The present disclosure is related to expandable packing elements, packing element cartridge, and methods of deploying packing element cartridge in sealing oil and gas wells.
Packers are commonly used in the oil and gas industry for drilling, intervention or well completion systems to provide a seal between the outside of production tubing and the inside of a wellbore wall, which may be open or include a casing or liner. A packer generally includes a sealing device, a holding or setting device, and an inside passage for fluids. Packer elements, i.e., a part of the sealing device, encircle the packing element cartridge and are designed to expand against casing or wellbore wall. The packing elements are commonly made of elastomers, which may limit their low and high temperature ratings as well as chemical resistance. Parts forming a packing assembly, i.e., the tools used in running and setting a packer, are designed to be mounted as separate parts in situ. This results in relatively complex assembly procedures and requires specialized personnel. Field re-dress, consequently, may become relatively difficult.
Due to the limited amount of expansion that packer elements are generally capable of, it is normal that packer elements of more than one size in outer diameter are necessary to seal casings of various weight ranges. Seal performance may also be improved using anti-extrusion parts, such as springs, or other low expansion backup systems to improve sealing. Accordingly, packer design may be weight range specific, requiring tool changes when the packers are run and set in various casing weight ranges. While expandable packing elements, such as inflatable, swellable and cup seals, are available for a wide range of seal bore sizes, they have relative low pressure ratings, limiting their application. In addition, such expandable elements may not be retrievable.
Therefore, room remains for the improvement of packing elements and packing element subassemblies, particularly in expandability, pressure rating, temperature rating, retrieve-ability and ease of use.
An aspect of the present disclosure relates to a packing element comprising a tube having a longitudinal length. The tube includes a first end and a second end opposing the first end, an external portion including a plurality of circumferential ribs, and an internal portion opposing the external portion. The internal portion of the tube includes i) a central portion extending along a portion of the longitudinal length of the tube between the first end and second end of the tube, wherein the central portion includes a relief, ii) a first tapered portion radially tapering along the longitudinal length from the central portion towards the first end of the tube, and iii) a second tapered portion tapering along the longitudinal length from the central portion towards the second end of the tube.
Another aspect of the present disclosure relates to a packing element cartridge. The packing element cartridge includes a tubular housing having a longitudinal length and a mandrel including a first ramped surface and a first portion that is positioned within the tubular housing and is slidable longitudinally relative to the tubular housing. In addition, the tubular housing includes a second ramped surface opposing the first ramped surface of the tubular housing. A packing element, as described above, is disposed around the mandrel, wherein the first proximal portion and the second proximal portion of the packing element slidably contact the ramped surfaces. Upon moving the mandrel longitudinally into the tubular housing, a distance between the ramped surfaces decreases and the tapered portions of the packing element slide up the ramped surfaces, radially expanding the packing element. Upon moving the mandrel longitudinally out from the tubular housing, the distance between the ramped surfaces increases and the tapered portions of the packing element slide down the ramped surfaces, radially contracting the packing element.
A further aspect of the present disclosure relates to a method of deploying a packing element cartridge. The method includes running a packing element cartridge between a wellbore and production pipe and moving the mandrel longitudinally into said tubular housing. Upon moving the mandrel longitudinally into the tubular housing, a distance between the ramped surfaces of the mandrel and tubular housing decreases and the tapered portions of the packing element described above slide up the ramped surfaces, radially expanding the packing element.
Yet an additional aspect of the present disclosure relates to a well bore including a well bore annulus and a packing element cartridge placed within said annulus. The packing element cartridge includes a tubular housing having a longitudinal length and a mandrel including a first ramped surface and a first portion that is positioned within the tubular housing and is slidable longitudinally relative to the tubular housing. In addition, the tubular housing includes a second ramped surface opposing the first ramped surface of the tubular housing. A packing element, as described above, is disposed around the mandrel, wherein the first proximal portion and the second proximal portion of the packing element slidably contact the ramped surfaces. Upon moving the mandrel longitudinally into the tubular housing, a distance between the ramped surfaces decreases and the tapered portions of the packing element slide up the ramped surfaces, radially expanding the packing element. Upon moving the mandrel longitudinally out from the tubular housing, the distance between the ramped surfaces increases and the tapered portions of the packing element slide down the ramped surfaces, radially contracting the packing element.
The above-mentioned and other features of this disclosure, and the manner of attaining them, may become more apparent and better understood by reference to the following description of embodiments described herein taken in conjunction with the accompanying drawings, wherein:
In light of the above, the present application is directed to packing elements, packing element cartridges including packing elements, and methods of deploying packing element cartridges in sealing oil and gas wells. The cartridges may be used as stand-alone devices or form a part of downhole tools. The packing element cartridges are run in between a wellbore, i.e., the open hole drilled through the earth, and production pipe, i.e., the pipe used to extract the oil or gas. In embodiments, casings or liners are present in the wellbores and the packing element cartridges are run in between the casings or liners and the production pipe. The packing element cartridges herein are adaptable to a variety of bore sizes such as, for example, wellbores having a diameter in the range of 5.75 to 12.0 inches (nominal), including all values and ranges therein, such as 5.875 inches to 6.30 inches, 6.125 inches, 8.5 inches, 9.25 inches, 9.625 etc. For liner packers, the diameter may be in there range of 6 inches to 6.5 inches, covering 7 inch liner weights from 20 lb/ft to 32 lb/ft, including all values and ranges therein. The packing element cartridge may provide relatively high expansion, in the range of 10% to 20% relative to the gauge diameter, including all values and ranges therein, and pressure ratings of at least 10 ksi to 25 ksi, including all values and ranges therein.
The external portion 112 of the tube 102, forming the outer surface of the tube 102, may include a plurality of ribs 116, each extending partially or completely around the tube in a circumferential manner, arranged along the length of the tube 102. Alternatively, the ribs 116 may be formed from one or more ribs wrapped spirally or radially around the tube 102. As illustrated, the ribs 116 are formed along the entire length Lp of the tube 102. However, in embodiments, the ribs may be spaced along the length of the tube and flat surfaces may be present from which the ribs extend.
The internal portion 114 of the tube 102 opposes the external portion or surface 112, forming the inner surface of the tube 102. The internal portion 114 includes a central portion 118, which extends along the longitudinal length Lp of the tube 102 between the first end 104 and the second end 106. In preferred embodiments, the central portion 118 includes a relief 120 formed radially in the surface around axis A-A and may be concave. The relief 120 may have a length that is 15% to 45% of the total length of the tube, including all values and ranges therein, such as 30%. In addition, the relief may have a radius of curvature in the range of 3 inches to 10 inches. The relief 120 may promote greater expansion of the packing element 100, when it is deployed in the wellbore. Furthermore, the relief 120 may allow tension on the sealing element to cause the packing element 100 to collapse.
The central portion 118 may also include lands 122, 124 on either side of the relief. The lands may individually exhibit a length in the range of 2% to 7% of the tube. Including all values and ranges therein. The internal portion 114 also includes opposing tapered portions, i.e., a first tapered portion 126 and a second tapered portion 128 wherein the thickness of the tube 102 is reduced (see t1 and t2) extending along the longitudinal length away from the central portion 118 and towards the first end 104 and second end 106. The length of the tapers may each be in the range of 10% to 30% of the length Lp of the packing element, including all values and ranges therein. Furthermore, the tapers result in a thickness reduction of 25% to 75%, wherein the thickness at the land t1 is greater than the thickness of the taper near the ends of the tube t2, and t2=y*t1, wherein y is in the range of 0.25 to 0.75, including all values and increments therein, such as 0.5. In embodiments, the tapers 126, 128 are radial, i.e., that is the taper is defined around axis A-A.
In addition, the internal portion of the tube 102 may also include collars, i.e., a first collar 132 and a second collar 134, at the opposing ends 104, 106 of the tube 102. The collars may exhibit a thickness t3 of 70% to 90% relative to the lands t1, wherein t2=z*t3, wherein z is in the range of 0.7 to 0.9, including all values and ranges therein and t3>t2. The thinnest portion of the relief, exhibits a 35% to 45% reduction in thickness relative to the collar. The collars may also exhibit a length of 5% to 10% of Lp.
In addition to the features described above, in embodiments such as illustrated in
In any embodiment, the tube 102 is formed from elastomers. In addition, or alternatively, the tube is formed from fluoropolymers. Examples of materials include polytetrafluoroethylene (PTFE), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), fluoroelastomer (FKM) such as VITON, perfluoroelastomer (FFKM) such as KALREZ, ethylene-propylene-diene-monomer (EPDM), and tetrafluoroethylene-propylene (TFE/P). In preferred embodiments, PTFE or fluoroelastomers are used as they may provide additional heat and chemical resistance. The tubes may be formed by machining or from a number of molding methods, including melt flow processes wherein at least a portion of the polymer material is caused to flow under heat and pressure. These processes may include, for example, injection molding, compression molding, transfer molding, etc.
As noted above, the packing elements are employed in downhole tools to create a seal in the annulus between the tool and the borehole. In one embodiment, illustrated in
The mandrel 312 slides longitudinally, telescopically collapsing, at least in part, further into the tubular housing 310 when the packing element cartridge 300 set into place in the wellbore and set. When deployed, the mandrel 312 collapses and moves longitudinally along axis B-B into the tubular housing 310, reducing the length of the packing element cartridge 300. For example, the setting stroke Ss, the distance that the mandrel travels into the tubular housing, may be up to 20% of the overall length Lt of the packing element cartridge 300 when fully expanded, including all values and ranges therein.
In embodiments, the exterior surface 314 of the tubular housing includes radial taper 316 extending around central axis B-B of the packing element cartridge 300, which may be concentric with the central axis of the packing element A-A. In addition, the taper 316 extends towards interior surface 318 and the central portion 320 of the packing element cartridge. In such a manner a first end 322 of the tubular housing 310 has a smaller thickness than the opposing second end 324. The exterior surface 328 of the mandrel 312 also includes a taper 330 around the radius of the mandrel 312 extending towards the interior surface 332 and central portion 320 of the packing element cartridge forming the elongated hollow shaft 313. The tapers 316, 330 are disposed at opposing angles α, β, respectively, in the range of 5° to 15° relative to the central axis B-B, including all values and increments therein, such as 10°. Angles α, β may be equal or different.
In addition, the tubular housing and mandrel include opposing ramped surfaces 338, 340. As illustrated the opposing ramped surfaces are formed from split cones, but the ramped surfaces may also be machined into the mandrel. An example of the split cones, cone 338 is illustrated in
In embodiments, illustrated in
As illustrated in
It may therefore be appreciated that when the mandrel 312 collapses telescopically into the tubular housing 310, the first ramped surface 338 is stationary relative to the mandrel 312 and moves relative to the tubular housing 310 and the second ramped surface 340. On the other hand, when the mandrel 312 is collapsed, the mandrel 312 moves relative to the second ramped surface 340 (or vice versa) and the second ramped surface 340 remains stationary relative to the tubular housing 310.
In addition, referring again to
At each end of the packing element 104, 106 are provided back-ups or radially tapered split rings 360, 362. The split rings may be formed from low alloy steel, such as AISI 4140. In addition, other materials may be used as well such as S13Cr stainless steel, L80 steel, 13% Cr steel, INCONEL 718, etc. The radially tapered split rings may prevent the extrusion or deformation of the packing element into the annulus between the mandrel, or the tubular housing, and the well bore. In addition, the radially tapered split rings may aid in centering the packing element within the borehole. In embodiments, the tapered split rings also improve sealing performance at relatively high pressure, such as in the range of 10 ksi to 25 ksi, including all values and ranges therein, such as from 15 ksi to 22.5 ksi, and achieve sealing in bigger hole sizes, having an expansion in the range of 10% to 20% relative to the gauge diameter, including all values and ranges therein.
The split ring also includes a step or shoulder 365 in the inner surface 363, which extends radially around the split ring 360, where the inner diameter expands and continues to taper toward the second side 366. The step 365 is positioned 10% to 30% along the longitudinal length Ls, including all values and ranges therein, from the first side 364 of the split ring 360. When the mandrel is collapsed into the tubular housing, the step 365 may engage abutment shoulders 367, 369 provided on the mandrel 312 and tubular housing 310 as illustrated in
The split ring includes a split 368 from one end 364 to the second end 366 allowing the ring to open and expand as the packing element 100 expands. The split also extends radially around at least a portion of the circumference of the split ring between the first end 364 and the second end 366. As illustrated in
Or, in further embodiments, the split may form other geometries. For example, the split may extend at an angle to the central axis around the circumference of the split ring and then extend back, wherein the split forms one or more points or fingers. In other embodiments, the split may follow a straight line from the first end to the second end, which may be parallel to or at an angle to the central axis of the split ring. In addition, the split ring 360 includes a mating profile 370 that mates with an end of the packing element (see 104, 106 in
As illustrated in
Referring again to
Specifically, at the pressure side, fluid pressure pushes the packing element in one end until deflection occurs due to compression opening a gap between the packing element and the tapers on the mandrel, allowing the ingress of fluid. Fluid is prevented from flowing out the other side by the packing element sealing against the back-ups and ramped surfaces. The packing element end and the split may expand in the range of 10% to 20% relative to the gauge diameter, including all values and ranges therein, ring at the pressure side and the splits on the split cones.
Piston gauge rings and gauge shoulders 396, 398 may be provided on either end of the packing element cartridge 300. The piston gauge rings may protect the packing element cartridge against damage when running in the hole. Furthermore, the gauge rings provide engagement surfaces for activating and expanding or collapsing the packing element cartridge.
In embodiments, one or more seals are provided between the packing element cartridge 300 and the production pipe 400. As illustrated a first seal 402 is positioned in a first channel 404 defined in the inner surface 332 of the mandrel 312. A second seal 406 is positioned in a second channel 408 defined in the inner surface 318 of the tubular housing 310. The seals may extend out from the channels and contact the production pipe surface. Alternatively, 1, 3 and up to 10 seals may be present along the length of the packing element cartridge 300. The seals may exhibit one of a variety of geometries such as “T” seals, “S” seals, oval seals, square seals, rectangular seals, or other geometries. In preferred embodiments, the seals are “S” seals. In addition, the seals may be formed from an elastomer or a fluoropolymer, such as polytetrafluoroethylene (PTFE), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), fluoroelastomer (FKM) such as VITON, perfluoroelastomer (FFKM) such as KALREZ, ethylene-propylene-diene-monomer (EPDM), and tetrafluoroethylene-propylene (TFE/P).
A shearable body, such as a shear pin, shear screw, shear ring or shear wire, is provided to retain the packing element in the unset or extended position during run in. It may be appreciated that depending on the size and forces required to run in the packing element cartridge more than one shearable body may be utilized. As illustrated in
The embodiment illustrated in
In embodiments, the tubular housing 310′ defines an expanded bore 311′ having a larger diameter Db′ than the diameter Dth′ of the remainder of the tubular housing 310′, which receives the mandrel 312′. The bore 311′ may be open to the inner diameter of the tubular housing 310′ forming a portion of the interior surface 318′ and a shelf 319′ on the interior surface as illustrated. Alternatively, an elongated channel may be provided, wherein a wall separates the elongated channel from the inner diameter of the tubular housing and the wall forms the interior surface. The mandrel also includes an elongated hollow shaft 313′ that fits within the expanded bore 311′, between the interior surface 318′ of the tubular housing 310′ and the production pipe 400′.
Again, the mandrel 312′ slides telescopically collapsing, at least in part, further into the tubular housing 310′ when the packing element cartridge 300′ set into place in the wellbore and set. When deployed the mandrel 312′ collapses and moves longitudinally along axis B′-B′ relative to the tubular housing 310′, reducing the length of the packing element cartridge 300′. For example, the setting stroke Ss′, the distance that the mandrel travels into the tubular housing, may be up to 20% of the overall length Lt′ of the packing element cartridge 300′ when fully expanded, including all values and ranges therein, such as 1% to 20%. The materials used in this embodiment are the same or similar to those described above.
In retrievable embodiments, a spring 315′ is provided between the shelf 319′ of the tubular housing 310′ and the end of the mandrel 312′. As the mandrel 312′ is collapsed into the tubular housing 310′, the spring 315′ is compressed. The spring may include for example a coil spring or a machined spring. A mechanical interlock may be provided to prevent the spring from prematurely forcing the mandrel 312′ back out of the housing. In one embodiment, the shear pin 410′ provided in a through hole 412′ in the mandrel 312′ described above, may be replaced with a relatively high tensile set screw or hardened dowel pin to hold the spring in a compressed manner when deployed. In addition, or alternatively, the packing element 100′ may pre-compress the spring 315′ before the packing element cartridge 300′ is compressed via the guides described further herein. Accordingly, the spring 315′ may be pre-compressed during assembly of the packing element 100′ and prior to running the packing element cartridge downhole.
In addition, similar to the above non-retrievable embodiments, retrievable embodiments include the exterior surface 314′ of the tubular housing includes taper 316′ around the radius of the tubular housing 310′ extending towards in interior surface 318′ and the central portion 320′ of the packing element cartridge. In such a manner a first end 322′ of the tubular housing 310′ has a smaller thickness than the opposing second end 324′. The exterior surface 328′ of the mandrel 312′ also includes a taper 330′ around the radius of the mandrel 312′ extending towards the interior surface 332′ and central portion 320′ of the packing element cartridge. The tapers 316′, 330′ are disposed at opposing angles α′, β′, respectively, in the range of 5° to 15° relative to the central axis B′-B′. Angles α′, β′ may be the same or different.
The tubular housing and mandrel include ramped surfaces 338′, 340′, which may be formed from split cones such as those previously described with reference to
Also similar to the above, referring again to
In retrievable embodiments, when tension is applied to an end of the packing element cartridge 300′ and the packing element 100′ (such as through the guides discussed further below), the mandrel 312′ is pulled at least partially out from the tubular housing 310′. The distance between the ramped surfaces 338′, 340′ increases and the tapered surfaces 126′, 128′ of the packing element 100′ slide back down along the ramped surfaces 338′, 340′. This reduced the diameter of the packing element 100′, which contracts away from the wellbore 303′ and towards the mandrel 312′.
Again, at each end of the packing element 104′, 106′ is provided a back-up or radially tapered split ring 360′, 362′, which are described above with reference to
Again, the split ring also includes a step or shoulder 365′ in the inner surface 363′, which extends radially around the split ring 360′, where the inner diameter expands and continues to taper toward the second side 366′. The step 365′ is positioned 10% to 30% along the longitudinal length Ls′, including all values and ranges therein, from the first side 364′ of the split ring 360′. The inner diameter taper of the split rings 360′, 362′ are complementary to the taper of the mandrel 330′ and tubular housing 316′ respectively, allowing the split rings to slide up and down against the tapers of the mandrel and tubular body, which also provides for expansion and contraction of the packing element 100′.
Also, again, the split ring includes a split 368′ from one end 364′ to the second end 366′ allowing the ring to open and expand as the packing element 100′ expands. The split also extends radially around at least a portion of the circumference of the split ring between the first end 364′ and the second end 366′. As illustrated in
Or, in further embodiments, the split may form other geometries. For example, the split may extend at an angle to the central axis around the circumference of the split ring and then extend back, wherein the split forms one or more points or fingers. In other embodiments, the split may follow a straight line from the first end to the second end, which may be parallel to or at an angle to the central axis of the split ring.
In addition, the split ring 360′ includes a mating profile 370′ that mates with an end of the packing element latch hooks 136′, 138′ (illustrated in
As alluded to above, the split rings 360′, 362′ are again affixed to guides 380′, 382′ that ride in tracks 384′, 386′ or channels defined in the exterior surface 328′ of the mandrel 312′ as illustrated in
Similar to the above embodiments of
Again, in embodiments, one or more seals are provided between the packing element cartridge 300′ and the production pipe 400′. As illustrated a first seal 402′ is positioned in a first channel 404′ defined in the inner surface 332′ of the mandrel 312′. A second seal 406′ is positioned in a second channel 408′ defined in the inner surface 318′ of the tubular housing 310′. The seals may extend out from the channels contacting the production pipe surface. Alternatively, 1, 3 and up to 10 seals may be present along the length of the packing element cartridge 300′. The seals may exhibit one of a variety of geometries such as “S” seals, oval seals, square seals, rectangular seals, or other geometries. In preferred embodiments, the seals are “S” seals. In addition, the seals may be formed from an elastomer or a fluoropolymer, such as polytetrafluoroethylene (PTFE), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), fluoroelastomer (FKM) such as VITON, perfluoroelastomer (FFKM) such as KALREZ, ethylene-propylene-diene-monomer (EPDM), and tetrafluoroethylene-propylene (TFE/P).
Further, as described above, a shearable body 410′, such as a shear pin, shear screw, shear ring or shear wire, is provided to retain the packing element in the unset or extended position during run in. It may be appreciated that depending on the size and forces required to run in the packing element cartridge more than one shearable body may be utilized. As illustrated in
As may be understood from the above, a number of elements between the retrievable and non-retrievable assemblies are shared. Therefore, by changing a few of the elements, e.g., providing or removing a compression spring and removing or providing a locking ring, respectively, the packing element cartridge may be easily converted between retrievable or non-retrieval assemblies.
A method of deploying the packing element cartridge described above is also provided, including running a packing element cartridge in the annulus between a wellbore and production pipe, using an appropriate deployment tool. The packing element cartridge may be deployed as a standalone tool mounted on tubing or run mounted on a downhole tool including packers, plugs, hangers, etc. The setting tool is therefore capable of applying stroke with a minimum setting force. In embodiments, the wellbore includes a liner or a casing and the packing element cartridge is run in between the production pipe and said liner or casing. The packing element cartridge is set by applying a force against the mandrel, moving the mandrel longitudinally into the tubular body and expanding the packing element. Force may be applied by a piston built in a downhole tool where the packing element cartridge is assembled. Stated another way, the setting device forms a part of the tool that the cartridge is mounted on. The method of deploying may include shearing any shearable bodies present between the tubular housing and the mandrel. Once the packing element cartridge is deployed and cavities are formed between the packing element and the mandrel, the cavities are filled with fluid, such as the gas or oil that is being produced by the well.
In further embodiments, the packing element cartridge may be removed from the well. Tension may be applied to the packing element cartridge so as to extend the mandrel relative to the tubular housing, collapsing the packing element and unsetting the packing element cartridge.
The packing element cartridge may be used in well bores for zonal isolation, including fracking, production and injection applications, gravel packing, annular barriers for sand screens and annual barriers for inflow control devices and plugs. Thus, also provided herein is a packing element cartridge as described in the above embodiments, included in a well bore, and particularly within an annulus that is defined within the well bore, such as an annulus defined between 1) between the bore itself and a casing or production pipe or 2) between casings or casing and production pipe. In addition, due to the ability to use fluoropolymers as the packing elements, the packing elements and, therefore, the packing element cartridge may withstand cryogenic temperatures as well as higher temperatures than most of elastomeric elements at lower cost. In some embodiments, the packing element cartridge described herein may also be mounted directly to the production tubing. In such a manner as the tubing is fed into the wellbore, the packing element cartridge is fed with the tubing.
The modular design of the expandable packing element cartridge described herein allows for pre-assembly of the packing element with backup system and carrier body, which may be slid into place as a cartridge of the tool (cartridge) and retained by a fixed body and a linear actuator (piston, sliding sleeve, or other) to set the element by compressing the cartridge. This may simplify the assembly procedure, which is made in a separate process, and facilitates field re-dress. Furthermore, the need for additional slip cone systems may be eliminated, particularly in embodiments where hardened teeth are provided on the back-ups, in a packing element cartridge, plug or hanger.
It may be appreciated that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The embodiments herein may be capable of other embodiments and of being practiced or of being carried out in various ways. Also, it may be appreciated that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Reference to first, second, etc., are for purposes of clarity and do not necessarily imply any particular order. In addition, the components of the individual embodiments described herein are interchangeable with components of any the other embodiments described above.
The foregoing description of several methods and embodiments has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the claims to the precise steps and/or forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be defined by the claims appended hereto.
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Number | Date | Country | |
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20140332239 A1 | Nov 2014 | US |