Jack element for a drill bit

• US 8,281,882 B2
• Filed: 05/29/2009
• Issued: 10/09/2012
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Hall, David R., Leany, Francis E., Fox, Joe, Wilde, Tyson J.
• Primary Examiner(s): DANG, HOANG C
• Application Number:
  US12/475,344
• Publication Number:
  US 20090260894A1
• Time in Patent Office: 1,229 Days
• Field of Search: 175/385, 175/408, 175/404, 175/426
• US Class Current: 175/385
• CPC Class Codes: E21B 10/46 characterised by wear resisting parts, e.g. diamond inserts
• CPC Class Codes: E21B 10/54 the bit being of the rotary drag type, e.g. fork-type bits
• CPC Class Codes: E21B 10/62 characterised by parts, e.g. cutting elements, which are detachable or adjustable E21B10/64 takes precedence; for roller bits E21B10/20; for augers E21B10/44

Abstract

A drill bit has an axis of rotation and a working face with a plurality of blades extending outwardly from a bit body. The blades form, in part, an inverted conical region, and a plurality of cutters with a cutting surface is arrayed along the blades. A jack element is coaxial with the axis of rotation and extends within the inverted conical region within a range defined by the cutting surface of at least one cutter.

Claims

1. A drill bit, comprising:

a shank;

a bit body attached to said shank, said bit body having an axis of rotation, said bit body including;

a working face having a plurality of blades extending outwardly therefrom, said plurality of blades forming an inverted conical region;

a plurality of cutters positioned on said plurality of blades, said plurality of cutters including;

a first cutter having a first point most distant from said working face relative to said plurality of cutters;

a second cutter proximate said axis of rotation, said second cutter having a another point nearest said working face relative to said plurality of cutters;

a pocket formed within said working face;

a channel connecting said pocket to a bore of said drill bit; and

,

a jack element disposed within said pocket, said jack element having a distal end within said inverted conical region, said distal end extending away from said working face a distance between said first point and said second point, said jack element limiting a depth to which at least one of said plurality of cutters engages a formation.

2. The drill bit of claim 1, wherein said distal end includes a surface comprising a material with a hardness of at least 63 HRc.

3. The drill bit of claim 1, wherein said working face has a cross-sectional area that is from about 4 times to about 12 times a cross-sectional area of said jack element.

4. The drill bit of claim 1, wherein said distal end of said jack element extends away from said working face a distance from about 0.100 inches to about 3 inches.

5. The drill bit of claim 1, wherein said jack element is tapered.

6. The drill bit of claim 1, wherein said jack element is press-fit into a sleeve, said sleeve being brazed into said pocket.

7. A drill bit, comprising:

a shank;

a bit body attached to said shank, said bit body having an axis of rotation, said bit body including;

a working face having a plurality of blades extending outwardly therefrom, said blades forming an inverted conical region;

a plurality of cutters positioned on said plurality of blades, said plurality of cutters including a cutter proximate said axis of rotation, said cutter having a point nearest said working face relative to said plurality of cutters and a diameter extending therefrom to another point;

a pocket formed within said working face;

a channel connecting said pocket to a bore of said drill bit; and

,

a jack element disposed within said pocket, said jack element having a distal end within said inverted conical region, said distal end extending away from said working face a distance that falls between said point and said another point.

8. The drill bit of claim 7, wherein said jack element is press-fit into a sleeve, said sleeve being brazed into said pocket.

9. A drill bit, comprising:

a shank;

a bit body attached to said shank, said bit body having an axis of rotation, said bit body including;

a working face having a plurality of blades extending outwardly therefrom, said blades forming an inverted conical region;

a plurality of cutters positioned on said plurality of blades, said plurality of cutters including at least one cutter configured to a cut a region of a formation to a depth;

a pocket formed within said working face;

a channel connecting said pocket to a bore of said drill bit; and

,

a jack element disposed within said pocket, said jack element having a distal end within said inverted conical region, said distal end extending away from said working face to a distance within said region.

10. The drill bit of claim 9, wherein said at least one cutter is proximate said axis of rotation, said at least one cutter having a point nearest said working face relative to said plurality of cutters.

11. The drill bit of claim 9, wherein said jack element is press-fit into a sleeve, said sleeve being brazed into said pocket.

12. A drill bit, comprising:

a shank;

a bit body attached to said shank, said bit body having an axis of rotation, said bit body including;

a working face having a plurality of blades extending outwardly therefrom, said blades forming an inverted conical region;

a plurality of cutters positioned on said plurality of blades, said plurality of cutters including a cutter proximate said axis of rotation, said cutter having a point nearest said working face relative to said plurality of cutters and a diameter extending therefrom to another point;

a pocket formed within said working face;

a sleeve brazed into said pocket; and

,

a jack element press-fit into said sleeve, said jack element having a distal end within said inverted conical region, said distal end extending away from said working face a distance that falls between said point and said another point.