EP0183536A2 - Acier magnétique à haute résistance à la corrosion et à haute résistance mécanique pour masse-tige de forage et masse-type fabriquée avec cet acier - Google Patents

Acier magnétique à haute résistance à la corrosion et à haute résistance mécanique pour masse-tige de forage et masse-type fabriquée avec cet acier Download PDF

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Publication number
EP0183536A2
EP0183536A2 EP85308615A EP85308615A EP0183536A2 EP 0183536 A2 EP0183536 A2 EP 0183536A2 EP 85308615 A EP85308615 A EP 85308615A EP 85308615 A EP85308615 A EP 85308615A EP 0183536 A2 EP0183536 A2 EP 0183536A2
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EP
European Patent Office
Prior art keywords
drill collar
steel
drill
balance
content
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
EP85308615A
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German (de)
English (en)
Other versions
EP0183536A3 (en
EP0183536B1 (fr
Inventor
Takanori Dainigijutsukenkyusho Nakazawa
Toru Dainigijutsukenkyusho Suzuki
Tetsu Dainigijutsukenkyusho Sakamoto
Isamu Yamauchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
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Nippon Steel Corp
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Filing date
Publication date
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Priority to AT85308615T priority Critical patent/ATE45991T1/de
Publication of EP0183536A2 publication Critical patent/EP0183536A2/fr
Publication of EP0183536A3 publication Critical patent/EP0183536A3/en
Application granted granted Critical
Publication of EP0183536B1 publication Critical patent/EP0183536B1/fr
Expired legal-status Critical Current

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Classifications

    • 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
    • E21B17/16—Drill collars
    • 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum

Definitions

  • the present invention relates to a non-magnetic steel alloy having high resistance to stress corrosion cracking, suitable for use as the material of drill collars, and relates to the drill collars made of the steel.
  • Drill collars made of high-strength, non-magnetic steels are used in the petroleum drilling operation under such severe conditions.
  • the drill collar is a member which is provided on the upper side of a drill bit so as to load the drill bit thereby enhancing the drilling efficiency.
  • the drill collar is constituted by a thick-walled steel pipe of, for example, 250 mm in outside diameter, 70 mm in thickness and 10 m in length.
  • the drill collar is required to have a considerable strength and toughness, e.g., a proof stress of about 60 to 80 kgf/mm2 and elongation of about 25% or greater.
  • high Mn-steels and Ni-Cr steels have been used as high-strength non-magnetic steels.
  • An example of such steels is X50MnCrV20 14 (1.3819) specified by DIN.
  • the high Mn steel has a lower corrosion resistance than Ni-Cr steels, although the corrosion resistance of the high Mn steel can be increased by addition of Cr.
  • the high Mn steel is undesirable for the usage of drilling under the condition rich in colorine ions, because the resistance to stress corrosion cracking is impaired by the presence of Mn.
  • the strength of the high Mn steel relies mainly upon strengthening effect of precipitation of carbides.
  • precipitation strengthened austenitic stainless steels have been known as a kind of the high-strength Ni-Cr austenitic steels.
  • An example of such austenitic stainless steel is A 286 (AISI 660) which makes use of the precipitation strengthening due to intermetallic compound y l : [Ni 3 (Al,Ti)], or is described in Metal Science Journal, 1970, Vol. 4, Page 122 and in Metallurgical Transactions A, Vol. 7A, November 1976, Pages 1743 to 1746.
  • this steel does not exhibit satisfactory corrosion resistance because the Cr content thereof is as small as 15% or so.
  • this stainless steel is apt to cause carbides of Ti, due to containment of about 0.05% of C.
  • the Ti carbides of large sizes are formed during solidification of an ingot or billet. Such large-sized carbides cannot be removed completely even by subsequent heating and rolling.
  • the large Ti carbides tend to initiate cracks of the material and to promote propagation of cracks, thus impairing ductility and toughness of the material.
  • the distribution of the large Ti carbides, which adversely affect the properties of the material varies in the radial direction as well as in the longitudinal direction of the round bar. It is, therefore, not possible to obtain satisfactory homogeneousness of the round bar steel as the blank material of the drill collar.
  • the conventional high-strength non-magnetic steels are unsatisfactory in their properties such as corrosion resistance, particularly stress corrosion cracking, ductility and toughness, and do not have required homogeneousness, thus impairing the life and durability of drill collars.
  • an object of the invention is to provide a non-magnetic steel having high corrosion resistance as well as high strength suitable for use as the material of drill collars, thereby overcoming the above-described problems of the prior art.
  • Another object of the invention is to provide the use of the non-magnetic steel described above as the material of a drill collar.
  • Still another object of the invention is to provide a drill collar having superior resistance to stress corrosion cracking and high strength used in petroleum drilling operation effected under severe conditions such as atmosphere containing greater amount of chlorides and high temperature.
  • the present inventors have found that satisfactory resistance to stress corrosion cracking can be obtained if Cr and Ni contents in the steel are sufficiently high.
  • the inventors have found also that the ductility, toughness and homogeneousness can be remarkably improved by extremely reducing the contents of C and N both of which are apt to form compounds in association with carbide formers and nitride formers such as Ti, Cr, Mo, Nb and V.
  • the present invention makes it possible to obtain a non-magnetic steel having high corrosion resistance and high strength suitable for use as the material of a drill collar, which steel essentially consists, by weight %, of: not greater than 0.02% of C, not greater than 2.0% of Si, not greater than 2.0% of Mn, 25 to 40% of Ni, 18 to 30% of Cr, 0.1 to 1.5% of Al, 1.5 to 3.0% of Ti, 0.0005 to 0.020% of Ca, not greater than 0.020% of N and the balance Fe and incidental impurities.
  • the steel in accordance with the invention may further contain one or two kinds or more selected from the group consisting of not greater than 3.0% of Mo, not greater than 0.5% of Zr, not greater than 0.5% of Nb and not greater than 0.5% of V.
  • the drill collar of the invention which is adapted to be attached to a drill bit through a near bit stabilizer, comprises a cylindrical main body made of an alloy consisting essentially, by weight, of not greater than 0.020% of C, not greater than 2.0% of Si, not greater than 2.0% of Mn, 25 - 40% of Ni, 18 to 30% of Cr, 0.1 to 1.5% of Al, 1.5 to 3.0% of Ti, 0.0005 to 0.020% of Ca, not greater than 0.020% of N and the balance Fe and incidental impurities.
  • Si and Mn are elements which are essential as deoxidation agents.
  • an excessively large Si content impairs the hot workability of the material, while the presence of M n in excess of 2.0% reduces the resistance to stress corrosion cracking. Therefore, the Si and Mn contents are limited to be not greater than 2.0%, respectively.
  • Ni and Cr are fundamental elements in the steel of the invention. Referring first to Ni, this element is the major constituent necessary for maintaining, in combination with Cr which will be mentioned later, a stable austenitic phase which is essential for the non-magnetic property of the steel. Ni serves also as a strengthening element, because the steel of the invention is a so-called precipitation-hardened steel in which the strength has been increased as a result of precipitation of intermetallic compound y'-phase: [Ni 3 (Al,Ti)] through aging treatment. In order that the drill collar for deep oil well drilling exhibits the required resistance to stress corrosion cracking under operating condition rich in chlorine ions, the Ni content should be not less than 25%. The Ni content, however, need not exceed 40% because the effect for improving the resistance to stress corrosion cracking is saturated at 40%.
  • the Cr content should not be less than 18%. A Cr content exceeding 30%, however, impairs the hot workability and makes austenitic phase unstable. Therefore, the upper limit of Cr content is set at 30%.
  • Figs. la and lb show, how time to rupture in stress corrosion test is varied in accordance with change in the Cr content and Ni content, respectively.
  • the experiment was conducted by using two types of test pieces: namely, a first type test pieces obtained from steels each of which basically contains 0.010% of C, 0.5% of Si, 1.2% of Mn, 0.5% of Al, 2.0% of Ti, 0.0010% of Ca and 0.005% of N and further containing 30% of Ni and variable amount of Cr; and a second type test pieces obtained from steels each containing, in addition to the above-mentioned basic elements, 20% of Cr and variable amount of Ni.
  • the test pieces each having a diameter of 6 mm at its parallel portion were subjected to a constant load type stress corrosion cracking test conducted in a boiling, saturated salt 2 water at a stress of 80 kgf/m m 2 .
  • Al is the element which forms the precipitates for strengthening the steel of the invention: namely, an intermetallic compound y': [Ni 3 (Al, Ti)].
  • Al also has an effect for suppressing the precipitation of n-phase which is precipitates of grain boundary reaction type adversely affecting the ductility and toughness of the steel.
  • An excessively large Al content reduces the precipitation hardening effect because it decreases the matching strain occarring between the austenite phase and the y' phase.
  • the Al content is selected to range between 0.1 and 1.5%.
  • Ti is a major element which forms the intermetallic compound y': [Ni 3 (Al, Ti)], and the strength of the alloy is increased as the Ti content is increased.
  • the drill collar In order that the drill collar can withstand the large ground pressure encountered during drilling, the drill collar has to have a high strength. To keep this high strength, the Ti content has to be at least 1.5%. The addition of Ti in excess of 3% seriously impairs the hot workability of the alloy. For these reasons, the Ti content should range between 1.5% and 3%.
  • Ca as an element for improving the hot workability should be contained by an amount not less than 0.0005%.
  • the formation of carbides or nitrides of Ti, Cr, Mo, Nb, Zr and V is reduced by limiting the C and N contents, thereby ensuring high ductility, toughness and homogeneousness required for the steel used for drill collar.
  • this element forms large Ti carbides through reaction with Ti in the course of solidification.
  • the solid-solution of such large Ti carbide is difficult to be effected in the subsequent heating, rolling or solid-solution heat treatment.
  • drill collars are inevitably subjected to impacts due to change in the driving torque or change in the nature of the earth during drilling.
  • the drill collar therefore, should have high ductility, toughness and homogeneousness, in order to prevent breakage by such impacts.
  • the C content has to be not greater than 0.02%.
  • the carbon content is not more than 0.015%.
  • N has a tendency of forming large compounds through reaction with Ti, i.e., Ti nitrides. This tendency is greater than the tendency of formation of large Ti carbides exhibited by C. In order to ensure the ductility, toughness and homogeneousness which are necessary for the drill collars, therefore, the N content should be limited suitably.
  • the upper limit of N content should be selected to be less than 0.020% which is lower than the upper limit of C content.
  • the preferable range of nitrogen is of not more than 0.010%. The adequate ranges of C and N contents are determined in view of the following effects.
  • Fig. 2 shows the results of an experiment which was conducted for the purpose of investigation of the relationship between the mechanical properties and C and N contents.
  • the experiment was carried out as follows. Two types of material were prepared. The first type of alloy basically containing 0.5% of Si, 1.2% of Mn, 20% of Cr, 34% of Ni, 0.5% of Al, 2% of Ti and 0.0010% of Ca, with the addition of 0.006% of N and variable amount of C. The second type of alloy was prepared by adding 0.010% of C and variable amount of N to the basic composition described above.
  • the melts of these materials were solidified and rolled or forged into round bars of 150 mm in diameter which were then subjected to a solution treatment effected at a temperature of 950 to 1100°C in 30 to 90 min and an aging treatment effected at a temperature of 700 - 850°C in 1 to 10 hours. Then, tensile test pieces in accordance with the tensile test piece No. 4 in JIS were provided at the sampling positions shown in Fig. 2. The thus obtained test pieces were then subjected to a tensile test conducted under JIS Z 2241. The results of the tensile test are shown in Fig. 2.
  • the steel of the invention can further contain limited amount of one, two or more elements selected from the group consisting of Mo, Zr, Nb and V, in order to improve the proof stress of the drill collar.
  • Mo is an element which produces a solid solution strengthening effect, and is important for attaining high proof stress.
  • An Mo content exceeding 3% seriously increases the hot deformation resistance of the material, so that the processing such as rolling and forging is made difficult.
  • the Mo content therefore, should be not greater than 3.0%.
  • Zr, Nb and V can be in the state of the solid-solution in the intermetallic compound y' which brings about the precipitation strengthening effect.
  • the addition of these elements increases the amount of precipitation of y', thus enhancing the proof stress. Since the excessive addition of these elements impairs the ductility and toughness, the content of each of these elements is limited to 0.5% at the greatest.
  • the steel of the invention having the described composition are produced by a steel making process using, for example, an electric furnace, and is changed into an ingot or billet by a subsequent ingot-making, blooming or by a continuous casting.
  • the billets are formed into round bars through rolling or forging, and, after a subsequent solution heat treatment effected at a temperature in the range of 950 to 1100°C for a period of time of 30 to 90 min followed by water-cooling and an aging treatment effected at a temperature of 700 to 850°C for a period of time of 1 to 10 hours, it becomes a blank material available for the drill collars having austenitic structure in which y' intermetallic compounds are uniformly precipitated.
  • the solid-solution treatment and aging treatment may be omitted if temperature of the rolling or forging is appropriate.
  • Each of molten alloys of about 1000 kg having the chemical compositions shown in Table 1 prepared by a vacuum melting furnace was cast at about 1500°C into an ingot having a square cross section of about 400 mm in one side and a length of about 700 mm, the ingot being then forged at a temperature of about 1150°C into a rounded bar having a size shown in Table 1.
  • the rounded bar was then subjected to a solution heat treatment in which the bar is held at a temperature in the range of 1050°C for a period of time of 60 min and was water-cooled, the rounded bar being then subjected to an aging treatment in which the bar was held at a temperature in the range of 800°C for a period of time of 2 hours.
  • the rounded bars thus heat-heated were used in tests for researching the properties of each alloy.
  • Table 2 shows the properties of the materials as observed at positions 20 mm and 60 mm below the surface of the rounded bars. From the result of the investigation of the properties, it was seen that the steel of the invention exhibited superior resistance to stress corrosion cracking, as well as high homogeneousness of the material, as compared with known steels which were shown by way of comparison.
  • the steel in accordance with the invention has high strength and superior corrosion resistance, particularly the resistance to stress corrosion cracking, as well as a high degree of homogeneousness and, therefore, can be used very effectively as the blank material of high-performance drill collars for use in drilling of oil well under severe working conditions.
  • a molten steel alloy having chemical composition No. 1 in Table 1 was prepared through a conventional vacuum oxygen carburization process (VOD process) by use of an electric arc furnace of 50 to 100 ton in capacity and was casted into an ingot of 600 x 600 mm in cross section and 2500 mm in length at a temperature of about 1500°C.
  • the ingot was hot-rolled at 1150°C into a bloom of 320 x 340 mm in cross-sectional size, which bloom was again hot-rolled into a rounded bar of 90 to 290 mm in diameter.
  • the rounded bar was subjected to rough turning to prepare a sized rounded bar of 80 to 280 mm in diameter.
  • the rounded bar was then subjected to a solution heat treatment in which the bar was held at about 1050°C for a period of time of 60 min and was then water-cooled.
  • the solution-heat-treated round bar was subjected to a trepanning to prepare a cylindrical main body of 32 to 90 mm in inner diameter and of 600 to 900 mm in length.
  • the cylindrical main body was subjected to aging heat treatment in which it was held at 800°C for 2 hours, which main body was then subjected to a threading step to prepare a threaded portion therein.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Geology (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Organic Chemistry (AREA)
  • Fluid Mechanics (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Hard Magnetic Materials (AREA)
  • Drilling Tools (AREA)
EP85308615A 1984-11-30 1985-11-27 Acier magnétique à haute résistance à la corrosion et à haute résistance mécanique pour masse-tige de forage et masse-type fabriquée avec cet acier Expired EP0183536B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85308615T ATE45991T1 (de) 1984-11-30 1985-11-27 Nichtmagnetischer stahl mit hoher korrosionsbestaendigkeit und hoher festigkeit fuer verwendung in schwerstange und schwerstange aus diesem werkstoff.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP59251908A JPS61130464A (ja) 1984-11-30 1984-11-30 高耐食性高強度ドリルカラ−用非磁性鋼
JP251908/84 1984-11-30

Publications (3)

Publication Number Publication Date
EP0183536A2 true EP0183536A2 (fr) 1986-06-04
EP0183536A3 EP0183536A3 (en) 1987-05-13
EP0183536B1 EP0183536B1 (fr) 1989-08-30

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EP85308615A Expired EP0183536B1 (fr) 1984-11-30 1985-11-27 Acier magnétique à haute résistance à la corrosion et à haute résistance mécanique pour masse-tige de forage et masse-type fabriquée avec cet acier

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EP (1) EP0183536B1 (fr)
JP (1) JPS61130464A (fr)
AT (1) ATE45991T1 (fr)
DE (1) DE3572696D1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0246092A2 (fr) * 1986-05-15 1987-11-19 Exxon Research And Engineering Company Alliages résistant à la fissuration par corrosion sous tension
EP0386730A1 (fr) * 1989-03-09 1990-09-12 Krupp VDM GmbH Alliage de nickel-chrome-fer
US5567383A (en) * 1994-06-15 1996-10-22 Daido Tokushuko Kabushiki Kaisha Heat resisting alloys
CN1038353C (zh) * 1993-09-11 1998-05-13 中国科学院金属研究所 高强度无磁钻铤用钢
EP1078190A1 (fr) * 1998-05-01 2001-02-28 Grant Prideco, Inc Tige de forage a parois epaisses
US6372181B1 (en) 2000-08-24 2002-04-16 Inco Alloys International, Inc. Low cost, corrosion and heat resistant alloy for diesel engine valves
US7651575B2 (en) 2006-07-07 2010-01-26 Eaton Corporation Wear resistant high temperature alloy
CN103206175A (zh) * 2013-03-15 2013-07-17 山西北方风雷工业集团有限公司 高抗疲劳钻铤
CN103820736A (zh) * 2014-01-09 2014-05-28 马鞍山市恒毅机械制造有限公司 一种出钢口钻头合金钢材料及其制备方法
CN115466838A (zh) * 2022-09-21 2022-12-13 河南中原特钢装备制造有限公司 一种控制无磁钻铤用钢析出物的冷却方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115011858B (zh) * 2022-06-23 2023-03-17 沈阳航空航天大学 高强度高塑性CoCrNiAlTi多主元合金及其制备方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2803539A (en) * 1954-08-24 1957-08-20 Jessop William & Sons Ltd Fe-cr-ni alloys
DE1261677B (de) * 1959-06-04 1968-02-22 Schoeller Bleckmann Stahlwerke Verwendung von nichtmagnetisierbaren, austenitischen Stahllegierungen fuer Schwerstangen
US3659882A (en) * 1968-12-02 1972-05-02 Schoeller Bleckman Stahlwerke Nonmagnetic corrosion-resistant drill string members
FR2135963A5 (fr) * 1971-04-08 1972-12-22 Ver Deutsche Metallwerke Ag

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2803539A (en) * 1954-08-24 1957-08-20 Jessop William & Sons Ltd Fe-cr-ni alloys
DE1261677B (de) * 1959-06-04 1968-02-22 Schoeller Bleckmann Stahlwerke Verwendung von nichtmagnetisierbaren, austenitischen Stahllegierungen fuer Schwerstangen
US3659882A (en) * 1968-12-02 1972-05-02 Schoeller Bleckman Stahlwerke Nonmagnetic corrosion-resistant drill string members
FR2135963A5 (fr) * 1971-04-08 1972-12-22 Ver Deutsche Metallwerke Ag

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0246092A2 (fr) * 1986-05-15 1987-11-19 Exxon Research And Engineering Company Alliages résistant à la fissuration par corrosion sous tension
EP0246092A3 (fr) * 1986-05-15 1989-05-03 Exxon Research And Engineering Company Alliages résistant à la fissuration par corrosion sous tension
EP0386730A1 (fr) * 1989-03-09 1990-09-12 Krupp VDM GmbH Alliage de nickel-chrome-fer
CN1038353C (zh) * 1993-09-11 1998-05-13 中国科学院金属研究所 高强度无磁钻铤用钢
US5567383A (en) * 1994-06-15 1996-10-22 Daido Tokushuko Kabushiki Kaisha Heat resisting alloys
EP1078190A1 (fr) * 1998-05-01 2001-02-28 Grant Prideco, Inc Tige de forage a parois epaisses
EP1078190A4 (fr) * 1998-05-01 2003-04-09 Grant Prideco Inc Tige de forage a parois epaisses
US6372181B1 (en) 2000-08-24 2002-04-16 Inco Alloys International, Inc. Low cost, corrosion and heat resistant alloy for diesel engine valves
US7651575B2 (en) 2006-07-07 2010-01-26 Eaton Corporation Wear resistant high temperature alloy
CN103206175A (zh) * 2013-03-15 2013-07-17 山西北方风雷工业集团有限公司 高抗疲劳钻铤
CN103820736A (zh) * 2014-01-09 2014-05-28 马鞍山市恒毅机械制造有限公司 一种出钢口钻头合金钢材料及其制备方法
CN115466838A (zh) * 2022-09-21 2022-12-13 河南中原特钢装备制造有限公司 一种控制无磁钻铤用钢析出物的冷却方法

Also Published As

Publication number Publication date
JPH0218381B2 (fr) 1990-04-25
JPS61130464A (ja) 1986-06-18
DE3572696D1 (en) 1989-10-05
EP0183536A3 (en) 1987-05-13
EP0183536B1 (fr) 1989-08-30
ATE45991T1 (de) 1989-09-15

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