JPH0610154A - Method for treating surface of oil well pipe joint - Google Patents
Method for treating surface of oil well pipe jointInfo
- Publication number
- JPH0610154A JPH0610154A JP4191392A JP19139292A JPH0610154A JP H0610154 A JPH0610154 A JP H0610154A JP 4191392 A JP4191392 A JP 4191392A JP 19139292 A JP19139292 A JP 19139292A JP H0610154 A JPH0610154 A JP H0610154A
- Authority
- JP
- Japan
- Prior art keywords
- metal
- oil well
- surface treatment
- metal seal
- well pipe
- 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.)
- Withdrawn
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、シール性に優れた油井
管継手の表面処理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for oil well pipe joints having excellent sealing properties.
【０００２】[0002]
【従来の技術】油井の深さは数千ｍにおよび、近年では
1万ｍにも達しようとしている。このような油井に竪て
込まれる油井管は膨大な数にのぼるが、これらは総て管
継手によって一連に接続される。かかる管継手には、管
及び管継手自体の重量に起因する軸方向の引張力、周囲
から外周面に及ぼされる地圧力、内部流体による内周面
への押圧力等、各種の苛酷な力が作用する。2. Description of the Related Art The depth of an oil well reaches several thousand meters, and in recent years,
It is about to reach 10,000 meters. Although the number of oil well pipes that are vertically inserted into such an oil well is enormous, they are all connected in series by pipe joints. Such pipe joints are subjected to various harsh forces such as an axial tensile force due to the weight of the pipe and the pipe joint itself, a ground pressure exerted from the periphery to the outer peripheral surface, and a pressing force exerted by the internal fluid on the inner peripheral surface. To work.
【０００３】これらの力が油井深度の増大に従い、一層
苛酷なものとなることはいうまでもない。このような厳
しい条件下において使用し得る管継手にあっては、強大
な引張荷重に耐え得ると同時に確実なシール性を有する
ことが要求される。そこで、上記要求に応ずるべく従来
より多くの提案がなされてきた。Needless to say, these forces become more severe as the depth of the oil well increases. A pipe joint that can be used under such severe conditions is required to withstand a large tensile load and at the same time have a reliable sealing property. Therefore, many proposals have been made to meet the above requirements.
【０００４】耐引張荷重に関しては、継手部分における
ねじ部の形状、ピッチ等を改良することで良好な結果が
得られている。一方、シール性に関しては、図２に示す
ように一般に継手のねじなし部にメタル対メタルシール
部を設けることでシール性を確保するようにしている。
尚、図２において、１は油井管、２は継手、３はねじ
部、４はメタル対メタルシール部である。Regarding the tensile load resistance, good results have been obtained by improving the shape, pitch, etc. of the threaded portion in the joint portion. On the other hand, with respect to the sealing property, generally, as shown in FIG. 2, a metal-to-metal sealing part is provided in the non-threaded part of the joint to ensure the sealing property.
In FIG. 2, 1 is an oil well pipe, 2 is a joint, 3 is a threaded portion, and 4 is a metal-to-metal seal portion.
【０００５】然るに、メタル対メタルシール部にあって
は、締め付け時の焼付きの問題があった。該シール部
は、通常 100〜 200kg/mm2の高面圧力が加えられてお
り、締め付け時の潤滑が不足するとシール部に焼付きが
生じ易い。この焼付きが発生すると、シール性能が損な
われて、管継手全体としてのシール性に対する信頼が失
われ、原油もしくはガス漏れ等の事故に至ることがあっ
た。However, the metal-to-metal seal portion has a problem of seizure during tightening. A high surface pressure of 100 to 200 kg / mm 2 is usually applied to the seal portion, and seizure easily occurs in the seal portion if lubrication during tightening is insufficient. When this seizure occurs, the sealing performance is impaired, the reliability of the sealing performance of the pipe joint as a whole is lost, and an accident such as a crude oil or gas leak may occur.
【０００６】そのため、その対策の１つとして従来、メ
タル対メタルシール部の耐焼付き性改善の方法として、
特公平1-12995 に示されているように銅、亜鉛等のメッ
キ或いは、特開昭63-50462に示されているように、メタ
ルシール部にイオン化した粒子を照射しメタルシール部
の表面改質が行なわれている。また、近年鋼管素材の高
級化に伴いＣＶＤ、ＰＶＤ等のドライコーティング技術
の適用も試みられている。Therefore, as one of the measures, conventionally, as a method for improving the seizure resistance of the metal-to-metal seal portion,
As shown in Japanese Patent Publication No. 1-12995, copper or zinc is plated, or as disclosed in JP-A-63-50462, the metal seal is irradiated with ionized particles to modify the surface of the metal seal. Quality is being done. Further, in recent years, as the quality of steel pipe materials has become higher, attempts have been made to apply dry coating techniques such as CVD and PVD.
【０００７】[0007]
【発明が解決しようとする課題】然しながら、上記の如
き従来方法では、焼付き発生という致命的な事故はほぼ
防げるものの依然として、継手全体としてのシール性に
対する信頼を完全に回復し得ない。なぜなら、焼付きが
発生しない場合においてもシール性が失われる軸方向引
張力或いはガス内圧の限界値にばらつきが大きいという
問題が残されたままであるからである。However, with the above-mentioned conventional method, although a fatal accident such as seizure can be almost prevented, the reliability of the sealability of the joint as a whole cannot be completely restored. This is because there is still a problem that there is a large variation in the limit value of the axial tensile force or the gas internal pressure that causes the sealing property to be lost even when seizure does not occur.
【０００８】この発明は、かかる点からシール性の限界
値のばらつきが少なく、シール性の優れた油井管継手の
表面処理方法を提供することを目的とする。From this point of view, it is an object of the present invention to provide a surface treatment method for oil well pipe fittings which has less variation in the limit value of the sealability and is excellent in the sealability.
【０００９】[0009]
【課題を解決するための手段】本発明は、メタル対メタ
ルシール部を有する油井管継手の表面処理方法におい
て、メタル対メタルシール部の表面にビッカース硬さ 2
50以下の被膜硬さの表面処理被膜を形成するものであ
り、メタル対メタルシール部の表面処理前の表面最大粗
さをｘ（μm ）、表面処理被膜厚みをｙ（μm ）とする
とき、 5≦ｘ≦20 ｙ≧ 1.4ｘ−5 の関係を満たすようにするものである。The present invention provides a surface treatment method for an oil well pipe joint having a metal-to-metal seal portion, wherein the surface of the metal-to-metal seal portion has a Vickers hardness of 2
A surface-treated film having a film hardness of 50 or less is formed. When the maximum surface roughness of the metal-to-metal seal portion before surface treatment is x (μm) and the surface-treated film thickness is y (μm), The relationship of 5 ≦ x ≦ 20 y ≧ 1.4x−5 is satisfied.
【００１０】[0010]
【作用】本発明者は、油井管ねじ継手のシール性につい
て調査したところ、メタル対メタルシール部の表面処理
前表面最大粗さと、表面処理被膜厚みと、被膜硬さが大
きく影響していることが確認できた。シール性は、メタ
ル対メタルシール部の表面処理前表面最大粗さが大きい
ほど、表面処理被膜厚みと被膜硬さがある範囲からずれ
るほど、シール性が悪くかつばらつきが大きいことが明
らかとなった。The present inventor investigated the sealability of the oil well pipe threaded joint, and found that the maximum surface roughness before surface treatment of the metal-to-metal seal portion, the thickness of the surface-treated coating, and the coating hardness had a great influence. Was confirmed. Regarding the sealability, it was revealed that the larger the maximum surface roughness before the surface treatment of the metal-to-metal seal part is, the more the surface treatment coating thickness and the coating hardness deviate from a certain range, the poorer the sealing performance and the greater the variation. .
【００１１】従って、シール性は、メタル対メタルシー
ル部の表面処理前表面最大粗さと表面処理被膜の性質に
より大きく変化することがわかった。即ち、図３に示す
ように、メタル対メタルシール部の表面処理前の表面粗
さと、表面処理被膜の位置関係が(a) の場合は、表面最
大粗さが被膜厚みより非常に大きい場合シール性が損な
われ、(b) の場合は、表面最大粗さが被膜厚みより小さ
い場合シール性が保たれると考えられる。尚、図３にお
いて、５は被膜、６はカップリング側シール部、７はピ
ン側シール部、８は潤滑油（コンパウンド）である。Therefore, it was found that the sealability greatly varies depending on the maximum surface roughness before surface treatment of the metal-to-metal seal portion and the property of the surface-treated coating. That is, as shown in Fig. 3, if the surface roughness of the metal-to-metal seal before surface treatment and the positional relationship of the surface-treated coating are (a), the maximum surface roughness is much larger than the coating thickness. In the case of (b), the sealability is considered to be maintained when the maximum surface roughness is smaller than the film thickness. In FIG. 3, 5 is a film, 6 is a coupling side seal portion, 7 is a pin side seal portion, and 8 is a lubricating oil (compound).
【００１２】この検討結果より、本発明の目的を有効に
達成するために必要とされるべき要件を見出すため、メ
タル対メタルシール部の表面処理前表面最大粗さ、表面
処理被膜の厚みと硬度を種々変化させてシール性につい
て調査したところ、次のような要件が新たに見出され
た。From the results of this study, in order to find out the requirements that are needed to effectively achieve the object of the present invention, the maximum surface roughness before the surface treatment of the metal-to-metal seal portion, the thickness and the hardness of the surface-treated coating film are obtained. As a result of investigating the sealing property with various changes, the following requirements were newly found.
【００１３】(1) 表面処理被膜厚みｙ（μm ）、メタル
対メタルシール部の表面処理前の表面最大粗さｘ（μm
）に関して 5≦ｘ≦20、ｙ≧ 1.4ｘ−5 の関係にある
こと。(1) Surface treatment coating thickness y (μm), maximum surface roughness before surface treatment of metal-to-metal seal part x (μm)
5) x ≦ 20, y ≧ 1.4x−5.
【００１４】図１に、被膜厚みの平均とメタル対メタル
シール部の表面処理前表面最大粗さとシール性の関係を
示す。この図は、被膜硬さがビッカース硬さで 250以下
の表面処理被膜条件下で、被膜厚みと表面処理前表面最
大粗さに対するシール性について調べた結果である。こ
れより、メタル対メタルシール部の表面処理前表面最大
粗さと被膜厚みがシール性に大きな影響を及ぼしている
ことがわかる。また、表面処理前表面最大粗さが 5μm
より小さい領域では焼付きが発生し易く、20μm より大
きくなると、極端にシール性が悪くなる。FIG. 1 shows the relationship between the average film thickness, the maximum surface roughness of the metal-to-metal seal portion before surface treatment, and the sealing property. This figure shows the results of an examination of the sealability against the coating thickness and the maximum surface roughness before surface treatment under the conditions of the surface-treated coating having a Vickers hardness of 250 or less. From this, it is understood that the maximum surface roughness before the surface treatment and the film thickness of the metal-to-metal seal portion have a great influence on the sealing property. The maximum surface roughness before surface treatment is 5 μm
In a smaller area, seizure is likely to occur, and when it exceeds 20 μm, the sealing property is extremely deteriorated.
【００１５】また、 5≦ｘ≦20では、ｙ≧ 1.4ｘ−5 の
領域でシール性が保たれていることがわかる。尚、被膜
厚みが、20μm より大きくなると、膜の接着強度或いは
表面処理費の増大の点から問題がある。従って、実用
上、被膜厚みは最大20μm 程度が望ましい。Further, it is understood that when 5 ≦ x ≦ 20, the sealing property is maintained in the region of y ≧ 1.4x−5. If the coating thickness exceeds 20 μm, there is a problem in that the adhesive strength of the film or the surface treatment cost increases. Therefore, for practical purposes, the maximum film thickness is about 20 μm.
【００１６】(2) メタル対メタルシール部の表面処理被
膜硬さが、ビッカース硬さで 250以下の表面処理被膜で
あること。(2) The surface treatment film hardness of the metal-to-metal seal portion is Vickers hardness of 250 or less.
【００１７】表１に、表面処理メッキ種とシール性の関
係を示す。この表は、被膜厚みｙ（μm ）、表面処理前
表面最大粗さｘ（μm ）とする場合に、 5≦ｘ≦20、ｙ
≧ 1.4ｘ−5 の関係が成立する条件下で、膜種に対する
シール性について調べた結果である。表より、Ｃｕメッ
キ、Ｚｎメッキ、Ｓｎメッキ、Ｎｉ−Ｚｎメッキが好適
であることがわかる。これは、表面の凹凸に被膜が入り
込み、ギャップを埋めてシール性を保つために役立つと
考えられる。そこで、更に、種々の実験（詳細せず）を
行ない、所期の目的を達成するビッカース硬さの臨界値
を考究したところ、ビッカース硬さで 250以下のもので
あればよいことが明らかとなった。Table 1 shows the relationship between the surface treatment plating species and the sealing property. This table shows that when the coating thickness is y (μm) and the maximum surface roughness before surface treatment is x (μm), 5 ≦ x ≦ 20, y
It is the result of investigating the sealing property against the membrane species under the condition that the relation of ≧ 1.4x−5 holds. From the table, it can be seen that Cu plating, Zn plating, Sn plating, and Ni-Zn plating are suitable. It is considered that this is useful for the coating to enter the irregularities on the surface, fill the gap, and maintain the sealing property. Therefore, further experiments (without details) were conducted to investigate the critical value of Vickers hardness that achieves the intended purpose, and it became clear that the Vickers hardness of 250 or less is sufficient. It was
【００１８】[0018]
【表１】 [Table 1]
【００１９】[0019]
【実施例】本発明の実施例を以下に説明する。外径88.9
mm、 肉厚6.45mmの油井管を用いて、次の実験を実施し
た。油井管の鋼種は、表２にその成分を示す如く炭素鋼
（Ａ）と13Ｃｒ鋼（Ｂ）の２種である。それぞれの継手
について、パイプが降伏する圧力の80％のガス内圧をか
けてシール性を調査した。実験結果を表３に示す。表３
において、本発明に基づいて、メタル対メタルシール部
の表面最大粗さ、表面処理被膜厚と硬度を適当な範囲に
規制したNo.1〜10はいずれもリークの発生はなかった。
これに対して、比較例No.11 、12はシール部の表面最大
粗さ（ｘ）が 5より小さい、或いは20より大きいため、
No.13 、14は膜厚みｙ（μm ）、表面粗さｘ（μm ）が
所定の関係を満足しないため、No.15 、16は膜硬さが 2
50より大きいため、No.17 は膜厚みｙ（μm ）、表面粗
さｘ（μm ）が所定の関係を満足せず、更に膜硬さが 2
50より大きいため、いずれもリークが発生している。EXAMPLES Examples of the present invention will be described below. Outer diameter 88.9
The following experiment was carried out using an oil well pipe with a thickness of 6.45 mm and a wall thickness of 6.45 mm. The steel types of oil country tubular goods are carbon steel (A) and 13Cr steel (B) as shown in Table 2 below. The sealability of each joint was investigated by applying an internal gas pressure of 80% of the yield pressure of the pipe. The experimental results are shown in Table 3. Table 3
In No. 1 to 10, in which the maximum surface roughness of the metal-to-metal seal portion, the surface treatment film thickness, and the hardness were regulated to appropriate ranges based on the present invention, no leakage occurred.
On the other hand, in Comparative Examples Nos. 11 and 12, the maximum surface roughness (x) of the seal portion is smaller than 5 or larger than 20,
Nos. 13 and 14 have film hardness y (μm) and surface roughness x (μm) that do not satisfy the specified relationship, so Nos. 15 and 16 have film hardness of 2
Since it is larger than 50, No. 17 does not satisfy the predetermined relationship between the film thickness y (μm) and surface roughness x (μm), and the film hardness is 2
Since it is greater than 50, there are leaks in all cases.
【００２０】[0020]
【表２】 [Table 2]
【００２１】[0021]
【表３】 [Table 3]
【００２２】即ち、本発明に基づいて、メタル対メタル
シール部の表面処理前表面最大粗さ、表面処理被膜厚み
と硬度を適当な範囲に規制することによりシール性に優
れた油井管継手の表面処理方法が得られる。That is, according to the present invention, the maximum surface roughness before surface treatment of the metal-to-metal seal portion, the thickness of the surface-treated coating and the hardness of the surface of the oil well pipe joint having excellent sealing performance are controlled by controlling the thickness and hardness within appropriate ranges. A treatment method is obtained.
【００２３】[0023]
【発明の効果】以上のように本発明によれば、シール性
の限界値のばらつきが少なく、信頼性の高い、シール性
の優れた油井管継手の表面処理方法を得ることができ
る。As described above, according to the present invention, it is possible to obtain a surface treatment method for oil well pipe joints with high reliability and high sealability, with less variation in the limit value of sealability.
【図１】図１は表面最大粗さと被膜厚みとシール性の関
係を示す線図である。FIG. 1 is a diagram showing the relationship between maximum surface roughness, coating thickness, and sealability.
【図２】図２は継手部を示す要部断面図である。FIG. 2 is a sectional view of an essential part showing a joint part.
【図３】図３は表面粗さと被膜厚みの関係を示す模式図
である。FIG. 3 is a schematic diagram showing the relationship between surface roughness and coating thickness.
１ 油井管 ２ 継手 ３ ねじ部 ４ メタル対メタルシール部 ５ 被膜 1 Oil well pipe 2 Joint 3 Screw part 4 Metal-to-metal seal part 5 Coating
Claims (1)
継手の表面処理方法において、 メタル対メタルシール部の表面にビッカース硬さ 250以
下の被膜硬さの表面処理被膜を形成するものであり、 メタル対メタルシール部の表面処理前の表面最大粗さを
ｘ（μm ）、表面処理被膜厚みをｙ（μm ）とすると
き、 5≦ｘ≦20 ｙ≧ 1.4ｘ−5 の関係を満たすようにすることを特徴とする油井管継手
の表面処理方法。1. A surface treatment method for an oil country tubular goods joint having a metal-to-metal seal part, wherein a surface-treated film having a Vickers hardness of 250 or less is formed on the surface of the metal-to-metal seal part. When the maximum surface roughness before surface treatment of the metal seal part is x (μm) and the thickness of the surface treatment coating is y (μm), the relation of 5 ≦ x ≦ 20 y ≧ 1.4x-5 should be satisfied. A surface treatment method for an oil country tubular goods joint characterized by the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4191392A JPH0610154A (en) | 1992-06-26 | 1992-06-26 | Method for treating surface of oil well pipe joint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4191392A JPH0610154A (en) | 1992-06-26 | 1992-06-26 | Method for treating surface of oil well pipe joint |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0610154A true JPH0610154A (en) | 1994-01-18 |
Family
ID=16273844
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4191392A Withdrawn JPH0610154A (en) | 1992-06-26 | 1992-06-26 | Method for treating surface of oil well pipe joint |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0610154A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6027145A (en) * | 1994-10-04 | 2000-02-22 | Nippon Steel Corporation | Joint for steel pipe having high galling resistance and surface treatment method thereof |
| JP2002130552A (en) * | 2000-10-24 | 2002-05-09 | Sumitomo Metal Ind Ltd | Oil well pipe screw joint with excellency in environmental conservation |
| WO2003006867A1 (en) | 2001-07-13 | 2003-01-23 | Sumitomo Metal Industries, Ltd. | Pipe thread joint |
| WO2005098300A1 (en) | 2004-04-06 | 2005-10-20 | Sumitomo Metal Industries, Ltd. | Threaded joint for steel pipe and process for producing the same |
-
1992
- 1992-06-26 JP JP4191392A patent/JPH0610154A/en not_active Withdrawn
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6027145A (en) * | 1994-10-04 | 2000-02-22 | Nippon Steel Corporation | Joint for steel pipe having high galling resistance and surface treatment method thereof |
| JP2002130552A (en) * | 2000-10-24 | 2002-05-09 | Sumitomo Metal Ind Ltd | Oil well pipe screw joint with excellency in environmental conservation |
| WO2003006867A1 (en) | 2001-07-13 | 2003-01-23 | Sumitomo Metal Industries, Ltd. | Pipe thread joint |
| US6957834B2 (en) | 2001-07-13 | 2005-10-25 | Sumitomo Metal Industries, Ltd. | Threaded joint for pipes |
| WO2005098300A1 (en) | 2004-04-06 | 2005-10-20 | Sumitomo Metal Industries, Ltd. | Threaded joint for steel pipe and process for producing the same |
| US7866706B2 (en) | 2004-04-06 | 2011-01-11 | Sumitomo Metal Industries, Ltd. | Threaded joint for steel pipe |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2128506B1 (en) | Screw joint for steel pipe | |
| EP1920180B1 (en) | Threaded joint for steel pipes | |
| US4758025A (en) | Use of electroless metal coating to prevent galling of threaded tubular joints | |
| EP0786616A1 (en) | Steel pipe joint having high galling resistance and surface treatment method thereof | |
| EP1967690B1 (en) | High-strength sealed connection for expandable tubulars | |
| EP1705265B1 (en) | Surface adjustment treatment prior to chemical treatment of steel product | |
| OA12939A (en) | Threaded pipe with surface traetment. | |
| EP1458908B1 (en) | A tubular member having an anti-galling coating | |
| CN101245880A (en) | Tube fitting with separable tube gripping device | |
| JP3876656B2 (en) | Threaded joints for pipes | |
| JPH0972467A (en) | Threaded joint with excellent seizure resistance under no grease lubrication | |
| JPH08233164A (en) | Screw joint excellent in seizure resistance with no lubricant applied | |
| JPH0610154A (en) | Method for treating surface of oil well pipe joint | |
| JPH08233163A (en) | Screw joint excellent in seizure resistance with no lubricant applied | |
| US9644771B1 (en) | Threaded coupling | |
| US10273765B2 (en) | Threaded connection | |
| JP3605253B2 (en) | Threaded joint for steel pipe | |
| JP4613899B2 (en) | Special threaded joint for oil well pipe and manufacturing method thereof | |
| JPH0699354A (en) | Surface treating method for steel pipe joint | |
| JPS6179797A (en) | Oil well pipe joint having excellent resistance to galling and corrosion | |
| JPS6026695A (en) | Joint for oil well pipe | |
| JPH08145248A (en) | Screw coupling for oil well steel pipe | |
| JP2008185204A (en) | Special screw joint for oil well pipe | |
| JP2002130552A (en) | Oil well pipe screw joint with excellency in environmental conservation | |
| JPH08277974A (en) | Surface processing method for oil well steel pipe joint |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19990831 |