Drill bits with core feature for directional drilling applications and methods of use thereof

Patent metadata

Field	Value
Publication number	US-2016177629-A1
Application number	US-201514956897-A
Country	US
Kind code	A1
Filing date	Dec 2, 2015
Priority date	Dec 22, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A drill bit for obtaining core sample fragments from a subterranean formation includes a bit body having a bit centerline and a bit face, a plurality of blades extending radially along the bit face, including a coring blade, a plurality of cutting elements on the blades, and a non-planar insert embedded in the bit body proximate the bit centerline. One of the cutting elements is a first cutting element on the coring blade at a first radial position from the bit centerline, and at least a portion of the coring blade is radially outward from a most radially interior cutting part of the first cutting element.

First claim

What is claimed:

1 . A drill bit comprising:
a bit body having a bit centerline and a bit face; a plurality of blades extending radially along the bit face, the plurality of blades including a coring blade; a plurality of cutting elements on the plurality of blades, the plurality of cutting elements including a first cutting element on the coring blade at a first radial position closest to the bit centerline; and a non-planar insert in the bit body proximate to the bit centerline, the coring blade having at least a portion that is radially outward from a most radially interior cutting part of the first cutting element.

2 . The drill bit of claim 1 , wherein the coring blade defines a radially interior surface, the radially interior surface being substantially vertical.

3 . The drill bit of claim 1 , wherein the coring blade defines a radially interior surface, the radially interior surface being a continuously angled surface.

4 . The drill bit of claim 3 , wherein the continuously angled surface is angled and interfaces the bit face at a radial position farther from the bit centerline than the first radial position.

5 . The drill bit of claim 3 , further comprising:
a gage surface extending from the plurality of blades at the radially outermost region of the drill bit, each gage surface being angled toward the bit centerline.

6 . The drill bit of claim 5 , wherein the continuously angled surface has an angle that is equal to or greater than the angle of the angled gage surface.

7 . The drill bit of claim 3 , wherein the continuously angled surface has an angle ranging from about 0.5 degrees to about 6 degrees from the bit centerline.

8 . A drill bit for obtaining core sample fragments from a subterranean formation, the drill bit comprising:
a bit body having a bit centerline and a bit face; a plurality of blades extending radially along the bit face, at least one of the blades being a coring blade defining a radially interior surface; a plurality of cutting elements on the plurality of blades, at least one of the plurality of cutting elements being a first cutting element located at a first radial position from the bit centerline, and at least one of the cutting elements being a core trimming cutting element that is affixed to the coring blade on the radially interior surface axially spaced from the first cutting element and at a greater radial distance from the bit centerline than the first cutting element; and a non-planar insert affixed to the bit body proximate to the bit centerline.

9 . The drill bit of claim 8 , wherein the radially interior surface is continuously angled outward from the first radial position to the bit face.

10 . The drill bit of claim 8 , wherein the radially interior surface is substantially vertical.

11 . The drill bit of claim 8 , wherein a radially interior portion of the core trimming cutter is offset radially outwardly from a radially interior portion of the first cutting element from about 0.02 inches to about 0.06 inches.

12 . The drill bit of claim 8 , wherein the plurality of cutting elements comprises one or more cutters having a substantially planar cutting face, conical cutting elements, or rotatable cutting elements.

13 . The drill bit of claim 12 , wherein the first cutting element and the core trimming cutting element are both conical cutting elements having an apex.

14 . The drill bit of claim 13 , wherein the first cutting element apex and the core trimming cutting element apex have an axial offset equal to the radius of the first cutting element plus the radius of the core trimming cutting element plus a spacing ranging from about 0.05 inches to about 1 inch.

15 . The drill bit of claim 13 , wherein the first cutting element apex and the core trimming cutting element apex both point inwardly toward the bit centerline and downwardly away from the bit body.

16 . The drill bit of claim 13 , wherein the first cutting element apex and the core trimming cutting element apex are oriented such that the first cutting element apex and the core trimming cutting element apex are at an angle ranging from about 30 degrees to about 90 degrees with respect to a line parallel to the bit centerline.

17 . The drill bit of claim 13 , wherein a conical insert is embedded in the bit body and an apex of the conical insert is axially above an apex of the core trimming cutter by at least 0.3 inches.

18 . The drill bit of claim 8 , wherein a plurality of cutting elements in a gage region of the bit have a back rake angle ranging from about 5 degrees to about 35 degrees, and wherein the core trimming cutting element has a back rake angle less than the back rake angle of the plurality of cutting elements in the gage region of the bit.

19 . A method of obtaining a core sample fragment from a subterranean formation during directional drilling, the method comprising:
coupling a drill bit to a steerable tool at a lower end of a drill string, the drill bit comprising:
a bit body having a bit centerline and a bit face;
a plurality of blades extending radially along the bit face,
at least one of the plurality of blades being a coring blade having a continuously angled surface extending from the bit face to a first radial position from the bit centerline;

a plurality of cutting elements on the plurality of blades, one of the plurality of cutting elements being a first cutting element on the coring blade at the first radial position from the bit centerline;
a gage surface extending from the plurality of blades at the radially outermost region of the drill bit, each gage surface being angled toward the bit centerline, the continuously angled surface having an angle substantially the same as the angled gage surface of the coring blade; and
a conical insert embedded in the bit body at the bit centerline or between the bit centerline and the first radial position;
rotating the drill string to engage and cut the formation; tilting the drill bit using the steerable tool to drill the formation at a non-vertical direction; and using the drill bit to weaken the core sample fragment in order to cause the core sample fragment to break away from the formation after the core sample fragment reaches a length.

20 . The method of claim 19 , wherein the continuously angled surface has an angle ranging from about 0.5 degrees to about 6.0 degrees from the bit centerline.

Assignees

• Smith International

Inventors

• Azar Michael G

Classifications

• E21B10/02 Primary

  Core bits (characterised by wear resisting parts E21B10/48) · CPC title

• E21B25/10

  Formed core retaining or severing means (E21B25/06, E21B25/08 take precedence) · CPC title

• E21B10/43

  characterised by the arrangement of teeth or other cutting elements · CPC title