Abstract: A whipstock for use in sidetrack drilling operations in a well bore. The whipstock has a whipstock case with a whipstock body disposed therein. The whipstock is to be comprised of a drillable material so that after the whipstock has been set, the well bore can be re-opened simply by drilling through the whipstock. The whipstock body is preferably comprised of high compressive strength cement. The whipstock: also includes an offset mandrel attached to the whipstock: case. The whipstock mandrel has a whipstock bore and may have an inflation packer attached to a lower end thereof. The inflation packer is actuated through the whipstock bore to seal against the well bore and anchor the whipstock in place.

Abstract: The retrieving tool includes a first mandrel having an upper end adapted for attachment to a running string, and a lower end. A second mandrel is positioned below the lower end of the first mandrel. The second mandrel and first mandrel are interconnected by a cam/grip link mechanism. An external actuator cylinder extends over the upper mandrel into attachment to the lower mandrel such that the cam grip mechanism is moved into engagement with the upper end of a whipstock by movement of the upper mandrel away from the lower mandrel and the cam grip mechanism is released by movement of the lower mandrel through its connection to the external actuator toward the upper mandrel.

Abstract: A millout whipstock has a cylindrical body with a stabbing nose at the bottom and a deflection shoe at the top. A drill string extending through the deflection shoe is connected to a pressure housing keyed in a torque key housing in the body. A piston, mounted in a piston housing secured in the body beneath the pressure housing, has an upper portion extending through the pressure housing and is pinned in a raised position by shear pins. A slip expander at the bottom of the piston engages slips supported adjacent openings in the side wall of the body. A fluid path extending through the drill string, pressure housing, piston housing, and piston, is closed off by a rupture disk. The body is lowered by the drill string onto a cement plug in the casing. The slips are set by applying fluid pressure in the drill string to shear the shear pins and force the piston and expander downward wedging the slips outward to grip the casing.

Abstract: A method for enhancing the productive capacity of a primary wellbore containing a conduit string such as casing involving removing at least a partial radial section of the casing to provide an aperture therein, setting tubing carrying a guide surface in the vicinity of the aperture and drilling a lateral wellbore at an angle to the primary wellbore using a coiled tubing conveyed drilling assembly.

Abstract: A whipstock and method of using same wherein first and second opposing ends of the whipstock are joined by opposing back and guide surfaces and the second or upper end of the whipstock is composed of at least two surfaces, the first surface being angled so as to direct a well tool impinging thereon toward the guide surface and the second surface being angled so as to provide support for the whipstock when placed in a wellbore at an angle to the long axis of the wellbore.

Abstract: A method for setting a whipstock in a wellbore on a packer-anchor which employs a wireline that carries a setting assembly which severs a shear member carried by the setting assembly after the whipstock is set onto the packer-anchor.

Abstract: A retrievable whipstock which can be hydraulically set within a wellbore and following the drilling procedure mechanically released and retrieved for future use. The whipstock includes a whip which directs a milling tool from the main well and a hydraulically actuated packer or anchor for setting the whipstock in the wellbore. The whip includes ratchet teeth on its side edges for mating engagement with a retrieval tool. The retrieval tool includes a nose piece to ensure proper orientation relative to the whipstock and a clamping ring with ratchet teeth to engage the teeth of the whip. The whipstock is released through the application of tension through the retrieval tool allowing removal from the wellbore.

Abstract: Offshore well slots are recovered by cutting off old drive or surface pipe below the mud line to form a stub end. A new drivepipe is installed with a guide and shield device disposed on the scarfed lower end or "mule shoe" of the new drivepipe. The guide and shield device includes a saddle contiguous with the lower end of the new drivepipe having one or more hooks formed on the outer surface thereof for engagement with the stub end to locate the device and the new drivepipe. Shear pins interconnect the new drivepipe with the device and are sheared in response to downward driving action on the new drivepipe or allowing the full weight of the drivepipe to be exerted on the shield device after engagement with the old drivepipe.

Abstract: The present invention comprises a novel method and apparatus for sinking drill holes in underground rock formations while generating drill cores as rock samples. More particularly, the present invention discloses a method and apparatus which allows for an expanded analysis of ground formations over a larger area through the extraction of drill cores as rock samples. The method and apparatus herein disclosed allows one to drill a number of core shaft sections from the base of a main shaft section in various directions in order to obtain a number of sample cores.

Abstract: Apparatus and method for deflecting the drilling direction of a rotary drill string and drill bit through a borehole wall include an anchor, a housing, and a chute. The anchor anchors the apparatus in the borehole. The housing is connectable to the anchor and has an uphole end, a downhole end, a sidewall extending between the uphole end and the downhole end, and a passageway extending through the housing. The passageway has an entrance through the uphole end of the housing and an exit through the sidewall of the housing. The chute is slidably disposed in the housing passageway and has an uphole end, a downhole end, a sidewall extending between the uphole end and the downhole end, and a passageway extending through the chute from the uphole end through the downhole end. The chute passageway passes the drill bit and drill string through the chute.

Abstract: A directional guidance device, for deflecting a drill bit away from the longitudinal axis of a substantially horizontal section of a wellbore, takes advantage of gravitational force to move a deflector member therein between first and second positions. In the first position, the deflector member prevents the drill bit from advancing past the directional guidance device. In the second position, the deflector member allows the bit to pass out of the guidance device, and deflects the bit away from the longitudinal axis of the horizontal section of the wellbore.

Abstract: A bit assembly for undercutting a blind bore extending along a bore axis between an open outer end and a closed inner end and having a substantially cylindrical wall of a predetermned diameter centered on the bore axis and extending between the ends comprises a pusher body normally seated in the closed inner end of the bore and having an outwardly turned camming surface inclined to the bore axis, and a bit having a shaft extending along a longitudinal bit axis and having an inner end, an outer end, and a pair of longitudinally extending sides terminating at the inner end. One of the sides is at least partially cylindrical and centered on the bit axis and the inner end is formed with a camming surface engageable with the camming surface of the body and inclined to the bit axis. A blade fixed permanently and stationarily on the inner end projects radially from the one side of the shaft, the other side being cut back toward the bit axis.

Abstract: In order to salvage a slot path on an offshore platform wherein the original conductor pipe has become clogged or otherwise rendered unusable, the original conductor is cut off below mudline, thereby leaving a stub forming a base upon which a suitably oriented deflector trough is attached. A new or replacement conductor is installed along the same slot path until the deflector trough causes the new conductor to follow a deviated path so as to avoid the original conductor. The direction of the deflector trough is selected to avoid existing wells already driven from such structure.

Abstract: A system for the formation of a bore hole, particularly for use in enhancing the recovery of oil from an oil bearing underground formation using an assembly including a piston sliding in a guide tube. The forward end of the piston body terminates in a drillhead including multiple ports for passing drilling fluid into the formation. Pressurized fluid flowing through the piston body applies pressure against the drillhead to cause it to move into the formation at the same time as it is cutting a pathway for itself. In a preferred embodiment, the forward end of the guide tube includes a whipstock through which the piston body turns from a vertical to a horizontal direction into the formation to provide a radial for the injection of steam. A rigid metal piston body may be used which plastically deforms when passing through the whipstock and becomes rigid thereafter as it moves through the formation.

Abstract: A borehole guide for drilling interpenetrating boreholes which may be parallel to one another or inclined to one another. The borehole guide is clamped in position in an already drilled borehole by inflating an inflatable member. Thereafter a drill which is directed by the guide is used to drill a second borehole which overlaps the first hole. A number of the borehole guides may be used end to end, and their relative orientation may be varied to direct the second borehole, within limits, along a desired path.

Abstract: A method and apparatus for forming substantially horizontal drain holes into a subterranean formation from a substantially vertical cased wellbore. A casing anchor is set in the casing adjacent the formation and a whipstock is used to mill a window in the casing. A flexible drill string is then used to drill the horizontal drain hole through the window. In one modification, a deflection tool having a deflection surface which has a radius of curvature of between 11 and 28 feet is used for both the milling and drilling operations. In another modification, the milling operation is carried out with a sidetracking whipstock which is then replaced with the above-described deflection tool to carry out the drilling operation. In still another modification, a whipstock adaptor is positioned onto a sidetracking whipstock after the milling operation to convert the sidetracking whipstock into a deflecting tool having the desired radius of curvature for carrying out the drilling operation.

Abstract: The invention provides a guide means for deflecting drilling means at a desired location in a well bore to enable the drilling of either a sharply deviated extension thereof or a lateral branch bore. A frame carrying spaced drill tubing holding members is lowered along with the drill bit and tubing into the well bore. Latch means, operable from the surface, release spring members which act to deflect the lower tubing holding member, the tubing and drill bit into the desired orientation. The latch means may be reset from the surface, realigning the tubing holding members so that the guide means assembly may be readily withdrawn from the well bore.