ROTARY STEERABLE DRILLING APPARATUS
First Claim
1. An apparatus for steering a drill bit used to drill a bore hole in an earthen formation, said apparatus forming a portion of a bottom hole assembly of a drill string to which said drill bit is coupled, said steering apparatus comprising:
- (a) a bendable member adapted to be incorporated into said bottom hole assembly, said bendable member having a preferential direction in which said bendable member bends, wherein the amount of bending of said bendable member in said preferential direction determines the degree of change in the direction of said drilling;
(b) means for adjusting in situ the amount of said bending of said bendable member in said preferential direction so as to adjust the degree of directional change in said drilling.
9 Assignments
0 Petitions
Accused Products
Abstract
A rotary steering apparatus for a drill string in which a bending section induces a bend in a portion of the bottom hole assembly of the drill string by using the rotation of the drive shaft that drives the drill bit during normal drilling, while operating at a reduced or zero drilling mud flow rate, to drive a reduction gear that rotates a nut or cam so as to place a tension tube into tension. The tension tube abuts a flexible housing and places the flexible housing in compression. The flexible housing has a local weakening formed in it that causes it to preferentially bend in a predetermined direction. Compression in the flexible housing causes the housing to bend, which bends a portion of the bottom hole assembly so as to alter the direction of drilling. Rotation of the drive shaft at reduced or zero mud flow rate also causes the drive shaft to drive rotation of a second reduction gear the output of which rotates the bent portion of the bottom hole assembly thereby altering its tool face angle.
20 Citations
68 Claims
-
1. An apparatus for steering a drill bit used to drill a bore hole in an earthen formation, said apparatus forming a portion of a bottom hole assembly of a drill string to which said drill bit is coupled, said steering apparatus comprising:
-
(a) a bendable member adapted to be incorporated into said bottom hole assembly, said bendable member having a preferential direction in which said bendable member bends, wherein the amount of bending of said bendable member in said preferential direction determines the degree of change in the direction of said drilling; (b) means for adjusting in situ the amount of said bending of said bendable member in said preferential direction so as to adjust the degree of directional change in said drilling. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
-
25. An apparatus for steering a drill bit used to drill a bore hole in an earthen formation, said apparatus forming a portion of a bottom hole assembly of a drill string in which said drill bit is coupled to a drive shaft, said steering apparatus comprising:
-
(a) a bendable member adapted to be incorporated into said bottom hole assembly, said bendable member having a preferential direction in which said bendable member bends when a force is applied to said bendable member, wherein the amount of bending of said bendable member in said preferential direction determines the degree of change in the direction of said drilling; and (b) a force applying member adapted to be mounted in said bottom hole assembly so as to apply a force to said bendable member that bends said bendable member in said preferential direction, said force applying member coupled to said drive shaft so that rotation of said drive shaft causes said force applying member to apply said force to said bendable member that bends said bendable member in said preferential direction. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
-
-
47. An apparatus for steering a drill bit used to drill a bore hole in an earthen formation, said apparatus forming a portion of a bottom hole assembly of a drill string to which said drill bit is coupled, rotation of said drill bit being driven by a drive shaft coupled to said drill string, said steering apparatus comprising:
-
(a) a bendable member adapted to be incorporated into said bottom hole assembly, said bendable member having a preferential direction in which said bendable member bends when a force is applied to said bendable member, said preferential direction in which said bendable member bends being angularly oriented at a first tool face angle with respect to a portion of said bottom hole assembly, wherein the amount of bending of said bendable member in said preferential direction determines the degree of change in the direction of said drilling; and (b) a coupling that couples said drive shaft to said bendable member so that rotation of said drive shaft changes said first tool face angle of said preferential direction in which of said bendable member bends. - View Dependent Claims (48, 49, 50, 51, 52, 53, 54)
-
-
55. A method of steering a drill bit coupled to a drill string having a bottom hole assembly and drilling a bore hole into an earthen formation, said method comprising the steps of:
-
(a) rotating said drill bit so as to drill said bore hole into said earthen formation in a first direction by rotating a drive shaft coupled to said drill bit while simultaneously pumping a drilling fluid through said drill string at a first flow rate; and (b) changing the direction in which said drill bit drills said bore hole by bending a bendable portion of said bottom hole assembly in situ in said bore hole. - View Dependent Claims (56, 57, 58, 59, 60, 61, 62, 63, 64)
-
-
65. A method of steering a drill bit coupled to a drill string having a bottom hole assembly and drilling a bore hole into an earthen formation, said method comprising the steps of:
-
(a) rotating said drill bit so as to drill said bore hole into said earthen formation in a first direction by rotating a drive shaft coupled to said drill bit while simultaneously pumping a drilling fluid through said drill string at a first flow rate, at least a first portion of said bottom hole assembly having a bend formed therein; (b) changing the direction in which said drill bit drills said bore hole, wherein; (i) said change in the direction in which said drill bit drills said bore hole is effected by rotating said first portion of said bottom hole assembly having said bend formed therein relative to a second portion of said bottom hole assembly disposed uphole of said first portion; (ii) said first portion of said bottom hole assembly having said bend formed therein is rotated relative to a second portion of said bottom hole assembly using a tool face setting mechanism; (iii) said relative rotation of first portion of said bottom hole assembly is effected by rotating said drive shaft while pumping said drilling fluid through said drill string at a second flow rate lower than said first flow rate, said rotation of said drill string while pumping drilling fluid at said second flow rate causing said drive shaft to drive said tool face setting mechanism so as to rotate said first portion of said bottom hole assembly relative to said second portion. - View Dependent Claims (66, 67, 68)
-
Specification