Abstract: A method for lateral drilling into a subterranean formation whereby a shoe is positioned in a well casing, the shoe defining a passageway extending from an upper opening in the shoe through the shoe to a side opening in the shoe. A rod and casing mill assembly are inserted into the well casing and through the passageway in the shoe until a casing mill end of the casing mill assembly substantially abuts the well casing. The rod and casing mill assembly are rotated until the casing mill end substantially forms a perforation in the well casing. An internally rotating nozzle is attached to an end of a hose and is pushed through the passageway and the perforation into the subterranean formation, and fluid is ejected from tangential jets into the subterranean formation for impinging upon and eroding the subterranean formation.

Abstract: A flexible milling assembly for milling an orifice through a well casing. The milling assembly can include a drive yoke, and a plurality of straight and split yoke assemblies—all linked together and to a cutter head with universal blocks that enable the components to pivot relative to each other. A string of joint tubing connected to a prime mover on the surface is used to lower the milling assembly into a well and supply the driving torque. A split shoe coupled to a guide tube is positioned within the well casing where the orifice is to be milled. The milling assembly is guided through a curved passage within the split shoe to bring the cutter head into contact with the well casing. A protector assembly can be provided to enclose and protect the milling assembly when it is tripping into and out of the well casing.

Abstract: A flexible milling assembly for milling an orifice through a well casing. The milling assembly can include a drive yoke, and a plurality of straight and split yoke assemblies—all linked together and to a cutter head with universal blocks that enable the components to pivot relative to each other. A string of joint tubing connected to a prime mover on the surface is used to lower the milling assembly into a well and supply the driving torque. A split shoe coupled to a guide tube is positioned within the well casing where the orifice is to be milled. The milling assembly is guided through a curved passage within the split shoe to bring the cutter head into contact with the well casing. A protector assembly can be provided to enclose and protect the milling assembly when it is tripping into and out of the well casing.

Abstract: A flexible milling assembly for milling an orifice through a well casing. The milling assembly can include a drive yoke, and a plurality of straight and split yoke assemblies—all linked together and to a cutter head with universal blocks that enable the components to pivot relative to each other. A string of joint tubing connected to a prime mover on the surface is used to lower the milling assembly into a well and supply the driving torque. A split shoe coupled to a guide tube is positioned within the well casing where the orifice is to be milled. The milling assembly is guided through a curved passage within the split shoe to bring the cutter head into contact with the well casing. A protector assembly can be provided to enclose and protect the milling assembly when it is tripping into and out of the well casing.

Abstract: A jet drill coupled to a distal end of a flexible jet lance is lowered into a well casing and advanced through a curved passage formed in a deflection shoe oriented to direct the jet drill through an orifice milled in the well casing. The jet drill is actuated with a pressurized fluid produced by a pump on the surface that is conveyed through a high pressure hose that runs through the flexible jet lance. Force transmitted through a thrust liner of the jet lance advances the jet drill while the lateral bore is being drilled. The thrust liner comprises helical coils of steel wire providing a high elastic modulus and buckling resistance, even while passing through the curved passage. Tension cables in the jet lance maintain tension on the thrust liner and enable the assembly to be pulled from the lateral bore and well.

Abstract: A method for lateral drilling into a subterranean formation whereby a shoe is positioned in a well casing, the shoe defining a passageway extending from an upper opening in the shoe through the shoe to a side opening in the shoe. A rod and casing mill assembly are inserted into the well casing and through the passageway in the shoe until a casing mill end of the casing mill assembly substantially abuts the well casing. The rod and casing mill assembly are rotated until the casing mill end substantially forms a perforation in the well casing. An internally rotating nozzle is attached to an end of a hose and is pushed through the passageway and the perforation into the subterranean formation, and fluid is ejected from tangential jets into the subterranean formation for impinging upon and eroding the subterranean formation.

Abstract: An internally rotating nozzle for facilitating drilling through a subterranean formation is rotatably mounted internally within a housing connected to a hose for receiving high pressure fluid. The rotor includes at least two tangential jets oriented off of center for ejecting fluid to generate torque and rotate the rotor and cut a substantially cylindrical tunnel in the subterranean formation.

Abstract: A jet drill coupled to a distal end of a flexible jet lance is lowered into a well casing and advanced through a curved passage formed in a deflection shoe oriented to direct the jet drill through an orifice milled in the well casing. The jet drill is actuated with a pressurized fluid produced by a pump on the surface that is conveyed through a high pressure hose that runs through the flexible jet lance. Force transmitted through a thrust liner of the jet lance advances the jet drill while the lateral bore is being drilled. The thrust liner comprises helical coils of steel wire providing a high elastic modulus and buckling resistance, even while passing through the curved passage. Tension cables in the jet lance maintain tension on the thrust liner and enable the assembly to be pulled from the lateral bore and well.

Abstract: A flexible milling assembly for milling an orifice through a well casing. One embodiment includes a drive yoke, and a plurality of straight and split yoke assemblies—all linked together and to a cutter head with universal blocks that enable the components to pivot relative to each other. A string of joint tubing connected to a prime mover on the surface is used to lower the milling assembly into a well and supply the driving torque. A split shoe coupled to a guide tube is positioned within the well casing where the orifice is to be milled. The milling assembly is guided through a curved passage within the split shoe to bring the cutter head into contact with the well casing. A protector assembly can be provided to enclose and protect the milling assembly when it is tripping into and out of the well casing.

Abstract: An internally rotating nozzle for facilitating drilling through a subterranean formation is rotatably mounted internally within a housing connected to a hose for receiving high pressure fluid. The rotor includes at least two tangential jets oriented off of center for ejecting fluid to generate torque and rotate the rotor and cut a substantially cylindrical tunnel in the subterranean formation.

Abstract: An internally rotating nozzle for facilitating drilling through a subterranean formation is rotatably mounted internally within a housing connected to a hose for receiving high pressure fluid. The rotor includes at least two tangential jets oriented off of center for ejecting fluid to generate torque and rotate the rotor and cut a substantially cylindrical tunnel in the subterranean formation.

Abstract: An internally rotating nozzle for facilitating drilling through a subterranean formation is rotatably mounted internally within a housing connected to a hose for receiving high pressure fluid. The rotor includes at least two tangential jets oriented off of center for ejecting fluid to generate torque and rotate the rotor and cut a substantially cylindrical tunnel in the subterranean formation.

Abstract: A method for facilitating horizontal drilling by positioning in a well casing a shoe defining a passageway extending from an upper opening in the shoe through the shoe to a side opening in the shoe. A rod is connected, through at least one block and pin assembly operative as a universal joint, to a casing mill end, and inserted into the well casing and through the passageway in the shoe until the casing mill end substantially abuts the well casing. The rod and casing mill end are then rotated until the casing mill end substantially forms a perforation in the well casing. The rod and casing mill end are then withdrawn from the well casing, and a nozzle attached to the end of a flexible hose is extended through the passageway to the perforation. Fluid is then ejected from the nozzle and impinges and erodes subterranean formation material.

Abstract: The objects of the invention are provided using a method for horizontal drilling in which a shoe having an elbow-shaped cavity therein is lowered to a selected point. An explosive charge is placed at the far end of the shoe adjacent to the well casing. Impact transferring means are positioned between the explosive charge and the vertical portion of the well above the shoe. An impact is struck on the surface of the transfer means to cause an impact-type detonator to discharge, causing the explosive charge to discharge. This perforates the casing of the well at the tip of the shoe. The shoe and the tubing above it are then cleared and a hydraulic drilling device is inserted into the shoe. The shoe guides the hydraulic drilling device into place and high pressure liquid is pumped through the hydraulic device which extends through the perforation in the well casing into the earth's strata.