WO2022230595A1 - 油井用鋼管 - Google Patents
油井用鋼管 Download PDFInfo
- Publication number
- WO2022230595A1 WO2022230595A1 PCT/JP2022/016384 JP2022016384W WO2022230595A1 WO 2022230595 A1 WO2022230595 A1 WO 2022230595A1 JP 2022016384 W JP2022016384 W JP 2022016384W WO 2022230595 A1 WO2022230595 A1 WO 2022230595A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- steel pipe
- oil well
- pin
- box
- plating layer
- Prior art date
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 218
- 239000010959 steel Substances 0.000 title claims abstract description 218
- 239000003129 oil well Substances 0.000 title claims abstract description 212
- 238000007747 plating Methods 0.000 claims abstract description 172
- 229910007567 Zn-Ni Inorganic materials 0.000 claims abstract description 132
- 229910007614 Zn—Ni Inorganic materials 0.000 claims abstract description 132
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 131
- 239000000956 alloy Substances 0.000 claims abstract description 131
- 239000000126 substance Substances 0.000 claims abstract description 56
- 239000000203 mixture Substances 0.000 claims abstract description 29
- 238000000576 coating method Methods 0.000 claims description 23
- 230000001050 lubricating effect Effects 0.000 claims description 22
- 239000011248 coating agent Substances 0.000 claims description 19
- 229910052742 iron Inorganic materials 0.000 abstract description 10
- 229910052804 chromium Inorganic materials 0.000 abstract description 9
- 229910052799 carbon Inorganic materials 0.000 abstract description 8
- 239000010410 layer Substances 0.000 description 201
- 238000005554 pickling Methods 0.000 description 81
- 238000005238 degreasing Methods 0.000 description 61
- 238000000034 method Methods 0.000 description 55
- 238000012360 testing method Methods 0.000 description 43
- 229910000990 Ni alloy Inorganic materials 0.000 description 27
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 25
- 238000007654 immersion Methods 0.000 description 23
- 238000001336 glow discharge atomic emission spectroscopy Methods 0.000 description 22
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 21
- 238000004519 manufacturing process Methods 0.000 description 18
- 239000011701 zinc Substances 0.000 description 18
- 238000004381 surface treatment Methods 0.000 description 15
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 13
- 239000011651 chromium Substances 0.000 description 13
- 238000007739 conversion coating Methods 0.000 description 13
- 230000008878 coupling Effects 0.000 description 13
- 238000010168 coupling process Methods 0.000 description 13
- 238000005859 coupling reaction Methods 0.000 description 13
- 239000000463 material Substances 0.000 description 13
- 238000004458 analytical method Methods 0.000 description 12
- 239000012535 impurity Substances 0.000 description 12
- 238000005520 cutting process Methods 0.000 description 8
- 230000002093 peripheral effect Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- 238000007789 sealing Methods 0.000 description 7
- 239000011230 binding agent Substances 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 6
- 238000009713 electroplating Methods 0.000 description 6
- 238000000227 grinding Methods 0.000 description 6
- 238000005488 sandblasting Methods 0.000 description 6
- 238000005406 washing Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- 238000000921 elemental analysis Methods 0.000 description 5
- 239000004519 grease Substances 0.000 description 5
- 239000000314 lubricant Substances 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 230000000573 anti-seizure effect Effects 0.000 description 4
- 238000005422 blasting Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910052725 zinc Inorganic materials 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 3
- 238000007689 inspection Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- -1 polytetrafluoroethylene Polymers 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910052582 BN Inorganic materials 0.000 description 2
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 description 2
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- VEQPNABPJHWNSG-UHFFFAOYSA-N Nickel(2+) Chemical compound [Ni+2] VEQPNABPJHWNSG-UHFFFAOYSA-N 0.000 description 2
- 241000209094 Oryza Species 0.000 description 2
- 235000007164 Oryza sativa Nutrition 0.000 description 2
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- PTFCDOFLOPIGGS-UHFFFAOYSA-N Zinc dication Chemical compound [Zn+2] PTFCDOFLOPIGGS-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- 235000010216 calcium carbonate Nutrition 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910001385 heavy metal Inorganic materials 0.000 description 2
- 238000002354 inductively-coupled plasma atomic emission spectroscopy Methods 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 2
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 229910001453 nickel ion Inorganic materials 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 235000021317 phosphate Nutrition 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 235000009566 rice Nutrition 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- ITRNXVSDJBHYNJ-UHFFFAOYSA-N tungsten disulfide Chemical compound S=[W]=S ITRNXVSDJBHYNJ-UHFFFAOYSA-N 0.000 description 2
- LRXTYHSAJDENHV-UHFFFAOYSA-H zinc phosphate Chemical compound [Zn+2].[Zn+2].[Zn+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O LRXTYHSAJDENHV-UHFFFAOYSA-H 0.000 description 2
- 229910000165 zinc phosphate Inorganic materials 0.000 description 2
- 241001163841 Albugo ipomoeae-panduratae Species 0.000 description 1
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- 239000004962 Polyamide-imide Substances 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- IQBJFLXHQFMQRP-UHFFFAOYSA-K calcium;zinc;phosphate Chemical compound [Ca+2].[Zn+2].[O-]P([O-])([O-])=O IQBJFLXHQFMQRP-UHFFFAOYSA-K 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000001192 hot extrusion Methods 0.000 description 1
- CPSYWNLKRDURMG-UHFFFAOYSA-L hydron;manganese(2+);phosphate Chemical compound [Mn+2].OP([O-])([O-])=O CPSYWNLKRDURMG-UHFFFAOYSA-L 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- QLOAVXSYZAJECW-UHFFFAOYSA-N methane;molecular fluorine Chemical compound C.FF QLOAVXSYZAJECW-UHFFFAOYSA-N 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 229910052961 molybdenite Inorganic materials 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 238000007746 phosphate conversion coating Methods 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 229920002312 polyamide-imide Polymers 0.000 description 1
- 229920013716 polyethylene resin Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 239000009719 polyimide resin Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 150000004760 silicates Chemical class 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010913 used oil Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L15/00—Screw-threaded joints; Forms of screw-threads for such joints
- F16L15/08—Screw-threaded joints; Forms of screw-threads for such joints with supplementary elements
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/22—Electroplating: Baths therefor from solutions of zinc
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/48—After-treatment of electroplated surfaces
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
- C25D7/04—Tubes; Rings; Hollow bodies
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/02—Couplings; joints
- E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
- E21B17/042—Threaded
Definitions
- the present disclosure relates to oil well steel pipes, and more particularly to oil well steel pipes formed with threaded joints.
- Oil well steel pipes are used for mining oil fields and natural gas fields (hereafter, oil fields and natural gas fields are collectively referred to as "oil wells").
- oil wells oil fields and natural gas fields are collectively referred to as "oil wells"
- oil well pipe connection body represented by a casing or tubing.
- the oil country tubular goods connecting body is formed by screwing together threaded joints formed at the ends of oil country tubular goods. Also, there are cases where an inspection is carried out on the connected body of oil country tubular goods. When performing an inspection, the oil country tubular goods connecting body is pulled up and the threaded joint is unscrewed.
- the steel pipe for oil country tubular goods that has been unscrewed and removed from the connected body of oil country tubular goods is inspected. After the inspection, the oil country tubular goods are screwed again and reused as a part of the oil country tubular goods connection.
- An oil well steel pipe has a pipe body including a first end and a second end.
- the tube body includes a pin formed at the first end and a box formed at the second end.
- the pin has a pin contact surface including external threads on the outer peripheral surface of the first end of the tube body.
- the box has a box contact surface including internal threads on the inner peripheral surface of the end of the tube body opposite the pin (second end). When threaded joints formed at the ends of oil well steel pipes are screwed together, the pin contact surface contacts the box contact surface.
- pin contact surface and box contact surface are repeatedly subjected to strong friction when screwing and unscrewing oil well steel pipes. If these parts do not have sufficient resistance to friction, galling (irreparable seizure) will occur when screws are repeatedly tightened and unscrewed. Therefore, steel pipes for oil wells are required to have sufficient durability against friction, ie, excellent seizure resistance.
- compound grease containing heavy metals called dope has been used to improve seizure resistance.
- the seizure resistance of the oil well steel pipe can be improved.
- heavy metals such as Pb, Zn and Cu contained in compound grease may affect the environment. Therefore, there is a demand for the development of steel pipes for oil wells that have excellent anti-seizure properties without using compound grease.
- Patent Document 1 International Publication No. 2016/170031
- a Zn-Ni alloy plating layer is formed on the pin contact surface or box contact surface instead of compound grease.
- Zn in the Zn—Ni alloy plating layer formed on the contact surface of the steel pipe for oil country tubular goods enhances the corrosion resistance of the base material of the oil country tubular goods by sacrificial corrosion protection.
- Patent Document 1 describes that the Zn—Ni alloy is also excellent in wear resistance properties.
- An object of the present disclosure is to provide an oil well steel pipe provided with a Zn-Ni alloy plating layer having excellent anti-seizure properties.
- the oil well steel pipe is a tube body including a first end and a second end;
- the chemical composition of the tube body is, in mass %, C: 0.01 to 0.60%, Cr: 0 to 8.0%, and Fe: containing 80.0% or more,
- the pipe body is a pin formed at the first end; a box formed at the second end;
- the pin is including a pin contact surface including an externally threaded portion;
- the box is including a box contact surface including an internal thread;
- the steel pipe for oil well further comprises: a Zn—Ni alloy plating layer formed on at least one of the pin contact surface and the box contact surface;
- the C-enriched layer is defined as a region containing 1.5 times or more the C content of the pipe body in terms of % by mass, In the Zn—Ni alloy plating layer, the thickness of the C-enriched layer in the thickness direction of the pipe body is 0 to 1.50 ⁇ m.
- the oil well steel pipe according to the present disclosure has a Zn-Ni alloy plating layer and has excellent seizure resistance.
- FIG. 1 is a diagram showing a part of the results of performing depth direction analysis by GD-OES from the surface of the Zn—Ni alloy plating layer of the oil well steel pipe of Test No. 2 of the example.
- FIG. 2 is a diagram showing a part of the results of performing a depth direction analysis by GD-OES from the surface of the Zn—Ni alloy plating layer of the oil well steel pipe according to the present embodiment.
- FIG. 3 is a configuration diagram showing an example of the oil well steel pipe according to this embodiment. 4 is a partial cross-sectional view showing a cross section (longitudinal cross section) of the coupling of the oil well steel pipe shown in FIG. 3 along the pipe axis direction.
- FIG. 1 is a diagram showing a part of the results of performing depth direction analysis by GD-OES from the surface of the Zn—Ni alloy plating layer of the oil well steel pipe of Test No. 2 of the example.
- FIG. 2 is a diagram showing a part of the results of performing
- FIG. 5 is a cross-sectional view parallel to the axial direction of the oil well steel pipe of the portion near the pin of the oil well steel pipe shown in FIG.
- FIG. 6 is a cross-sectional view parallel to the axial direction of the oil well steel pipe of the oil well steel pipe shown in FIG. 4 in the vicinity of the box.
- FIG. 7 is a partial cross-sectional view showing a cross section (longitudinal cross section) of the coupling of the oil well steel pipe according to the present embodiment, different from FIG. 4, along the pipe axis direction.
- FIG. 10 is an enlarged view of the box contact surface shown in FIG. 6;
- FIG. FIG. 11 is an enlarged view of the pin contact surface in a configuration different from that of FIG.
- FIG. 12 is an enlarged view of the box contact surface in a configuration different from that of FIG.
- the Zn-Ni alloy plating layer is known to have excellent wear resistance due to its high hardness. It is generally believed that the higher the wear resistance, the higher the seizure resistance. Therefore, the Zn—Ni alloy plating layer has been applied to oil well steel pipes that require seizure resistance.
- the large-diameter oil well steel pipe has a longer sliding distance during screw tightening and screw unscrewing than the conventional oil well steel pipe. Therefore, even steel pipes for oil wells having a Zn—Ni alloy plating layer may not exhibit excellent seizure resistance in large-diameter steel pipes for oil wells.
- the chemical composition of the pipe body on which the Zn-Ni alloy plating layer is formed also affects the seizure resistance.
- the chemical composition of the pipe body contains, by mass%, C: 0.01 to 0.60%, Cr: 0 to 8.0%, and Fe: 80.0% or more, especially
- the inventors of the present invention have found that large steel pipes for oil wells tend to have low seizure resistance. Accordingly, the present inventors manufactured various steel pipes for oil wells having a pipe body having the chemical composition described above and a Zn—Ni alloy plating layer, and investigated their seizure resistance in detail.
- the present inventors conducted a more detailed investigation of oil well steel pipes that have a pipe body having the chemical composition described above and have a Zn—Ni alloy plating layer, but do not have excellent seizure resistance.
- the oil well steel pipe was subjected to elemental analysis in the depth direction from the surface of the Zn-Ni alloy plating layer by glow discharge optical emission spectrometry (GD-OES). This point will be specifically described with reference to the drawings.
- GD-OES glow discharge optical emission spectrometry
- FIG. 1 is a diagram showing part of the results of performing a depth direction analysis by GD-OES from the surface of the Zn-Ni alloy plating layer for the oil well steel pipe of Test No. 2 in the example.
- FIG. 1 was obtained by the method described below. More specifically, in FIG. 1, depth direction analysis by GD-OES is performed, the horizontal axis is the depth ( ⁇ m) from the surface of the Zn—Ni alloy plating layer, the vertical axis is Zn, Fe, and It is a content profile in the depth direction in which the content of C (% by mass) is plotted.
- the "depth direction" of the Zn--Ni alloy plating layer referred to here corresponds to the thickness direction of the pipe body.
- a region where the C content is 1.5 times or more that of the pipe body is also referred to as a "C-enriched layer.”
- the dashed line in the figure indicates the C content that is 1.5 times that of the pipe body. That is, referring to FIG. 1, the region where the C content exceeds the dashed line corresponds to the C-enriched layer.
- the present inventors have found that, in a steel pipe for oil well use having a pipe body having the above-described chemical composition and a Zn—Ni alloy plating layer, by thinning the C-enriched layer in the Zn—Ni alloy plating layer, We thought that the seizure resistance of steel pipes could be improved. In this case, the Zn—Ni alloy plating layer may be difficult to peel off even if screw tightening and unscrewing are repeated under high surface pressure.
- the present inventors manufactured various steel pipes for oil wells having a pipe body having the chemical composition described above and a Zn—Ni alloy plating layer, and investigated the C-enriched layer in the Zn—Ni alloy plating layer. Thickness and seizure resistance were investigated in detail.
- FIG. 2 is a diagram showing a part of the results of performing a depth direction analysis by GD-OES from the surface of the Zn—Ni alloy plating layer of the oil well steel pipe according to the present embodiment.
- FIG. 2 is a content profile in the depth direction according to Test No. 3 in Examples described later.
- FIG. 2 was obtained by the method described below.
- the Zn-Ni alloy plating layer has a thin C-enriched layer. Furthermore, as will be described in detail in the examples described later, in the steel pipe for oil wells shown in FIG. 1, the number of screw tightening and screw unscrewing operations without seizure was 5 times. On the other hand, the oil well steel pipe shown in FIG. 2 could be screwed and unscrewed 10 times or more without seizure.
- the pin and box formed at the end of the pipe body of the oil well steel pipe are formed by cutting. Since heat is applied to the surfaces of the pin and the box during cutting, an oxide film is formed on the surface of the pin and the box after cutting. Therefore, in order to remove the oxide film formed by cutting, of the pin and/or box surface that has been cut, the area where the Zn-Ni alloy plating layer is formed is subjected to pickling or the like. As a result, the oxide film has been removed.
- the oil well steel pipe according to the present embodiment contains, by mass %, C: 0.01 to 0.60%, Cr: 0 to 8.0%, and Fe: 80.0% or more. It has a tube body with a chemical composition that Therefore, a passivation film, which is formed with stainless steel materials having a high Cr content, is not formed.
- a passivation film which is formed with stainless steel materials having a high Cr content, is not formed.
- an unstable oxide film is likely to be formed on the surfaces of the pins and the box during cutting.
- the pin and box have complicated shapes, the cutting conditions are different for each part, and the cutting temperature and cutting speed are also different. As a result, in the pipe body having the chemical composition described above, oxide films with different thicknesses are likely to be formed on the surfaces of the pins and the box.
- an oxide film with a different thickness is formed at each part, even if the pickling is performed under uniform conditions, some of the oxide film may remain or the pipe body may partially dissolve. there's a possibility that.
- carbon (C)-derived impurities in the tube body may remain on the surface of the pin and/or the box.
- the present inventors presume that a thick C-enriched layer is formed in the Zn--Ni alloy plating layer as a result of forming the Zn--Ni alloy plating layer with a large amount of C-derived impurities remaining.
- the thickness of the C-enriched layer in the Zn-Ni alloy plating layer in the thickness direction of the pipe body is set to 0 to 1.50 ⁇ m, the steel pipe for oil wells having a large diameter can be obtained.
- the inventors of the present invention have also found that excellent seizure resistance can be obtained.
- the gist of the steel pipe for oil wells completed based on the above knowledge is as follows.
- a steel pipe for oil wells a tube body including a first end and a second end;
- the chemical composition of the tube body is, in mass %, C: 0.01 to 0.60%, Cr: 0 to 8.0%, and Fe: containing 80.0% or more,
- the pipe body is a pin formed at the first end; a box formed at the second end;
- the pin is including a pin contact surface including an externally threaded portion;
- the box is including a box contact surface including an internal thread;
- the steel pipe for oil well further comprises: a Zn—Ni alloy plating layer formed on at least one of the pin contact surface and the box contact surface;
- the C-enriched layer is defined as a region containing 1.5 times or more the C content of the pipe body in terms of % by mass, In the Zn—Ni alloy plating layer, the thickness of the C-enriched layer in the thickness direction of the pipe body is 0 to 1.50 ⁇ m.
- the oil well steel pipe according to [1] The Zn—Ni alloy plating layer has a thickness of 5 to 25 ⁇ m, Steel pipe for oil wells.
- Oil well steel pipe First, the configuration of the oil well steel pipe according to this embodiment will be described.
- a steel pipe for oil wells has a well-known configuration.
- Oil well steel pipes include T&C type oil well steel pipes and integral type oil well steel pipes. Each type of oil well steel pipe will be described in detail below.
- FIG. 3 is a configuration diagram showing an example of the oil well steel pipe 1 according to this embodiment.
- FIG. 3 is a configuration diagram of a so-called T&C (Threaded and Coupled) oil well steel pipe 1 .
- oil well steel pipe 1 includes pipe body 10 .
- the pipe body 10 extends in the pipe axial direction.
- a cross section of the pipe body 10 perpendicular to the pipe axis direction is circular.
- the tube body 10 includes a first end 10A and a second end 10B.
- the first end 10A is the end opposite to the second end 10B.
- a coupling 12 is attached to one end of the pin tube body 11 . More specifically, the coupling 12 is screwed to one end of the pin tube 11 .
- FIG. 4 is a partial cross-sectional view showing a section (longitudinal section) parallel to the pipe axis direction of the coupling 12 of the oil well steel pipe 1 shown in FIG. 3 and 4,
- tube body 10 includes pin 40 and box 50.
- the pin 40 is formed on the first end portion 10A of the tube body 10 .
- the pin 40 is inserted into the box 50 of another oil well steel pipe 1 (not shown) and fastened to the box 50 of the other oil well steel pipe 1 by screws.
- the box 50 is formed at the second end 10B of the pipe body 10. At the time of fastening, the pin 40 of the other oil well steel pipe 1 is inserted into the box 50 and fastened with the pin 40 of the other oil well steel pipe 1 by screws.
- FIG. 5 is a cross-sectional view parallel to the axial direction of the oil well steel pipe 1 of the portion near the pin 40 of the oil well steel pipe 1 shown in FIG.
- the dashed line portion in FIG. 5 shows the configuration of the box 50 of the other steel pipe 1 for oil wells when fastening with the other steel pipe 1 for oil wells.
- the pin 40 has a pin contact surface 400 on the outer peripheral surface of the first end 10A of the pipe body 10. As shown in FIG. The pin contact surface 400 comes into contact with the box 50 of the other oil well steel pipe 1 at the time of fastening with the other oil well steel pipe 1 .
- the pin contact surface 400 includes at least a male threaded portion 41 formed on the outer peripheral surface of the first end portion 10A.
- Pin contact surface 400 may further include pin seal surface 42 and pin shoulder surface 43 .
- the pin seal surface 42 is arranged on the outer peripheral surface of the first end portion 10A closer to the distal end side of the first end portion 10A than the male thread portion 41 is. That is, the pin seal surface 42 is arranged between the male threaded portion 41 and the pin shoulder surface 43 .
- the pin seal surface 42 is provided in a tapered shape. Specifically, the outer diameter of the pin seal surface 42 gradually decreases from the male threaded portion 41 toward the pin shoulder surface 43 in the longitudinal direction (pipe axis direction) of the first end portion 10A.
- the pin seal surface 42 contacts the box seal surface 52 (described later) of the box 50 of the other oil well steel pipe 1 . More specifically, when the pin 40 is inserted into the box 50 of the other oil well steel pipe 1 during fastening, the pin seal surface 42 contacts the box seal surface 52 . By further screwing the pin 40 into the box 50 of the other oil well steel pipe 1 , the pin seal surface 42 comes into close contact with the box seal surface 52 . As a result, during fastening, the pin seal surface 42 is in close contact with the box seal surface 52 to form a seal based on metal-to-metal contact. Therefore, the airtightness can be improved in the steel pipes 1 for oil wells that are fastened to each other.
- the pin shoulder surface 43 is arranged on the tip surface of the first end portion 10A. That is, in the pin 40 shown in FIG. 5, the male threaded portion 41, the pin seal surface 42, and the pin shoulder surface 43 are arranged in order from the center of the tube body 10 toward the first end portion 10A.
- the pin shoulder surface 43 faces and comes into contact with the box shoulder surface 53 (described later) of the box 50 of the other oil well steel pipe 1 . More specifically, when the pin 40 is inserted into the box 50 of the other oil well steel pipe 1 , the pin shoulder surface 43 comes into contact with the box shoulder surface 53 during fastening. Thereby, high torque can be obtained at the time of fastening. Also, the positional relationship between the pin 40 and the box 50 in the fastened state can be stabilized.
- pin contact surface 400 of the pin 40 includes at least the male threaded portion 41 . That is, pin contact surface 400 may include external threads 41 and not include pin seal surface 42 and pin shoulder surface 43 . Pin contact surface 400 includes external threads 41 and pin shoulder surface 43 and may not include pin seal surface 42 . Pin contact surface 400 may include external threads 41 and pin seal surface 42 and may not include pin shoulder surface 43 .
- FIG. 6 is a cross-sectional view parallel to the axial direction of the oil well steel pipe 1 of the portion near the box 50 of the oil well steel pipe 1 shown in FIG.
- the dashed line portion in FIG. 6 shows the configuration of the pin 40 of another oil well steel pipe 1 when fastening with another oil well steel pipe 1 .
- box 50 has a box contact surface 500 on the inner peripheral surface of second end 10B of tube body 10 .
- the pin 40 of the other oil well steel pipe 1 is screwed into the box contact surface 500 and contacts the pin contact surface 400 of the pin 40 when the box contact surface 500 is fastened with the other oil well steel pipe 1 .
- the box contact surface 500 includes at least a female threaded portion 51 formed on the inner peripheral surface of the second end portion 10B. At the time of fastening, the female threaded portion 51 meshes with the male threaded portion 41 of the pin 40 of another oil well steel pipe.
- the box contact surface 500 may further include a box sealing surface 52 and a box shoulder surface 53.
- the box seal surface 52 is arranged closer to the pipe main body 10 than the internal thread portion 51 on the inner peripheral surface of the second end portion 10B. That is, the box seal surface 52 is arranged between the female threaded portion 51 and the box shoulder surface 53 .
- the box seal surface 52 is tapered. Specifically, in the box seal surface 52, the inner diameter gradually decreases from the female threaded portion 51 toward the box shoulder surface 53 in the longitudinal direction (pipe axis direction) of the second end portion 10B.
- the box seal surface 52 contacts the pin seal surface 42 of the pin 40 of the other oil well steel pipe 1 . More specifically, when the pin 40 of the other oil well steel pipe 1 is screwed into the box 50 at the time of fastening, the box seal surface 52 comes into contact with the pin seal surface 42. is in close contact with the pin seal surface 42 . As a result, during fastening, the box seal surface 52 is in close contact with the pin seal surface 42 to form a seal based on metal-to-metal contact. Therefore, the airtightness can be improved in the steel pipes 1 for oil wells that are fastened to each other.
- the box shoulder surface 53 is arranged closer to the pipe main body 10 than the box seal surface 52 is. That is, in the box 50, the box shoulder surface 53, the box seal surface 52, and the internal thread portion 51 are arranged in this order from the center of the pipe body 10 toward the tip of the second end portion 10B.
- the box shoulder surface 53 faces and contacts the pin shoulder surface 43 of the pin 40 of the other oil well steel pipe 1 . More specifically, when fastening, the box shoulder surface 53 contacts the pin shoulder surface 43 by inserting the pin 40 of the other oil well steel pipe 1 into the box 50 . Thereby, high torque can be obtained at the time of fastening. Also, the positional relationship between the pin 40 and the box 50 in the fastened state can be stabilized.
- the box contact surface 500 includes at least the female threaded portion 51 .
- the female threaded portion 51 of the box contact surface 500 of the box 50 corresponds to the male threaded portion 41 of the pin contact surface 400 of the pin 40 and contacts the male threaded portion 41 .
- Box seal surface 52 corresponds to pin seal surface 42 and contacts pin seal surface 42 .
- Box shoulder surface 53 corresponds to pin shoulder surface 43 and contacts pin shoulder surface 43 .
- the box contact surface 500 includes the female threaded portion 51 and does not include the box seal surface 52 and the box shoulder surface 53. If pin contact surface 400 includes external threads 41 and pin shoulder surface 43 but does not include pin seal surface 42 , box contact surface 500 includes internal threads 51 and box shoulder surface 53 but does not include box seal surface 52 . If pin contact surface 400 includes male threads 41 and pin seal surface 42 but does not include pin shoulder surface 43 , box contact surface 500 includes female threads 51 and box seal surface 52 but does not include box shoulder surface 53 .
- the pin contact surface 400 may include multiple external threads 41 , may include multiple pin seal surfaces 42 , and may include multiple pin shoulder surfaces 43 .
- the pin shoulder surface 43, the pin seal surface 42, the male threaded portion 41, the pin seal surface 42, the pin shoulder surface 43, the pin seal surface from the tip of the first end portion 10A toward the center of the pipe body 10. 42 and the male threaded portion 41 may be arranged in this order.
- the pin 40 includes a male threaded portion 41, a pin seal surface 42 and a pin shoulder surface 43
- the box 50 includes a female threaded portion 51, a box seal surface 52 and a box shoulder surface 53.
- pin 40 may include external threads 41 and not include pin seal surface 42 and pin shoulder surface 43
- box 50 includes internal threads 51 and does not include box seal surface 52 and box shoulder surface 53
- FIG. 7 shows that pin 40 includes male threaded portion 41 and does not include pin seal surface 42 and pin shoulder surface 43
- box 50 includes female threaded portion 51 and does not include box seal surface 52 and box shoulder surface 53.
- the oil well steel pipe 1 may have the configuration shown in FIG.
- the oil well steel pipe 1 shown in FIGS. 3, 4 and 7 is a so-called T&C oil well steel pipe 1 in which a pipe body 10 includes a pin pipe body 11 and a coupling 12 .
- the oil well steel pipe 1 according to the present embodiment may be of the integral type instead of the T&C type.
- FIG. 8 is a partial cross-sectional view of the integral type oil well steel pipe 1 according to this embodiment.
- an integral type oil well steel pipe 1 includes a pipe body 10 .
- the tube body 10 includes a first end 10A and a second end 10B.
- the first end 10A is arranged opposite to the second end 10B.
- the pipe body 10 includes the pin pipe body 11 and the coupling 12 . That is, in the T&C oil well steel pipe 1, the pipe body 10 is configured by fastening two separate members (the pin pipe body 11 and the coupling 12).
- the pipe body 10 is integrally formed.
- the pin 40 is formed on the first end portion 10A of the pipe body 10. At the time of fastening, the pin 40 is inserted and screwed into the box 50 of the other integral type oil well steel pipe 1 and fastened to the box 50 of the other integral type oil well steel pipe 1 .
- a box 50 is formed at the second end 10B of the tube body 10 . At the time of fastening, the pin 40 of the other integral type oil well steel pipe 1 is inserted and screwed into the box 50 to be fastened with the pin 40 of the other integral type oil well steel pipe 1 .
- the configuration of the pin 40 of the integral type oil well steel pipe 1 is the same as the configuration of the pin 40 of the T&C type oil well steel pipe 1 shown in FIG.
- the configuration of the box 50 of the integral type oil well steel pipe 1 is the same as the configuration of the box 50 of the T&C type oil well steel pipe 1 shown in FIG. 8, the pin shoulder surface, the pin seal surface, and the male screw portion 41 are arranged in this order from the tip of the first end portion 10A toward the center of the pipe body 10 in the pin 40.
- the female screw portion 51, the box sealing surface, and the box shoulder surface are arranged in this order.
- the pin contact surface 400 of the pin 40 of the integral type oil well steel pipe 1 only needs to include at least the male threaded portion 41 .
- the box contact surface 500 of the box 50 of the integral-type oil well steel pipe 1 may include at least the female thread portion 51. As shown in FIG.
- the oil well steel pipe 1 may be of the T&C type or the integral type.
- the chemical composition of the pipe body 10 is C: 0.01 to 0.60%, Cr: 0 to 8.0%, and Fe: 80.0% in mass%. contains more than That is, in the oil well steel pipe 1 according to the present embodiment, the chemical composition of the pipe body 10 contains 0.01 to 0.60% carbon (C) and 80.0% or more iron (Fe). However, as long as it does not contain more than 8.0% of chromium (Cr), it is not particularly limited, and other elements may be contained. In addition, "%" regarding an element in this specification means the mass %.
- the pipe body 10 of the oil well steel pipe 1 has, for example, C: 0.01 to 0.60%, Cr: 0 to 8.00%, P: 0.100% or less, S: 0.100%.
- N 0.100% or less
- O 0.100% or less
- Si 0 to 2.0%
- Mn 0 to 2.0%
- Al 0 to 1.0%
- Mo 0 to 5 .0%
- V 0-2.0%
- Nb 0-1.0%
- impurities are those that are mixed from ore, scrap, or the manufacturing environment as raw materials when steel materials are industrially manufactured. means to be
- a C-enriched layer may be formed in the Zn--Ni alloy plating layer as described later.
- the higher the C content the thicker the C-enriched layer is likely to be formed.
- the thickness of the C-enriched layer is set to 0 to 1.50 ⁇ m. can do.
- the pipe body 10 of the oil well steel pipe 1 according to the present embodiment has C: 0.10 to 0.60%, Cr: 0 to 8.0%, and Fe: 80.0% by mass%. It may have a chemical composition containing the above, and has a chemical composition containing C: 0.15 to 0.60%, Cr: 0 to 8.0%, and Fe: 80.0% or more. You may have Even in these cases, the oil well steel pipe 1 according to the present embodiment is such that the thickness of the C-enriched layer in the Zn—Ni alloy plating layer in the thickness direction of the pipe body 10 is set to 0 to 1.50 ⁇ m. can be done.
- a Zn—Ni alloy plating layer is formed on at least one of the pin contact surface 400 and the box contact surface 500 .
- the Zn—Ni alloy plating layer is formed on the pin contact surface 400 and may not be formed on the box contact surface 500 .
- the Zn—Ni alloy plating layer is formed on the box contact surface 500 and may not be formed on the pin contact surface 400 .
- a Zn—Ni alloy plating layer may be formed on the pin contact surface 400 and the box contact surface 500 .
- FIG. 9 is a cross-sectional view of the vicinity of the pin contact surface 400 when the Zn—Ni alloy plating layer 100 is formed on the pin contact surface 400.
- oil well steel pipe 1 further includes a Zn—Ni alloy plating layer 100 formed on pin contact surface 400 of pin 40 .
- the Zn--Ni alloy plating layer 100 may be formed on a portion of the pin contact surface 400 or may be formed on the entire pin contact surface 400.
- the pin seal surface 42 has a particularly high surface pressure in the final stage of screw tightening. Therefore, when the Zn—Ni alloy plating layer 100 is partially formed on the pin contact surface 400 , the Zn—Ni alloy plating layer 100 is preferably formed at least on the pin seal surface 42 .
- a Zn—Ni alloy plating layer 100 may be formed over the pin contact surface 400 as described above.
- FIG. 10 is a cross-sectional view near the box contact surface 500 when the Zn—Ni alloy plating layer 100 is formed on the box contact surface 500.
- a Zn—Ni alloy plated layer 100 is formed on box contact surface 500 in this case.
- the Zn—Ni alloy plating layer 100 may be formed on a portion of the box contact surface 500 or may be formed on the entire box contact surface 500 .
- the surface pressure of the box seal surface 52 becomes particularly high in the final stage of screw tightening. Therefore, when the Zn—Ni alloy plating layer 100 is partially formed on the box contact surface 500 , the Zn—Ni alloy plating layer 100 is preferably formed at least on the box sealing surface 52 .
- the Zn—Ni alloy plating layer 100 is formed on at least one of the pin contact surface 400 and the box contact surface 500 .
- the Zn--Ni alloy plated layer 100 is made of a Zn--Ni alloy.
- a Zn—Ni alloy contains zinc (Zn) and nickel (Ni).
- Zn—Ni alloys may contain impurities.
- the impurities of the Zn—Ni alloy are substances other than Zn and Ni, which are included in the Zn—Ni alloy plating layer 100 during the production of the oil well steel pipe 1, etc., and do not affect the effects of the present embodiment. means a substance contained at a content of
- the Zn--Ni alloy plating layer 100 contains Zn.
- Zn is a less noble metal than Fe. Therefore, the Zn—Ni alloy plating layer 100 is preferentially corroded (sacrificial corrosion protection) than the steel material. This enhances the corrosion resistance of the oil well steel pipe 1 .
- the chemical composition of the Zn--Ni alloy plating layer 100 can be measured by the following method.
- a sample containing the Zn—Ni alloy plating layer 100 (including the contact surface on which the Zn—Ni alloy plating layer 100 is formed) is taken from the oil well steel pipe 1 .
- the sampled Zn—Ni alloy plating layer 100 is dissolved in 10% hydrochloric acid to obtain a solution.
- the resulting solution was subjected to elemental analysis by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) to determine the Ni content (% by mass) in the Zn—Ni alloy plating layer 100. , and the Zn content (% by mass).
- ICP-AES Inductively Coupled Plasma Atomic Emission Spectrometry
- the thickness of the Zn—Ni alloy plating layer 100 is not particularly limited.
- the thickness of the Zn--Ni alloy plating layer 100 is, for example, 1-20 ⁇ m. If the thickness of the Zn—Ni alloy plating layer 100 is 1 ⁇ m or more, the seizure resistance can be further improved. Even if the thickness of the Zn—Ni alloy plating layer 100 exceeds 20 ⁇ m, the above effect is saturated.
- the lower limit of the thickness of the Zn—Ni alloy plating layer 100 is preferably 3 ⁇ m, more preferably 5 ⁇ m.
- the upper limit of the thickness of the Zn—Ni alloy plating layer 100 is preferably 18 ⁇ m, more preferably 15 ⁇ m.
- the thickness of the Zn--Ni alloy plating layer 100 in this embodiment can be measured by the following method.
- Zn- The thickness of the Ni alloy plating layer 100 is measured.
- the measurement is performed by a method conforming to ISO (International Organization for Standardization) 21968 (2005).
- the measurement points are four points (0°, 90°, 180°, and 270°) in the circumferential direction of the oil well steel pipe 1 .
- the arithmetic mean value of the measurement results is taken as the thickness of the Zn—Ni alloy plating layer 100 .
- [C-enriched layer] In the oil well steel pipe 1 according to the present embodiment, when a region in the Zn—Ni alloy plating layer 100 containing C that is 1.5 times or more the C content of the pipe body 10 is defined as a C-enriched layer, The thickness of the C-enriched layer in the thickness direction of 10 is 0 to 1.50 ⁇ m. In this case, the oil well steel pipe 1 has excellent seizure resistance.
- the surface layers of the pin contact surface 400 and the box contact surface 500 contain impurities derived from C. Easy to survive.
- the Zn--Ni alloy plating layer 100 By forming the Zn--Ni alloy plating layer 100 while C-derived impurities remain, it is considered that a thick C-enriched layer is formed in the Zn--Ni alloy plating layer 100.
- FIG. As used herein, the term “C-enriched layer” means a region where the C content is 1.5 times or more that of the pipe body 10 .
- the thickness of the C-enriched layer in the thickness direction of the pipe body 10 is preferably thin.
- the upper limit of the thickness of the C-enriched layer is preferably 1.00 ⁇ m, more preferably 0.80 ⁇ m, still more preferably 0.50 ⁇ m, still more preferably 0.30 ⁇ m, still more preferably 0.10 ⁇ m. is.
- the thickness of the C-enriched layer may be 0 ⁇ m. In this case, since the C-enriched layer does not exist, the adhesion of the Zn—Ni alloy plating layer 100 to the pipe body 10 is greatly improved, and the seizure resistance of the oil well steel pipe 1 can be further improved.
- the thickness of the C-enriched layer can be obtained as follows. Specifically, from the surface of the Zn—Ni alloy plating layer 100, elemental analysis is performed in the depth direction using GD-OES.
- GD-OES measurement conditions are as follows. GD-OES uses, for example, a Marcus-type high-frequency glow discharge optical emission spectrometer (GD-Profiler 2) manufactured by Horiba, Ltd. In this case, a pulse sputtering mode is used as the measurement mode, and high-purity argon (Ar) gas is used as the sputtering gas. Further, elemental analysis is performed in the depth direction of the Zn—Ni alloy plating layer 100 (thickness direction of the pipe body 10) with a discharge area of 2 mm ⁇ , an RF output of 20 W, and an Ar pressure of 700 Pa.
- the horizontal axis is the depth ( ⁇ m) from the surface of the Zn—Ni alloy plating layer 100
- the vertical axis is Zn, Fe, and C content. (% by mass) is plotted to create a content profile in the depth direction (see FIGS. 1 and 2).
- 1 and 2 the Zn content and Fe content are represented using the first axis
- the C content is represented using the second axis. Since the C content is very small compared to the Zn content and the Fe content, it is plotted in this way, but the Zn content, the Fe content, and the C content are all on the same axis. can be expressed as 1 and 2, the measured thickness of the Zn—Ni alloy plating layer 100 formed on the oil well steel pipe 1 is different. Therefore, the numerical values shown on the horizontal axis are different between FIG. 1 and FIG.
- the stable Zn content region and the Zn A region where the Fe content decreases and the Fe content increases and a region where the Fe content stabilizes are confirmed.
- the Fe content is 80.0% or more.
- the depth at which the Fe content of the pipe body 10 is 90.0% is defined as the "specific depth position" based on the Fe content profile in the depth direction by GD-OES. Specific depth positions are indicated by dashed lines in FIGS. Further, in this embodiment, the specific depth position is defined as the boundary between the Zn—Ni alloy plating layer 100 and the pipe body 10 . That is, in this embodiment, the Zn—Ni alloy plating layer 100 is formed on the surface layer (outside the pipe body 10) from the specific depth position.
- impurities such as oil may adhere to the surface of the Zn--Ni alloy plating layer 100.
- a chemical conversion treatment film may be formed on the Zn—Ni alloy plated layer 100 in some cases.
- impurities and coatings on the Zn--Ni alloy plated layer 100 make the Zn content unstable in the Zn content profile in the depth direction by GD-OES.
- the C-enriched layer is defined as a region containing 1.5 times or more the C content of the pipe body 10, the Zn—Ni alloy plating layer 100 Among them, the depth direction analysis by GD-OES shows that the Zn content is unstable in the surface direction of the Zn—Ni alloy plating layer 100 from the specific depth position where the Fe content of the pipe body 10 is 90.0%.
- the thickness of the C-enriched layer in the thickness direction of the pipe body 10 is 0 to 1.50 ⁇ m in the region until the change is exhibited.
- the content at which the C content is 1.5 times that of the pipe body 10 is indicated by the dashed line in the figures. 1 and 2, in the Zn—Ni alloy plating layer 100 (that is, the area on the left side of the specific depth position in the figure), the area where the C content is equal to or higher than the broken line in the figure is the C concentration corresponds to a layer.
- the C-enriched layer is confirmed to have a certain thickness.
- no C-enriched layer was confirmed.
- the depth direction analysis by GD-OES is performed under the above-described measurement conditions, and the horizontal axis is the depth ( ⁇ m) from the surface of the Zn—Ni alloy plating layer 100, and the vertical axis is Zn. , Fe, and C contents (% by mass) in the depth direction.
- the Zn—Ni alloy plating layer 100 is identified from the obtained profile. From the obtained profile and the specified Zn--Ni alloy plating layer 100, the thickness ( ⁇ m) of the C-enriched layer in the Zn--Ni alloy plating layer 100 can be obtained.
- the oil well steel pipe 1 of the present embodiment may further include a chemical conversion coating on the Zn—Ni alloy plating layer 100 .
- the chemical conversion coating is not particularly limited, and may be a known chemical conversion coating.
- the chemical conversion coating may be, for example, an oxalate conversion coating, a phosphate conversion coating, a borate conversion coating, or a chromate coating. .
- the chemical conversion coating is a chromate coating, the chromate coating preferably does not contain hexavalent chromium.
- the oil well steel pipe 1 may be stored outdoors for a long period of time until it is actually used in an oil drilling area.
- the chemical conversion coating can improve the corrosion resistance of the pin contact surface 400 and suppress the formation of rust (white rust) on the pin contact surface 400 when the oil well steel pipe 1 is exposed to the atmosphere outdoors for a long period of time.
- the film thickness of the chemical conversion coating is not particularly limited. The film thickness of the chemical conversion coating is, for example, 10 to 200 nm.
- the lubricating coating further enhances the lubricity of the oil well steel pipe 1 .
- the lubricating coating 110 may be formed on the Zn--Ni alloy plating layer 100. Further, referring to FIG. 12 , when Zn—Ni alloy plating layer 100 is formed on box contact surface 500 , lubricating coating 110 may be formed on Zn—Ni alloy plating layer 100 .
- the lubricating coating 110 may be solid, semi-solid, or liquid.
- a commercially available lubricant can be used for the lubricating coating 110 .
- Lubricating coating 110 contains, for example, lubricating particles and a binder.
- the lubricating coating 110 may contain solvent and other ingredients as needed.
- Lubricating particles are not particularly limited as long as they are particles having lubricity.
- Lubricating particles are, for example, graphite, MoS2 ( molybdenum disulfide), WS2 ( tungsten disulfide), BN (boron nitride), PTFE (polytetrafluoroethylene), CFx (graphite fluoride) and CaCO3 (calcium carbonate ) is one or more selected from the group consisting of
- the binder is, for example, one or two selected from the group consisting of organic binders and inorganic binders.
- the organic binder is, for example, one or two selected from the group consisting of thermosetting resins and thermoplastic resins.
- Thermosetting resins are, for example, one or more selected from the group consisting of polyethylene resins, polyimide resins and polyamideimide resins.
- the inorganic binder is, for example, one or two selected from the group consisting of alkoxysilanes and compounds containing siloxane bonds.
- a commercially available lubricant is, for example, SEAL-GUARD ECF (trade name) manufactured by JET-LUBE Co., Ltd.
- Other lubricating coatings 110 are, for example, lubricating coatings 110 containing rosins, metal soaps, waxes and lubricating powders.
- the oil well steel pipe 1 of the present embodiment is not limited to the following manufacturing method as long as it has the above configuration. However, the manufacturing method described below is a suitable example of manufacturing the oil well steel pipe 1 of the present embodiment.
- the method for manufacturing the oil well steel pipe 1 includes a preparation step (S1) of preparing a blank pipe having a pin 40 or a box 50 formed thereon, a surface treatment step (S2), and a Zn—Ni alloy plating layer forming step (S3). and In the present embodiment, a degreasing step and a pickling step are performed in the surface treatment step (S2).
- the Zn—Ni alloy plating layer 100 can have a C-enriched layer of 0 to 1.50 ⁇ m.
- Preparation step (S1) In the preparation step (S1), a blank pipe in which the pin 40 or the box 50 is formed is prepared.
- the “base pipe in which a pin or a box is formed” refers to the pipe body 10 and the pin pipe body 11 in the T&C type oil well steel pipe 1, and the pipe body in the integral type oil well steel pipe 1. 10.
- a blank tube in which the pin 40 or the box 50 is formed is manufactured, for example, by the following method.
- Material is manufactured using molten steel. Specifically, a slab (slab, bloom, or billet) is produced by continuous casting using molten steel. You may manufacture an ingot by an ingot casting method using molten steel. If desired, the slab, bloom or ingot may be bloomed to produce a billet.
- a raw material (slab, bloom, or billet) is manufactured by the above steps.
- the prepared material is hot-worked to manufacture a mother tube.
- the hot working method may be piercing-rolling by the Mannesmann method or hot extrusion. Well-known quenching and well-known tempering are performed on the mother pipe after hot working to adjust the strength of the mother pipe.
- a blank tube is manufactured by the above steps.
- a blank pipe for the coupling 12 is also prepared.
- the manufacturing method of the blank tube for the coupling 12 is the same as the manufacturing method of the blank tube described above.
- the outer surfaces of both ends of the blank pipe for the pin tube body 11 are threaded to form the pin 40 including the pin contact surface 400 .
- a blank pipe (pin pipe body 11) having pins 40 formed thereon is prepared when the oil well steel pipe 1 is of the T&C type.
- the coupling 12 may also be prepared. Specifically, the inner surfaces of both ends of the blank tube for coupling 12 are threaded to form box 50 including box contact surfaces 500 . Through the above steps, the coupling 12 is manufactured.
- the outer surface of the first end portion 10A of the blank pipe is threaded to form the pin 40 including the pin contact surface 400 . Further, threading is performed on the inner surface of the second end 10B of the blank tube to form the box 50 including the box contact surface 500 .
- a blank pipe (pipe main body 10) formed with pins 40 and boxes 50 is prepared for the case where the oil well steel pipe 1 is of the integral type.
- the surface treatment step (S2) includes a degreasing step and a pickling step.
- the order of the degreasing step and the pickling step is not particularly limited. That is, the pickling process may be performed on the blank pipe that has been subjected to the degreasing process, or the degreasing process may be performed on the blank pipe that has been subjected to the pickling process. Also, the degreasing step and the pickling step may be repeated as appropriate. That is, in the surface treatment step (S2) according to the present embodiment, the degreasing step may be further performed on the blank tube on which the degreasing step and the pickling step have been performed.
- pickling treatment may be further performed on the blank tube that has been subjected to the degreasing step and the pickling step.
- the degreasing step and the pickling step are appropriately combined to reduce the thickness of the C-enriched layer in the Zn—Ni alloy plating layer 100 from 0 to It can be adjusted within the range of 1.50 ⁇ m. Each step will be described in detail below.
- the blank pipe (pipe main body 10) is degreased (degreasing step).
- the blank pipe to be degreased may be the blank pipe prepared in the preparation step (S1) described above, or may be the blank pipe that has already been degreased in the degreasing step. It may be a blank pipe that has been subjected to a pickling treatment in a pickling process described later.
- electrolytic degreasing is performed as a degreasing treatment to wash oil and the like adhering to the contact surface of the blank pipe.
- the electrolytic degreasing may be anodic electrolytic degreasing using the blank tube as the anode, or may be cathodic electrolytic degreasing using the blank tube as the cathode.
- anodic electrolytic degreasing is performed as electrolytic degreasing.
- anodic electrolytic degreasing it is highly effective in degreasing the processing oil and the like on the surface of the blank tube.
- the bath used for electrolytic degreasing is not particularly limited, and a known bath can be used.
- Electrolytic degreasing baths are, for example, alkaline degreasing baths containing phosphates and silicates.
- Conditions for electrolytic degreasing are not particularly limited, and well-known conditions can be appropriately adjusted.
- Conditions for electrolytic degreasing are, for example, electrolytic degreasing bath temperature: 20 to 70° C., current density: 1 to 100 A/dm 2 , and current application time: 1 to 10 minutes.
- the raw pipe (pipe main body 10) is subjected to pickling treatment (pickling step).
- the blank pipe to be pickled may be the blank pipe prepared in the preparation step (S1) described above, or the blank pipe degreased in the degreasing step described above. Alternatively, it may be a blank tube that has already been pickled in a pickling process.
- electrolytic pickling may be performed as the pickling treatment, or immersion pickling may be performed.
- cathodic electrolytic pickling when performing electrolytic pickling, cathodic electrolytic pickling may be performed using the blank tube as a cathode, or anodic electrolytic pickling may be performed using the blank tube as an anode. .
- cathodic electrolytic pickling is preferably carried out.
- Cathodic electrolytic pickling has a weaker effect of dissolving the tube than anodic electrolytic pickling. Therefore, C-derived impurities are less likely to be formed in the blank pipe, and a thicker C-enriched layer is less likely to be formed in the Zn—Ni alloy plating layer 100 of the manufactured oil well steel pipe 1 . Therefore, in the pickling step of the present embodiment, when performing electrolytic pickling as the pickling treatment, it is preferable to perform cathodic electrolytic pickling.
- the bath used for electrolytic pickling is not particularly limited, and a known bath can be used.
- Electrolytic pickling baths are, for example, 5-30% sulfuric acid.
- the conditions for the electrolytic pickling are not particularly limited, and can be appropriately adjusted to well-known conditions. Conditions for electrolytic pickling are, for example, electrolytic pickling bath temperature: 20 to 60° C., current density: 1 to 100 A/dm 2 , and current application time: 1 to 60 minutes.
- immersion pickling may be performed in the pickling process according to the present embodiment.
- immersion pickling is carried out, a portion of the blank tube to be pickled is immersed in a bath.
- the immersion pickling bath is not particularly limited, and a known bath can be used.
- the immersion pickling bath is hydrochloric acid.
- hydrochloric acid is used as an immersion pickling bath, C-derived impurities in the blank pipe are easily removed, and a thick C-enriched layer is difficult to form in the Zn—Ni alloy plating layer 100 of the manufactured oil well steel pipe 1 .
- the immersion pickling bath used in the pickling step of the present embodiment is, for example, 5 to 30% hydrochloric acid.
- Conditions for the immersion pickling are not particularly limited, and can be appropriately adjusted to well-known conditions. Conditions for immersion pickling are, for example, immersion pickling bath temperature: 0 to 50° C. and immersion time: 0.5 to 10 minutes.
- water washing it is preferable to carry out water washing as appropriate.
- Conditions for washing with water are not particularly limited, and well-known conditions can be used. Degradation of the electrolytic degreasing bath, the electrolytic pickling bath, and the immersion pickling bath can be suppressed by appropriately washing the tube with water.
- the surface treatment step (S2) of the present embodiment may further include at least one step of a grinding process and a Ni strike plating process.
- the grinding process includes, for example, sandblasting and mechanical grinding finishing.
- Sandblasting is a process in which a blasting material (abrasive) and compressed air are mixed and projected onto a contact surface.
- the blasting material is, for example, spherical shot material and angular grid material.
- Sandblasting can increase the surface roughness of the contact surface.
- Sandblasting can be carried out by a well-known method. For example, a compressor compresses air and mixes the compressed air with the blasting material.
- the material of the blast material is, for example, stainless steel, aluminum, ceramic, alumina, and the like. Conditions such as the blasting speed of the sandblasting process are not particularly limited, and can be appropriately adjusted under known conditions.
- Ni strike plating layer is formed on the surface of the blank pipe.
- the Ni strike plating layer is a very thin base plating layer and enhances adhesion of the Zn—Ni alloy plating layer 100, which will be described later.
- Plating baths used in the Ni strike plating process are not particularly limited, and well-known baths can be used. Also, the conditions for forming the Ni strike plating layer are not particularly limited, and can be adjusted as appropriate.
- the Zn—Ni alloy plating layer 100 may include a Ni strike plating layer.
- Zn—Ni alloy plated layer forming step (S3) In the Zn—Ni alloy plating layer forming step (S3), on the pin contact surface 400 of the blank pipe on which the pins 40 are formed after the surface treatment step (S2) and/or on the blank pipe on which the box 50 is formed A Zn—Ni alloy plating layer 100 is formed by electroplating on the box contact surface 500 of .
- the plating bath is not particularly limited, and a known plating bath can be used.
- the plating bath contains, for example, zinc ions: 1 to 100 g/L and nickel ions: 1 to 100 g/L.
- the plating bath may be a chloride bath containing chloride ions or a sulfide bath containing sulfide ions.
- the Zn--Ni alloy plated layer 100 is formed by electroplating.
- Conditions for electroplating are not particularly limited, and can be appropriately adjusted to well-known conditions. Electroplating conditions are, for example, plating bath pH: 1 to 10, plating bath temperature: 10 to 60° C., current density: 1 to 100 A/dm 2 , and treatment time: 0.1 to 30 minutes.
- plating bath pH 1 to 10
- plating bath temperature 10 to 60° C.
- current density 1 to 100 A/dm 2
- treatment time 0.1 to 30 minutes.
- the oil well steel pipe 1 of the present embodiment having the configuration described above is manufactured.
- the method for manufacturing the oil well steel pipe 1 according to the present embodiment may further include at least one step of the following chemical conversion treatment step and film forming step. These steps are optional steps. Therefore, these steps may not be performed.
- the manufacturing method of this embodiment may implement a chemical conversion treatment process as needed. That is, the chemical conversion treatment step is an arbitrary step.
- a chemical conversion coating is formed on the Zn—Ni alloy plating layer 100 .
- well-known chemical conversion treatment may be performed.
- the chemical conversion treatment may be, for example, oxalate chemical treatment, phosphate chemical treatment, or borate chemical treatment.
- phosphating chemical treatment it may be performed using zinc phosphate, may be performed using manganese phosphate, or may be performed using zinc calcium phosphate. Processing may be performed.
- the treatment liquid may include, for example, 1 to 150 g/L of phosphate ions, 3 to 70 g/L of zinc ions, 1 to 100 g/L of nitrate ions, and 0 to 30 g/L of nickel ions.
- a chemical conversion treatment solution containing L can be used.
- the liquid temperature of the chemical conversion treatment liquid is, for example, 20 to 100.degree. In this manner, a chemical conversion film can be formed by appropriately setting well-known conditions and carrying out the chemical conversion treatment.
- the manufacturing method of this embodiment may perform a film-forming process as needed. That is, the film forming process is an arbitrary process.
- the lubricating coating 110 is formed on the Zn-Ni alloy plating layer 100 and/or on the contact surface (the pin contact surface 400 or the box contact surface 500) on which the Zn-Ni alloy plating layer 100 is not formed. Form.
- a composition or lubricant containing the components of the lubricating coating 110 described above is applied.
- the lubricating coating 110 can be formed.
- the coating method is not particularly limited. Application methods are, for example, spraying, brushing and dipping. When spray application is employed, the composition or lubricant may be heated and sprayed in a fluid state. The composition or lubricant is dried to form a lubricating coating 110 .
- the oil well steel pipe 1 of the present embodiment will be described more specifically by way of examples.
- the conditions in the following examples are examples of conditions adopted for confirming the feasibility and effect of the steel pipe 1 for oil wells of this embodiment. Therefore, the oil well steel pipe 1 of the present embodiment is not limited to this one condition example.
- a Zn-Ni alloy plated layer was formed after various pretreatments were performed on the contact surface of the pipe body (base pipe).
- the oil well steel pipe used was VAM21 (trade name) having a pipe main body with an outer diameter of 244.48 mm and a wall thickness of 13.84 mm.
- the main body of the used oil well steel pipe was made of low alloy steel.
- the pipe body of the steel pipe for oil wells used in this example has, in mass%, C: 0.24 to 0.31%, Si: 1.0% or less, Mn: 1.0% or less, P : 0.02% or less, S: 0.01% or less, and Cr: 0.40 to 0.70%.
- anode in the "electrolytic degreasing” column means that anodic electrolytic degreasing was performed.
- electrolytic degreasing a commercially available electrolytic degreasing detergent was used as an electrolytic degreasing bath.
- other electrolytic degreasing conditions were carried out under the preferable conditions described above.
- Electrolytic pickling was performed as a pickling process on the water-washed blank tube of each test number.
- Cathodic electrolytic pickling or anodic electrolytic pickling was performed as the electrolytic pickling.
- Table 1 shows the electrolytic pickling treatment performed on the blank tube of each test number. Specifically, in Table 1, “cathode” in the “electrolytic pickling” column means that cathodic electrolytic pickling was performed. In Table 1, “anode” in the “electrolytic pickling” column means that anodic electrolytic pickling was performed. Other electrolytic pickling conditions were the above-described preferred conditions.
- Immersion pickling was carried out as a pickling process for the water-washed tube of each test number.
- Table 1 shows the immersion pickling bath used for each test number. Specifically, in Table 1, "HCl” in the “immersion pickling” column means that an aqueous solution of hydrochloric acid was used as the immersion pickling bath. In Table 1, “H 2 SO 4 " in the "immersion pickling” column means that an aqueous sulfuric acid solution was used as the immersion pickling bath. Other conditions for immersion pickling were the preferred conditions described above.
- Ni strike plating process was performed on the blank pipes of each test number except for test number 4 to form a Ni strike plating layer. On the other hand, no Ni strike plating layer was formed on the blank tube of test number 4. In addition, the conditions of the Ni strike plating process were carried out under the preferable conditions described above.
- a Zn-Ni alloy plating layer forming process was performed on the blank pipe after immersion pickling or the blank pipe after the Ni strike plating process.
- a commercially available well-known plating bath was used as the plating bath.
- Other conditions of the Zn--Ni alloy plated layer forming step were carried out under the preferred conditions described above.
- the thickness of the Zn--Ni alloy plating layer was in the range of 5-25 ⁇ m. Oil well steel pipes of each test number were manufactured by the manufacturing process described above.
- a GD-OES depth direction analysis and a seizure resistance test were carried out on the manufactured oil well steel pipes.
- Depth direction analysis by GD-OES was performed on the oil well steel pipes of each test number. Specifically, elemental analysis was performed in the depth direction using GD-OES from the surface of the Zn—Ni alloy plating layer of the oil well steel pipe of each test number. Based on the obtained results, a content profile in the depth direction as shown in FIGS. 1 and 2 was created. The Zn—Ni alloy plating layer was identified by the method described above.
- Table 2 shows the C content in the oil well steel pipe of each test number as "C concentration in steel (% by mass)". Furthermore, Table 2 shows a value that is 1.5 times the C content as "C concentration standard (mass%)".
- C concentration standard (mass%) In the Zn-Ni alloy plating layer specified from the content profile in the depth direction of each test number obtained by the above method and the C content (0.42% by mass or more) of the C-enriched layer, The thickness of the C-enriched layer was obtained.
- Table 2 shows the thickness of the C-enriched layer in the oil well steel pipe of each test number obtained as "C-enriched layer ( ⁇ m)".
- the test was terminated when seizure occurred on the seal surface (pin seal surface or box seal surface).
- the seal surface pin seal surface or box seal surface.
- the maximum number of repeated fastenings was set to 10 times.
- the seizure resistance evaluation index was defined as the maximum number of times of fastening that does not cause irreversible seizure on the threads or seizure on the sealing surface.
- the thickness of the C-enriched layer exceeded 1.50 ⁇ m in the Zn-Ni alloy plating layer.
- the result of the seizure resistance test was 5 times or less. That is, the oil well steel pipes of test numbers 1, 2 and 4 did not have excellent seizure resistance.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- General Engineering & Computer Science (AREA)
- Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
- Electroplating Methods And Accessories (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
Abstract
Description
第1端部と第2端部とを含む管本体を備え、
前記管本体の化学組成は、質量%で、
C:0.01~0.60%、
Cr:0~8.0%、及び、
Fe:80.0%以上を含有し、
前記管本体は、
前記第1端部に形成されているピンと、
前記第2端部に形成されているボックスとを含み、
前記ピンは、
雄ねじ部を含むピン接触表面を含み、
前記ボックスは、
雌ねじ部を含むボックス接触表面を含み、
前記油井用鋼管はさらに、
前記ピン接触表面上と、前記ボックス接触表面上との少なくとも一方に形成されているZn-Ni合金めっき層を備え、
質量%で、前記管本体のC含有量の1.5倍以上のCを含有する領域をC濃化層と定義したとき、
前記Zn-Ni合金めっき層において、前記管本体の肉厚方向における前記C濃化層の厚さが0~1.50μmである。
油井用鋼管であって、
第1端部と第2端部とを含む管本体を備え、
前記管本体の化学組成は、質量%で、
C:0.01~0.60%、
Cr:0~8.0%、及び、
Fe:80.0%以上を含有し、
前記管本体は、
前記第1端部に形成されているピンと、
前記第2端部に形成されているボックスとを含み、
前記ピンは、
雄ねじ部を含むピン接触表面を含み、
前記ボックスは、
雌ねじ部を含むボックス接触表面を含み、
前記油井用鋼管はさらに、
前記ピン接触表面上と、前記ボックス接触表面上との少なくとも一方に形成されているZn-Ni合金めっき層を備え、
質量%で、前記管本体のC含有量の1.5倍以上のCを含有する領域をC濃化層と定義したとき、
前記Zn-Ni合金めっき層において、前記管本体の肉厚方向における前記C濃化層の厚さが0~1.50μmである、
油井用鋼管。
[1]に記載の油井用鋼管であって、
前記Zn-Ni合金めっき層の厚さは5~25μmである、
油井用鋼管。
[1]又は[2]に記載の油井用鋼管であって、
前記Zn-Ni合金めっき層上に潤滑被膜を備える、
油井用鋼管。
初めに、本実施形態による油井用鋼管の構成について説明する。油井用鋼管は周知の構成を有する。油井用鋼管は、T&C型の油井用鋼管と、インテグラル型の油井用鋼管とがある。以下、各タイプの油井用鋼管について詳述する。
図3は、本実施形態による油井用鋼管1の一例を示す構成図である。図3は、いわゆるT&C型(Threaded and Coupled)の油井用鋼管1の構成図である。図3を参照して、油井用鋼管1は、管本体10を備える。
図5は、図4に示す油井用鋼管1のうちのピン40近傍部分の、油井用鋼管1の管軸方向に平行な断面図である。図5中の破線部分は、他の油井用鋼管1と締結する場合の、他の油井用鋼管1のボックス50の構成を示す。図5を参照して、ピン40は、管本体10の第1端部10Aの外周面に、ピン接触表面400を備える。ピン接触表面400は、他の油井用鋼管1との締結時において、他の油井用鋼管1のボックス50と接触する。
図6は、図4に示す油井用鋼管1のうちのボックス50近傍部分の、油井用鋼管1の管軸方向に平行な断面図である。図6中の破線部分は、他の油井用鋼管1と締結する場合の、他の油井用鋼管1のピン40の構成を示す。図6を参照して、ボックス50は、管本体10の第2端部10Bの内周面に、ボックス接触表面500を備える。ボックス接触表面500は、他の油井用鋼管1との締結時において、他の油井用鋼管1のピン40がねじ込まれ、ピン40のピン接触表面400と接触する。
図3、図4及び図7に示す油井用鋼管1は、管本体10が、ピン管体11とカップリング12とを含む、いわゆる、T&C型の油井用鋼管1である。しかしながら、本実施形態による油井用鋼管1は、T&C型ではなく、インテグラル型であってもよい。
本実施形態による油井用鋼管1では、管本体10の化学組成は、質量%で、C:0.01~0.60%、Cr:0~8.0%、及び、Fe:80.0%以上を含有する。すなわち、本実施形態による油井用鋼管1において、管本体10の化学組成は、0.01~0.60%の炭素(C)と、80.0%以上の鉄(Fe)とが含有していれば、8.0%を超えるクロム(Cr)が含有されない限り、特に限定されず、その他の元素を含有していてもよい。なお、本明細書において元素に関する「%」は、質量%を意味する。
本実施形態による油井用鋼管1では、ピン接触表面400及びボックス接触表面500の少なくとも一方の接触表面上に、Zn-Ni合金めっき層が形成されている。つまり、Zn-Ni合金めっき層は、ピン接触表面400上に形成されており、ボックス接触表面500上に形成されていなくてもよい。また、Zn-Ni合金めっき層は、ボックス接触表面500上に形成されており、ピン接触表面400上に形成されていなくてもよい。また、Zn-Ni合金めっき層は、ピン接触表面400上及びボックス接触表面500上に形成されていてもよい。
図9は、Zn-Ni合金めっき層100がピン接触表面400上に形成されている場合のピン接触表面400近傍の断面図である。図9を参照して、油井用鋼管1はさらに、ピン40のピン接触表面400上に形成されているZn-Ni合金めっき層100を備える。
図10は、Zn-Ni合金めっき層100がボックス接触表面500上に形成されている場合のボックス接触表面500近傍の断面図である。図10を参照して、この場合、ボックス接触表面500上にZn-Ni合金めっき層100が形成されている。Zn-Ni合金めっき層100は、ボックス接触表面500の一部に形成されていてもよく、ボックス接触表面500全体に形成されていてもよい。ボックスシール面52は、ねじ締め最終段階で特に面圧が高くなる。したがって、Zn-Ni合金めっき層100がボックス接触表面500上に部分的に形成されている場合、Zn-Ni合金めっき層100は、少なくともボックスシール面52に形成されていることが好ましい。
上述のとおり、Zn-Ni合金めっき層100は、ピン接触表面400及びボックス接触表面500の少なくとも一方の接触表面上に形成されている。ここで、Zn-Ni合金めっき層100は、Zn-Ni合金からなる。具体的に、Zn-Ni合金は、亜鉛(Zn)及びニッケル(Ni)を含有する。Zn-Ni合金は不純物を含有する場合がある。ここで、Zn-Ni合金の不純物とは、Zn及びNi以外の物質で、油井用鋼管1の製造中等にZn-Ni合金めっき層100に含有され、本実施形態の効果に影響を与えない範囲の含有量で含まれる物質を意味する。
Zn-Ni合金めっき層100の厚さは特に限定されない。Zn-Ni合金めっき層100の厚さはたとえば、1~20μmである。Zn-Ni合金めっき層100の厚さが1μm以上であれば、耐焼付き性をさらに高めることができる。Zn-Ni合金めっき層100の厚さが20μmを超えても、上記効果は飽和する。Zn-Ni合金めっき層100の厚さの下限は好ましくは3μmであり、より好ましくは5μmである。Zn-Ni合金めっき層100の厚さの上限は好ましくは18μmであり、より好ましくは15μmである。
本実施形態による油井用鋼管1は、Zn-Ni合金めっき層100において、管本体10のC含有量の1.5倍以上のCを含有する領域をC濃化層と定義したとき、管本体10の肉厚方向におけるC濃化層の厚さが0~1.50μmである。この場合、油井用鋼管1は優れた耐焼付き性を有する。
[化成処理被膜]
本実施形態の油井用鋼管1はさらに、Zn-Ni合金めっき層100上に、化成処理被膜を備えてもよい。化成処理被膜は、特に限定されず、周知の化成処理被膜でよい。化成処理被膜は、たとえば、シュウ酸塩化成処理被膜であってもよく、リン酸塩化成処理被膜であってもよく、ホウ酸塩化成処理被膜であってもよく、クロメート被膜であってもよい。化成処理被膜がクロメート被膜である場合、クロメート被膜には6価クロムを含まないのが好ましい。
油井用鋼管1ではさらに、Zn-Ni合金めっき層100上、化成処理被膜上、Zn-Ni合金めっき層100が形成されていない接触表面上(ピン接触表面400上又はボックス接触表面500上)に、潤滑被膜を備えてもよい。潤滑被膜は、油井用鋼管1の潤滑性をさらに高める。
本実施形態の油井用鋼管1の製造方法について、以下に説明する。なお、本実施形態の油井用鋼管1は、上記構成を有すれば、製造方法は以下の製造方法に限定されない。ただし、以下に説明する製造方法は、本実施形態の油井用鋼管1を製造する好適な一例である。
準備工程(S1)では、ピン40又はボックス50が形成されている素管を準備する。本明細書において、「ピン又はボックスが形成されている素管」とは、T&C型の油井用鋼管1における管本体10、ピン管体11、及び、インテグラル型の油井用鋼管1における管本体10のいずれかを意味する。
下地処理工程(S2)では、準備された素管(管本体10)に対して、Zn-Ni合金めっき層100を形成する前の下地処理を実施する。本実施形態による下地処理工程(S2)は、脱脂工程と酸洗工程とを含む。
本実施形態による下地処理工程(S2)では、素管(管本体10)に対して、脱脂処理を実施する(脱脂工程)。ここで、脱脂処理が実施される素管とは、上述の準備工程(S1)で準備された素管であってもよく、既に脱脂工程で脱脂処理が実施された素管であってもよく、後述する酸洗工程で酸洗処理が実施された素管であってもよい。本実施形態による脱脂工程では、脱脂処理として電解脱脂を実施して、素管の接触表面上に付着した油分等を洗浄する。電解脱脂は、素管を陽極とする陽極電解脱脂でもよく、素管を陰極とする陰極電解脱脂でもよい。好ましくは、本実施形態による脱脂工程では、電解脱脂として陽極電解脱脂を実施する。陽極電解脱脂を実施した場合、素管表面の加工油等を脱脂する効果が高い。
本実施形態による下地処理工程(S2)では、素管(管本体10)に対して、酸洗処理を実施する(酸洗工程)。ここで、酸洗処理が実施される素管とは、上述の準備工程(S1)で準備された素管であってもよく、上述の脱脂工程で脱脂処理が実施された素管であってもよく、既に酸洗工程で酸洗処理が実施された素管であってもよい。本実施形態では、酸洗処理として電解酸洗を実施してもよく、浸漬酸洗を実施してもよい。
本実施形態の下地処理工程(S2)ではさらに、研削加工工程と、Niストライクめっき工程との少なくとも1工程を含んでもよい。
Zn-Ni合金めっき層形成工程(S3)では、下地処理工程(S2)後のピン40が形成されている素管のピン接触表面400上、及び/又は、ボックス50が形成されている素管のボックス接触表面500上に、電気めっきにより、Zn-Ni合金めっき層100を形成する。
本実施形態による油井用鋼管1の製造方法はさらに、次の化成処理工程、及び、成膜工程の少なくとも1工程を実施してもよい。これらの工程は任意の工程である。したがって、これらの工程は実施しなくてもよい。
本実施形態の製造方法は、必要に応じて、化成処理工程を実施してもよい。つまり、化成処理工程は任意の工程である。化成処理工程を実施する場合、Zn-Ni合金めっき層100上に化成処理被膜を形成する。化成処理工程では、周知の化成処理を実施すればよい。化成処理は、たとえば、シュウ酸塩化成処理であってもよく、リン酸塩化成処理であってもよく、ホウ酸塩化成処理であってもよい。たとえば、リン酸塩化成処理を実施する場合、リン酸亜鉛を用いた化成処理を実施してもよく、リン酸マンガンを用いた化成処理を実施してもよく、リン酸亜鉛カルシウムを用いた化成処理を実施してもよい。
本実施形態の製造方法は、必要に応じて、成膜工程を実施してもよい。つまり、成膜工程は任意の工程である。成膜工程では、Zn-Ni合金めっき層100上、及び/又は、Zn-Ni合金めっき層100が形成されていない接触表面(ピン接触表面400又はボックス接触表面500)上に、潤滑被膜110を形成する。
各試験番号の油井用鋼管に対して、GD-OESによる深さ方向分析を実施した。具体的には、各試験番号の油井用鋼管のZn-Ni合金めっき層の表面から、深さ方向に対して、GD-OESを用いて深さ方向に元素分析を実施した。得られた結果に基づいて、図1及び図2に示されるような深さ方向の含有量プロファイルを作成した。なお、上述の方法で、Zn-Ni合金めっき層を特定した。
各試験番号の油井用鋼管について、耐焼付き性試験を実施した。耐焼付き性試験は、長距離での摺動を想定して、繰返し締結を実施することにより行った。具体的には、各試験番号の油井用鋼管を用いて、室温(約25℃)でねじ締め及びねじ戻しを繰り返した。締結トルクは62940N・mとした。ねじ締め及びねじ戻しを1回行うごとに、ピン接触表面及びボックス接触表面を目視により観察した。目視観察により、接触表面(ピン接触表面及びボックス接触表面)における焼付きの発生状況を確認した。
表2を参照して、試験番号3、及び、5~9の油井用鋼管では、Zn-Ni合金めっき層において、C濃化層の厚さが0~1.50μmであった。その結果、耐焼付き性試験の結果が、6回以上であった。すなわち、試験番号3、及び、5~9の油井用鋼管は、優れた耐焼付き性を有していた。
10 管本体
10A 第1端部
10B 第2端部
40 ピン
41 雄ねじ部
50 ボックス
51 雌ねじ部
100 Zn-Ni合金めっき層
110 潤滑被膜
400 ピン接触表面
500 ボックス接触表面
Claims (3)
- 油井用鋼管であって、
第1端部と第2端部とを含む管本体を備え、
前記管本体の化学組成は、質量%で、
C:0.01~0.60%、
Cr:0~8.0%、及び、
Fe:80.0%以上を含有し、
前記管本体は、
前記第1端部に形成されているピンと、
前記第2端部に形成されているボックスとを含み、
前記ピンは、
雄ねじ部を含むピン接触表面を含み、
前記ボックスは、
雌ねじ部を含むボックス接触表面を含み、
前記油井用鋼管はさらに、
前記ピン接触表面上と、前記ボックス接触表面上との少なくとも一方に形成されているZn-Ni合金めっき層を備え、
質量%で、前記管本体のC含有量の1.5倍以上のCを含有する領域をC濃化層と定義したとき、
前記Zn-Ni合金めっき層において、前記管本体の肉厚方向における前記C濃化層の厚さが0~1.50μmである、
油井用鋼管。 - 請求項1に記載の油井用鋼管であって、
前記Zn-Ni合金めっき層の厚さは5~25μmである、
油井用鋼管。 - 請求項1又は請求項2に記載の油井用鋼管であって、
前記Zn-Ni合金めっき層上に潤滑被膜を備える、
油井用鋼管。
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP22795511.9A EP4332344A1 (en) | 2021-04-28 | 2022-03-31 | Oil-well steel pipe |
JP2023517211A JPWO2022230595A1 (ja) | 2021-04-28 | 2022-03-31 | |
AU2022266352A AU2022266352A1 (en) | 2021-04-28 | 2022-03-31 | Oil-Well Steel Pipe |
CA3214979A CA3214979A1 (en) | 2021-04-28 | 2022-03-31 | Oil-well steel pipe |
US18/557,395 US20240200176A1 (en) | 2021-04-28 | 2022-03-31 | Steel pipe for oil well |
MX2023012616A MX2023012616A (es) | 2021-04-28 | 2022-03-31 | Tubo de acero para pozos de petroleo. |
BR112023021449A BR112023021449A2 (pt) | 2021-04-28 | 2022-03-31 | Tubo de aço para poço de petróleo |
CN202280030815.7A CN117255887A (zh) | 2021-04-28 | 2022-03-31 | 油井用钢管 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021-075844 | 2021-04-28 | ||
JP2021075844 | 2021-04-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022230595A1 true WO2022230595A1 (ja) | 2022-11-03 |
Family
ID=83848056
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/016384 WO2022230595A1 (ja) | 2021-04-28 | 2022-03-31 | 油井用鋼管 |
Country Status (10)
Country | Link |
---|---|
US (1) | US20240200176A1 (ja) |
EP (1) | EP4332344A1 (ja) |
JP (1) | JPWO2022230595A1 (ja) |
CN (1) | CN117255887A (ja) |
AR (1) | AR125465A1 (ja) |
AU (1) | AU2022266352A1 (ja) |
BR (1) | BR112023021449A2 (ja) |
CA (1) | CA3214979A1 (ja) |
MX (1) | MX2023012616A (ja) |
WO (1) | WO2022230595A1 (ja) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008527249A (ja) * | 2005-01-13 | 2008-07-24 | 住友金属工業株式会社 | 鋼管用ねじ継手 |
WO2009057754A1 (ja) * | 2007-11-02 | 2009-05-07 | Sumitomo Metal Industries, Ltd. | 潤滑被膜を備えた管ねじ継手 |
WO2016170031A1 (en) | 2015-04-23 | 2016-10-27 | Vallourec Oil And Gas France | Threaded tubular element provided with a metallic anti-corrosion and anti-galling coating |
WO2020149310A1 (ja) * | 2019-01-16 | 2020-07-23 | 日本製鉄株式会社 | 管用ねじ継手及び管用ねじ継手の製造方法 |
-
2022
- 2022-03-31 EP EP22795511.9A patent/EP4332344A1/en active Pending
- 2022-03-31 WO PCT/JP2022/016384 patent/WO2022230595A1/ja active Application Filing
- 2022-03-31 CA CA3214979A patent/CA3214979A1/en active Pending
- 2022-03-31 AU AU2022266352A patent/AU2022266352A1/en active Pending
- 2022-03-31 MX MX2023012616A patent/MX2023012616A/es unknown
- 2022-03-31 BR BR112023021449A patent/BR112023021449A2/pt unknown
- 2022-03-31 US US18/557,395 patent/US20240200176A1/en active Pending
- 2022-03-31 CN CN202280030815.7A patent/CN117255887A/zh active Pending
- 2022-03-31 JP JP2023517211A patent/JPWO2022230595A1/ja active Pending
- 2022-04-27 AR ARP220101100A patent/AR125465A1/es unknown
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008527249A (ja) * | 2005-01-13 | 2008-07-24 | 住友金属工業株式会社 | 鋼管用ねじ継手 |
WO2009057754A1 (ja) * | 2007-11-02 | 2009-05-07 | Sumitomo Metal Industries, Ltd. | 潤滑被膜を備えた管ねじ継手 |
WO2016170031A1 (en) | 2015-04-23 | 2016-10-27 | Vallourec Oil And Gas France | Threaded tubular element provided with a metallic anti-corrosion and anti-galling coating |
WO2020149310A1 (ja) * | 2019-01-16 | 2020-07-23 | 日本製鉄株式会社 | 管用ねじ継手及び管用ねじ継手の製造方法 |
Also Published As
Publication number | Publication date |
---|---|
AR125465A1 (es) | 2023-07-19 |
JPWO2022230595A1 (ja) | 2022-11-03 |
CA3214979A1 (en) | 2022-11-03 |
BR112023021449A2 (pt) | 2023-12-19 |
US20240200176A1 (en) | 2024-06-20 |
CN117255887A (zh) | 2023-12-19 |
AU2022266352A1 (en) | 2023-11-16 |
EP4332344A1 (en) | 2024-03-06 |
MX2023012616A (es) | 2023-11-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3633253B1 (en) | Threaded connection for pipes or tubes and method for producing threaded connection for pipes or tubes | |
EP1705265B1 (en) | Surface adjustment treatment prior to chemical treatment of steel product | |
CN108474502B (zh) | 管用螺纹接头和管用螺纹接头的制造方法 | |
WO2018003455A1 (ja) | 管用ねじ継手及び管用ねじ継手の製造方法 | |
JP7301891B2 (ja) | 管用ねじ継手 | |
AU2023266308A1 (en) | Threaded connection for oil country tubular goods and method for producing threaded connection for oil country tubular goods | |
CN111051757B (zh) | 管用螺纹接头及管用螺纹接头的制造方法 | |
WO2022230595A1 (ja) | 油井用鋼管 | |
WO2020149310A1 (ja) | 管用ねじ継手及び管用ねじ継手の製造方法 | |
WO2023037910A1 (ja) | 油井用金属管 | |
JP2018123831A (ja) | 管用ねじ継手及び管用ねじ継手の製造方法 | |
JP2018123349A (ja) | 管用ねじ継手及び管用ねじ継手の製造方法 | |
WO2023243170A1 (ja) | 油井用金属管 | |
JP2018123346A (ja) | 管用ねじ継手及びその製造方法 | |
WO2024154524A1 (ja) | 油井用金属管 | |
OA19360A (en) | Threaded joint for pipe and method for producing threaded joint for pipe. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22795511 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2023517211 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 3214979 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 4180 Country of ref document: AO |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112023021449 Country of ref document: BR |
|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2023/012616 Country of ref document: MX Ref document number: P6002757/2023 Country of ref document: AE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202280030815.7 Country of ref document: CN Ref document number: 2301006959 Country of ref document: TH |
|
WWE | Wipo information: entry into national phase |
Ref document number: 18557395 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2022266352 Country of ref document: AU Ref document number: AU2022266352 Country of ref document: AU |
|
ENP | Entry into the national phase |
Ref document number: 2022266352 Country of ref document: AU Date of ref document: 20220331 Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202393030 Country of ref document: EA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2022795511 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2022795511 Country of ref document: EP Effective date: 20231128 |
|
ENP | Entry into the national phase |
Ref document number: 112023021449 Country of ref document: BR Kind code of ref document: A2 Effective date: 20231016 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 523451286 Country of ref document: SA |