CA1287080C - Connector means for use on oil and gas well tubing or the like - Google Patents
Connector means for use on oil and gas well tubing or the likeInfo
- Publication number
- CA1287080C CA1287080C CA000487258A CA487258A CA1287080C CA 1287080 C CA1287080 C CA 1287080C CA 000487258 A CA000487258 A CA 000487258A CA 487258 A CA487258 A CA 487258A CA 1287080 C CA1287080 C CA 1287080C
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- female
- sealing surfaces
- threaded portion
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Abstract
ABSTRACT OF THE DISCLOSURE
Connector means for joining together two adjacent pipe members in a fluid/pressure tight relationship comprising an externally threaded male element cooperatively engageable with an internally threaded female element, the male and female elements each respectively including three adjacent complementary annular sealing surfaces positioned axially adjacent the threaded portion associated respectively therewith, the three adjacent complementary sealing surfaces being arranged in an irregular pattern such that when the male and female elements are threadingly secured together, the three adjacent sealing surfaces associated respectively with the male and female elements sealingly engage one another to form three independent adjacent pressure-tight seals. The sealing arrangement of the present invention is ideally suited for use on both an integral joint system and on a coupled joint system and may be arranged and located in the particular connection so as to form an internally shouldered connection and/or an externally shouldered connection.
Connector means for joining together two adjacent pipe members in a fluid/pressure tight relationship comprising an externally threaded male element cooperatively engageable with an internally threaded female element, the male and female elements each respectively including three adjacent complementary annular sealing surfaces positioned axially adjacent the threaded portion associated respectively therewith, the three adjacent complementary sealing surfaces being arranged in an irregular pattern such that when the male and female elements are threadingly secured together, the three adjacent sealing surfaces associated respectively with the male and female elements sealingly engage one another to form three independent adjacent pressure-tight seals. The sealing arrangement of the present invention is ideally suited for use on both an integral joint system and on a coupled joint system and may be arranged and located in the particular connection so as to form an internally shouldered connection and/or an externally shouldered connection.
Description
~ ~37~ 3 CONNECTOR .~EA~S FOR USE ON OIL
AND_GAS WELL TUBING OR T~IE LIKE
The present invention relates to a joinder means Eor use in connecting together oil and gas well tubing and/or casing, and more particularly, to several embodiments of a joinder arrangement wherein three independent adjacent metal-to-metal pressure seals are utilized as the primary sealing means to assure a pressure-tight joint when the male and female elements of the connection are properly secured together. The present sealing arrangement is ideally suited Eor use as a premium connector and provides a multiple sealing system which ensures maximum sealing integrity. Although the present sealing arrangement is primarily designed for use in connecting together oil and gas well tubing and/or casing, the present sealing arrangement is likewise adaptable for use in a multiplicity of other pipe joinder applications.
8ACKGROUND OF THE INVE~TION
The oil and gas industry has been continually drilling wells deeper and deeper into extremely high underground pressure areas or zones, which zones many times contain hostile and coreosive chemicals such as hydrogen ~sulfide. To compLete a well for oil and/or gas production normally requires cementing casing in the well hole to prevent cave-ins and other phenomenon both during and after the drilling operation. Once the casing is positioned within the well hole, tubular pipes of reduced diameter, commonly known as tubing, are positioned within the well casing and extend the full length thereof for effectively carrying the hydrocarbons and gases contained within the production formation to the surface. These tubular pipes or tubing are manufactured ~y steel mills in average lengths of -1- ~ .
approximately 30 to ~0 feet and tnerefore must be connected or joined together as they are lowered into the well by means of mechanical connector devices. Connectors ~or t~le tight joinder o~ such well tubing are well known in the petroleum industry.
These connectors perform many functions but their primary function is essentially twofold, namely, (1) to adequately hold the string of pipes together within the weLl hole and (~) to adequately seal the connected togethee tubular members against the internal and/or external pressures commonly associated with drilling for and pumping oil and/or gas. Hereinbefoee, pressure seals were simply created by interEerence fit of the male and female threads associated with the respective tubing to be joined. Such joinder means generally comprises a male extremity or pin associated with one tube element and a female extremity or box associated with the other tube element, each of which is respectively fitted with corresponding threads such that when the male extremity is threadingly positioned into the female extremity, the locking of said threads occurs. This joinder method became inadequate for many wells when well depths reached approximately 10,000 feet due primarily to the higher pressures associated witn the oil and gas formations found at such depths. These related higher pressures have therefore produced a need for connectors or connecting means having a pressure sealing ability capable of adequately withstanding both the internal and external pressures associated With such well depths.
Metal-to-metal pressure seals were first successfully introduced into the oil and yas industry by the ~Iydril Company based upon Stone U.S. Patent No. 2,006,520. The seal disclosed in the Stone patent was based upon a wedged fit between a seal surEace on the male extremity or pin and a corresponding seal `~ r ~ 3 surface associated with the Eemale extremity or boxt which sur-Eaces engaged just prior to shouldeeing. Although this sealing arrangement provides an effective seaL, it functions WithOUt any back-up sealing means in case of failure, a feature necessary for maximum sealing integrity in today's deep well environment. In addition, the sealing arrangement of Stone is also very susceptible to handling damage due to its location on the connector. If the seal element surfaces are even slightly scratched or otherwise damaged, the seal will not seat properly and the gas and/or oil pressures generated during drilling and pumping operations will easily move past the seal area and into the connector body where such pressure will eventually or immediately cause failure. Long term storage of the known prior art connectors also causes problems in that such storage causes the sealing surfaces to deteriocate due to pitting and other corrosion, all of which cause deterioration of the sealing capability of the connector. Such failures cannot be tolerated not only because they are very expensive but also, and more importantly, because they are extremely dangerous to the lives of those working in the area of the well.
A successful incorporation of two adjacent metal seals in a coupling device was marketed by Vallourec SteeL and is disclosed in Duret U.S. Patent No. 3,489,437. This sealing arrangement has been fairly successful except that, again, it is highly suscepti~le to damage during normal field handling and during running operations. For example, iE the double seal surfaces of Duret are even slightly dented, nicked, or galled prior to make-up of the connection, such defects will cause the pressure seals formed by the mating of said seal surfaces to deteriorate and the associated pressures will again migrate ~r~
through the seal area causing leakage and/or -joint faiLure. In addition, the Duret sealing configuration is extremely sensitive to leakage and/or failure due to the sharpness of the angles of the seal element surfaces relative to the Longitudinal axis oE
the pipe. For example, if any foreign matter, not matter how small, is trapped between the seal surfaces during make-up, the respective seals will not seat properly and therefore will not provide an adequate pressure seal. Because of its sensitivity and susceptibility to im~proper seating due to damage caused during field handling, stabbing, and other phases of a drilling operation, this sealing arrangement is not widely utilized in the United States.
It rapidly became apparent that back-up seal elements were necessary for insurance against pressure leaks and the often resulting connector failures associated tnerewith~ ~any independent sealing devices such as rings and gas~ets have been utilized as botn back-up and prima~y seals. The two most effective seals in use today utilize teflon seal elements trapped or at least partially trapped in the joinder connection so as to block any pressure from mlgrating therethrough. These seals were marketed by Atlas 13radford of N.L. Industries, Inc.
and are disclosed in Taylor U.S. Patent No. 2,9~0,45L and ~ehring U.S. Patent No. 3,047,316. ~hese sealing rings and/or gaskets have ser~ed well as back-up sealing elements. However, the effectiveness of such sealing means has deteriorated within the last ten years due to the fact that oil and gas well drillings have reached well depths far beyond 10,000 feet and, in addition, drilling to such depths has exposed the well tubing and its connections to many corrosive elements such as hydrogen sulfide. As a result, seal failures have also occurred due to 3~
the corrosive effect of hydrogen sulfide. Most hydrogen sulfide ~ailures are associated with high stress levels in the metal connectors. The teflon seal rings generate very high stress levels during make-up of the connection in order to obtain an ade~uate pressure sealing barrier and thereEore are highly susceptible to sucn corrosive failure. In addition, replacement of one or more defective sealing rings is extremely time consuming and costly since the defective portion of the string of pipe must be tripped out of and then ~ack into the well hole. This pro~lem is accented in the international marketplace where stocking of replacement parts is always a problem and very expensive.
Consequently, no known joinder means utilized in drilling opeeations for connecting together a series of tubular pipes incorporates an adequate combination of pressure seals for ensuring maximum sealing integrity at all times. In addition, none of the known prior art devices are as effective and reliable as the present construction and none utilizes a sealing arrangement which is not easily destroyed or neutralized by damage or other defects arising during storage, normal field handling, stabbing and running operations, or any other drilling activity.
SUMMARY O THE INVE_TION
The present connector means overcomes many of the disadvantages and shortcomings associated with known pipe joinder means, and teaches the construction and operation o~
several emoodiments of an improved connector means for coupling together tubular pipes, in particular, tubular pipes used in well drilling operations wnich are subjected to substantial pressures, corrosive chemicals, physical stresses and ~2~
construction hazards as the depth of the wells go deepe:r and deeper.
In one embodiment of ~he present invention there is provided connector means for joining together two adjacent pipe members comprising a male member having an externally threaded portion associated therewith and an unthreaded annular portion positioned axially adjacent the threaded portion, a female member having an internally threaded portion associated therewith adaptable for cooperatively engaging the threaded portion of the male member, the female member including a corresponding unthreaded annular portion positioned axially adjacent the female threaded portion, the unthreaded portions respectively including three complemen-tary adjacent annular sealing surfaces arranged in an irre-gular pattern such that when the male and female m~mbers arethreadingly secured together, the three adjacent sealing surfaces associated respectively with the male and female members sealingly engage one another to form three inde-pendent adjacent pressure-tight seals wherein the three adjacent sealing surfaces include a first surface angularly positioned relative to the longitudinal axis of the pipe members such that the angular displacement of the first surface relative to the longitudinal axis is in a ran~e from between approximately 90 to 125, a second surface angu-larly positioned relative to the longitudinal axis of thepipe members such that the second surface lies in a plane substantially parallel to the longitudinal axis of the pipe members, and a third surface angularly positioned relative to the longitudinal axis of the pipe members such that the angular displacement of the third surface relative to the longitudinal axis is greater than the angular displacement of the second s~lrface relative to the longitudinal axis.
According to another embodiment of the present inven-tion there is provided joinder means for connecting together two adjacent pipe members in fluid/pressure tight relation-, . , ~iJ
~7~
- 6a -ship with each other, the joinder means including a male element having an externally threaded end port:ion and a female element having an internally threaded end portion cooperatively engageable with the threaded port.ion of the male element, the male element having a group of three adjacent sealing surfaces positioned axially forward of the male threaded portion and the female element having a group of three adjacent complementary sealing surfaces positioned axially rearward of the female threaded portion, each of the lo group of three adjacent sealing surfaces including a fixst surface angularly positioned relative to the longitudinal axis ~~'7~ 3 of the pipe members such that the f.irst sur:Eace :is angularly displaced -there:Erom in t.he range from between approxlma-tely 90 to 125, a second su.rEace located adjacent to the first surface, the second surface being angularly positioned relative to the longitudinal axis of the pipe members such that the second sur:Eace is angularly displaced -therefrom in the range from between approximately 0 to 20, and a third surface located adjacent to the second surface, the third surface being angularly positioned relative to -the second surface such tha-t the -third surface i5 in angular displacement therefrom in -the range from approximately 10 to 75, the group of three adjacent sealing surfaces being positioned respectively on -the male and female elements such that when the male and female elements are threadingly secured together, the sealing surfaces associated with the male and female elements sealingly engage one another to form -three independent adjacent pressure-tight seals.
According to yet another embodiment of the present invention there is provided joinder means Eor connecting -together to adjacent pipe members in fluid/pressure tight relationship wi-th each other, the joinder means including a male element having an externally threaded end portion and a female element having an in-ternally threaded end portion coopera-tively engageable with the threaded portion of the male element, the male element having a group of three adjacent sealing surfaces positioned axially rearward of the male threaded portion and the female element having a group of three adjacent complementary sealing surfaces positioned axially forward of the female threaded portion, each of the group of three adjacent sealing surfaces including a first surface angularly positioned rela-tive to the longitudinal axis oE -the pipe members such that the first surface is ,~
angularly displaced therefrom in the range Erom between approximately 90 -to 125, a second surEace located adjacent to the first surface, -the second surface being angularly positioned relative to the longitudinal axis of the pipe members such that the second surface is angularly displaced therefrom in the range from between approximately 0 to 20, and a third surface located adjacent to the second surface, the third surface being angularly positioned relative to the second surface such that the third surface is in angular displacement therefrom in the range from approximately 10 to 75, the group of three adjacent sealing surfaces being positioned respectively on the male and female elements such that when the male and female elements are threadingly secured together, the sealing surfaces associated with the male and female elements sealingly engage one ano-ther to form three independent adjacent pressure-tight seals.
According to a preferred embodiment the connector means of the present invention comprises a sealing arrangement wherein three independent adjacent metal-to-metal pressure seals are formed whenever the male and female elements of the subject connection are properly made-up power-tight. In particular, the male element o~ the present construction includes an externally threaded extremi-ty or pin portion having an unthreaded annular section positioned axially Eorward of -the male threaded area. This unthreaded section lies subs-tantially adjacent the terminal end of the pin and includes three adjacen-t sealing surfaces.
Similarly, the female element of the present construction includes an internally threaded extremity or box portion having a corresponding unthreaded annular section positioned axially rearward of the female threaded area. The unthreaded section of the female extremity likewise includes three complementary adjacen-t annular sealing surfaces such -that when the ~1 7~
pin and box portions of the subjec-t connector are -threadedly secured together, the three sealin~
surEaces associated respectively therewith seal.in~ly engage one another thereby forming three independent adjacent positive metal-to-meta:L pressure seals. The three adjacent pressure seals of the present invention are likewise arranged in an irregular pattern relative to each o-ther so as to provide maximum resistance to pressure leakage due to damage, distortion, or failure of any two pressure seals in the subject seal group.
Therefore, even if two of -the -three independent sealing surfaces associ.ated with the male and female elements of the present connector means are damaged -thereby preventing the sealing surfaces from properly seating, the remaining pressure seal in the subject seal group will still seat properly and prevent leakage. Additionally, the sealing surfaces forming the third pressure seal of the present invention are so positioned relative to the adjacent sealing surfaces as -to subs-tantially negate the possibility of damage thereto thereby effectively ensuring a-t least one pressure-tight seal at all times.
The sealing arrangement of the present invention is ideally suited for use on both an integral joint system and on a coupled joint system and additional seals may likewise be integrated into the subject connection without negating -the proprietary nature of the invention. The subject seal group may likewise be utilized as a sealing system Eor constraining bo-th internal and external pressures, depending upon the position and location of the seal group in the connection.
A feature of one embodiment of the present invention provides improved means for sealing between adjacent connected -together pipe members, particularly, pipe members used in oil and gas well drilling and production operations.
- 8a -Another feature of one embodiment oE the present :invention provides a multiple sealing sys-tem wh.ich effectively eliminates leakage prohlems a-t the ~oints of joinder between adjacent pipes.
Another feature of one embodiment oE the presen-t invention provides a multiple sealing system which ensures maximum sealing integrity at the points of joinder between adjacent pipes.
Another feature o-E one embodiment of -the present invention provides an improved pressure seal wherein the sealing arrangement includes three independent adjacent pressure seals.
Another feature of one embodiment of the present invention provides an irnproved connector means wherein the three independent adjacent pressure seals are arranged in an irregular pattern relative to each other so as to provide a redundant sealing system.
Another feature of one embodimen-t of the present invention provides an improved pressure seal arrangement wherein the sealing surfaces associated with at least one of said pressure seals are so positioned as to substantially negate the possibility of damage thereto during make-up of the joint connection.
Another feature of one embodiment of the present invention -teaches the construction of a multiple sealing system which includes three adjacent positive metal-to-metal pressure seals adaptable for use in all well casing and tubing applications.
Another feature of one embodiment of the present invention provides improved connec-tor means wherein the seal group placement is designed to accept normal field handling without undue damage.
Another feature of one embodiment of the present invention provides an improved pressure seal group which remains pressure tight after repea-ted make-up and break-out of the seal arrangement.
- 8b -7S)8~
Another feature of one embodiment oE the present invention teaches the construction oE an improved pressure sealing arrangement e~hibiting repea-table sealing capability.
Another fea-ture of one embodiment oE -the present invention provides joinder means for pipes that provide a premium seal therebetween without the use of additional sealer materials or other subs-tances.
Another feature of one embodiment oE the present invention provides an improved pressure sealing arrangement which is streamlined n construction to facilitate the well running operation.
Another feature of one embodiment of -the present invention teaches the construction and operation of a multiple sealing system adaptable Eor use in both an integral joint connection and a coupled joint connection.
These and other features and advantages of the present invention will become apparent -to those skilled in the art after considering the following detailed specification which discloses - 8c-sevecal representative em~odiments of the present pipe joining and sealin~ means in conjunction With the accompanying drawings.
BRIEF DESCRIPTION OF 'rHE DR~WING
FIGURE l is a partial cut-away cross-sectional view showing portions of two adjacent pipes connected together according to tne teachings of one embodiment of the present invention;
FIGURE 2 is a partial cross-sectional view showing an alternative embodiment for sealingly connecting together two adjacent pipes, said joinder means disclosing an internally shouldered connection;
FIGURE 3 is an exploded side elevational view of portions of two adjacent pipes utilizing the connector means shown in FIGURE 2;
FIGURE 4 is a partial cross-sectional view similar to :FIGURE 2 s~owing another embodiment for sealingly connecting together two adjacent pipes, said joinder means disclosing an externally shouldered connection;
FIGURE 5 is a partial cut away cross-sectional view similar to FIGURE l showing still another embodiment Eor sealingly connecting together two adjacent pipes, said joinder means disclosing both an internally and an e~ternally shouldered connection; and FIGURE 6 is an enlarged partial cross-sectional view of the sealing arrangement illustrated in FIGURES 1-5.
DETAIL:ED DESCRIPTION_OF THE INVENTION
Referring to the drawings more particularly by reference numbers wherein like numerals refer to like parts, the number l0 in FIGURE l illustrates a portion of two adjacent tubular pipes 12 and 14 constructed and connected together in fluid/pressure tight relationship with each othec according ~o the teaching oE
one embodiment of the present invention. Tne sealing means 30 employed by the present invention comprises a positive metal-to-metal pressure sealing system which includes three separate adjacent sealing surfaces integrally formed adjacent one end portion of the male element of the present joinder means and a corresponding sealing surface arrangement integrally formed adjacent one end portion oE the female element of the present joinder means, said complementary sealing surfaces being cooperatively engagable with each other whenever the male and female elements of the peesent connection are properly secured together. The multiple sealing system 30 of the present invention produces three independent adjacent pressure seals positioned and arranged in an irregular pattern so as to achieve maximum sealing integrity at all times as ~est illustrated in FIGURE 6.
In the preferred embodiment as shown in FIGURE 1, the present pipe joinder means is utilized in a coupled joint arrangement wherein two male elements are joined together by means of a female coupling device 20. In particular, tne pipes 12 and 14 each include a maLe extremity or pin portion 16,- each pin portion 16 including a tapered externally threaded surEace area such as the threaded portion 18. Each pin portion 16 also includes an unthreaded portion as shown at 30, said unthreaded portion being positioned axially Eorward of the threaded area 18 and including the three adjacent sealing surfaces of tne present invention as will be hereinafter more fully described. A
coupling connector 20 in the form of a dou~le female sleeve member is utilized to sealingly connect together the respective pin portions 16 of the adjacent pipe members 12 and 14. The ~3~
coupling 20 is unitary in construction and includes an annular portion 22 having an opening 24 extending therethrough adaptable to communicate with the Eluid opening extending through the respective pipe members 12 and 14. Although the size of the opening 24 need not correspond to the size of the fLuid opening extending through the pipes 12 and 14, it is generally preferred that the diameter of the opening 24 correspond substantially to the inner diameter of the tubular members 12 and 14 so as not to interfere with or otherwise resteict the flow of fluid or gas therethrough, The coupling or collar 20 also includes an elongated annular flange or box portion 26 extending outwardly away from the annular portion 22 on each opposite side thereof, each annular flange 26 forming a cavity 27 adaptable fof receiving the pin 16 of the pipes 12 and 1~. Each cavity 27 lies in communication with the opening 24 and each Elange 26 is provided with a tapered internally threaded surface area 28 extending circumferentiaLly along the inside portion thereof adaptable to threadingly engage the tnreaded portion 18 of the pipes 12 and 14. Each flange 26 also includes a corresponding unthreaded portion positioned axially rearward of the threaded area 28, said unthreaded portion likewise including three complementary sealing surfaces adapted to mate with and engage the corresponding sealing surfaces associated with the male pin 16 as shown at 30. Although the tapered shape of the threaded areas 18 and 28 allows easier introduction of the male pin 16 into the female box 26 and reduces the possibility of damage to the female threads 28 during assem~ly of the connection, it is recognized that any thread form including non-tapered threads may be utilized in the present inventionO For example, the ~
mating threaded areas 1~ and 2~ may De either stralght or tapered, they may possess radial clearance or tightness, and their dimensionaL requirements may assume a wide variety of shapes and sizes.
Tne seal arrangement 30 of the present invention is accomplished by positioning one group of three adjacent sealing surfaces axially forward of the male threaded area 18 adjacent the terminal end of pin member 16 and positioning a second complementary group of three adjacent sealing surEaces axially rearward of the female threaded area 28 such tnat when the male and female elements 16 and 26 are threadedly engaged, the respective sealing surfaces mate with and enyage one another so as to form three adjacent independent metal-to-metal pressure seals as shown at 30 in FIGU~ES 1 and 6. Each seal surface group arrangement associated with the male and femaLe elements of the present invention includes a first annular sealing surface 32 positioned such that the plane of the surface 32 forms the angle A which a plane positioned parallel to the longitudinal axis of the pipes to be joi.ned together (FIGURE 6), the angle A ~eing generally in the eange from between approximately 90 to 125. Wl~en the male and female eLements 16 and 26 respectively are threadingly engaged and made-up power-tight, the respective suefaces 32 are placed in sealing abutment witn each other tnereby forming the first pressure seal.
of the present invention. The sealing surface or shoulder 32 associated with the female element 26 limits the axial travel of the rnale element 16 into the internal threaded cavity 27 of the female element 26 and serves as the primary torque generator so important for ensuring that the joint connection will not vi~rate apart during running and pumping operations. Although '7~3 it is generally preferred that the angle A be in the range Erom about 90 to 12~, positioning oE the seal surEaces 32 such that the angle A is greater than 125 may also provide suitable results 50 long as the size of the angle A permits a disengageable connection between the elements 16 and 26 in spite of the friction generated at the zone of a~utment.
Each seal surface group associated with the seal arrangelnent 30 includes a second annular sealing surface 34 positioned adjacent the first sealing surface 3~ such that the plane of the surface 34 lies in a plane substantially parallel to the longitudinal axis of the pipes to ~e joined together (FIGURE 6). When the male and female elements 16 and 26 respectively are threadingly secured and made-up power tight, the sealing surfaces 34 form the second adjacent positive metal-to-metal pressure seal of the present invention. This pressure seal is a flank seal or an extremely low angle seal in comparison to the first positive pressure seal formed by the sealing surfaces 32. It is important that the second sea1 formed by the mating surfaces 34 lie substantially parallel to the longitudinal axis of the connected pipe so that a slight stand-off of the first pressure seal formed by the sealing surfaces 32, which stand-off may be caused by the trapping of foreign material therebetween or other damage to the surfaces 32, will not neutralize and/or eliminate the sealing capability of the second pressure seal. Normally, the threads L8 and 28 associated with the male and female elements are on sucn a slight tapered angle that the sealing surfaces 34 can be machined so as to form the angle B with a plane positioned parallel to the longitudinal axis of the connected pipe, the angle B being in the range from approximately 1 to 5, although *~
slightly greater angles up to approximately 20 may :Likewise be utilized. However, it should be noted that as the angle B
~etween the sealing surEaces 34 and the longitudinal axis of the connected pipe increases, the second pressure seal formed ~y the engagement of the surfaces 34 becomes more sensitive in tnat any stand-off associated wih the first sealing surfaces 32 may cause a corresponding stand-off oE the second sealing surfaces 34.
This may produce some deterioration of the sealing capability of the second pressure seal, whicn problem can be avoided by positioning the sealing surfaces 34 such that tne angle B is in the range of about 1 to 5. In this situation, even if tne first sealing surfaces 32 are damaged or otherwise defective prior to joinder, the eelatively small inclination of the sealing surfaces 34 relative to the longitudinal axis of the connected pipe (angle B) s-till allows generation of the second pressure seal even if the damage to the first sealing surfaces 32 restricts make-up of the connection. The second pressure seal tnerefore acts as a back-up seal and ensures seal int~grity between the first and second pressuce seals.
Each seal surface group associated with the seaL
arrangement 30 also includes a third annular sealing surface 36 positioned adjacent the second sealing surface 34 such that, when mated together in abuttirlg relationship as previously descriDed, the sealing surfaces 36 form the third adjacent positive metal-to-metal pressure seal of the seal arrangement 30 (FIGURE 6). The complementary sealing surfaces 36 are positioned such that they form the angle C with a plane positioned parallel to the longitudinal axis of the connect pipe, the angle C being greater than the angle B as snown in FIGURE 6. It is important that the sealing surfaces 36 be t~70~
machinecl on an angle greater than the inclination of the seaLing surfaces 34 so t~at a third adjacent independent pressure seaL
is generated. Since the sealing surEaces 32 and 34 are most susGeptible to damage during normal Eield handling and installation, this third pressure seal provides a still further ~ack-up seal in the event tnat ~oth tne first and second seals Eormed by the surfaces 32 and 34 lose t~eir sealing capability.
Since this third pressure seal is positioned axially directly behind and adjacent the first and second pressure seals of the 10 seal group 30 and the seal surfaces 36 are inclined away from the sealing surfaces 32 and 34, the surfaces 36 are substantially less susceptible to damage prior to joinder. Tne seal arrangement 30 therefore provides a multiple redundant sealing system which maximizes the sealing integrity of the joint and increases its reliability even after repeated make-up and break-out of the joint. Although any inclination of the sealing surfaces 36 geeater than the inclination of the sealing surfaces 34 will produce satisfactory sealing capability, it is generally preferred that the inclination of tne surfaces 36 20 relative to the surEaces 34, namely, angle D (FIGURE 6), be in the range from approximately 10 to 75.
The seal arrangement 30 of the present invention is likewise easily adaptable for use on an integral joint system as shown in FIGURES 2-4. FIGURES 2 and 3 illustrate the connecting together of two adjacent pipes 38 and 40 wherein the female extremity or ~ox portion 42 is integrally formed on one end portion of the pipe 40 and includes an internally threaded area 44 adaptable for threadingly receiving the externally -threaded area 48 associated with the pin portion 46 of the adjacent pipe 38. The pin 46 and the box 42 are constructed and connected ~f~ 7~
together in a manner suostantially similar to the construction and joinder of the pin 16 and the box 26 (FIGURE 1) and each includes the three adjacent sealing surfaces 32-36 as previously descri~ed. ~hen the pipes 38 and 40 are properly made-up power-tight, the respective sealing surfaces 32-36 associated with the pin 46 sealingly mate with tne complementary surfaces 32-36 associated with the box 42 to produce the seal arrangement 30 of the present invention. Incorporation of the female extremity or box 42 on one end portion of the pipe ~0 eliminates the need of an additional coupling member such as the coupling connector 20. It should be noted that since the seal group 30 shown in FIGURES 1 and 2 lies adjacent to the inner diametee of the connected pipes, this connection is known as an inteenally shouldered connection and is ideally suited for controlling and sealing internal pressure within the string of pipes.
FIGURE 4 illustrates an integral joint connection similar to the connection disclosed in FIGU~ES 2 and 3 wherein the mating together of adjacent pipes 50 and 52 produces an externally shouldered connection. In particular, the pipe 50 includes an externally threaded extremity oc pin portion 54 having the three annual sealing surfaces 32-36 posi~ioned axially rearward of the male threaded area 56 as shown at 30.
Correspondingly, the pipe 52 includes an internally threaded extremity or box portion 58 having complementary sealing surfaces 32-36 positioned axially forward of the female threaded area 60 substantially adjacent the terminal end of the female extremity or box 58. In this arrangement~ when the male and female extremities 54 and 58 respectively are properly threadedly secured, the seaL group 30 of the present invention is formed adjacent the external surface of the pipes 50 and 52 ~ 3~
thereby pcoducing an externally snouldered connection. In comparison to the internally shouldered connection illustrated in FIGWRES 1-3, the externally shouldered connection oE FIGURE
is ideally suited for controlling and sealing external pressure. ~ith respect to the coupling arrangement illustrated in FIGURE l, it is also anticipated that the pin 16 and box 26 can likewise ~e constructed to form an externally shouldered connection as illustrated in FIGURE 4.
FIGURE 5 ilLustrates another coupled joint connec~ion 61 similar to the connection disclosed in FIGURE l wherein the mating together of adjacent pipes 62 and 64 produces both an internally and an externally shouldered connection. In the embodiment oE FIGURE 5, the pipes 62 and 64 each include an externally threaded extremity or pin portion 66 having the three annular sealing surfaces 32-36 of the present invention positioned and arranged axially adjacent both opposite ends of the male threaded portion 68 as shown at 30. CorrespondingLy, the coupling connector 70 includes an internally threaded extremity or ~ox portion 72 on each opposite end thereof substantially similar to the construction of the coupling connector 20 (FIGURE l). Each box portion 72 likewise includes complementary sealing surEaces 32-36 positioned and arranged axially adjacent both opposlte ends of the female threaded portion 74 as also shown at 30. In this arrangement, when the male and female extremities 66 and 72 respectively are pcoperly threadedly secured as previously described, the seal group 30 of the present invention is Eormed adjacent the inner diameter of the connected pipes 62 and 64 thereby producing an internally shouldered connection adjacent the terminal end of the respective male pin portions 66, and the present seal group 30 a~3 is also formed adjacent the external sur~ace of the pipes 62 and 64 theceby producing an externally shouldered connection adjacent the terminal end of the respective female box portions 72. The coupled joint arrangement 61 ~herefore produces both an internally and an externally shouldered connection and is ideally suited for simultaneously controlling and sealing both internal and external pressures.
As can be seen, the sealing arrangement 30 of the present invention provides a multiple redundant sealing system which ensures maximum sealing integrit~ of the made-up joint at all times, even when some of the sealing surfaces experience damage or are otherwise defective. As previously explained, the sealing surfaces 32-36 are specifically positioned as hereinbefore described so as to protect each other Erom possible damage during running operations just prior to make-up. There are basically two types of possible damage which may occur to the sealing surfaces 32-36 during running operations, namely, axial impact damage and radial impact damage. Either type of damage will cause a cut, dent or other deformation to the sealing surfaces which may cause deterioration of the seal formed by the damaged sealing surEaces. The positioning and inclination of the sealing surfaces 36 associated with the seal arrangement 30 is specifically designed to substantially negate the possibility of damage thereto during running operations thereby ensuring at least one pressure-tight seal at all times.
In particular, the sealing surfaces 36 are less susceptible to radial impact damage due to the fact that they are positioned sufficiently axially rearwacd with respect to the sealing surfaces 34 so as to protect them from radial damage. In addition, the sealing surfaces 32 and 34 ~oth protect the surEaces 36 from axial impact damage. Additionally, the sealing capability of ttle sealing surfaces are often times neutralized due to corrosion wnich often develops from trapped moisture during storage. Tne present sealing arrangement 30 substantially reduces this occurrence since corrosion would have to attack and neutralize all three sealing surfaces 32-36.
Therefore~ the present invention produces a seal arrangement 30 whicn provides adequate redundancy in the sealing system to allow seal generation even if dalnage to the connection occurs prior to make-up of -the joint connection.
It is important to note that in order to machine a group of complementary sealing surfaces such as tne surfaces 32, 34, and 36 so that all such surfaces engage in sealing relationship with each other when mated together requires a machine tool or lathe capable of fa~rica-ting parts to tolerances ~iyhter than +.OOL inches. Similarly, it should be noted tnat the complementary threads la and 28 should be free of any defects which may break their continuity. Thread defects include imperfections such as visible tears, cuts, grinds, shoulders, or any other discontinuity such as seams, overlaps, pits~ tool marks, dents, handLing damage and so forth. In addition, the pin and box threads should be of SuCh form and finish and should be machined uniformly within the specific limits to assure interchangeability and the ability to withstand power make-up and brea~-out WithOut injury to the threads or tne seal surfaces associated witn either member. The threads 18 and 28 and the respective sealing surfaces 32, 34 and 36 should likewise be treated so as to minimize galling and maximize the leak resistant characteristics of the joint. For example, the mating threads and the sealing surfaces may be coated With manganese phospate or moly-disulfide or t~ey may be plated with zinc, chrome or any other surface treatment~ In addition, the pin shou1ders and bo~ faces should be free oE any defects which would cause a faLse stand-off of the joint in the made~up position. Additionally, the sealing surfaces 32, 3~ and 36 shouLd be finished in a manner to assure a pressuee-tight joint when properly made-up power-tight. 'rhe made-up joint should also be shou1der-tight. The shoulders or sealing surfaces 32 provide the stop that positions the engaging sealing surfaces 34 and 36 in their proper interference fit. ~'he sealing surfaces shouLd also have a surface Einish free of any defects which could cause surface galling of the mating surEaces when tne joint is made-up properly. Because of the criticality of the tolerances involved in machining the sealing surfaces 32-36 and the associated threads such as the threads 18 and 28, considerable skill and know-how is required in both the tooling and machining of the present joinder means.
The general configuration of the connection means incorporating the seal group 30 could be greatly varied since the thread form and the generaL shape of the male and female elements is not relative to the performance of tne present seal arrangement as previously explained. The overall thickness and length of the three adjacent sea:Ls of the present invention may likewise be varied to meet any particular job requirement. In addition, the present seal arrangement 30 may be utilized on well tu~ing and/or casing, or other pipe membees regardless of whether said pipes are forged, upset, non-upset, cold or hot swagged~ Additionally, other seals may likewise be incorporated into the present connector means without negating the proprietary nature of this invention such as including ~ ~37~
additional theeads, teflon rings, or other additional metal seals placed in other areas of the subject connection. The present seaL group 30 may also ~e utili~ed as a multiple sealing system Eor contraining internal and/or external pressure depending upon the location of the subject seal group in the mated connection as previously explained.
Thus there nad been shown and described novel means for joining and sealingly connecting together two adjacent pipe members, which joinder means fulfills all the objects and advantages sought therefor. Many changes, modifications, variations, and other uses and applications of tne present constructions will, however, become apparent to those skilled in tne art after considering this specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.
AND_GAS WELL TUBING OR T~IE LIKE
The present invention relates to a joinder means Eor use in connecting together oil and gas well tubing and/or casing, and more particularly, to several embodiments of a joinder arrangement wherein three independent adjacent metal-to-metal pressure seals are utilized as the primary sealing means to assure a pressure-tight joint when the male and female elements of the connection are properly secured together. The present sealing arrangement is ideally suited Eor use as a premium connector and provides a multiple sealing system which ensures maximum sealing integrity. Although the present sealing arrangement is primarily designed for use in connecting together oil and gas well tubing and/or casing, the present sealing arrangement is likewise adaptable for use in a multiplicity of other pipe joinder applications.
8ACKGROUND OF THE INVE~TION
The oil and gas industry has been continually drilling wells deeper and deeper into extremely high underground pressure areas or zones, which zones many times contain hostile and coreosive chemicals such as hydrogen ~sulfide. To compLete a well for oil and/or gas production normally requires cementing casing in the well hole to prevent cave-ins and other phenomenon both during and after the drilling operation. Once the casing is positioned within the well hole, tubular pipes of reduced diameter, commonly known as tubing, are positioned within the well casing and extend the full length thereof for effectively carrying the hydrocarbons and gases contained within the production formation to the surface. These tubular pipes or tubing are manufactured ~y steel mills in average lengths of -1- ~ .
approximately 30 to ~0 feet and tnerefore must be connected or joined together as they are lowered into the well by means of mechanical connector devices. Connectors ~or t~le tight joinder o~ such well tubing are well known in the petroleum industry.
These connectors perform many functions but their primary function is essentially twofold, namely, (1) to adequately hold the string of pipes together within the weLl hole and (~) to adequately seal the connected togethee tubular members against the internal and/or external pressures commonly associated with drilling for and pumping oil and/or gas. Hereinbefoee, pressure seals were simply created by interEerence fit of the male and female threads associated with the respective tubing to be joined. Such joinder means generally comprises a male extremity or pin associated with one tube element and a female extremity or box associated with the other tube element, each of which is respectively fitted with corresponding threads such that when the male extremity is threadingly positioned into the female extremity, the locking of said threads occurs. This joinder method became inadequate for many wells when well depths reached approximately 10,000 feet due primarily to the higher pressures associated witn the oil and gas formations found at such depths. These related higher pressures have therefore produced a need for connectors or connecting means having a pressure sealing ability capable of adequately withstanding both the internal and external pressures associated With such well depths.
Metal-to-metal pressure seals were first successfully introduced into the oil and yas industry by the ~Iydril Company based upon Stone U.S. Patent No. 2,006,520. The seal disclosed in the Stone patent was based upon a wedged fit between a seal surEace on the male extremity or pin and a corresponding seal `~ r ~ 3 surface associated with the Eemale extremity or boxt which sur-Eaces engaged just prior to shouldeeing. Although this sealing arrangement provides an effective seaL, it functions WithOUt any back-up sealing means in case of failure, a feature necessary for maximum sealing integrity in today's deep well environment. In addition, the sealing arrangement of Stone is also very susceptible to handling damage due to its location on the connector. If the seal element surfaces are even slightly scratched or otherwise damaged, the seal will not seat properly and the gas and/or oil pressures generated during drilling and pumping operations will easily move past the seal area and into the connector body where such pressure will eventually or immediately cause failure. Long term storage of the known prior art connectors also causes problems in that such storage causes the sealing surfaces to deteriocate due to pitting and other corrosion, all of which cause deterioration of the sealing capability of the connector. Such failures cannot be tolerated not only because they are very expensive but also, and more importantly, because they are extremely dangerous to the lives of those working in the area of the well.
A successful incorporation of two adjacent metal seals in a coupling device was marketed by Vallourec SteeL and is disclosed in Duret U.S. Patent No. 3,489,437. This sealing arrangement has been fairly successful except that, again, it is highly suscepti~le to damage during normal field handling and during running operations. For example, iE the double seal surfaces of Duret are even slightly dented, nicked, or galled prior to make-up of the connection, such defects will cause the pressure seals formed by the mating of said seal surfaces to deteriorate and the associated pressures will again migrate ~r~
through the seal area causing leakage and/or -joint faiLure. In addition, the Duret sealing configuration is extremely sensitive to leakage and/or failure due to the sharpness of the angles of the seal element surfaces relative to the Longitudinal axis oE
the pipe. For example, if any foreign matter, not matter how small, is trapped between the seal surfaces during make-up, the respective seals will not seat properly and therefore will not provide an adequate pressure seal. Because of its sensitivity and susceptibility to im~proper seating due to damage caused during field handling, stabbing, and other phases of a drilling operation, this sealing arrangement is not widely utilized in the United States.
It rapidly became apparent that back-up seal elements were necessary for insurance against pressure leaks and the often resulting connector failures associated tnerewith~ ~any independent sealing devices such as rings and gas~ets have been utilized as botn back-up and prima~y seals. The two most effective seals in use today utilize teflon seal elements trapped or at least partially trapped in the joinder connection so as to block any pressure from mlgrating therethrough. These seals were marketed by Atlas 13radford of N.L. Industries, Inc.
and are disclosed in Taylor U.S. Patent No. 2,9~0,45L and ~ehring U.S. Patent No. 3,047,316. ~hese sealing rings and/or gaskets have ser~ed well as back-up sealing elements. However, the effectiveness of such sealing means has deteriorated within the last ten years due to the fact that oil and gas well drillings have reached well depths far beyond 10,000 feet and, in addition, drilling to such depths has exposed the well tubing and its connections to many corrosive elements such as hydrogen sulfide. As a result, seal failures have also occurred due to 3~
the corrosive effect of hydrogen sulfide. Most hydrogen sulfide ~ailures are associated with high stress levels in the metal connectors. The teflon seal rings generate very high stress levels during make-up of the connection in order to obtain an ade~uate pressure sealing barrier and thereEore are highly susceptible to sucn corrosive failure. In addition, replacement of one or more defective sealing rings is extremely time consuming and costly since the defective portion of the string of pipe must be tripped out of and then ~ack into the well hole. This pro~lem is accented in the international marketplace where stocking of replacement parts is always a problem and very expensive.
Consequently, no known joinder means utilized in drilling opeeations for connecting together a series of tubular pipes incorporates an adequate combination of pressure seals for ensuring maximum sealing integrity at all times. In addition, none of the known prior art devices are as effective and reliable as the present construction and none utilizes a sealing arrangement which is not easily destroyed or neutralized by damage or other defects arising during storage, normal field handling, stabbing and running operations, or any other drilling activity.
SUMMARY O THE INVE_TION
The present connector means overcomes many of the disadvantages and shortcomings associated with known pipe joinder means, and teaches the construction and operation o~
several emoodiments of an improved connector means for coupling together tubular pipes, in particular, tubular pipes used in well drilling operations wnich are subjected to substantial pressures, corrosive chemicals, physical stresses and ~2~
construction hazards as the depth of the wells go deepe:r and deeper.
In one embodiment of ~he present invention there is provided connector means for joining together two adjacent pipe members comprising a male member having an externally threaded portion associated therewith and an unthreaded annular portion positioned axially adjacent the threaded portion, a female member having an internally threaded portion associated therewith adaptable for cooperatively engaging the threaded portion of the male member, the female member including a corresponding unthreaded annular portion positioned axially adjacent the female threaded portion, the unthreaded portions respectively including three complemen-tary adjacent annular sealing surfaces arranged in an irre-gular pattern such that when the male and female m~mbers arethreadingly secured together, the three adjacent sealing surfaces associated respectively with the male and female members sealingly engage one another to form three inde-pendent adjacent pressure-tight seals wherein the three adjacent sealing surfaces include a first surface angularly positioned relative to the longitudinal axis of the pipe members such that the angular displacement of the first surface relative to the longitudinal axis is in a ran~e from between approximately 90 to 125, a second surface angu-larly positioned relative to the longitudinal axis of thepipe members such that the second surface lies in a plane substantially parallel to the longitudinal axis of the pipe members, and a third surface angularly positioned relative to the longitudinal axis of the pipe members such that the angular displacement of the third surface relative to the longitudinal axis is greater than the angular displacement of the second s~lrface relative to the longitudinal axis.
According to another embodiment of the present inven-tion there is provided joinder means for connecting together two adjacent pipe members in fluid/pressure tight relation-, . , ~iJ
~7~
- 6a -ship with each other, the joinder means including a male element having an externally threaded end port:ion and a female element having an internally threaded end portion cooperatively engageable with the threaded port.ion of the male element, the male element having a group of three adjacent sealing surfaces positioned axially forward of the male threaded portion and the female element having a group of three adjacent complementary sealing surfaces positioned axially rearward of the female threaded portion, each of the lo group of three adjacent sealing surfaces including a fixst surface angularly positioned relative to the longitudinal axis ~~'7~ 3 of the pipe members such that the f.irst sur:Eace :is angularly displaced -there:Erom in t.he range from between approxlma-tely 90 to 125, a second su.rEace located adjacent to the first surface, the second surface being angularly positioned relative to the longitudinal axis of the pipe members such that the second sur:Eace is angularly displaced -therefrom in the range from between approximately 0 to 20, and a third surface located adjacent to the second surface, the third surface being angularly positioned relative to -the second surface such tha-t the -third surface i5 in angular displacement therefrom in -the range from approximately 10 to 75, the group of three adjacent sealing surfaces being positioned respectively on -the male and female elements such that when the male and female elements are threadingly secured together, the sealing surfaces associated with the male and female elements sealingly engage one another to form -three independent adjacent pressure-tight seals.
According to yet another embodiment of the present invention there is provided joinder means Eor connecting -together to adjacent pipe members in fluid/pressure tight relationship wi-th each other, the joinder means including a male element having an externally threaded end portion and a female element having an in-ternally threaded end portion coopera-tively engageable with the threaded portion of the male element, the male element having a group of three adjacent sealing surfaces positioned axially rearward of the male threaded portion and the female element having a group of three adjacent complementary sealing surfaces positioned axially forward of the female threaded portion, each of the group of three adjacent sealing surfaces including a first surface angularly positioned rela-tive to the longitudinal axis oE -the pipe members such that the first surface is ,~
angularly displaced therefrom in the range Erom between approximately 90 -to 125, a second surEace located adjacent to the first surface, -the second surface being angularly positioned relative to the longitudinal axis of the pipe members such that the second surface is angularly displaced therefrom in the range from between approximately 0 to 20, and a third surface located adjacent to the second surface, the third surface being angularly positioned relative to the second surface such that the third surface is in angular displacement therefrom in the range from approximately 10 to 75, the group of three adjacent sealing surfaces being positioned respectively on the male and female elements such that when the male and female elements are threadingly secured together, the sealing surfaces associated with the male and female elements sealingly engage one ano-ther to form three independent adjacent pressure-tight seals.
According to a preferred embodiment the connector means of the present invention comprises a sealing arrangement wherein three independent adjacent metal-to-metal pressure seals are formed whenever the male and female elements of the subject connection are properly made-up power-tight. In particular, the male element o~ the present construction includes an externally threaded extremi-ty or pin portion having an unthreaded annular section positioned axially Eorward of -the male threaded area. This unthreaded section lies subs-tantially adjacent the terminal end of the pin and includes three adjacen-t sealing surfaces.
Similarly, the female element of the present construction includes an internally threaded extremity or box portion having a corresponding unthreaded annular section positioned axially rearward of the female threaded area. The unthreaded section of the female extremity likewise includes three complementary adjacen-t annular sealing surfaces such -that when the ~1 7~
pin and box portions of the subjec-t connector are -threadedly secured together, the three sealin~
surEaces associated respectively therewith seal.in~ly engage one another thereby forming three independent adjacent positive metal-to-meta:L pressure seals. The three adjacent pressure seals of the present invention are likewise arranged in an irregular pattern relative to each o-ther so as to provide maximum resistance to pressure leakage due to damage, distortion, or failure of any two pressure seals in the subject seal group.
Therefore, even if two of -the -three independent sealing surfaces associ.ated with the male and female elements of the present connector means are damaged -thereby preventing the sealing surfaces from properly seating, the remaining pressure seal in the subject seal group will still seat properly and prevent leakage. Additionally, the sealing surfaces forming the third pressure seal of the present invention are so positioned relative to the adjacent sealing surfaces as -to subs-tantially negate the possibility of damage thereto thereby effectively ensuring a-t least one pressure-tight seal at all times.
The sealing arrangement of the present invention is ideally suited for use on both an integral joint system and on a coupled joint system and additional seals may likewise be integrated into the subject connection without negating -the proprietary nature of the invention. The subject seal group may likewise be utilized as a sealing system Eor constraining bo-th internal and external pressures, depending upon the position and location of the seal group in the connection.
A feature of one embodiment of the present invention provides improved means for sealing between adjacent connected -together pipe members, particularly, pipe members used in oil and gas well drilling and production operations.
- 8a -Another feature of one embodiment oE the present :invention provides a multiple sealing sys-tem wh.ich effectively eliminates leakage prohlems a-t the ~oints of joinder between adjacent pipes.
Another feature of one embodiment oE the presen-t invention provides a multiple sealing system which ensures maximum sealing integrity at the points of joinder between adjacent pipes.
Another feature o-E one embodiment of -the present invention provides an improved pressure seal wherein the sealing arrangement includes three independent adjacent pressure seals.
Another feature of one embodiment of the present invention provides an irnproved connector means wherein the three independent adjacent pressure seals are arranged in an irregular pattern relative to each other so as to provide a redundant sealing system.
Another feature of one embodimen-t of the present invention provides an improved pressure seal arrangement wherein the sealing surfaces associated with at least one of said pressure seals are so positioned as to substantially negate the possibility of damage thereto during make-up of the joint connection.
Another feature of one embodiment of the present invention -teaches the construction of a multiple sealing system which includes three adjacent positive metal-to-metal pressure seals adaptable for use in all well casing and tubing applications.
Another feature of one embodiment of the present invention provides improved connec-tor means wherein the seal group placement is designed to accept normal field handling without undue damage.
Another feature of one embodiment of the present invention provides an improved pressure seal group which remains pressure tight after repea-ted make-up and break-out of the seal arrangement.
- 8b -7S)8~
Another feature of one embodiment oE the present invention teaches the construction oE an improved pressure sealing arrangement e~hibiting repea-table sealing capability.
Another fea-ture of one embodiment oE -the present invention provides joinder means for pipes that provide a premium seal therebetween without the use of additional sealer materials or other subs-tances.
Another feature of one embodiment oE the present invention provides an improved pressure sealing arrangement which is streamlined n construction to facilitate the well running operation.
Another feature of one embodiment of -the present invention teaches the construction and operation of a multiple sealing system adaptable Eor use in both an integral joint connection and a coupled joint connection.
These and other features and advantages of the present invention will become apparent -to those skilled in the art after considering the following detailed specification which discloses - 8c-sevecal representative em~odiments of the present pipe joining and sealin~ means in conjunction With the accompanying drawings.
BRIEF DESCRIPTION OF 'rHE DR~WING
FIGURE l is a partial cut-away cross-sectional view showing portions of two adjacent pipes connected together according to tne teachings of one embodiment of the present invention;
FIGURE 2 is a partial cross-sectional view showing an alternative embodiment for sealingly connecting together two adjacent pipes, said joinder means disclosing an internally shouldered connection;
FIGURE 3 is an exploded side elevational view of portions of two adjacent pipes utilizing the connector means shown in FIGURE 2;
FIGURE 4 is a partial cross-sectional view similar to :FIGURE 2 s~owing another embodiment for sealingly connecting together two adjacent pipes, said joinder means disclosing an externally shouldered connection;
FIGURE 5 is a partial cut away cross-sectional view similar to FIGURE l showing still another embodiment Eor sealingly connecting together two adjacent pipes, said joinder means disclosing both an internally and an e~ternally shouldered connection; and FIGURE 6 is an enlarged partial cross-sectional view of the sealing arrangement illustrated in FIGURES 1-5.
DETAIL:ED DESCRIPTION_OF THE INVENTION
Referring to the drawings more particularly by reference numbers wherein like numerals refer to like parts, the number l0 in FIGURE l illustrates a portion of two adjacent tubular pipes 12 and 14 constructed and connected together in fluid/pressure tight relationship with each othec according ~o the teaching oE
one embodiment of the present invention. Tne sealing means 30 employed by the present invention comprises a positive metal-to-metal pressure sealing system which includes three separate adjacent sealing surfaces integrally formed adjacent one end portion of the male element of the present joinder means and a corresponding sealing surface arrangement integrally formed adjacent one end portion oE the female element of the present joinder means, said complementary sealing surfaces being cooperatively engagable with each other whenever the male and female elements of the peesent connection are properly secured together. The multiple sealing system 30 of the present invention produces three independent adjacent pressure seals positioned and arranged in an irregular pattern so as to achieve maximum sealing integrity at all times as ~est illustrated in FIGURE 6.
In the preferred embodiment as shown in FIGURE 1, the present pipe joinder means is utilized in a coupled joint arrangement wherein two male elements are joined together by means of a female coupling device 20. In particular, tne pipes 12 and 14 each include a maLe extremity or pin portion 16,- each pin portion 16 including a tapered externally threaded surEace area such as the threaded portion 18. Each pin portion 16 also includes an unthreaded portion as shown at 30, said unthreaded portion being positioned axially Eorward of the threaded area 18 and including the three adjacent sealing surfaces of tne present invention as will be hereinafter more fully described. A
coupling connector 20 in the form of a dou~le female sleeve member is utilized to sealingly connect together the respective pin portions 16 of the adjacent pipe members 12 and 14. The ~3~
coupling 20 is unitary in construction and includes an annular portion 22 having an opening 24 extending therethrough adaptable to communicate with the Eluid opening extending through the respective pipe members 12 and 14. Although the size of the opening 24 need not correspond to the size of the fLuid opening extending through the pipes 12 and 14, it is generally preferred that the diameter of the opening 24 correspond substantially to the inner diameter of the tubular members 12 and 14 so as not to interfere with or otherwise resteict the flow of fluid or gas therethrough, The coupling or collar 20 also includes an elongated annular flange or box portion 26 extending outwardly away from the annular portion 22 on each opposite side thereof, each annular flange 26 forming a cavity 27 adaptable fof receiving the pin 16 of the pipes 12 and 1~. Each cavity 27 lies in communication with the opening 24 and each Elange 26 is provided with a tapered internally threaded surface area 28 extending circumferentiaLly along the inside portion thereof adaptable to threadingly engage the tnreaded portion 18 of the pipes 12 and 14. Each flange 26 also includes a corresponding unthreaded portion positioned axially rearward of the threaded area 28, said unthreaded portion likewise including three complementary sealing surfaces adapted to mate with and engage the corresponding sealing surfaces associated with the male pin 16 as shown at 30. Although the tapered shape of the threaded areas 18 and 28 allows easier introduction of the male pin 16 into the female box 26 and reduces the possibility of damage to the female threads 28 during assem~ly of the connection, it is recognized that any thread form including non-tapered threads may be utilized in the present inventionO For example, the ~
mating threaded areas 1~ and 2~ may De either stralght or tapered, they may possess radial clearance or tightness, and their dimensionaL requirements may assume a wide variety of shapes and sizes.
Tne seal arrangement 30 of the present invention is accomplished by positioning one group of three adjacent sealing surfaces axially forward of the male threaded area 18 adjacent the terminal end of pin member 16 and positioning a second complementary group of three adjacent sealing surEaces axially rearward of the female threaded area 28 such tnat when the male and female elements 16 and 26 are threadedly engaged, the respective sealing surfaces mate with and enyage one another so as to form three adjacent independent metal-to-metal pressure seals as shown at 30 in FIGU~ES 1 and 6. Each seal surface group arrangement associated with the male and femaLe elements of the present invention includes a first annular sealing surface 32 positioned such that the plane of the surface 32 forms the angle A which a plane positioned parallel to the longitudinal axis of the pipes to be joi.ned together (FIGURE 6), the angle A ~eing generally in the eange from between approximately 90 to 125. Wl~en the male and female eLements 16 and 26 respectively are threadingly engaged and made-up power-tight, the respective suefaces 32 are placed in sealing abutment witn each other tnereby forming the first pressure seal.
of the present invention. The sealing surface or shoulder 32 associated with the female element 26 limits the axial travel of the rnale element 16 into the internal threaded cavity 27 of the female element 26 and serves as the primary torque generator so important for ensuring that the joint connection will not vi~rate apart during running and pumping operations. Although '7~3 it is generally preferred that the angle A be in the range Erom about 90 to 12~, positioning oE the seal surEaces 32 such that the angle A is greater than 125 may also provide suitable results 50 long as the size of the angle A permits a disengageable connection between the elements 16 and 26 in spite of the friction generated at the zone of a~utment.
Each seal surface group associated with the seal arrangelnent 30 includes a second annular sealing surface 34 positioned adjacent the first sealing surface 3~ such that the plane of the surface 34 lies in a plane substantially parallel to the longitudinal axis of the pipes to ~e joined together (FIGURE 6). When the male and female elements 16 and 26 respectively are threadingly secured and made-up power tight, the sealing surfaces 34 form the second adjacent positive metal-to-metal pressure seal of the present invention. This pressure seal is a flank seal or an extremely low angle seal in comparison to the first positive pressure seal formed by the sealing surfaces 32. It is important that the second sea1 formed by the mating surfaces 34 lie substantially parallel to the longitudinal axis of the connected pipe so that a slight stand-off of the first pressure seal formed by the sealing surfaces 32, which stand-off may be caused by the trapping of foreign material therebetween or other damage to the surfaces 32, will not neutralize and/or eliminate the sealing capability of the second pressure seal. Normally, the threads L8 and 28 associated with the male and female elements are on sucn a slight tapered angle that the sealing surfaces 34 can be machined so as to form the angle B with a plane positioned parallel to the longitudinal axis of the connected pipe, the angle B being in the range from approximately 1 to 5, although *~
slightly greater angles up to approximately 20 may :Likewise be utilized. However, it should be noted that as the angle B
~etween the sealing surEaces 34 and the longitudinal axis of the connected pipe increases, the second pressure seal formed ~y the engagement of the surfaces 34 becomes more sensitive in tnat any stand-off associated wih the first sealing surfaces 32 may cause a corresponding stand-off oE the second sealing surfaces 34.
This may produce some deterioration of the sealing capability of the second pressure seal, whicn problem can be avoided by positioning the sealing surfaces 34 such that tne angle B is in the range of about 1 to 5. In this situation, even if tne first sealing surfaces 32 are damaged or otherwise defective prior to joinder, the eelatively small inclination of the sealing surfaces 34 relative to the longitudinal axis of the connected pipe (angle B) s-till allows generation of the second pressure seal even if the damage to the first sealing surfaces 32 restricts make-up of the connection. The second pressure seal tnerefore acts as a back-up seal and ensures seal int~grity between the first and second pressuce seals.
Each seal surface group associated with the seaL
arrangement 30 also includes a third annular sealing surface 36 positioned adjacent the second sealing surface 34 such that, when mated together in abuttirlg relationship as previously descriDed, the sealing surfaces 36 form the third adjacent positive metal-to-metal pressure seal of the seal arrangement 30 (FIGURE 6). The complementary sealing surfaces 36 are positioned such that they form the angle C with a plane positioned parallel to the longitudinal axis of the connect pipe, the angle C being greater than the angle B as snown in FIGURE 6. It is important that the sealing surfaces 36 be t~70~
machinecl on an angle greater than the inclination of the seaLing surfaces 34 so t~at a third adjacent independent pressure seaL
is generated. Since the sealing surEaces 32 and 34 are most susGeptible to damage during normal Eield handling and installation, this third pressure seal provides a still further ~ack-up seal in the event tnat ~oth tne first and second seals Eormed by the surfaces 32 and 34 lose t~eir sealing capability.
Since this third pressure seal is positioned axially directly behind and adjacent the first and second pressure seals of the 10 seal group 30 and the seal surfaces 36 are inclined away from the sealing surfaces 32 and 34, the surfaces 36 are substantially less susceptible to damage prior to joinder. Tne seal arrangement 30 therefore provides a multiple redundant sealing system which maximizes the sealing integrity of the joint and increases its reliability even after repeated make-up and break-out of the joint. Although any inclination of the sealing surfaces 36 geeater than the inclination of the sealing surfaces 34 will produce satisfactory sealing capability, it is generally preferred that the inclination of tne surfaces 36 20 relative to the surEaces 34, namely, angle D (FIGURE 6), be in the range from approximately 10 to 75.
The seal arrangement 30 of the present invention is likewise easily adaptable for use on an integral joint system as shown in FIGURES 2-4. FIGURES 2 and 3 illustrate the connecting together of two adjacent pipes 38 and 40 wherein the female extremity or ~ox portion 42 is integrally formed on one end portion of the pipe 40 and includes an internally threaded area 44 adaptable for threadingly receiving the externally -threaded area 48 associated with the pin portion 46 of the adjacent pipe 38. The pin 46 and the box 42 are constructed and connected ~f~ 7~
together in a manner suostantially similar to the construction and joinder of the pin 16 and the box 26 (FIGURE 1) and each includes the three adjacent sealing surfaces 32-36 as previously descri~ed. ~hen the pipes 38 and 40 are properly made-up power-tight, the respective sealing surfaces 32-36 associated with the pin 46 sealingly mate with tne complementary surfaces 32-36 associated with the box 42 to produce the seal arrangement 30 of the present invention. Incorporation of the female extremity or box 42 on one end portion of the pipe ~0 eliminates the need of an additional coupling member such as the coupling connector 20. It should be noted that since the seal group 30 shown in FIGURES 1 and 2 lies adjacent to the inner diametee of the connected pipes, this connection is known as an inteenally shouldered connection and is ideally suited for controlling and sealing internal pressure within the string of pipes.
FIGURE 4 illustrates an integral joint connection similar to the connection disclosed in FIGU~ES 2 and 3 wherein the mating together of adjacent pipes 50 and 52 produces an externally shouldered connection. In particular, the pipe 50 includes an externally threaded extremity oc pin portion 54 having the three annual sealing surfaces 32-36 posi~ioned axially rearward of the male threaded area 56 as shown at 30.
Correspondingly, the pipe 52 includes an internally threaded extremity or box portion 58 having complementary sealing surfaces 32-36 positioned axially forward of the female threaded area 60 substantially adjacent the terminal end of the female extremity or box 58. In this arrangement~ when the male and female extremities 54 and 58 respectively are properly threadedly secured, the seaL group 30 of the present invention is formed adjacent the external surface of the pipes 50 and 52 ~ 3~
thereby pcoducing an externally snouldered connection. In comparison to the internally shouldered connection illustrated in FIGWRES 1-3, the externally shouldered connection oE FIGURE
is ideally suited for controlling and sealing external pressure. ~ith respect to the coupling arrangement illustrated in FIGURE l, it is also anticipated that the pin 16 and box 26 can likewise ~e constructed to form an externally shouldered connection as illustrated in FIGURE 4.
FIGURE 5 ilLustrates another coupled joint connec~ion 61 similar to the connection disclosed in FIGURE l wherein the mating together of adjacent pipes 62 and 64 produces both an internally and an externally shouldered connection. In the embodiment oE FIGURE 5, the pipes 62 and 64 each include an externally threaded extremity or pin portion 66 having the three annular sealing surfaces 32-36 of the present invention positioned and arranged axially adjacent both opposite ends of the male threaded portion 68 as shown at 30. CorrespondingLy, the coupling connector 70 includes an internally threaded extremity or ~ox portion 72 on each opposite end thereof substantially similar to the construction of the coupling connector 20 (FIGURE l). Each box portion 72 likewise includes complementary sealing surEaces 32-36 positioned and arranged axially adjacent both opposlte ends of the female threaded portion 74 as also shown at 30. In this arrangement, when the male and female extremities 66 and 72 respectively are pcoperly threadedly secured as previously described, the seal group 30 of the present invention is Eormed adjacent the inner diameter of the connected pipes 62 and 64 thereby producing an internally shouldered connection adjacent the terminal end of the respective male pin portions 66, and the present seal group 30 a~3 is also formed adjacent the external sur~ace of the pipes 62 and 64 theceby producing an externally shouldered connection adjacent the terminal end of the respective female box portions 72. The coupled joint arrangement 61 ~herefore produces both an internally and an externally shouldered connection and is ideally suited for simultaneously controlling and sealing both internal and external pressures.
As can be seen, the sealing arrangement 30 of the present invention provides a multiple redundant sealing system which ensures maximum sealing integrit~ of the made-up joint at all times, even when some of the sealing surfaces experience damage or are otherwise defective. As previously explained, the sealing surfaces 32-36 are specifically positioned as hereinbefore described so as to protect each other Erom possible damage during running operations just prior to make-up. There are basically two types of possible damage which may occur to the sealing surfaces 32-36 during running operations, namely, axial impact damage and radial impact damage. Either type of damage will cause a cut, dent or other deformation to the sealing surfaces which may cause deterioration of the seal formed by the damaged sealing surEaces. The positioning and inclination of the sealing surfaces 36 associated with the seal arrangement 30 is specifically designed to substantially negate the possibility of damage thereto during running operations thereby ensuring at least one pressure-tight seal at all times.
In particular, the sealing surfaces 36 are less susceptible to radial impact damage due to the fact that they are positioned sufficiently axially rearwacd with respect to the sealing surfaces 34 so as to protect them from radial damage. In addition, the sealing surfaces 32 and 34 ~oth protect the surEaces 36 from axial impact damage. Additionally, the sealing capability of ttle sealing surfaces are often times neutralized due to corrosion wnich often develops from trapped moisture during storage. Tne present sealing arrangement 30 substantially reduces this occurrence since corrosion would have to attack and neutralize all three sealing surfaces 32-36.
Therefore~ the present invention produces a seal arrangement 30 whicn provides adequate redundancy in the sealing system to allow seal generation even if dalnage to the connection occurs prior to make-up of -the joint connection.
It is important to note that in order to machine a group of complementary sealing surfaces such as tne surfaces 32, 34, and 36 so that all such surfaces engage in sealing relationship with each other when mated together requires a machine tool or lathe capable of fa~rica-ting parts to tolerances ~iyhter than +.OOL inches. Similarly, it should be noted tnat the complementary threads la and 28 should be free of any defects which may break their continuity. Thread defects include imperfections such as visible tears, cuts, grinds, shoulders, or any other discontinuity such as seams, overlaps, pits~ tool marks, dents, handLing damage and so forth. In addition, the pin and box threads should be of SuCh form and finish and should be machined uniformly within the specific limits to assure interchangeability and the ability to withstand power make-up and brea~-out WithOut injury to the threads or tne seal surfaces associated witn either member. The threads 18 and 28 and the respective sealing surfaces 32, 34 and 36 should likewise be treated so as to minimize galling and maximize the leak resistant characteristics of the joint. For example, the mating threads and the sealing surfaces may be coated With manganese phospate or moly-disulfide or t~ey may be plated with zinc, chrome or any other surface treatment~ In addition, the pin shou1ders and bo~ faces should be free oE any defects which would cause a faLse stand-off of the joint in the made~up position. Additionally, the sealing surfaces 32, 3~ and 36 shouLd be finished in a manner to assure a pressuee-tight joint when properly made-up power-tight. 'rhe made-up joint should also be shou1der-tight. The shoulders or sealing surfaces 32 provide the stop that positions the engaging sealing surfaces 34 and 36 in their proper interference fit. ~'he sealing surfaces shouLd also have a surface Einish free of any defects which could cause surface galling of the mating surEaces when tne joint is made-up properly. Because of the criticality of the tolerances involved in machining the sealing surfaces 32-36 and the associated threads such as the threads 18 and 28, considerable skill and know-how is required in both the tooling and machining of the present joinder means.
The general configuration of the connection means incorporating the seal group 30 could be greatly varied since the thread form and the generaL shape of the male and female elements is not relative to the performance of tne present seal arrangement as previously explained. The overall thickness and length of the three adjacent sea:Ls of the present invention may likewise be varied to meet any particular job requirement. In addition, the present seal arrangement 30 may be utilized on well tu~ing and/or casing, or other pipe membees regardless of whether said pipes are forged, upset, non-upset, cold or hot swagged~ Additionally, other seals may likewise be incorporated into the present connector means without negating the proprietary nature of this invention such as including ~ ~37~
additional theeads, teflon rings, or other additional metal seals placed in other areas of the subject connection. The present seaL group 30 may also ~e utili~ed as a multiple sealing system Eor contraining internal and/or external pressure depending upon the location of the subject seal group in the mated connection as previously explained.
Thus there nad been shown and described novel means for joining and sealingly connecting together two adjacent pipe members, which joinder means fulfills all the objects and advantages sought therefor. Many changes, modifications, variations, and other uses and applications of tne present constructions will, however, become apparent to those skilled in tne art after considering this specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.
Claims (14)
1. Connector means for joining together two adjacent pipe members comprising a male member having an externally threaded portion associated therewith and an unthreaded annular portion positioned axially adjacent said threaded portion, a female member having an internally threaded portion associated therewith adaptable for cooperatively engaging the threaded portion of said male member, said female member including a corresponding unthreaded annular portion positioned axially adjacent said female threaded portion, said unthreaded portions respectively including three complementary adjacent annular sealing surfaces arranged in an irregular pattern such that when said male and female members are threadingly secured together, the three adjacent sealing surfaces associated respectively with the male and female members sealingly engage one another to form three independent adjacent pressure-tight seals, wherein the three adjacent sealing surfaces include a first surface angularly positioned relative to the longitudinal axis of the pipe members such that the angular displacement of the first surface relative to the longitudinal axis is in a range from between approximately 90° to 125°, a second surface angularly positioned relative to the longitudinal axis of the pipe members such that the second surface lies in a plane substantially parallel to the longitudinal axis of the pipe members, and a third surface angularly posi-tioned relative to the longitudinal axis of the pipe members such that the angular displacement of the third surface relative to the longitudinal axis is greater than the angu-lar displacement of the second surface relative to the longitudinal axis.
2. The connector means defined in claim 1 wherein the three adjacent sealing surfaces associated with said male member are positioned axially forward of said male threaded portion, and wherein the three complementary adjacent seal-ing surfaces associated with said female member are posi-tioned axially rearward of said female threaded portion.
3. The connector means defined in claim 1 wherein the three adjacent sealing surfaces associated with said male member are positioned axially rearward of said male threaded portion, and wherein the three complementary adjacent seal-ing surfaces associated with said female member are posi-tioned axially forward of said female threaded portion.
4. The connector means defined in claim 1 wherein said female member is incorporated into a coupling connector, said coupling connector having a female member positioned on both opposite ends thereof.
5. The connector means defined in claim 1 wherein said second surface forms an angle in the range from between approximately 0° to 20° with a plane parallel to the longi-tudinal axis of said pipe members.
6. The connector means defined in claim 1 wherein the threaded portions associated with said male and female members are correspondingly tapered.
7. The connector means defined in claim 1 wherein said three adjacent sealing surfaces are positioned and arranged on said male and female members respectively so as to form an externally shouldered connection.
8. The connector means defined in claim 1 wherein said three adjacent sealing surfaces are positioned and arranged on said male and female members respectively so as to form an internally shouldered connection.
9. The connector means defined in claim 1 wherein said three adjacent sealing surfaces are positioned and arranged axially adjacent both opposite ends of the threaded portion associated respectively with said male and female members so as to form an internally shouldered connection adjacent the terminal end of said male member and an externally shoul-dered connection adjacent the terminal end of said female member.
10. Joinder means for connecting together two adjacent pipe members in fluid/pressure tight relationship with each other, said joinder means including a male element having an externally threaded end portion and a female element having an internally threaded end portion cooperatively engageable with the threaded portion of said male element, said male element having a group of three adjacent sealing surfaces positioned axially forward of said male threaded portion and said female element having a group of three adjacent comple-mentary sealing surfaces positioned axially rearward of said female threaded portion, each of said group of three adja-cent sealing surfaces including a first surface angularly positioned relative to the longitudinal axis of said pipe members such that said first surface is angularly displaced therefrom in the range from between approximately 90° to 125°, a second surface located adjacent to said first sur-face, said second surface being angularly positioned rela-tive to the longitudinal axis of said pipe members such that said second surface is angularly displaced therefrom in the range from between approximately 0° to 20°, and a third sur-face located adjacent to said second surface, said third surface being angularly positioned relative to said second surface such that said third surface is angularly displaced therefrom in the range from approximately 10° to 75°, said group of three adjacent sealing surfaces being positioned respectively on said male and female elements such that when said male and female elements are threadingly secured together, the sealing surfaces associated with said male and female elements sealingly engage one another to form three independent adjacent pressure-tight seals.
11. The joinder means defined in claim 10 wherein said female element is incorporated into a coupling connector, said coupling connector having a female element positioned on both opposite ends thereof.
12. The joinder means defined in claim 10 including a group of three adjacent sealing surfaces positioned axially rearward of said male threaded portion and a corresponding group of three adjacent complementary sealing surfaces positioned axially forward of said female threaded portion, said groups of adjacent sealing surfaces being arranged such that when said male and female elements are threadingly secured together, said sealing surfaces form an internally shouldered connection adjacent the terminal end of said male element and an externally shouldered connection adjacent the terminal end of said female element.
13. Joinder means for connecting together to adjacent pipe members in fluid/pressure tight relationship with each other, said joinder means including a male element having an externally threaded end portion and a female element having an internally threaded end portion cooperatively engageable with the threaded portion of said male element, said male element having a group of three adjacent sealing surfaces positioned axially rearward of said male threaded portion and said female element having a group of three adjacent complementary sealing surfaces positioned axially forward of said female threaded portion, each of said group of three adjacent sealing surfaces including a first surface angu-larly positioned relative to the longitudinal axis of said pipe members such that said first surface is angularly dis-placed therefrom in the range from between approximately 90°
to 125°, a second surface located adjacent to said first surface, said second surface being angularly positioned relative to the longitudinal axis of said pipe members such that said second surface is angularly displaced therefrom in the range from between approximately 0° to 20°, and a third surface located adjacent to said second surface, said third surface being angularly positioned relative to said second surface such that said third surface is angularly displaced therefrom in the range from approximately 10° to 75°, said group of three adjacent sealing surfaces being positioned respectively on said male and female elements such that when said male and female elements are threadingly secured together, the sealing surfaces associated with said male and female elements sealingly engage one another to form three independent adjacent pressure-tight seals.
to 125°, a second surface located adjacent to said first surface, said second surface being angularly positioned relative to the longitudinal axis of said pipe members such that said second surface is angularly displaced therefrom in the range from between approximately 0° to 20°, and a third surface located adjacent to said second surface, said third surface being angularly positioned relative to said second surface such that said third surface is angularly displaced therefrom in the range from approximately 10° to 75°, said group of three adjacent sealing surfaces being positioned respectively on said male and female elements such that when said male and female elements are threadingly secured together, the sealing surfaces associated with said male and female elements sealingly engage one another to form three independent adjacent pressure-tight seals.
14. The joinder means defined in claim 13 wherein said female element is incorporated into a coupling connector, said coupling connector having a female element positioned on both opposite ends thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000487258A CA1287080C (en) | 1985-07-22 | 1985-07-22 | Connector means for use on oil and gas well tubing or the like |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000487258A CA1287080C (en) | 1985-07-22 | 1985-07-22 | Connector means for use on oil and gas well tubing or the like |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1287080C true CA1287080C (en) | 1991-07-30 |
Family
ID=4131022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000487258A Expired - Lifetime CA1287080C (en) | 1985-07-22 | 1985-07-22 | Connector means for use on oil and gas well tubing or the like |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1287080C (en) |
-
1985
- 1985-07-22 CA CA000487258A patent/CA1287080C/en not_active Expired - Lifetime
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKLA | Lapsed |
Effective date: 19980730 |