Hydraulic drilling apparatus and method

In hydraulic drilling apparatus:

• a drill head having a discharge nozzle for delivering a cutting jet of drilling fluid in an axial direction, means for supplying pressurized drilling fluid to the drill head, a plurality of radially facing discharge openings, and means responsive to orientation of the drill head for selectively discharging a portion of the drilling fluid through the radially facing openings to control the direction in which the hole is cut.

In hydraulic drilling apparatus:

• a drill head having a plurality of axially facing discharge nozzles spaced about an axis for delivering jets of drilling fluid in an axial direction, flow directors movable between axially advanced and retracted positions relative to the discharge nozzles for controlling the jets delivered by the nozzles, and means for moving the flow directors between their advanced and retracted positions to control the direction in which a hole is cut by the jets.

In hydraulic drilling apparatus:

• a drill head having a plurality of axially facing discharge nozzles spaced about the axis of the drill head for delivering jets of drilling fluid in an axial direction, and a pair of relatively rotatable throttle plates coaxially of the drill head and having flow control apertures which can be rotated into and out of registration with the discharge nozzles to control the relative amounts of drilling fluid delivered to respective ones of the nozzles.

In hydraulic drilling apparatus:

• a tubular drill string to which a pressurized drill fluid is supplied, a drill head at the distal end of the drill string for delivering an axially directed cutting jet of the drilling fluid, a side jet positioned near the distal end of the drill string for discharging a jet of fluid in a redial direction, and means responsive to orientation of the drill head for controlling operation of the side jet to steer the drill head.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a high speed jet of drilling fluid from the drill head to cut into the earth in front of the drill head, discharging a side jet of pressurized fluid in a radial direction from the distal end portion of the drill string to steer the drill head within the earth, and controlling the discharge of the side jet in accordance with the orientation of the end portion of the drill string.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a plurality of generally axially directed jets of the drilling fluid through nozzles spaced about the axis of the drill head, and controlling the cutting patterns of the respective jets to control the direction in which the hole is cut.

In apparatus for drilling a borehole in the earth:

• a drill head having a plurality of forwardly facing discharge nozzles for delivering cutting jets of drilling fluid in a generally axial direction to form a borehole, flow directing vanes movable between axially advanced and retracted positions to control the widths of the jets delivered by the nozzles, and means for moving the vanes between their advanced and retracted positions to control the discharge of fluid through the nozzles to control the direction in which the hole is cut.

In apparatus for drilling a borehole in the earth:

• a drill head having a plurality of forwardly facing discharge nozzles for delivering cutting jets of drilling fluid in a generally axial direction to form the borehole, and a pair of relatively rotatable throttle plates positioned co-axially of the drill head and having flow control apertures adapted to be selectively positioned in or out of registration with the nozzles to control the amount of fluid delivered through respective ones of the nozzles to control the direction in which the hole is cut.

In apparatus for drilling a borehole in the earth:

• a drill head having a plurality of forwardly facing discharge nozzles for delivering cutting jets of drilling fluid in a generally axial direction to form the borehole, flow directing vanes adapted to rotate about the axes of respective ones of the nozzles, and means for controlling the rate at which each of the vanes rotates to control the direction in which the hole is cut by controlling the discharge of fluid through the respective nozzles.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a plurality of generally axially directed jets of the drilling fluid through nozzles spaced about the axis of the drill head, and rotating apertured throttle plates relative to the nozzles to control the amount of drilling fluid discharged through respective ones of the nozzles to control the direction in which the hole is cut.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• supplying the drilling fluid through rotating vaned flow directors to a plurality of nozzles spaced about the axis of the drill head, and controlling the speed at which the flow directors rotate to control the cutting patterns of the respective jets and thereby control the direction in which the hole is cut.

In hydraulic drilling apparatus:

• a drill head having a discharge nozzle for delivering a cutting jet of drilling fluid in an axial direction, means for supplying pressurized drilling fluid to the drill head, a plurality of radially facing discharge openings, and valve members movable between open and closed positions relative to the radially facing openings in response to curvature of the drill string to control the direction in which the hole is cut.

In hydraulic drilling apparatus:

• a drill head having a plurality of axially facing discharge nozzles spaced about an axis for delivering jets of drilling fluid in an axial direction, flow directors movable between axially advanced and retracted positions relative to the discharge nozzles for controlling the jets delivered by the nozzles, and means responsive to the orientation of the drill head for moving the flow directors between their advanced and retracted positions to control the direction in which a hole is cut by the jets.

In hydraulic drilling apparatus:

• a tubular drill string to which a pressurized drill fluid is supplied, a drill head at the distal end of the drill string for delivering an axially directed cutting jet of the drilling fluid, a side jet positioned near the distal end of the drill string for discharging a jet of fluid in a radial direction, means for sensing curvature of the drill string, and means responsive to the sensing means for controlling operation of the side jet to steer the drill head.

In hydraulic drilling apparatus:

• a tubular drill string to which a pressurized drill fluid is supplied, a drill head at the distal end of the drill string for delivering an axially directed cutting jet of the drilling fluid, a discharge opening in the side wall of the drill string for discharging a jet of fluid in a radial direction, and a valve member movable between open and closed positions relative to the discharge opening for controlling operation of the side jet to steer the drill head.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a high speed jet of drilling fluid from the drill head to cut into the earth in front of the drill head, discharging a portion of the drilling fluid to control the direction in which the hole is cut, and controlling the discharge of the portion of the drilling fluid in accordance with curvature of the drill string to control the direction in which the hole is cut.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a high speed jet of drilling fluid from the drill head to cut into the earth in front of the drill head, discharging a portion of the drilling fluid to control the direction in which the hole is cut, and controlling the discharge of the portion of the drilling fluid in accordance with the orientation of the drill head to control the direction in which the hole is cut.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a high speed jet of drilling fluid from the drill head to cut into the earth in front of the drill head, discharging a side jet of pressurized fluid in a radial direction from the distal end portion of the drill string to steer the drill head within the earth, and controlling the discharge of the side jet in accordance with the curvature of the drill string.

In a method of drilling a borehole in the earth with a hydraulic drill head at the distal end of a tubular drill string to which a pressurized drilling fluid is applied, the steps of:

• discharging a high speed jet of drilling fluid from the drill head to cut into the earth in front of the drill head, discharging a side jet of pressurized fluid in a radial direction from the distal end portion of the drill string to steer the drill head within the earth, and controlling the discharge of the side jet by advancing and retracting a control rod in a direction parallel to the axis of the drill string in response to curvature of the drill string to open and close an orifice through which the side jet is discharged.