the outer diameter of the body 912, possibly beyond that of the API specification, which may be a significant drawback in many applications.

The point of make-up between the connector 910 and the first pipe section 940 is at the nose of the first externally threaded end 944. Similarly, the snap-up point between the connector 910 and the second tubing section 942 is at the nose of the second externally threaded end 946. When the first pipe section 940 is connected with the connector 910, the externally threaded end 944 is threaded into the first connector end 914 and abuts the first torque stop 932 of the reinforcement portion 930. Similarly, when second tubing section 942 is connected with connector 910, second externally threaded end 946 is threaded into second connector end 916 and abuts second torque stop 934 of reinforcement 930.

By keeping the material of the body 912 and the thread design on the

connection portions

914, 916 constant, the clamping surface 920 and the reinforcing portion 930 together allow the

pipe segments

940, 942 to be threaded into the connector 910 at a greater selected torque value than previous connectors (e.g., connector P01, etc.) in which threaded connector ends were immediately adjacent to one another.

The gripping portion 920, which is at least as long as the longitudinal length of the

jaws

956 or 958 that will be used on an appropriately sized power tong 950 for the connector 910, is long enough to be easily gripped by the power tong 950. When the connector 910 is installed using the power tong 950, the portion of the inner surface 918 of the connector 910 that includes the connecting

portions

915, 917 need not be gripped. The clip portion 920 provides the following portions of the connector 910: this portion is long enough to be easily gripped by the power tong 950 and can be gripped and torqued with a reduced chance of thread damage than if the outer surface 921 of the gripping connector 910 is coextensive with and torqued against one of the

connection portions

915, 917 that includes threads on the inner surface 918. By mitigating potential damage to the threads that may be caused by the application of torque during make-up, the connector 910 with the reinforced portion 930 facilitates threading to a greater torque value than an internally threaded end that clamps a standard API pipe connector with the jaws.

The power tong 950 clamps onto the clamping portion 920 of the connector 910 and, with an accompanying increase in make-up torque, any increase in clamping force on the extended connector can be concentrated to the clamping portion 920, thereby avoiding the application of force to the threads located on the

connection portions

915, 917 and mitigating the possibility of thread damage at a given torque value compared to the outside diameter of the internally threaded end connection portion of the connector 910 with the clamp.

The reinforcement 930 of the connector 910 proximate the

connection portions

915, 917 and the corresponding increase in torque required to engage the threads facilitates establishing the connection at a greater torque value. The connector 910 facilitates making a connection with greater torque without damaging threads or with a reduced likelihood of thread damage compared to a standard API connector.

The increase in torque that the connector can be made up due to the gripping surface and the reinforcing portion is independent of any particular thread configuration, and the threaded connector end can be threaded with a standard API interference fit thread. API interference fit threads on production tubing having an outer diameter of 2.375", 2.875", 3.5", or 4.5" typically comprise either API standard 8 on EUE interference fit threads or API standard 10 on no-thickness ("NU") interference fit threads. Larger outer diameter production tubing, such as 5.5", 7.0" or other sizes, may also include interference fit threads. For a given pipe outside diameter and a given steel grade (e.g., J-55, N-80, P-120, etc.), the connectors described herein, including each of the protective portion, the clamping portion, and the reinforcing portion, facilitate making connections at higher torque values relative to previous connectors using the same API interference fit threads.

An increase in the torque value to establish a connection requires that the connection be held at a greater force to prevent slippage of the jaws of the pliers. As will be the case in standard API threaded connectors, increasing the force on the box connector when making or breaking a connection means increasing the clamping force on the same part of the connector that is in threaded engagement with the pipe. As a result, an increase in connection torque and a corresponding increase in clamping force required to prevent slippage may result in a corresponding increased likelihood of thread damage when clamping the internally threaded end of the connector. Any increase in the clamping force of the connector is concentrated to the clamping portion without affecting the connecting portion. As a result, it will be possible to establish a connection with the connector with greater torque without thread damage than with a standard API connector. The concentration of force on the clamp portion and the additional strength and torque/turn ratio provided by the reinforcement portion facilitates the establishment of a connection between two pipes having interference fit threads compatible with the connector at greater torque values than previous connectors while reducing the likelihood of thread damage.

Connectors for threaded pipe sections can be connected with a given level of torque. For example, according to the API specification, previous connectors for 3.5"API interference fit threaded pipe sections made of J-55 grade steel with 8-stab EUE interference fit threads may be connected at a connection torque between about 1710 foot pounds and about 2850 foot pounds, with an optimal connection torque being about 2280 foot pounds. An extended and reinforced connector for the same 3.5"API EUE 8 stab pipe section made from J-55 grade steel may be applied with a torque between about 3000 foot pounds and about 3600 foot pounds.

Fig. 15 shows a connector 1010 including a reinforcing portion 1030 and a female clamping portion 1022.

Fig. 16 shows connector 1010 threading first production tubing section 1040 and second production tubing section 1042, where second production tubing section 1042 and connector 1010 are being engaged by power tong 1050.

FIG. 17 shows the connector 1010 in a production tubing string 1060 with a string 1062 running into the production tubing string 1060.

The connector 1010 includes the features described above in connection with the reinforcement portion 1030 and the female clip portion 1022. The torque stop 1034 is defined by an outer surface 1079 of the compression ring 1078. The torque stop 1032 is positioned immediately adjacent the stop 1011 and on the opposite side of the projection from the inner surface 1018, which defines the torque stop 1032 and the stop 1011.

The guard portion inner diameter 1071 is slightly narrower than the conduit inner diameter 1041. For example, connector 1010 may be designed for a 3.5"API EUE production tubing having a weight of 9.30 lbs/ft, an inner diameter of 2.992" along

tubing connection portions

1045 and 1047, and a through diameter of 2.867 ". A connector 1010 designed for such tubing may have a protective portion inner diameter 1071 of the sleeve 1076 with a value of 2.967 "which will provide a 0.025" reduction of the protective portion inner diameter 1071 of the sleeve 1076 relative to the tubing inner diameter 1041 while remaining 0.100 "higher than the through diameter of the

production tubing sections

1040, 1042. In another example, the protective portion inner diameter 1071 may be about 2.500 "for the same production tubing, which would provide a thicker sleeve 1076, but reduce the drift diameter of the production string 1060. A thicker sleeve 1076 extending farther away from the body 1012 may provide additional protection to the stem 1062, or may extend protection in the event that the stem 1062 damages the sleeve 1076 over time.

In connector 1010, just as in connector 810, the location of outer

diameter transition points

1023, 1024 between first outer diameter 1035 and second outer diameter 1037 along body 1012 each coincide with the location of

grip transition points

1028, 1029 along body 1012. In other connector designs, the outer diameter transition point may be located on a portion of the body other than the gripping transition point, or may be located on a portion of the body that limits the gripping surface length to a length less than the axial spacing between the connection portions, as shown in fig. 18, 19.

Fig. 18 is a connector 1110 including a female clip portion 1122. A first outer diameter transition point 1123 is located along the body 1112 intermediate the first clamp transition point 1128 and the first end 1114. The second outside diameter transition point 1124 is located along the body 1112 intermediate the second clamp transition point 1129 and the second end 1116. In other words, first outer diameter transition point 1123 is located on a portion of body 1112 that includes first connection portion 1115, and second outer diameter transition point 1124 is located on a portion of body 1112 that includes second connection portion 1117. The recessed clamp portion 1122 defined between the first and second

clamp transition points

1128, 1129 extends along a portion of the inner diameter 1118 of the body 1112 free of the threads of the first and

second connection portions

1115, 1117. As a result, a portion of the body 1112 having a smaller second outer diameter 1137 extends into each of the first and

second connection portions

1115, 1117.

The axial depth of the connecting

portions

1115, 1117 and the length of the recessed gripping portion 1122 are selected to allow the connecting

portions

1115, 1117 to engage the externally threaded portion of the pipe section and to allow the power tong to grip the tong gripping surface 1126 without gripping the body 1112 that is coextensive with one of the connecting

portions

1115, 1117. For a connector for a 3.5"API interference fit conduit, the distance between the first outer diameter transition portion 1123 and the first gripping transition point 1128 and the distance between the second outer diameter transition portion 1124 and the second gripping transition point 1129 may be about 0.375".

Fig. 19 is a connector 1210 that includes a female clip portion 1222. First outer diameter transition point 1123 is located axially inward along body 1212 from first connection portion 1215. Similarly, the second outer diameter transition point 1124 is located axially inward along the main body 1212 from the first connection portion 1217. A recessed clamp portion 1222 defined between a first clamp transition point 1228 and a second clamp transition point 1229 extends along a portion of the body 1212 a sufficient length to provide a clamping surface 1226. As a result, the portion of the body 1212 having the larger first outer diameter 1235 extends beyond each of the first and

second connection portions

1215, 1217. Connector 1210 will generally be expected to have greater strength and greater resistance to deformation when threading a tube into either of

connectors

1110, 1210 than connector 1110, as the wall thickness 1238 of connector 1210 may be greater than connector 1110, all other factors being equal.

Example connector for 3.5"API EUE production tubing

With respect to the profile of the outer surface 1121 of the body 1112, the extended connector is prepared with the body 1112 similar to the connector 1110, with the inner surface 1118 of the guard portion 1170 adjusted to include a sleeve, stop and press ring similar to that shown in connection with the connector 1010. The example connector 1110 is designed for connection with a 3.5"API EUE interference fit production tubing having an 8-thread configuration. According to the API specification, previous connectors for 3.5"API EUE tubing made from J-55 steel may be connected at a connection torque of between about 1710 foot pounds and about 2850 foot pounds, with an optimal connection torque of about 2280 foot pounds. An extended coupling, also made of J-55 steel, joined the same 3.5"API EUE pipe sections at torque values of about 3000 foot pounds and about 3600 foot pounds, with no thread damage in either case.

On an extended connector, with reference to connector 1110, the distance between outer

diameter transition points

1123, 1124 is 4.0 ". The recessed clip portions 1122 have a length of 3.25 ". The outer diameter of the connector 1110 at the first connecting portion 1115 and the second connecting portion 1117 is 4.5 ". The wall thickness 1138 along the reinforced portion 1130 is 0.625 ".

TABLE 1

Table 1 shows a matrix of tested connectors and torque values, showing for each set of conditions whether the threads, pipe sections, or both of the connectors are damaged. As shown in table 1, tightening the previous connector to a torque value of about 3000 or 3600 foot pounds is likely to result in galling of the threads of the previous connector, the pipe section, or both. Additionally, without being bound by any theory, when a grip is being established or has been established on the female threaded end of the connection, gripping the previous connector with sufficient force to hold it stable while tightening to about 3000 foot pounds or 3600 foot pounds itself may cause crushing and biting of the threads of the connector and the pipe section. Table 1 also shows that when an extended connector is clamped on the clamping portion, the extended connector is less likely to be damaged by being applied a torque of 3000 foot pounds or 3600 foot pounds than previous connectors. When clamped on the internally threaded end of one of the connection parts, thread damage occurs during testing. Again, without being bound by any theory, this may be due to an increase in the clamping force required to rotate the connector at higher torques and an increase in the likelihood of damage when clamping on the female threaded end rather than the clamping portion.

Each of the API collar and extension collar were also subjected to a 110000 pound pull test. When attached at 3600 foot pounds, the test passed. However, when disconnected, the API collar has damaged threads, as shown above in table 1. The API specification would require the pipe to be tested to 142460 pounds, but the data still indicates that the connection is sufficient for some applications, including low pressure wells with artificial lift.

Fig. 20 shows torque versus number of revolutions data for the data set shown in table 1. In fig. 20, data for an extended connector clamped on the clamping surface is shown in solid lines, data for an extended connector clamped on the internally threaded end is shown in dashed lines, and data for an API coupling is shown in dotted lines. This illustration is maintained in fig. 21 to 23, and fig. 21 to 23 show the data sets of fig. 20, respectively. When 3000 foot pounds of torque is applied to the extended connector, or more than 3600 foot pounds of torque is applied in the second data set, the first torque stop 1132 is engaged and rotation stops. At 2280 foot pounds, the extended connector has completed less than 1.5 revolutions. This and very steep data slope for the extended connector indicates that more torque is required to screw the male threaded end into the extended connector than into the API connector. As a result, the connection is tighter than with an API connector.

Torque versus time data for the API connector at 3600 foot pounds was not collected. The two data sets that applied 2280 foot pounds of torque were for a standard OD API connector and a scaled down API connector for tubule applications, respectively. However, as identified in table 1, applying a torque of 3600 damaged the API connector.

Fig. 21 to 23 show data of the extended connector only on the clamping surface, the extended connector on the internally threaded end and the conventional API connection on the internally threaded end in fig. 20, respectively. Fig. 20 allows easy comparison of data sets to observe trends in the data. However, fig. 21 to 23 allow easier observation of the respective data sets.

Applications of combined screw pump

Pipe connectors, particularly production tubing connectors intended for low pressure wells, are typically designed to minimize the amount of material and effort required to prepare the connector while still maintaining functionality. Such a solution of a connector will typically be used in low pressure wells, where artificial lift, such as a screw pump ("PCP"), may also be used. In view of the large number of production tubing connectors required for a typical oil well working in conjunction with tubing sections, an important motivation is to minimize the material cost of each connector and to manufacture the connectors with as little material as possible. However, the protective portion included in the connectors described herein may provide a cost advantage over previous connectors by mitigating rod wear and reducing the occurrence of rod breakage.

PCP can be applied to reservoirs containing large amounts of sand and gravel. The presence of a rotating rod string to drive the PCP rotor (in some cases, for applications in sandy reservoirs) may significantly increase the severity of rod wear and the likelihood of rod disconnection, thereby increasing some of the benefits of applying the connectors with protective portions described herein.

Additionally, with the clamp gripping portion and the reinforcing portion, during production through a tubular string that includes the PCP, the PCP rotor can cause rotation of the production tubular string by transmitting torque in addition to rod wear on its own stem. This rotation of the production string may loosen the connection between the connector and the tubing, causing the production string to fall into the well. In the case of a production string landing, expensive maintenance is required. This problem has previously been addressed by using torque anchors that prevent the PCP rotor torque from being transmitted to the production string. The torque anchor is connected to the production string at or immediately adjacent the downhole portion and includes an anchor block or similar feature that engages the inner surface of the casing or wellbore when the torque anchor is actuated, thereby preventing rotation of the production string due to the transmission of PCP rotor torque to the production string. In some cases, the torque anchor may puncture or otherwise damage the inner surface of the well casing.

For a torque of 3600 foot pounds applied to a connection between production tubing sections, torque transfer from the PCP rotor is less likely to result in loosening of the production string, and when using an extended coupling and connecting at 3000 or 3600 foot pounds, the need for a torque anchor when using a PCP in a production string is alleviated. The greater torque facilitated by the extended gripping and reinforcing portions reduces galling when PCP is used to produce from low pressure wells.

In contrast, with previous API standard interference fit connectors, the connection between the previous connector and the pipe section is typically established at about 2280 foot pounds, and torque transfer from the PCP rotor to the pipe string connected at that torque may result in loosening of the connection and dropping of the production string.

The torque expected to be generated by the PCP may be estimated based on the size and grade of the drive rod. Smaller 1 "drive rods are typically used for low flow rate, low lift PCP, and cannot handle large amounts of torque. These smaller rods may not provide enough torque to unthread the 3.5"API EUE interference fit threaded connection applying the optimal specification torque of 2280 foot pounds. A rod having a diameter of 1.25 "or 1.5" has a torsional strength in the range where such a coupling may loosen, and an extended coupling may provide the advantage of mitigating the loosening.

For any given size of PCP or PDM, the flow rate in PCP is proportional to RPM. The torque is linearly related to the pressure drop across the motor. The pressure drop in the PCP is caused by fluid viscosity, flow rate, lift height, pipe size, and other variables. These variables are known or may be estimated when designing a completion and sizing the PCP.

If the selected PCP to use is expected to produce higher torque than a standard API interference fit tubular connection, a pipe anchor will be used. However, even if the expected PCP torque is lower than the connection torque, galling may occur due to vibration and the possibility that the connection is not properly torqued according to specifications. As a result, increasing the torque in the connection will reduce the risk of galling, especially when using high flow rate, high lift PCPs.

In general, each PCP is selected based on the desired flow rate, the desired lift, the fluid viscosity, and other well-related parameters. The torque generated during operation will depend on the specifics of the PCP. High flow rate, high lift PCPs can produce very large torque values that far exceed typical pipe connection torques. At low flow rates, low lift, the torque is not likely to be high at all, even with high viscosity oils. From knowledge of the specifications of the PCP that have been selected for the well, it would be easy to identify a higher torque connection with extended connectors as a quantitatively beneficial preference. In other cases, an extended connector may not be explicitly required, but provides additional assurance that the release will be mitigated. The value of the protective portion of the connector described herein may be increased where the stem string includes a larger sized PCP rotor, as the larger PCP rotor may cause greater stem wear on the production string.

Merely by way of example

In the previous description, for purposes of explanation, numerous details were set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that these specific details are not required.

The above-described embodiments are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope, which is defined solely by the claims appended hereto.

Claims

1. A connector, comprising:

a body extending between a first end and a second end;

a first connecting portion proximate the first end for connecting a first tube;

a second connecting portion for connecting a second pipe adjacent to the second end; and

a protective portion extending along at least a portion of an inner surface of the body intermediate the first connection portion and the second connection portion, the protective portion comprising a protective material that is less abrasive to the stem than the body;

wherein a protective portion inner diameter of the main body and the protective material at least one portion along the protective portion is equal to or narrower than an inner diameter of other portions of the main body, and

wherein the first connection portion includes a first internally threaded end having threads on the inner surface for connection with the first pipe and the second connection portion includes a second internally threaded end having threads on the inner surface for connection with the second pipe.

2. The connector of claim 1, wherein the protective portion comprises a sleeve formed of the protective material secured within the body.

3. The connector of claim 2, further comprising a groove defined in the inner surface along the protective portion, and wherein the sleeve is secured within the body by seating within the groove.

4. The connector of claim 3, wherein the sleeve comprises a split sleeve.

5. The connector of claim 2, wherein the sleeve is secured against a stop intermediate the protective portion and the first connection portion.

6. The connector of claim 5, wherein the sleeve is secured against the stop by a compression ring intermediate the protective portion and the second connection portion.

7. The connector of claim 2, wherein the protective material comprises polyethylene having a 65 shore D hardness and a dynamic coefficient of friction of 0.10.

8. The connector of claim 2, wherein the protective material comprises nylon having a shore D hardness of between 75 and 85 and a dynamic coefficient of friction of 0.20.

9. The connector of claim 1, wherein the protective portion comprises a layer of protective material bonded to the inner surface.

10. The connector of claim 9, wherein the protective material comprises a thermosetting resin.

11. The connector of claim 10, wherein the thermosetting resin comprises a zirconium frit epoxy powder coating having a pencil hardness rating of 6H.

12. The connector of claim 9, wherein the protective material comprises an extrusion cured coating.

13. The connector of claim 9, wherein the protective material comprises a metal alloy coating.

14. The connector of claim 13, wherein the metal alloy coating comprises a coating having a rockwell C hardness between 45 and 55, a wear resistance between 12 and 16 taber wear index, and a dynamic coefficient of friction of 0.15.

15. The connector of claim 1, further comprising a gripping surface extending along an outer surface of the body intermediate the first and second connection portions for a gripping length at least as long as a jaw length of a pair of power tongs used to connect the connector with a production tubular.

16. The connector of claim 15, wherein:

the clamping surface comprises a concave clamping surface;

the body having a first outer diameter along the first and second connection portions and a second outer diameter along the recessed gripping surface; and is

The first outer diameter is greater than the second outer diameter.

17. The connector of claim 16, wherein:

a first outer diameter transition point between the first outer diameter and the second outer diameter is located intermediate the first end and the recessed gripping surface; and is

A second outer diameter transition point between the first outer diameter and the second outer diameter is located intermediate the second end and the recessed gripping surface.

18. The connector of claim 17, wherein:

the first outer diameter transition point is located on a portion of the outer surface that is coextensive with the first connection portion on the inner surface;

said second outer diameter transition point is located on a portion of said outer surface coextensive with said second connection portion on said inner surface; and is

A portion of the body having the second outer diameter extends axially outwardly from the jaw gripping portion into each of the first and second connection portions.

19. The connector of claim 17, wherein:

the first outer diameter transition point is located on a portion of the outer surface axially inward along the body from the first connection portion;

the second outer diameter transition point is located on a portion of the outer surface axially inward along the body from the second connection portion; and is

A portion of the body having the first outer diameter extends axially inward along the body from each of the first and second connection portions.

20. The connector of claim 15, wherein the threads comprise interference fit threads, and the connector further comprises a reinforcing portion of the body intermediate the first and second connection portions for resisting deformation of the body when a connection is established with the connector.

21. The connector of claim 20, wherein the reinforcement portion comprises:

a first torque stop defined on the inner surface adjacent the first connection portion for abutting the first pipe when the first pipe is connected with the first connection portion; and

a second torque stop defined on the inner surface proximate the second connection portion for abutting the second tube when the second tube is connected with the second connection portion.

22. The connector of claim 21, wherein the reinforcement portion further comprises a reinforcement member extending between the first torque stop and the second torque stop.

23. The connector of claim 22, wherein the protective portion extends along the inner surface and substantially along an entire length of the reinforcement member.

24. The connector of claim 23, wherein the stiffening member extends along the body and substantially along the entire length of the clamping portion.

25. The connector of claim 22, wherein an inner diameter of the body is constant along the reinforcement member between the first torque stop and the second torque stop.

26. The connector of claim 22, wherein the stiffening member extends along the body and substantially along the entire length of the clamping portion.

27. The connector of claim 15, wherein the gripping length is 3.5 inches and the connector has an outer diameter of 4.5 inches along the first and second connection portions.

28. The connector of claim 15, wherein the gripping length is two inches longer than the jaw length.

29. The connector of claim 15, wherein the gripping length is twice as long as the jaw length.

30. The connector of claim 15, wherein:

the grip length is 3.25 inches;

the connector has an outer diameter of 4.5 inches along the first and second connection portions; and is

The first and second pipes each comprise an API interference fit threaded production pipe section of 3.5 inch od.

31. The connector of claim 30, wherein the body is made of J-55 grade steel.

32. The connector of claim 31, wherein the body includes a reinforced portion and the reinforced portion includes a portion of the body having a wall thickness of 0.625 inches.

33. The connector of claim 32, wherein the protective portion inner diameter is at least 0.025 inches narrower than an inner diameter of other portions of the body.

34. The connector of claim 33, wherein the protective portion inner diameter is 2.5 inches.

35. The connector of claim 33, wherein the protective portion extends along the inner surface for a length of 2.0 inches.

36. The connector of claim 1, wherein the first and second pipes each comprise a production tubing section.

37. The connector of claim 1, wherein the first and second tubes each have an outer diameter of 2.375, 2.875, 3.5, 4.5, 5.5, or 7.0 inches.

38. The connector of claim 1, wherein the protective portion inner diameter is equal to or narrower than an inner diameter of a production tubing for which the connector is designed.

39. The connector of claim 1, wherein the protective portion inner diameter is equal to an inner diameter of a production tubing for which the connector is used.

40. A method of manufacturing a connector, comprising:

providing a connector comprising a body having an inner surface portion intermediate opposing first and second connection portions; and

securing a protective material to the inner surface portion to provide a protective portion along at least a portion of the inner surface portion;

wherein the protective material is less abrasive to the stem than the body; and is

The main body and the protective material have a protective portion inner diameter along at least a part of the protective portion equal to or narrower than an inner diameter of other parts of the main body, and

wherein the first connection portion includes a first internally threaded end having threads on the inner surface for connection with a first pipe and the second connection portion includes a second internally threaded end having threads on the inner surface for connection with a second pipe.

41. The method of claim 40, wherein securing a protective material to the inner surface portion includes applying a protective coating to the inner surface portion.

42. The method of claim 40, wherein securing a protective material to the inner surface portion includes securing a sleeve within a groove defined in the inner surface portion.

43. The method of claim 40, wherein securing a protective material to the inner surface portion includes securing a sleeve against a stop.

44. A method according to claim 40, wherein the protective portion internal diameter is equal to or narrower than the internal diameter of the production conduit for which the connector is to be used.

45. A connector for connecting a first pipe to a second pipe using a power tong having a tong length, the connector comprising:

a body extending between a first end and a second end;

a first connection portion proximate the first end and including threads on an inner surface of the connector for connecting a first pipe;

a second connection portion proximate the second end and including threads on the inner surface for connecting to a second pipe;

a protective portion extending along at least a portion of the inner surface intermediate the first connection portion and the second connection portion, the protective portion comprising a protective material that is less abrasive to the stem than the body; and

a gripping surface extending along an outer surface of the body intermediate the first and second connection portions, the gripping surface extending along the outer surface for a gripping length at least as long as the jaw length;

wherein a protective portion inner diameter of the main body and the protective material at least one portion along the protective portion is equal to or narrower than an inner diameter of other portions of the connector.

46. A connector according to claim 45, wherein the protective portion comprises a sleeve formed from the protective material secured within the body.

47. A connector according to claim 46, wherein the protective portion comprises a sleeve formed from the protective material secured within the body.

48. The connector of claim 47, further comprising a groove defined in the inner surface along the protective portion, and wherein the sleeve is secured within the body by seating within the groove.

49. The connector of claim 48, wherein the sleeve comprises a split sleeve.

50. A connector according to claim 46, wherein the sleeve is secured against a stop intermediate the protective portion and the first connection portion.

51. A connector according to claim 50, wherein the sleeve is secured against the stop by a compression ring intermediate the protective portion and the second connecting portion.

52. The connector of claim 45, wherein the protective material comprises polyethylene having a 65 Shore D hardness and a dynamic coefficient of friction of 0.10.

53. A connector according to claim 52, wherein the protective material comprises nylon having a Shore D hardness of between 75 and 85 and a dynamic coefficient of friction of 0.20.

54. The connector of claim 45, wherein the protective portion comprises a layer of protective material bonded to the inner surface.

55. The connector of claim 54, wherein the protective material comprises a thermosetting resin.

56. The connector of claim 55, wherein the thermosetting resin comprises a zirconium frit epoxy powder coating having a pencil hardness rating of 6H.

57. The connector of claim 54, wherein the protective material comprises an extrusion cured coating.

58. The connector of claim 54, wherein the protective material comprises a metal alloy coating.

59. The connector of claim 58, wherein the metal alloy coating comprises a coating having a Rockwell C hardness of between 45 and 55, a wear resistance of between 12 and 16 Taber abrasion index, and a dynamic coefficient of friction of 0.15.

60. The connector of claim 45, wherein:

the clamping surface comprises a concave clamping surface;

The first outer diameter is greater than the second outer diameter.

61. The connector of claim 45, further comprising a reinforcing portion of the body intermediate the first and second connection portions for resisting deformation of the body when connection is established with the connector.

62. The connector of claim 61, wherein the reinforcement portion comprises:

63. A connector according to claim 61, wherein

The grip length is 3.25 inches;

64. The connector of claim 63, wherein the body is made of J-55 grade steel.

65. The connector of claim 64, wherein the reinforcing portion comprises a portion of the body having a wall thickness of 0.625 inches.

66. The connector of claim 65, wherein the inner diameters of the body and the protective material are 0.025 inches narrower than the inner diameter of the remainder of the body.

67. The connector of claim 66, wherein the protective portion extends along the inner surface for a length of 2.0 inches.

68. The connector of claim 63, wherein the first and second pipes comprise production tubing and the API interference fit threaded production tubing section comprises 8-stab threads.

69. The connector of claim 63, wherein the first and second pipes comprise production tubing and the API interference fit threaded production tubing section comprises 10-stab threads.

70. A method of connecting a first pipe to a second pipe, comprising:

providing a connector, the connector comprising:

a protective portion extending along at least a portion of an inner surface of a body of the connector intermediate a pair of interference fit threaded connection portions, the protective portion comprising a protective material that is less abrasive to a post than the body;

a clamping surface on an outer surface of the body and intermediate a pair of connecting portions; and

a reinforcing portion of the main body, intermediate the pair of connecting portions, for resisting deformation of the connector when connection is established with the connector;

wherein a protective portion inner diameter of the body and the protective material at least one portion along the protective portion is equal to or narrower than an inner diameter of other portions of the connector;

clamping the clamping surface and the first pipe with a powered jaw;

rotating the connector relative to the first pipe with the power tong to connect the connector to the first pipe at a torque value;

gripping the gripping surface and gripping the second pipe with the power tong; and

rotating the second pipe relative to the connector with the power tong to connect the connector to the second pipe at the torque value.

71. The method of claim 70, wherein the connector further comprises a pair of torque stops proximate the connecting portion, each torque stop for abutting a nose of a tube threaded into the connecting portion proximate the torque stop.

72. The method of claim 71, wherein abutting the nose indicates that the torque value has been reached.

73. The method of claim 70, wherein the connection portion is threaded with API interference fit threads.

74. The method of claim 73, wherein the torque value exceeds the API optimum for a connector for a pipe having an outer diameter equal to the reference outer diameter value for the first and second pipes at the same grade of steel.

75. The method of claim 74, wherein the torque value exceeds an API maximum value for a connector for a pipe having an outer diameter equal to the reference outer diameter value for an equivalent grade of steel.

76. The method of claim 73, wherein:

the grip length is 3.25 inches;

the connector has an outer diameter of 4.5 inches along the pair of connecting portions; and is

77. The method of claim 76, wherein the body is manufactured from J-55 grade steel.

78. The method of claim 77, wherein the stiffened portion comprises a portion of the body having a wall thickness of 0.625 inches.

79. The method of claim 78, wherein the torque value exceeds an API maximum for a connector for a pipe having an outer diameter equal to a reference outer diameter value for the first and second pipes.

80. The method of claim 79, wherein the torque value is at least 3000 foot pounds.

81. The method of claim 80, wherein the torque value is 3600 foot pounds.

82. The method of claim 80, wherein the protective portion inner diameter is at least 0.025 inches narrower than an inner diameter of other portions of the body.

83. The method of claim 70, wherein the first and second pipes each comprise a production tubing section.

84. The method of claim 70, wherein the protective portion comprises a sleeve formed of the protective material secured within the body.

85. The method according to claim 84, wherein the sleeve is secured against a stop intermediate the protective portion and a first one of the pair of connection portions.

86. The method of claim 85, wherein the sleeve is secured against the stop by a compression ring intermediate the protective portion and a second one of the pair of connection portions.

87. The method of claim 84, wherein the protective material comprises polyethylene having a 65 Shore D hardness and a dynamic coefficient of friction of 0.10.

88. The method of claim 84, wherein said protective material comprises nylon having a Shore D hardness of between 75 and 85 and a dynamic coefficient of friction of 0.20.

89. The method of claim 70, wherein the protective portion comprises a layer of protective material bonded to the inner surface.

90. The method of claim 89, wherein the protective material comprises a thermosetting resin.

91. The method of claim 90, wherein the thermosetting resin comprises a zirconium frit epoxy powder coating having a pencil hardness rating of 6H.

92. The method of claim 70, wherein the protective material comprises an extrusion cured coating.

93. The method of claim 70, wherein the protective material comprises a metal alloy coating.

94. The method of claim 93, wherein the metal alloy coating comprises a coating having a rockwell C hardness between 45 and 55, a wear resistance between 12 and 16 taber wear index, and a dynamic coefficient of friction of 0.15.