US3572771A - Drill-collar construction - Google Patents
Drill-collar construction Download PDFInfo
- Publication number
- US3572771A US3572771A US788305A US3572771DA US3572771A US 3572771 A US3572771 A US 3572771A US 788305 A US788305 A US 788305A US 3572771D A US3572771D A US 3572771DA US 3572771 A US3572771 A US 3572771A
- Authority
- US
- United States
- Prior art keywords
- collars
- drill
- connectors
- elasticity
- modulus
- 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.)
- Expired - Lifetime
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
Definitions
- This invention relates to an improved drill-collar construction for use in rotary drilling of wells.
- drill bit When a well is drilled with conventional rotary equipment, the drill bit is attached to the lower end of a string of drill pipes, down which drilling fluid circulates.
- the portion of the drill string immediately above the bit is made up of a series of drill collars", which are heavy-walled pipe sections, each usually about 30 feet long, joined end-to-end.
- the purpose of drill collars is to supply the necessary weight to the bit to enable it to penetrate the earth formation. The harder the formation, the more weight required and the larger the number of drill collars needed.
- the drill collars are in compression, but the rest of the drill string should be in tension.
- the point of neutral stress should be located in the drill collars near the upper end of the series.
- drill collars are relatively inflexible, uneven drilling feed, changes in the earth formation, slanted formations, etc., as well as shifts in the neutral stress location, cause them to flex to some extent. Such flexing takes place mostly at joints between individual drill collars. Most drill collar failures are the result of fatigue at these joints.
- An object of my invention is to provide an improved drillcollar construction which forestalls fatigue failures at joints between individual collars.
- a more specific object is to provide an improved drill-collar construction in which the individual collars are joined to one another through connectors of material highly resistant to fatigue, for example titanium or a titaniumbase alloy.
- the single FIGURE is a longitudinal vertical section of a pair of drill collars and a connector in accordance with my invention.
- the drawing shows portions of two drill collars and 10a of seriesand a connector 12 which joins the two collars endto-end. Similar connectors are used between other collars of the series, not shown.
- the collars may be externally threaded and the connector internally threaded as illustrated (pin-andpin), or the collars may be internally threaded and the connector externally threaded (box and-box), or opposite ends of the connectors may be threaded externally and internally (combination). Commonly each collar is about 30 feet long, and
- each connector about 12 to 18 inches.
- the collars usually are of an alloy steel heat treated to provide a tensile strength of about 125,000 p.s.i., and a modulus of elasticity of about 29 million to 30 million p.s.i. Such collars have a wet fatigue strength in drilling mud of about 13,000 p.s.i.
- 1 form the connector 12 of a metal which has a tensile strength comparable to the steel of the drill collars 10 and 10a, but a substantially lower modulus of elasticity and greater fatigue resistance.
- My preferred metal for this purpose is titanium.
- titaniurn to include various titanium-base alloys, such as that which contains 6 percent aluminum, 4 percent vanadium, and the balance titanium, or those which contain small percentages of other known alloying elements including tin, zirconium, molybdenum, iron, chromium, etc.
- the metal used in the connector has a modulus of elasticity of about 16,200,000 p.s.i. and a wet fatigue strength in drilling mud of 95,000 p.s.i.
- any flexing in the series of drill collars takes place in the connectors, rather than in the drill collars themselves. Since these connectors have much greater fatigue resistance, fatigue failures are forestalled. Corrosion may take place in fatigue cracks.
- My invention provides prevents such corrosion, both by preventing fatigue cracks from forming and by use of a metal which is highly resistant to corrosion. Thus, my invention effectively prolongs the life of drill collars.
- a series of drill collars and short-length connectors threadedly engaged with the ends of said collars and joining them end-toend, said collars being'formed of an alloy steel which has a relatively high modulus of elasticity and low fatigue strength, said connectors being formed of titanium which has a lower modulus of elasticity and a higher fatigue strength, whereby flexing in the series of drill col ars takes place In said connectors rather than in the collars themselves.
Abstract
Description
Claims (2)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US78830568A | 1968-12-31 | 1968-12-31 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3572771A true US3572771A (en) | 1971-03-30 |
Family
ID=25144080
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US788305A Expired - Lifetime US3572771A (en) | 1968-12-31 | 1968-12-31 | Drill-collar construction |
Country Status (1)
Country | Link |
---|---|
US (1) | US3572771A (en) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4051906A (en) * | 1976-03-03 | 1977-10-04 | Trw Canada Limited | Extension rods used in percussive drilling |
US4278138A (en) * | 1980-01-21 | 1981-07-14 | Christensen, Inc. | Composite heavy metal drill collar |
US4548431A (en) * | 1981-12-17 | 1985-10-22 | Hughes Tool Company - Usa | Tool joint with internal/external make-up shoulders |
WO1986003275A1 (en) * | 1984-11-23 | 1986-06-05 | John Dawson Watts | Oilwell tubing connection |
JPS62501226A (en) * | 1984-11-23 | 1987-05-14 | ワツツ,ジヨン ダウソン | Oil well pipe connector |
US4676528A (en) * | 1984-04-30 | 1987-06-30 | Gray Theodor R | Method and apparatus for restoring tubular upsets |
US4974882A (en) * | 1986-07-18 | 1990-12-04 | Watts John Dawson | Oilwell tubing connection |
US5143411A (en) * | 1986-07-18 | 1992-09-01 | Watts John Dawson | Threaded tubular connection |
US5368109A (en) * | 1993-11-04 | 1994-11-29 | Slim Dril International Inc. | Apparatus for arcuate drilling |
US5505502A (en) * | 1993-06-09 | 1996-04-09 | Shell Oil Company | Multiple-seal underwater pipe-riser connector |
US6609735B1 (en) * | 1998-07-29 | 2003-08-26 | Grant Prideco, L.P. | Threaded and coupled connection for improved fatigue resistance |
US20040149492A1 (en) * | 2003-01-27 | 2004-08-05 | Taylor Bruce L. | Drilling assembly and method |
US20170276265A1 (en) * | 2016-03-22 | 2017-09-28 | Benteler Steel/Tube Gmbh | Octg pipe system and method of manufacturing thereof |
US9932772B2 (en) | 2011-09-20 | 2018-04-03 | Halliburton Energy Services, Inc. | Systems and methods for limiting torque transmission |
US11008819B2 (en) | 2017-10-30 | 2021-05-18 | OCTG Connections, LLC | Oil country tubular goods casing coupling |
US11970913B2 (en) | 2023-05-08 | 2024-04-30 | OCTG Connections, LLC | Oil country tubular goods casing coupling |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2536216A (en) * | 1946-06-17 | 1951-01-02 | Powell Edward Baden | Flexible connections in drill pipe strings |
US2941784A (en) * | 1955-07-05 | 1960-06-21 | Atlantic Refining Co | Logging while drilling |
US2955847A (en) * | 1957-01-08 | 1960-10-11 | Kennametal Inc | Cemented carbide drill rod pipe coupling having a replaceable wear element |
US3083043A (en) * | 1956-06-25 | 1963-03-26 | Thornhill Craver Company Inc | Taper thread system for coupling or joint |
US3126214A (en) * | 1964-03-24 | Lip fou |
-
1968
- 1968-12-31 US US788305A patent/US3572771A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3126214A (en) * | 1964-03-24 | Lip fou | ||
US2536216A (en) * | 1946-06-17 | 1951-01-02 | Powell Edward Baden | Flexible connections in drill pipe strings |
US2941784A (en) * | 1955-07-05 | 1960-06-21 | Atlantic Refining Co | Logging while drilling |
US3083043A (en) * | 1956-06-25 | 1963-03-26 | Thornhill Craver Company Inc | Taper thread system for coupling or joint |
US2955847A (en) * | 1957-01-08 | 1960-10-11 | Kennametal Inc | Cemented carbide drill rod pipe coupling having a replaceable wear element |
Non-Patent Citations (1)
Title |
---|
Esco - Catalog 504, Nov. 1967, 4 pages (Copy in class 285 subclass 422) * |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4051906A (en) * | 1976-03-03 | 1977-10-04 | Trw Canada Limited | Extension rods used in percussive drilling |
US4278138A (en) * | 1980-01-21 | 1981-07-14 | Christensen, Inc. | Composite heavy metal drill collar |
US4548431A (en) * | 1981-12-17 | 1985-10-22 | Hughes Tool Company - Usa | Tool joint with internal/external make-up shoulders |
US4676528A (en) * | 1984-04-30 | 1987-06-30 | Gray Theodor R | Method and apparatus for restoring tubular upsets |
WO1986003275A1 (en) * | 1984-11-23 | 1986-06-05 | John Dawson Watts | Oilwell tubing connection |
WO1986003274A1 (en) * | 1984-11-23 | 1986-06-05 | John Dawson Watts | Oilwell tubing connector |
JPS62501226A (en) * | 1984-11-23 | 1987-05-14 | ワツツ,ジヨン ダウソン | Oil well pipe connector |
US4813717A (en) * | 1984-11-23 | 1989-03-21 | Watts John Dawson | Oilwell tubing connection |
US4974882A (en) * | 1986-07-18 | 1990-12-04 | Watts John Dawson | Oilwell tubing connection |
US5143411A (en) * | 1986-07-18 | 1992-09-01 | Watts John Dawson | Threaded tubular connection |
US5505502A (en) * | 1993-06-09 | 1996-04-09 | Shell Oil Company | Multiple-seal underwater pipe-riser connector |
US5368109A (en) * | 1993-11-04 | 1994-11-29 | Slim Dril International Inc. | Apparatus for arcuate drilling |
US6609735B1 (en) * | 1998-07-29 | 2003-08-26 | Grant Prideco, L.P. | Threaded and coupled connection for improved fatigue resistance |
US20100230167A1 (en) * | 2003-01-27 | 2010-09-16 | Strataloc Technology Products Llc | Tension/collar/reamer assemblies and methods |
US20040149492A1 (en) * | 2003-01-27 | 2004-08-05 | Taylor Bruce L. | Drilling assembly and method |
US20070039757A1 (en) * | 2003-01-27 | 2007-02-22 | Nichols Richard A | Tension/collar/reamer assemblies and methods |
US7353888B2 (en) | 2003-01-27 | 2008-04-08 | Strataloc Technology Products Llc | Tension/collar/reamer assemblies and methods |
US20080142266A1 (en) * | 2003-01-27 | 2008-06-19 | Nichols Richard A | Tension/collar/reamer assemblies and methods |
US7730971B2 (en) | 2003-01-27 | 2010-06-08 | Strataloc Technology Products Llc | Tension/collar/reamer assemblies and methods |
US7059429B2 (en) | 2003-01-27 | 2006-06-13 | Strataloc Technology Products, Llc | Drilling assembly and method |
US7987926B2 (en) | 2003-01-27 | 2011-08-02 | Strataloc Technology Products Llc | Tension/collar/reamer assemblies and methods |
US9932772B2 (en) | 2011-09-20 | 2018-04-03 | Halliburton Energy Services, Inc. | Systems and methods for limiting torque transmission |
US10663091B2 (en) * | 2016-03-22 | 2020-05-26 | Benteler Steel/Tube Gmbh | OCTG pipe system and method of manufacturing thereof |
US20170276265A1 (en) * | 2016-03-22 | 2017-09-28 | Benteler Steel/Tube Gmbh | Octg pipe system and method of manufacturing thereof |
US11008819B2 (en) | 2017-10-30 | 2021-05-18 | OCTG Connections, LLC | Oil country tubular goods casing coupling |
US11680451B2 (en) | 2017-10-30 | 2023-06-20 | OCTG Connections, LLC | Oil country tubular goods casing coupling |
US11970913B2 (en) | 2023-05-08 | 2024-04-30 | OCTG Connections, LLC | Oil country tubular goods casing coupling |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: USX CORPORATION Free format text: CHANGE OF NAME;ASSIGNOR:UNITED STATES STEEL CORPORATION;REEL/FRAME:004748/0267 Effective date: 19870312 |
|
AS | Assignment |
Owner name: NATIONAL-OILWELL, A CORP. OF DE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:OILWELL, INC.;REEL/FRAME:004727/0470 Effective date: 19870327 Owner name: OILWELL, INC., A CORP. OF DE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:USX CORPORATION;REEL/FRAME:004727/0459 Effective date: 19870327 |