Abstract: A directional drilling system and method are provided for directional drilling a borehole by continuous rotating of the drill string in combination with an arrangement of drilling motor assemblies at the lower end of the drill string to effect drilling along a curved path and a substantially straight path. A first drilling motor assembly is coupled to a drill bit and operable to rotate the drill bit to effect drilling of the borehole. A second drilling motor assembly, positioned on the drill string above the first drilling motor assembly, is operable to rotate the first drilling motor assembly in a direction opposite the direction of rotation imparted to the drill string from the surface and to the drill bit by the first drilling motor assembly.

Abstract: A drill bit is disclosed, comprising: a drill bit head having a cutting face with one or more fixed cutting elements; a flow passage extending through the drill bit head to the cutting face; a flow interrupter within the drill bit head and positioned to interrupt flow of fluid through the flow passage; and a power section connected to drive the flow interrupter and cause, in operation, variable flow of fluid through the flow passage. A method of drilling is also disclosed comprising: flowing fluid through a flow passage extending through a drill bit head to a cutting face of the drill bit head, the cutting face having one or more fixed cutting elements; and driving a flow interrupter within the drill bit head with a power section to interrupt the flow of fluid through the flow passage and cause variable flow of fluid through the flow passage.

Abstract: An improved coiled tubing directional drilling method comprises: providing a bent housing which is rotatably coupled to the coiled tubing, rotating the drill bit, and rotating the bent housing. Apparatus for achieving the method comprises: a rotary connection between the coiled tubing and the bent housing and means for rotating the bent housing relative to the coiled tubing and to the drill bit. A fluid pressure-operated clutch enables alternate rotation and locking of the bent housing. Preferably, a first downhole motor rotates the drill bit and a second downhole motor rotates the bent housing through the clutch or alternately a speed reducer permits the bent housing to contra-rotate slowly under reactive torque developed by the rotating drilling bit.

Abstract: An improved coiled tubing directional drilling method comprises: providing a bent housing which is rotatably coupled to the coiled tubing, rotating the drill bit, and rotating the bent housing. Apparatus for achieving the method comprises: a rotary connection between the coiled tubing and the bent housing and means for rotating the bent housing relative to the coiled tubing and to the drill bit. A fluid pressure-operated clutch enables alternate rotation and locking of the bent housing. Preferably, a first downhole motor rotates the drill bit and a second downhole motor rotates the bent housing through the clutch or alternately a speed reducer permits the bent housing to contra-rotate slowly under reactive torque developed by the rotating drilling bit.

Abstract: A method for orienting a rotary drilling system comprised of a rotatable drilling string, a drilling string communication system and a drilling direction control device, the drilling direction control device comprising a deflectable drilling shaft connected with the drilling string. The method for orienting the rotary drilling system may involve the steps of orienting the drilling string at a desired orientation and sensing the desired orientation of the drilling string with the drilling string communication system. Further, the method involves the steps of communicating a desired orientation of the drilling string to a drilling direction control device and then actuating the drilling direction control device to deflect the drilling shaft to reflect the desired orientation of the drilling shaft. The desired orientation of the drilling shaft may be communicated directly to the drilling direction control device or to the drilling direction control device through a drilling string communication system.

Abstract: A downhole drilling assembly including a housing having an upper end for connection to a drill string and a lower end, a fluid passage extending through the housing from the upper end to the lower end, a power unit contained within the housing, a drive assembly extending within the housing between the power unit and the lower end of the housing such that a mandrel chamber is defined between the drive assembly and the housing, a radially movable first stabilizer associated with the housing and located between the power unit and the lower end of the housing, an axially movable mandrel contained within the mandrel chamber, the mandrel being associated with a stabilizer actuator for causing radial movement of the first stabilizer in response to axial movement of the mandrel, and a sensor apparatus located between the power unit and the lower end of the housing for sensing at least one drilling parameter.

Abstract: A drilling assembly and a method for directional drilling using the drilling assembly. The drilling assembly comprises a drilling bit, a near bit stabilizer and an adjustable gauge stabilizer. The near bit stabilizer is located a first axial distance from a distal end of the drilling assembly and has a near bit stabilizer gauge which is greater than a nominal drilling assembly gauge. The adjustable gauge stabilizer is located a second axial distance from the distal end, which is greater than the first axial distance, and is adjustable between an extended and retracted gauge. The retracted gauge is less than the near bit stabilizer gauge. A bit drop angle is created between the drilling assembly and the drilling bit, while a stabilizer angle is created between the near bit stabilizer and the adjustable gauge stabilizer.

Abstract: A drilling direction control device, improvements in drilling direction control devices, methods for orienting a rotary driling system, and methods for rotary drilling. The drilling direction control device includes a rotatable drilling shaft, a housing for rotatably supporting a length of the drilling shaft, and a deflection assembly contained within the housing for bending the drilling shaft between a first support location and a second support location. The deflection assembly includes an outer ring which is rotatably supported on a circular inner peripheral surface of the housing and which has a circular inner peripheral surface that is eccentric with respect to the housing. The deflection assembly also includes an inner ring which is rotatably supported on the circular inner peripheral surface of the outer ring and which has a circular inner peripheral surface which engages the drilling shaft and which is eccentric with respect to the circular inner peripheral surface of the outer ring.

Abstract: A fail-safe tubular receiving member for use in combination with a latch assembly to longitudinally support and rotationally orient the latch assembly in a wellbore. The latch assembly includes at least one outwardly biased, radially movable latch member which is receivable within a bore of the receiving member. A first recessed area and a second recessed area, accessible from the first recessed area, are defined by the bore. The first recessed area defines a first increased radial distance and is configured so that upon longitudinal alignment of the latch member and the first recessed area, the latch member moves radially outward for receipt in the first recessed area to support the latch assembly longitudinally such that longitudinal movement of the latch assembly relative to the receiving member further downhole is prevented.

Abstract: An apparatus and method for directing a first and a second object into a primary and a secondary borehole respectively from a main borehole communicating therewith at a borehole junction. The apparatus includes a deflector for positioning at the borehole junction to direct the first and second objects into the primary and secondary boreholes. A retainer holds the objects relative to each other such that when the first object is aligned to be directed into the primary borehole, the second object is aligned to be directed into the secondary borehole. A retainer orienting mechanism orients the retainer relative to the borehole junction so that the objects are aligned to be directed into the boreholes. The method includes positioning the deflector at the borehole junction and inserting the objects and the retainer into the main borehole. The retainer is oriented relative to the borehole junction so that the objects are aligned to be directed into their respective boreholes.

Abstract: A downhole drilling assembly including a housing having an upper end for connection to a drill string and a lower end, a fluid passage extending through the housing from the upper end to the lower end, a power unit contained within the housing, a drive assembly extending within the housing between the power unit and the lower end of the housing such that a mandrel chamber is defined between the drive assembly and the housing, a radially movable stabilizer associated with the housing, and an axially movable mandrel contained within the mandrel chamber, the mandrel being associated with a stabilizer actuator for causing radial movement of the stabilizer in response to axial movement of the mandrel.

Abstract: A single trip tool and method for cutting a subsurface window through a well casing and installing an anchoring and orienting sleeve in the casing adjacent the window for subsequent downhole well procedures and equipment installation. A mill held in position within the casing by a hydraulic and weight-set tubular anchor sleeve is used to cut multiple vertical slots in the casing wall to form a single, large window. An indexing mechanism controls circumferential placement of the mill to ensure contact between adjacent slots. The mill is supported for rotation and longitudinal movement by a carriage mount that advances along dual sloping rails causing the mill to form an increasingly deeper cut during its initial cutting movement. Following formation of the window, the mill is retrieved leaving the anchoring sleeve in place for subsequent well procedures. A second embodiment anchors and orients the cutting assembly with an internally contoured coupling that is part of the casing string.

Abstract: A diverting tool having a deflecting surface is equipped with an anchor that secures the tool at a desired subsurface location within the casing of a primary well bore to divert drilling equipment used to drill a lateral bore. An annular cup-type seal on the tool seals with the casing. A passage through the tool permits fluid bypass across the seal as the tool is lowered through the casing. The passage is closed from the well surface when the tool is anchored. After the lateral bore is drilled, the tool is used to divert a liner into the lateral bore. The upper end of the liner extends into the casing where it is centralized. The liner is cemented in the lateral bore and in the casing with the cement placed to effect sealing of the intersection of the liner and casing. A tubular mill removes the cement and liner from the casing above the diverter tool leaving a flush opening from the casing into the liner.

Abstract: A joint of tubular casing with a pre-formed window in its sidewall has a tubular sleeve fixedly attached to the interior of the tubular casing by a plurality of shearable set screws. The exterior surface of the sleeve is sealed to the interior surface of the tubular casing on opposing sides of the window. The window is filled with a fluid, and then the window is covered with one or more layers of a composite material such as fiberglass. In use, the joint of tubular casing is run down to the depth of interest in an earth borehole, and then the window is oriented with respect to the formation of interest at the depth. The joint of tubular casing is then cemented in place, after which the tubular sleeve is retrieved by the use of a fishing tool, causing the set screws to shear upon the upward movement of the fishing tool. After the interior sleeve is retrieved, a whipstock is lowered into the cased borehole, until it is oriented and anchored therein.

Abstract: Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations. A sensor permanently positioned in the drilling string between the drill bit and the drill motor detects a downhole parameter. An MWD tool may be provided within a non-magnetic portion of the drill string for receiving and transmitting a sensor representative signal to the surface. The sensor signal allows the drilling operation to be altered, and highly reliable and near-bit information thus improves the drilling operation.

Abstract: A keyless latch assembly automatically aligns and fixes the axial and circumferential position of a whipstock within a surrounding casing joint. Alignment and fixing of the whipstock ensures proper engagement and orientation of a drill bit relative to an access window formed in the casing wall. Spring loaded latches in the assembly register with and extend into corresponding receiving recesses formed on the inner surface of the casing joint. The recesses, which are spaced circumferentially around the interior of the casing joint, contain differing profiles that uniquely mate with corresponding profiles on the latches. The position of the latches relative to the recesses determines the amount of radial latch movement which controls the anchoring and orientation of the assembly within the casing. Confirmation of correct axial location and proper circumferential orientation may be made by surface monitoring of the setting string weight and turning torque.

Abstract: Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations. A sensor permanently positioned in the drilling string between the drill bit and the drill motor detects a downhole parameter. An MWD tool may be provided within a non-magnetic portion of the drill string for receiving and transmitting a sensor representative signal to the surface. The sensor signal allows the drilling operation to be altered, and highly reliable and near-bit information thus improves the drilling operation.

Abstract: A downhole adjustable stabilizer and method are disclosed for use in a well bore and along a drill string having a bit at the lower end thereof. A plurality of stabilizer blades are radially movable with respect to the stabilizer body, with outward movement of each stabilizer blade being in response to a radially movable piston positioned inwardly of a corresponding blade and subject to the pressure differential between the interior of the stabilizer and the well bore. A locking member is axially movable from an unlocked position to a locked position, such that the stabilizer blades may be locked in either their retracted or expanded positions. In the preferred embodiment of the invention, the stabilizer may be sequenced from a blade expanded position to a blade retracted position by turning on and off a mud pump at the surface.

Abstract: Improved techniques are provided for drilling a deviated borehole through earth formations utilizing a rotary bit powered by a drill motor, and for obtaining information regarding the borehole or earth formations while drilling. An inclinometer is positioned below the drill motor and within a sealed cavity of a housing fixed to a drill motor sub, and a transmitter within the sealed cavity forwards acoustic or radial wave signals to a receiver provided in a measurement-while-drilling tool. The MWD tool may be provided within a non-magnetic portion of the drill string, and further houses an accelerometer for sensing borehole direction. Both borehole inclination and directional signals are transmitted to the surface by the MWD tool, and the drilling trajectory is altered in response to the signals.