EP0239328A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Drill bits
Assignee: Smith International Inc
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Filing: 1987-03-20
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Granted: —
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Expires: 2007-03-20
Abstract
Abstract Drag-type drilling bits (20) are disclosed which have at least one blade (36) and a plurality of fluid flow channels (44) incorporated in the blade for conducting drilling fluid or drilling mud from the hollow interior (32) of the bit to discharge or ejection ports (46) located in the front cutting edge (40) of the blade. Rods (48) of diamonds or of like "hard" cutter insert materials are incorporated in the blade in such a configuration that as the blade wears away or erodes and small pieces of diamonds are lost during drilling, more diamonds are exposed to the formation for drilling. During erosion or wear of the blades, the fluid discharge ports (46) continue to operate to eject drilling fluid adjacent to substantially each diamond rod (48), whereby the flushing away of cuttings and cooling of the diamonds is greatly improved. In some embodiments of the invention rods of alternating hard and soft materials (52 and 58) are also disposed substantially parallel with the diamond or like "hard" cutter insert rods. When the soft material of the rods is exposed for drilling the formation, kerfs (64) are formed which are thereafter "chipped away" by the subsequently exposed hard material of the rods.
Inventors
- 👤 Kenneth William Jones
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 06:03
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/60; E21B10/602; E21B10/46; E21B10/54
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
250 words
A drill bit for drilling in subterranean formations and the like, comprising: a drill bit body having a pin end adapted for being removably attached to a drill string, an interior cavity which is in fluid communication with the drill string for receiving drilling fluid and at least two drilling blades attached to the drill bit body at the opposite end from the pin, each of the drilling blades having a leading edge for contacting the formation when the drill bit is used for drilling, and characterised by each drilling blade having: a plurality of elongate rods comprising hard drilling material, the rods being affixed to the blade in cavities in the blade and being exposed for drilling the formation at the leading edge of the blade with the respective longitudinal axes of the rods being substantially perpendicular to the direction of rotation of the blade, whereby, as the blade and the rods of hard drilling material erode during drilling, the rods continue to be exposed in the eroding leading edge of the blade; and a similar plurality of channels and means for conducting drilling fluid from the interior cavity of the drill bit body to each of the channels to form a fluid discharge port, whereby as the blade erodes during drilling, the drilling fluid continues to be ejected from the several discharge ports in the eroding leading edge of the blade and at least one fluid discharge port being located adjacent to the exposed end of each rod.
Claim 2
Dependent Claim
250 words
A drill bit for drilling in subterranean formations and the like, comprising: a drill bit body having a pin end adapted for being removably attached to a drill string, an interior cavity which is in fluid communication with the drill string for receiving drilling fluid and at least two drilling blades attached to the drill bit body at the opposite end from the pin, each of the drilling blades having a leading edge for contacting the formation when the drill bit is used for drilling, and characterised by each drilling blade having: a plurality of elongate rods comprising hard drilling material, the rods being affixed to the blade in cavities in the blade and being exposed for drilling the formation at the leading edge of the blade with the respective longitudinal axes of the rods being substantially perpendicular to the direction of rotation of the blade, whereby, as the blade and the rods of hard drilling material erode during drilling, the rods continue to be exposed in the eroding leading edge of the blade; and a similar plurality of channels and means for conducting drilling fluid from the interior cavity of the drill bit body to each of the channels to form a fluid discharge port, whereby as the blade erodes during drilling, the drilling fluid continues to be ejected from the several discharge ports in the eroding leading edge of the blade and at least one fluid discharge port being located adjacent to the exposed end of each rod.
Claim 3
Dependent Claim
12 words
The drill bit of Claim 1 wherein the elongate rods comprise diamonds.
Claim 4
Dependent Claim
20 words
The drill bit of Claim 2 wherein the elongate rods comprise a plurality of similarly shaped bodies of polycrystalline diamonds.
Claim 5
Dependent Claim
31 words
The drill bit of any one of Claims 1 to 4 wherein the diamonds are disposed in a matrix which is brazed into apertures in the blade with a brazing alloy.
Claim 6
Dependent Claim
35 words
The drill bit of any one of Claims 1 to 4 wherein the channels penetrate through the body of the blade parallel to the elongate rods and each fluid discharge port is beside a rod.
Claim 7
Dependent Claim
21 words
The drill bit of any one of Claims 1 to 4 comprising three blades in the form of a fishtail-type bit.
Claim 8
Dependent Claim
64 words
The drill bit of Claim 1 wherein at least a portion of the elongate rods comprise, relative to their respective longitudinal axes, alternately spaced hard and soft materials, whereby during drilling, when the soft material is exposed to the formation, kerfs are formed in the formation, and whereby the kerfs are eroded when the hard material of the rods are exposed to the formation.
Claim 9
Dependent Claim
15 words
The drill bit of Claim 7 wherein the hard material of the rods comprises diamonds.
Claim 10
Dependent Claim
18 words
The drill bit of Claim 7 or Claim 8 wherein the soft material of the rods comprises steel.
Claim 11
Dependent Claim
120 words
The drill bit of any one of Claims 1 to 4 further comprising a plurality of elongate rods of a second kind mounted into cavities in the blades substantially parallel with the first-mentioned elongate rods and having, relative to their respective longitudinal axes, alternating hard and soft materials, the rods of the second kind being disposed to be exposed at the respective leading edges of the blades to come into contact with the formation during drilling, whereby when the soft material of the rods of the second kind is exposed to the formation, kerfs are formed in the formation and when the hard material of the rods of the second kind is exposed to the formation, the kerfs are eroded.
Claim 12
Dependent Claim
25 words
The drill bit of Claim 10 wherein the rods of the second kind are substantially regularly and alternately spaced with the rods of hard material.
References Cited (Backward Citations)
No citation records indexed.
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