Directional drilling apparatus

Claim 2

Apparatus adapted for controlling the direction in which a borehole is being excavated and comprising: a body adapted for connection in a drill string including a borehole-excavating device; pressure-developing means on said body and operable for developing increased pressures in response to selected changes in the pressures of fluids being circulated through a drill string coupled to said body during the excavation of a borehole by a borehole-excavating device coupled thereto; wall-engaging means on said body and operable in response to increased pressures applied thereto for shifting said body laterally in relation to the axis of a borehole being excavated by a borehole-excavating device coupled to said body; and control means on said body and operable in response to selected changes in the pressures of such circulating fluids for selectively coupling said pressuredeveloping means to said wall-engaging means for operation of said wall-engaging means.

Claim 3

The apparatus of claim 1 wherein said pressure-developing means are operable in response to selected increases in the pressures of such circulating fluids.

Claim 4

The apparatus of claim 2 wherein said control means are operable in response to selected increases in the pressures of such circulating fluids.

Claim 5

The apparatus of claim 1 wherein said control means include first and second pressure conduits respectively coupled to said pressure-developing means and said guiding means, valve means adapted for movement relative to said body for selectively regulating pressure communication between said first and second conduits, and pressure-responsive actuating means coupled to said valve means and operable in response to selected increases in the pressures of such circulating fluids for selectively moving said valve means to a position for establishing pressure communication between said first and second conduits.

Claim 6

The apparatus of claim 4 wherein said valve means include a valve member adapted for opening and closing pressure communication between said first and second conduits upon movement of said valve member between selected positions; and said actuating means include a pressure-responsive actuating member operatively coupled to said pressure-developing means and adapted for moving said valve member to its said selected positions in response to predetermined changes in the pressures developed by said pressure-developing means.

Claim 7

The apparatus of claim 1 wherein said control means include first and second pressure conduits respectively coupled to said pressure-developing means and said guiding means, valve means adapted for movement relative to said body for selectively regulating pressure communication between said first and second conduits, means operatively arranged between said valve means and said body for alternately halting said valve means in a first position blocking pressure communication between said first and second conduits upon a first movement of said valve means and halting said valve means in a second position opening pressure communication between said first and second conduits upon a second movement of said valve means, and pressure-responsive actuating means coupled between said valve means and said pressure-developing means and operable in response to selected changes in the pressures developed by said pressure-developing means for moving said valve means.

Claim 8

The apparatus of claim 6 wherein said pressure-developing means are operable in response to selected increases in the pressures of such circulating fluids.

Claim 9

The apparatus of claim 7 wherein said pressure-responsive actuating means are operable in response to alternate increases and decreases in the pressures developed by said pressure-developing means.

Claim 10

A directional drilling tool comprising: an elongated body having a longitudinal circulating fluid passage therethrough and adapted for connection in a rotating drill string including a borehole-excavating device; wall-engaging means rotatably mounted on said body and including at least a first piston operatively arranged in a first chamber for lateral movement between retracted and extended positions in relation to said body; pressure-developing means on said body in communication with said longitudinal passage and including a second piston operatively arranged in a second chamber and adapted for movement from a first position to a second position in response to increases in the pressure of circulating fluids in said longitudinal passage for developing correspondingly increased pressures in a hydraulic fluid within said second chamber; control means adapted for selectively intercoupling said first and second pistons and including first and second conduits respectively coupled to said first and second chambers, valve means movably mounted on said body for movement between spaced positions and operatively arranged for selectively regulating communication between said first and second conduits in accordance with the position of said valve means, and valve-actuating means operable in response to selected changes in the pressure of such circulating fluids for selectively moving said valve means between said spaced positions; and clutch means operatively arranged between said wall-engaging means and said body for selectively securing said wall-engaging means in selected angular positions on said body.

Claim 11

A directional drilling tool comprising: an elongated body having a longitudinal circulating fluid passage therethrough and adapted for connection in a rotating drill string including a borehole-excavating device; wall-engaging means rotatably mounted on said body and including at least a first piston operatively arranged in a first chamber for lateral movement between retracted and extended positions in relation to said body; pressure-developing means on said body in communication with said longitudinal passage and including a second piston operatively arranged in a second chamber and adapted for movement from a first position to a second position in response to increases in the pressure of circulating fluids in said longitudinal passage for developing correspondingly increased pressures in a hydraulic fluid within said second chamber; control means adapted for selectively intercoupling said first and second pistons and including first and second conduits respectively coupled to said first and second chambers, valve means movably mounted on said body for movement between spaced positions and operatively arranged for selectively regulating communication between said first and second conduits in accordance with the position of said valve means, and valve-actuating means operable in response to selected changes in the pressure of such circulating fluids for selectively moving said valve means between said spaced positions; and clutch means operatively arranged between said wall-engaging means and said body for selectively securing said wall-engaging means in selected angular positions on said body.

Claim 12

The directional drilling tool of claim 9 wherein said valve-actuating means include a pressure-responsive actuator, and a third conduit coupling said pressure-responsive actuator to said second chamber for communicating increased pressures developed therein to said pressure-responsive actuator for operating said valve means.

Claim 13

The directional drilling tool of claim 10 wherein said valve means are movable between a first and a second one of said spaced positions upon an increase of pressure in said second chamber for intercoupling said first and second chambers only when said valve means are in said second position; and said valve-actuating means further include means operatively coupled to said valve means for alternately blocking movement of said valve means to said second position and permitting movement of said valve means to said first position upon successive increases of pressure in said second chamber.

Claim 14

The directional drilling tool of claim 10 wherein said valve means include a valve member operatively arranged on said body for movement relative thereto between first, second and third ones of said spaced positions and adapted for intercoupling said first and second chambers only when said valve member is in its said third positIon; and said actuating means include cam means operatively arranged between said body and said valve member for progressively indexing said valve member to each of its said positions upon successive increases of pressure in said second chambers.

Claim 15

The directional drilling tool of claim 10 wherein said valve means include a valve member operatively arranged on said body for movement relative thereto between first, second and third ones of said spaced positions and adapted for intercoupling said first and second chambers only when said valve member is in its said third position; and said actuating means include cam means operatively arranged between said body and said valve member for progressively indexing said valve member to each of its said positions upon successive cycles of an increase of pressure in said second chamber followed by a decrease of pressure therein.