Abstract Method and apparatus are described for changing the direction taken by a bore hole. A drill bit having at least one outlet orifice or nozzle for drilling fluid e,g, mud, is oriented so that the orifice is adjacent the portion of the interior lateral surface of the bore hole into which it is desired for the drill bit to proceed. The drilling fluid is pumped into the interior of a hollow drill string in the bore hole and out through the orifice in the drill bit. A portion of the drill string adjacent the bit is adapted to be closed in a fluidtight manner by means of a back pressure ball valve, and the portion of the drill string between the valve and the outlet orifice includes a slip joint adapted to be decreased in volume by an inward telescoping motion with vertical reciprocation of the drill string. Decreasing the volume of the drill beneath the above-mentioned valve will serve to compress the fluid therein forcing it out of the outlet orifice at an increased velocity. When the drill string is moved vertically upwardly, the valve opens allowing more drilling fluid to flow therethrough. Repetitive vertical reciprocation of the drill string to open and close the slip joint will result in highly accelerated jetting velocities through the outlet orifices in the drill bit.
The method defined in claim 1 comprising the additional step of vertically reciprocating an upper part of the drill pipe after said orienting step, said pumping step occurring during the upward stroke of said upper part said closing step occurring substantially at the commencement of the downward stroke of said upper part and said exerting step occurring simultaneously with said downward stroke.
Claim 2
Dependent Claim
49 words
The method defined in claim 1 wherein said orienting step comprises placing at least one of a plurality of outlet orifices placed around the periphery of said drill bit adjacent the portion of the interior surface of the bore hole into which said drill bit is to be deviated.
Claim 3
Dependent Claim
34 words
The method defined in claim 1 wherein said exerting step comprises decreasing the volume of said closed portion of said drill pipe thereby increasing the pressure on the volume of drilling fluid enclosed therein.
Claim 4
Dependent Claim
31 words
The method defined in claim 4 wherein said volume of said closed portion of said drill pipe is decreased by decreasing the length of said closed portion of said drill pipe.
Claim 5
Dependent Claim
69 words
The method defined in claim 5 wherein said drill pipe comprises at least two sections in axial alignment jointed at adjacent ends thereof by a slip joint having a telescoping portion therein, said closing step taking place at a point along the length of said drill pipe above said slip joint, the length of said closed portion of said drill pipe being decreased by closure of said slip joint.
Claim 6
Dependent Claim
95 words
The method defined in claim 6 comprising the additional step of vertically reciprocating the structure comprised of said drill pipe and the upper part of said slip joint after said orienting step, said structure being lifted on the upward stroke thereof a distance equivalent the length of travel of said telescoping portion of said slip joint, said pumping step occurring during the upward stroke of said structure, said closing step occurring substantially at the commencement of the downward stroke of said structure and said closure of said slip joint occurring simultaneously with said downward stroke.
Claim 7
Dependent Claim
272 words
A process for jet directional drilling using a slip joint and back pressure valve assembly in jet deflection drilling wherein the direction of a bore hole is deviated towards a predetermined direction by jetting substantial quantities of high pressure fluid in the preferred direction of bore hole deviation, said process substantially increasing the jet deflection drilling speed and the possibLe operating depth of jet deflection drilling and comprising the steps of: disposing said slip joint and back pressure valve assembly in the lower end of a hollow drill string above a jet deflection bit having at least one outlet orifice through which a relatively greater amount of drilling mud can be caused to flow than through other bit orifices, orienting said at least one outlet orifice towards an interior portion of said bore hole which is generally oriented in said particular direction, pumping a drilling fluid into the interior of said hollow drill string, extending said slip joint by exerting a lifting force on said drill string, admitting a substantial quantity of said drilling fluid past said back pressure valve into the central interior portion of said slip joint during said extending step, and rapidly closing said slip joint by releasing at least some of the lifting force on said drill string, and trapping said substantial quantity of drilling fluid behind said back pressure valve to force said substantial quantity of drilling fluid through said at least one outlet orifice during said closing step to thereby substantially increase the pressure and velocity of the jet-deflecting fluid thus increasing the jet deflection drilling speed and the possible depth of effective jet deflection drilling.