WO2010145674A1 - Wellbore tubing expansion cone - Google Patents

Wellbore tubing expansion cone Download PDF

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Publication number
WO2010145674A1
WO2010145674A1 PCT/EP2009/004301 EP2009004301W WO2010145674A1 WO 2010145674 A1 WO2010145674 A1 WO 2010145674A1 EP 2009004301 W EP2009004301 W EP 2009004301W WO 2010145674 A1 WO2010145674 A1 WO 2010145674A1
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WO
WIPO (PCT)
Prior art keywords
layer
expansion cone
hardness
multilayer coating
steel structure
Prior art date
Application number
PCT/EP2009/004301
Other languages
French (fr)
Inventor
Steinar Wasa Tverlid
Original Assignee
Statoil Asa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Statoil Asa filed Critical Statoil Asa
Priority to PCT/EP2009/004301 priority Critical patent/WO2010145674A1/en
Publication of WO2010145674A1 publication Critical patent/WO2010145674A1/en

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Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/02Subsoil filtering
    • E21B43/10Setting of casings, screens, liners or the like in wells
    • E21B43/103Setting of casings, screens, liners or the like in wells of expandable casings, screens, liners, or the like
    • E21B43/105Expanding tools specially adapted therefor
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/02Pretreatment of the material to be coated
    • C23C16/0272Deposition of sub-layers, e.g. to promote the adhesion of the main coating
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/40Oxides
    • C23C16/403Oxides of aluminium, magnesium or beryllium
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/04Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
    • C23C28/044Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material coatings specially adapted for cutting tools or wear applications
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/04Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
    • C23C28/048Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material with layers graded in composition or physical properties
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/20Carburising
    • C23C8/22Carburising of ferrous surfaces
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24Nitriding
    • C23C8/26Nitriding of ferrous surfaces
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/80After-treatment
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/10Wear protectors; Centralising devices, e.g. stabilisers
    • E21B17/1085Wear protectors; Blast joints; Hard facing

Definitions

  • the invention relates to a wellbore tubing expansion cone and a method for expanding an inner diameter of a tube portion, in particular a casing tube portion within a wellbore.
  • tubing expansion techniques are used to provide or to repair a casing within a wellbore.
  • the technique is used both for open- hole or cased-hole applications, and further is used to provide casing hangers.
  • the technique makes use of an expansion cone which is pulled or pushed through a tube portion of the casing or the like for radially expanding the inner diameter thereof, while plastically deforming the tube portion.
  • the expansion cone is moved through the tubular portion by a differential hydraulic pressure across the expansion cone itself and/or by a direct mechanical pull or push force.
  • the success of the expansion process fundamentally depends on the frictional conditions between the expansion cone and the wall of the tube. In order to provide for sufficient post-expansion mechanical properties of the tube, it is desirable to minimize friction in order to expand a tube having a wall as thick as possible. Further, the frictional conditions influence the wear mechanism, where galling of the expansion cone on the wall of the tube represents a major challenge.
  • a lubricating solid coating in particular a soft polytetrafluoroethylene (PTFE) lubricating film (WO 2004/067 961 A2).
  • the soft lubricating film coacts with a hard lubricating film provided on the outer surface of the expansion cone, for example a chemically polished chromium nitride coating in the form of a physical-vapor deposited coating (PVD coating).
  • PVD coating physical-vapor deposited coating
  • a lubricant is introduced in between the self-lubricating films.
  • the known lubrication systems are based on solid self-lubricating coatings both on the outer surface of the expansion cone and the inner surface of the tube.
  • the known systems are expensive in case of expanding the casing of a wellbore since it is necessary to coat the entire casing string, which could be as long as 2 km.
  • the known lubricating systems may cause environmental problems, in particular at offshore wellbores.
  • the body of known expansion cones is a steel structure which defines an outer conical circumferential surface portion adapted to expand the tube while being pushed or pulled through the tube.
  • the cone body may be one solid piece or may be composed of several segments, and may be shaped into a double cone axially tapering to the end portions of the double cone.
  • the cone body of known expansion systems is made of relatively hard steel with a supersaturated level of carbon like D2 tool steel (US 2007/0 215 360 A1 ). A high carbon steel like this has proved to be brittle when used for an expansion cone.
  • the expansion cone When used, the expansion cone is subject to a steady high load in a start and stop movement. It was found that tribological systems as known from US 2007/0 215 360 A1 or WO 2004/067 961 A2 tend to undergo a breakdown of the hard self-lubricating coating provided to prevent scuffing and galling in the expansion operation or crushing of the cone body.
  • the invention provides for a wellbore tubing expansion cone comprising a cone body having a steel structure defining an outer conical circumferential surface portion and a coating covering at least the conical surface portion of the steel structure and having a hardness higher than the hardness of the steel structure.
  • the expansion cone is characterized in that the steel structure, at least at its conical surface portion, comprises a subsurface diffusion-modified region hardened to a hardness higher than the hardness of the steel structure underlying the diffusion-modified region, but less than the hardness of the coating covering the diffusion-modified region.
  • the coating is a multilayer coating comprising a plurality of layers arranged one upon the other and the steel structure, the diffusion-modified region and the multilayer coating are adapted to provide a hardness distribution such that the hardness essentially steadily increases towards the outer surface of the cone body.
  • the expansion cone according to the invention overcomes the major problems of known expansion systems.
  • the layer structure of the expansion cone allows choosing the material properties of the steel structure on the one hand and the outermost coating of the cone body on the other hand independently of each other.
  • the multilayer coating can be chosen to show extreme hardness and a low coefficient of friction against steel and/or low chemical reactivity with steel to minimize friction at the interface with the tube to be expanded in order to minimize scuffing and galling.
  • the steel structure of the cone body can be chosen from a ductile, tough steel to overcome the brittleness problem of known expansion cones. It is a main feature of the invention to provide for a hardness distribution such that the hardness essentially steadily increases towards the outer surface of the cone body.
  • the steel structure may have reduced hardness while the outermost layer of the multilayer coating may show extreme hardness.
  • a structure with a reduced-hardness core and an extremely hard coating thereon, will exert a high hardness gradient, and tends to undergo a breakdown or crushing of the hard coating.
  • the invention provides a steel structure with a subsurface diffusion-modified region gradually raising the hardness of the steel structure itself in a subsurface region thereof.
  • the diffusion-modified region may be a nitrided and/or carbonized region and preferably also has a hardness distribution such that the hardness essentially steadily increases towards the multilayer coating.
  • the subsurface region is modified by diffusing atoms into the steel structure for making the surface harder and to provide a hardness gradient steadily joining the hardness gradient of the multilayer coating provided on the outer surface of the steel structure.
  • the multilayer coating may comprise a plurality of sequentially deposited layers of different hardness to also provide for a hardness gradient or hardness distribution which, within the multilayer coating, essentially steadily increases towards the outermost layer of the coating. Up to 200 layers may be provided.
  • At least one of the layers of the multilayer coating is a chemical vapour deposition layer (CVD) layer or a physical vapour deposition layer (PVD) layer or a plasma-assisted chemical vapour deposition layer (PACVD layer) or an amorphous diamond-like carbon layer (ADLC) layer.
  • CVD chemical vapour deposition layer
  • PVD physical vapour deposition layer
  • PAVD plasma-assisted chemical vapour deposition layer
  • ADLC amorphous diamond-like carbon layer
  • all layers of the multilayer coating except the outermost layer are CVD iayers.
  • the outermost layer may be chosen to make the surface of the expansion cone more inert or to act as a sacrificial wear layer, e.g., a self- lubricating layer.
  • the outermost layer may be an AI 2 O 3 layer, which may also be another CVD layer.
  • a PACVD layer which provides for a diamond-like surface, may be applied.
  • a hard vanadium carbide layer (VC layer) may be applied from a molten salt bath to form the outermost layer.
  • the outermost layer can be a CVD layer.
  • At least one layer of the multilayer coating is a TiC layer and/or at least one layer of the multilayer coating is a TiN layer and/or at least one layer of the multilayer coating is a TiCN layer.
  • the multilayer coating comprises at least one pair of a TiC layer and a TiN layer provided on top of the TiC layer to raise the hardness towards the outer surface of the expansion cone.
  • a plurality of the pairs are provided one on top of the other.
  • a TiCN layer is provided between adjacent TiC and TiN layers.
  • all of these layers are applied in a CVD coating process. While the basic metal of these nitride and carbide layers is preferably titanium (Ti), other metals like molybdenum (Mo) or tungsten (W) may be substituted for Ti.
  • the steel structure may be made of low-carbon tool steel, preferably a case- hardenable tool steel, but is preferably a powder metallurgy steel (PM steel).
  • low-carbon tool steel preferably a case- hardenable tool steel, but is preferably a powder metallurgy steel (PM steel).
  • the total thickness of the multilayer coating may be in a range between 2 to 7 ⁇ m, preferably between 4 to 5 ⁇ m.
  • the multilayer coating is applied to a polished surface of the diffusion-modified region of the steel structure, in particular on highly loaded areas of the cone body. Polishing the surface before applying the multilayer thereon provides for a good coating adhesion and reduces micro crack initiation spots, e.g. stress risers in the steel structure.
  • the invention further provides a method for expanding an inner diameter of a tube portion, in particular a casing tube portion within a wellbore. The method includes the steps of inserting an expansion cone as explained above into the tube portion and pulling or pushing the cone body thereof along the tube portion.
  • the expansion cone is inserted into a tube portion having an inner surface free of a solid self-lubricating layer. The method according to the invention lowers the costs of the expansion procedure since the tube portion need not be provided with a solid inner self- lubricating layer.
  • Fig. 1 is a longitudinal section through a tubular casing of a wellbore with an expansion cone inserted therein for expanding the inner diameter of the tubing;
  • Fig. 2a is a detail of a cross-section of the expansion cone taken at an arrow Il in Fig. 1 ;
  • Fig. 2b is a graph of the hardness of the expansion cone versus its radius
  • Fig. 3 is a detail of a multilayer coating of the expansion cone taken at an arrow III in Fig. 2a.
  • Fig. 1 shows a portion of a tube 1 within a wellbore (not shown), for example, a tubular casing of the wellbore with an inner diameter ID1 to be expanded to a larger inner diameter ID2 by means of an expansion cone 3 inserted into the tube 1.
  • the expansion cone 3 has a cone body 5 with an outer surface 7 shaped as a double cone axially tapering towards end portions 9, 11 of the cone body 5 from a shoulder portion 13 axially in between the end portions 9, 11.
  • the shoulder portion 13 has an outer diameter equal to or slightly smaller or larger than ID2.
  • the cone body 3 is inserted and pushed into the tube 1 by differential hydraulic pressure within the tube 1 and/or mechanical forces applied to the expansion cone 3 via a mechanical link member 15.
  • the cone body 5 is a one-piece steel structure, but may also be composed of several segments joining each other in circumferential direction as indicated at 17.
  • the cone body 5 is shaped to avoid edges at least at the load bearing outer surface 7. As long as the cone body 5 is a one-piece structure, a rounded shape is easily to be obtained. If the cone body 5 is segmented, it has a tendency to have sharp edges in the corners between the segments. Preferably, the edges between the segments are rounded, even if a small gap remains between adjacent segments. Rounding the edges improves the coating quality without degrading the expansion result, since from an expansion point of view it is not necessary to provide for a 100 % work piece support.
  • the cone body 5 comprises a steel structure of a ductile, tough powder metallurgy steel (PM steel) which defines the conical shape of the cone body.
  • the outer conical circumferential surface portion of the steel structure of the cone body 5 is covered with a multilayer coating 19, which is shown in the figures not to scale.
  • the multilayer coating 19 is bonded to a polished outer surface of a subsurface diffusion-modified region 21 (not to scale either) of the steel structure. While the diffusion-modified region 21 has a radial thickness D1 of about 3 mm, the total radial thickness D2 of the multilayer coating 19 is in the range of about 4 to 5 ⁇ m.
  • the diffusion-modified region 21 and the multilayer coating 19 have a hardness distribution which essentially steadily increases towards the outer surface of the cone body with a maximum of the hardness at the outermost layer of the multilayer coating 19.
  • the steel structure 5 is made of a ductile, tough steel, for example, a powder metallurgy steel chosen mainly under the aspect of ductility and/or toughness
  • the multilayer coating 19 is adapted to show a low coefficient of friction against the steel material of the tube 1 and low chemical reactivity with steel with an extreme hardness at least of the outermost layer of the multilayer coating 19 to prevent scuffing and galling at the interface between the expansion cone 3 and the inner surface of the tube 1.
  • the diffusion-modified region 21 steadily raises the hardness gradient from the hardness of the steel structure to the hardness of the innermost layer of the multilayer structure 19 to prevent breakdown or crushing of the multilayer coating 19 during the expansion operation.
  • the diffusion-modified region is a nitrided or a carbonized region applied, for example, by a gas-diffusing technique to the steel structure.
  • the multilayer coating 19 is composed of a plurality of individual layers, preferably up to 200 layers, applied one upon the other to the outer surface of the diffusion-modified region 21.
  • the layers have staggered hardness and are all deposited by a chemical vapour deposition technique.
  • the outermost layer may be deposited by another technique, for example, a plasma- assisted CVD technique, or by a molten salt bath dipping technique.
  • Fig. 3 shows an example of the multilayer coating 19.
  • the coating 19 comprises a plurality of pairs of individual TiC and TiN layers on top of each other with the TiN layer of each pair on top of the TiC layer.
  • a TiCN layer is arranged to improve adherence between adjacent TiC and TiN layers.
  • the hardness of the individual layers is staggered from layer to layer and increases towards the outer surface of the expansion cone 3.
  • the TiC, TiN and TiCN layers are provided through a CVD process.
  • the outermost layer of the multilayer coating 19 is a vanadium carbide layer (VC layer) which is applied through a molten salt bath process.
  • the VC layer has proved to be a hard, wear-resistant cover layer.
  • the outermost layer can be an AI 2 O 3 layer, also applied by a CVD coating process to make the surface more inert.
  • the outermost layer can be a heavy-metal carbide layer which, when applied through a plasma-assisted CVD process, provides for a diamond-like surface layer which will act as a sacrificial wear layer. A layer like this has self- lubricating properties and is hard enough to withstand wear.

Abstract

A wellbore tubing expansion cone comprises a cone body (5) having a steel structure defining an outer conical circumferential surface portion and further comprises a coating (19) covering at least the conical surface portion of the steel structure and having a hardness higher than the hardness of the steel structure. The steel structure, at least at its conical surface portion, comprises a subsurface diffusion-modified region (21) hardened to a hardness higher than the hardness of the steel structure underlying the diffusion-modified region (21), but less than the hardness of the coating (19) covering the diffusion-modified region (21). The coating (19) is a multilayer coating comprising a plurality of layers arranged one upon another. The steel structure, the diffusion-modified region (21) and the multilayer coating (19) are adapted to provide a hardness distribution such that the hardness essentially steadily increases towards the outer surface of the cone body (5).

Description

Wellbore Tubing Expansion Cone
The invention relates to a wellbore tubing expansion cone and a method for expanding an inner diameter of a tube portion, in particular a casing tube portion within a wellbore.
In the petroleum industries, tubing expansion techniques are used to provide or to repair a casing within a wellbore. The technique is used both for open- hole or cased-hole applications, and further is used to provide casing hangers.
The technique makes use of an expansion cone which is pulled or pushed through a tube portion of the casing or the like for radially expanding the inner diameter thereof, while plastically deforming the tube portion. The expansion cone is moved through the tubular portion by a differential hydraulic pressure across the expansion cone itself and/or by a direct mechanical pull or push force.
The success of the expansion process fundamentally depends on the frictional conditions between the expansion cone and the wall of the tube. In order to provide for sufficient post-expansion mechanical properties of the tube, it is desirable to minimize friction in order to expand a tube having a wall as thick as possible. Further, the frictional conditions influence the wear mechanism, where galling of the expansion cone on the wall of the tube represents a major challenge.
In order to reduce the friction between the expansion cone and the tube, it is known to coat the inner surface of the tube with a lubricating solid coating, in particular a soft polytetrafluoroethylene (PTFE) lubricating film (WO 2004/067 961 A2). The soft lubricating film coacts with a hard lubricating film provided on the outer surface of the expansion cone, for example a chemically polished chromium nitride coating in the form of a physical-vapor deposited coating (PVD coating). Additionally, a lubricant is introduced in between the self-lubricating films. A similar system for lubricating the interface between an expansion cone and a tube is known from US 2007/0 215 360 A1.
The known lubrication systems are based on solid self-lubricating coatings both on the outer surface of the expansion cone and the inner surface of the tube. The known systems are expensive in case of expanding the casing of a wellbore since it is necessary to coat the entire casing string, which could be as long as 2 km. The known lubricating systems may cause environmental problems, in particular at offshore wellbores.
The body of known expansion cones is a steel structure which defines an outer conical circumferential surface portion adapted to expand the tube while being pushed or pulled through the tube. The cone body may be one solid piece or may be composed of several segments, and may be shaped into a double cone axially tapering to the end portions of the double cone. The cone body of known expansion systems is made of relatively hard steel with a supersaturated level of carbon like D2 tool steel (US 2007/0 215 360 A1 ). A high carbon steel like this has proved to be brittle when used for an expansion cone. To reduce brittleness of the expansion cone it is known from US 2005/0 269 074 A1 to make the body of the expansion cone from a high chromium, low carbon steel and to raise the carbon content in a subsurface region of the cone body by gas-carburizing to a supersaturated state to form a hardened carbide case on the surface of the cone body.
When used, the expansion cone is subject to a steady high load in a start and stop movement. It was found that tribological systems as known from US 2007/0 215 360 A1 or WO 2004/067 961 A2 tend to undergo a breakdown of the hard self-lubricating coating provided to prevent scuffing and galling in the expansion operation or crushing of the cone body.
It is a main object of the invention to provide a wellbore tubing expansion cone having improved resistance both to fracturing and surface wear.
The invention provides for a wellbore tubing expansion cone comprising a cone body having a steel structure defining an outer conical circumferential surface portion and a coating covering at least the conical surface portion of the steel structure and having a hardness higher than the hardness of the steel structure.
The expansion cone is characterized in that the steel structure, at least at its conical surface portion, comprises a subsurface diffusion-modified region hardened to a hardness higher than the hardness of the steel structure underlying the diffusion-modified region, but less than the hardness of the coating covering the diffusion-modified region. The coating is a multilayer coating comprising a plurality of layers arranged one upon the other and the steel structure, the diffusion-modified region and the multilayer coating are adapted to provide a hardness distribution such that the hardness essentially steadily increases towards the outer surface of the cone body.
The expansion cone according to the invention overcomes the major problems of known expansion systems. The layer structure of the expansion cone allows choosing the material properties of the steel structure on the one hand and the outermost coating of the cone body on the other hand independently of each other. The multilayer coating can be chosen to show extreme hardness and a low coefficient of friction against steel and/or low chemical reactivity with steel to minimize friction at the interface with the tube to be expanded in order to minimize scuffing and galling. To be resistant to fracturing, the steel structure of the cone body can be chosen from a ductile, tough steel to overcome the brittleness problem of known expansion cones. It is a main feature of the invention to provide for a hardness distribution such that the hardness essentially steadily increases towards the outer surface of the cone body. The steel structure may have reduced hardness while the outermost layer of the multilayer coating may show extreme hardness. A structure with a reduced-hardness core and an extremely hard coating thereon, will exert a high hardness gradient, and tends to undergo a breakdown or crushing of the hard coating. To prevent such breakdown, the invention provides a steel structure with a subsurface diffusion-modified region gradually raising the hardness of the steel structure itself in a subsurface region thereof. The diffusion-modified region may be a nitrided and/or carbonized region and preferably also has a hardness distribution such that the hardness essentially steadily increases towards the multilayer coating. The subsurface region is modified by diffusing atoms into the steel structure for making the surface harder and to provide a hardness gradient steadily joining the hardness gradient of the multilayer coating provided on the outer surface of the steel structure.
The multilayer coating may comprise a plurality of sequentially deposited layers of different hardness to also provide for a hardness gradient or hardness distribution which, within the multilayer coating, essentially steadily increases towards the outermost layer of the coating. Up to 200 layers may be provided.
In order to enhance the adherence between the layers of the multilayer coating, at least one of the layers of the multilayer coating is a chemical vapour deposition layer (CVD) layer or a physical vapour deposition layer (PVD) layer or a plasma-assisted chemical vapour deposition layer (PACVD layer) or an amorphous diamond-like carbon layer (ADLC) layer. Preferably, all layers of the multilayer coating except the outermost layer are CVD iayers. The outermost layer may be chosen to make the surface of the expansion cone more inert or to act as a sacrificial wear layer, e.g., a self- lubricating layer. To make the outer surface inert, the outermost layer may be an AI2O3 layer, which may also be another CVD layer. To provide a sacrificial wear layer, a PACVD layer, which provides for a diamond-like surface, may be applied. Alternatively, a hard vanadium carbide layer (VC layer) may be applied from a molten salt bath to form the outermost layer. Of course, also the outermost layer can be a CVD layer.
In a preferred embodiment, at least one layer of the multilayer coating is a TiC layer and/or at least one layer of the multilayer coating is a TiN layer and/or at least one layer of the multilayer coating is a TiCN layer. Particularly the multilayer coating comprises at least one pair of a TiC layer and a TiN layer provided on top of the TiC layer to raise the hardness towards the outer surface of the expansion cone. Preferably, a plurality of the pairs are provided one on top of the other. To enhance adherence of the different layers with respect to each other, a TiCN layer is provided between adjacent TiC and TiN layers. Preferably, all of these layers are applied in a CVD coating process. While the basic metal of these nitride and carbide layers is preferably titanium (Ti), other metals like molybdenum (Mo) or tungsten (W) may be substituted for Ti.
The steel structure may be made of low-carbon tool steel, preferably a case- hardenable tool steel, but is preferably a powder metallurgy steel (PM steel).
While the diffusion-modified region of the steel structure is preferably about several millimeters thick, for example, 3 mm, the total thickness of the multilayer coating may be in a range between 2 to 7 μm, preferably between 4 to 5 μm.
Preferably, the multilayer coating is applied to a polished surface of the diffusion-modified region of the steel structure, in particular on highly loaded areas of the cone body. Polishing the surface before applying the multilayer thereon provides for a good coating adhesion and reduces micro crack initiation spots, e.g. stress risers in the steel structure. The invention further provides a method for expanding an inner diameter of a tube portion, in particular a casing tube portion within a wellbore. The method includes the steps of inserting an expansion cone as explained above into the tube portion and pulling or pushing the cone body thereof along the tube portion. Preferably, the expansion cone is inserted into a tube portion having an inner surface free of a solid self-lubricating layer. The method according to the invention lowers the costs of the expansion procedure since the tube portion need not be provided with a solid inner self- lubricating layer.
Below, preferred embodiments of the invention will be described with respect to a drawing. In the drawing:
Fig. 1 is a longitudinal section through a tubular casing of a wellbore with an expansion cone inserted therein for expanding the inner diameter of the tubing;
Fig. 2a is a detail of a cross-section of the expansion cone taken at an arrow Il in Fig. 1 ;
Fig. 2b is a graph of the hardness of the expansion cone versus its radius; and
Fig. 3 is a detail of a multilayer coating of the expansion cone taken at an arrow III in Fig. 2a.
Fig. 1 shows a portion of a tube 1 within a wellbore (not shown), for example, a tubular casing of the wellbore with an inner diameter ID1 to be expanded to a larger inner diameter ID2 by means of an expansion cone 3 inserted into the tube 1. The expansion cone 3 has a cone body 5 with an outer surface 7 shaped as a double cone axially tapering towards end portions 9, 11 of the cone body 5 from a shoulder portion 13 axially in between the end portions 9, 11. The shoulder portion 13 has an outer diameter equal to or slightly smaller or larger than ID2. To expand the tube 1 from the inner diameter ID1 to ID2, the cone body 3 is inserted and pushed into the tube 1 by differential hydraulic pressure within the tube 1 and/or mechanical forces applied to the expansion cone 3 via a mechanical link member 15. The cone body 5 is a one-piece steel structure, but may also be composed of several segments joining each other in circumferential direction as indicated at 17. The cone body 5 is shaped to avoid edges at least at the load bearing outer surface 7. As long as the cone body 5 is a one-piece structure, a rounded shape is easily to be obtained. If the cone body 5 is segmented, it has a tendency to have sharp edges in the corners between the segments. Preferably, the edges between the segments are rounded, even if a small gap remains between adjacent segments. Rounding the edges improves the coating quality without degrading the expansion result, since from an expansion point of view it is not necessary to provide for a 100 % work piece support.
As shown in Fig. 2a, the cone body 5 comprises a steel structure of a ductile, tough powder metallurgy steel (PM steel) which defines the conical shape of the cone body. The outer conical circumferential surface portion of the steel structure of the cone body 5 is covered with a multilayer coating 19, which is shown in the figures not to scale. The multilayer coating 19 is bonded to a polished outer surface of a subsurface diffusion-modified region 21 (not to scale either) of the steel structure. While the diffusion-modified region 21 has a radial thickness D1 of about 3 mm, the total radial thickness D2 of the multilayer coating 19 is in the range of about 4 to 5 μm.
As shown in Fig. 2b, the diffusion-modified region 21 and the multilayer coating 19 have a hardness distribution which essentially steadily increases towards the outer surface of the cone body with a maximum of the hardness at the outermost layer of the multilayer coating 19. While the steel structure 5 is made of a ductile, tough steel, for example, a powder metallurgy steel chosen mainly under the aspect of ductility and/or toughness, the multilayer coating 19 is adapted to show a low coefficient of friction against the steel material of the tube 1 and low chemical reactivity with steel with an extreme hardness at least of the outermost layer of the multilayer coating 19 to prevent scuffing and galling at the interface between the expansion cone 3 and the inner surface of the tube 1. The diffusion-modified region 21 steadily raises the hardness gradient from the hardness of the steel structure to the hardness of the innermost layer of the multilayer structure 19 to prevent breakdown or crushing of the multilayer coating 19 during the expansion operation.
The diffusion-modified region is a nitrided or a carbonized region applied, for example, by a gas-diffusing technique to the steel structure.
The multilayer coating 19 is composed of a plurality of individual layers, preferably up to 200 layers, applied one upon the other to the outer surface of the diffusion-modified region 21. The layers have staggered hardness and are all deposited by a chemical vapour deposition technique. The outermost layer may be deposited by another technique, for example, a plasma- assisted CVD technique, or by a molten salt bath dipping technique.
Fig. 3 shows an example of the multilayer coating 19. The coating 19 comprises a plurality of pairs of individual TiC and TiN layers on top of each other with the TiN layer of each pair on top of the TiC layer. In between adjacent TiN and TiC layers, a TiCN layer is arranged to improve adherence between adjacent TiC and TiN layers. The hardness of the individual layers is staggered from layer to layer and increases towards the outer surface of the expansion cone 3. The TiC, TiN and TiCN layers are provided through a CVD process.
The outermost layer of the multilayer coating 19 is a vanadium carbide layer (VC layer) which is applied through a molten salt bath process. The VC layer has proved to be a hard, wear-resistant cover layer. In another embodiment, the outermost layer can be an AI2O3 layer, also applied by a CVD coating process to make the surface more inert. In another embodiment, the outermost layer can be a heavy-metal carbide layer which, when applied through a plasma-assisted CVD process, provides for a diamond-like surface layer which will act as a sacrificial wear layer. A layer like this has self- lubricating properties and is hard enough to withstand wear.

Claims

Claims
1. Wellbore tubing expansion cone comprising a cone body (5) having a steel structure defining an outer conical circumferential surface portion (7); and a coating (19) covering at least the conical surface portion (7) of the steel structure and having a hardness higher than the hardness of the steel structure, characterized in that the steel structure at least at its conical surface portion (7) comprises a subsurface diffusion-modified region (21) hardened to a hardness higher than the hardness of the steel structure underlying the diffusion- modified region (21), but less than the hardness of the coating (19) covering the diffusion-modified region (21), wherein the coating (19) is a multilayer coating comprising a plurality of layers arranged one upon another and wherein the steel structure, the diffusion-modified region (21) and the multilayer coating (19) are adapted to provide a hardness distribution such that the hardness essentially steadily increases towards the outer surface of the cone body (5).
2. Expansion cone according to claim 1 , wherein the diffusion-modified region (21) is a nitrided and/or carbonized region of the steel structure.
3. Expansion cone according to claim 2, wherein the diffusion-modified region (21 ) has a hardness distribution such that the hardness essentially steadily increases towards the multilayer coating (19).
4. Expansion cone according to any one of claims 1 to 3, wherein the diffusion-modified region (21) has a thickness of more than 1 mm, preferably more than 2 mm.
5. Expansion cone according to any one of claims 1 to 4, wherein at least one of the layers of the multilayer coating (19) is a chemical vapor deposition layer (CVD layer) and/or a physical vapor deposition layer (PVD layer) or a plasma-assisted chemical vapor deposition layer
5 (PACVD layer) or an amorphous diamond-like carbon layer (ADLC layer).
6. Expansion cone according to claim 5, wherein at least one layer of the multilayer coating (19) is a TiC layer and/or at least one layer of theo multilayer coating (19) is a TiN layer and/or at least one layer of the multilayer coating (19) is a TiCN layer.
7. Expansion cone according to claim 6, wherein the multilayer coating (19) comprises at least one pair of a TiC layer and a TiN layer provideds on top of the TiC layer.
8. Expansion cone according to claim 7, wherein the multilayer coating (19) comprises a plurality of said pairs one on top of the other. o
9. Expansion cone according to one of claims 7 or 8, wherein a TiCN layer is provided between adjacent TiC and TiN layers.
10. Expansion cone according to any one of claims 5 to 9, wherein the multilayer coating (19) has a thickness of 2 to 7 μm, in particular 4 to5 5 μm.
11. Expansion cone according to any one of claims 1 to 10, wherein the multilayer coating (19) is applied to a polished outer surface of the diffusion-modified region (21). 0
12. Expansion cone according to any one of claims 1 to 11 , wherein at least the outermost layer of the multilayer coating (19) is a vanadium carbide layer or an AI2O3 layer or a PACVD layer.
13. Expansion cone according to any one of claims 1 to 12, wherein at least the outermost layer is a sacrificial wear layer, in particular an amorphous diamond-like carbon layer (ADLC layer).
14. Expansion cone according to any one of claims 1 to 13, wherein cone body (5) is a one-piece steel body or is composed of a plurality of steel segments (17).
15. Expansion cone according to any one of claims 1 to 14, wherein the steel structure is made of a powder metallurgy steel (PM steel).
16. Method for expanding an inner diameter of a tube portion, in particular a casing tube portion (1) within a wellbore, the method comprising the steps of: inserting an expansion cone (3) according to any one of claims 1 to 14 into the tube portion (1 ) and pulling or pushing the cone body thereof along the tube portion.
17. Method according to claim 16, wherein the expansion cone (3) is inserted into a tube portion (1) having an inner surface free of a solid self-lubricating layer.
PCT/EP2009/004301 2009-06-15 2009-06-15 Wellbore tubing expansion cone WO2010145674A1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2490924A (en) * 2011-05-18 2012-11-21 Volnay Engineering Services Ltd Downhole tool formed with multiple coatings
CN103758477A (en) * 2013-12-27 2014-04-30 中国石油天然气股份有限公司 Expansion cone with TiN or TiAlN film and machining method thereof
WO2022098764A3 (en) * 2020-11-03 2022-06-09 Saudi Arabian Oil Company Diamond coating on the cone for expandable tubulars

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1418807A (en) * 1972-02-14 1975-12-24 Alusuisse Methods of increasing the wear resistance of the working surfaces of extrusion dies
US20050269074A1 (en) * 2004-06-02 2005-12-08 Chitwood Gregory B Case hardened stainless steel oilfield tool
EP1698713A1 (en) * 2005-03-01 2006-09-06 Ceco Ltd Scratch-resistant material and method to manufacture
US20090029132A1 (en) * 2005-11-17 2009-01-29 Boehlerit Gmbh & Co. Kg., Coated hard metal member

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1418807A (en) * 1972-02-14 1975-12-24 Alusuisse Methods of increasing the wear resistance of the working surfaces of extrusion dies
US20050269074A1 (en) * 2004-06-02 2005-12-08 Chitwood Gregory B Case hardened stainless steel oilfield tool
EP1698713A1 (en) * 2005-03-01 2006-09-06 Ceco Ltd Scratch-resistant material and method to manufacture
US20090029132A1 (en) * 2005-11-17 2009-01-29 Boehlerit Gmbh & Co. Kg., Coated hard metal member

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2490924A (en) * 2011-05-18 2012-11-21 Volnay Engineering Services Ltd Downhole tool formed with multiple coatings
GB2490924B (en) * 2011-05-18 2013-07-10 Volnay Engineering Services Ltd Improvements in and relating to downhole tools
CN103758477A (en) * 2013-12-27 2014-04-30 中国石油天然气股份有限公司 Expansion cone with TiN or TiAlN film and machining method thereof
WO2022098764A3 (en) * 2020-11-03 2022-06-09 Saudi Arabian Oil Company Diamond coating on the cone for expandable tubulars
US11898422B2 (en) 2020-11-03 2024-02-13 Saudi Arabian Oil Company Diamond coating on the cone for expandable tubulars

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