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US4655303A Expired / Lapsed US ⏱️ 0.0 years remaining

Drill bit

Assignee: BP Corp North America Inc
•
Filing: 1985-11-22
•
Granted: 1987-04-07
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Expires: 2005-11-22
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Abstract

Abstract An improved drill bit and a method for making the same. A body having an upper end is adapted for connection to a source of rotary motion. A curved surface formed on the lower end of the body includes a plurality of cutting elements embedded therein. A port provides drilling fluid between the curved surface and the bore during drilling. The cutting elements and fluid courses formed on the curved surface define a gap between the surface and the bore during drilling. The gap is formed to provide no more than a substantially linear reduction in drilling fluid pressure with increasing bit radius. In making the bit, a bottomhole pattern and a substantially constant flow area are selected. Dimensions of the lower drill bit surface are calculated to provide the selected flow area over the surface when the bit is in position above the bottomhole pattern. Thereafter, the lower bit surface, including fluid courses thereon, is constructed in accordance with the calculated dimensions and diamonds are embedded therein to support the drill bit surface over the bottomhole pattern by a distance which produces the selected flow area.

Inventors

  • 👤 Warren J. Winters
  • 👤 J. Ford Brett
  • 👤 Tommy M. Warren

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 17:04
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/60; E21B10/46

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 123 words
A drill bit for use in drilling a bore, comprising: a body having an upper end adapted for connection to a source of rotary motion and a curved surface formed at a lower end thereof; a plurality of cutting elements imbedded in and extending above the curved surface, the distance the cutting elements extend above the curved surface decreases with increasing distance from the center of the curved surface; a port formed in the body for providing fluid therethrough to the curved surface; and a plurality of fluid courses formed in the curved surface for distributing fluid from the port across the curved surface in a manner where there is a substantially linear reduction in fluid pressure with increasing distance from the port.
Claim 2
Dependent Claim 123 words
A drill bit for use in drilling a bore, comprising: a body having an upper end adapted for connection to a source of rotary motion and a curved surface formed at a lower end thereof; a plurality of cutting elements imbedded in and extending above the curved surface, the distance the cutting elements extend above the curved surface decreases with increasing distance from the center of the curved surface; a port formed in the body for providing fluid therethrough to the curved surface; and a plurality of fluid courses formed in the curved surface for distributing fluid from the port across the curved surface in a manner where there is a substantially linear reduction in fluid pressure with increasing distance from the port.
Claim 3
Dependent Claim 17 words
The drill bit of claim 1 wherein the port extends longitudinally through the center of the body.
Claim 4
Dependent Claim 20 words
The drill bit of claim 1 wherein the depth of the fluid courses decreases with increasing distance from the port.
Claim 5
Dependent Claim 20 words
The drill bit of claim 1 wherein the width of the fluid courses increases with increasing distance from the port.
Claim 6
Dependent Claim 25 words
The drill bit of claim 3 wherein the fluid courses extend from the port to a point adjacent an outer cylindrical surface of the body.

References Cited (Backward Citations)

US2966949A Cited
US3135341A Cited
US3310126A Cited
US4098363A Cited
SU929806A1 Cited
US4554986A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-04-06 1990-10-06 1991-04-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-04-06 1994-10-06 1995-04-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-04-06 1998-10-06 1999-04-07 $7700.00 Window Closed / Lapsed

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