Abstract: Apparatus for rotationally locking the swivel of a drillstring during downhole backoff, directional drilling, and similar operations, and for continuous monitoring of the torque level in the drillstring. A first member has a collar which attaches to one side of the swivel, the collar having a main plate attached thereto and extending outwardly from the swivel. A second member is suspended from the plate, and has a set of jaws which can be closed to grip the swivel and thereby rotationally lock the swivel. A means for measuring forces between the first and second members is disposed between the first and second members, and in combination with appropriate processing and controls permits monitoring of torque on the drillstring while the drillstring is raised and lowered as desired.

Abstract: A tong unit having a ring gear, an upper cage plate, and a jaw assembly is disclosed. The cage plate has a removable window section, through which the jaw assembly may be inserted into and removed from the central opening in the ring gear. The jaw assembly may be attached to the removable window section, so that the window section and the jaw assembly can be lifted out and inserted together.

Abstract: Casing cutter for severing multiple tubulars in a well bore has a pair of cutter blades pivotally mounted on a support body. The blades are pivotally mounted for gradual movement outside of the support body when downward force is applied to proximate ends of the cutter blades. The support body is rotated inside the innermost of the multiple tubulars, while the cutter blades sever the tubulars of progressively increasing diameter. Should the cutter blades or pivotal connections become unusable, the tool body can be rotated about the vertical axis and secured to a downhole string by the opposite end. A substitute pair of cutter blades are then engaged on the tool body and operated to cut the casings similar to the first set of the cutter blades.

Abstract: A release mechanism for removing a subsurface safety control valve from a production string in a well bore is mounted below the safety valve in operational engagement with the safety valve and the production string. The release mechanism has a two-part construction, with the upper part being normally locked to the lower part and released from the lower part when changing of the safety valve is required.

Abstract: Disclosed is a remotely operable top drive safety valve assembly having first and second valve elements. An actuator sleeve moves longitudinally on the main body of the top drive safety valve assembly under the influence of an operating arm. When operating the first valve element, a lock plate is preferably installed over the second valve element stem, and an arm is externally fixed to the stem of the first valve element and is disposed in a cutout in the wall of the actuator sleeve. Movement of the actuator sleeve up and down moves the arm, and thereby moves the first valve element between open and closed positions. When operating the second valve element, the arm on the upper valve element stem is removed, a lock plate is preferably installed over the first valve element stem, an arm is installed on the second valve element stem, and a linkage assembly is installed which operationally engages the second valve element stem arm with the actuator sleeve.

Abstract: A method and apparatus for the application of a sleeve upon a tubular, such as a pipe string, used in downhole applications, for example in oil and gas exploration or recovery. A mould is located around the tubular into which a composite material is injected. The material is cured at ambient temperature. Optional heating may then be applied to enhance the properties of the sleeve. The heating temperatures are well below those at which the structural integrity of the metal tubular would be compromised as regards its fitness for downhole use. Embodiments of wear protectors are illustrated for sleeves with and without wear pads.