Abstract: An improved method and/or apparatus for completing a wellbore is provided. In one embodiment, a method of lining a pre-drilled wellbore is provided. The method includes the act of providing a casing assembly, the casing assembly including a string of casing; and a retractable joint comprising an inner tubular and an outer tubular. The method further includes the acts of running the casing assembly into the pre-drilled wellbore and actuating the retractable joint, thereby reducing the length of the casing assembly through movement between the inner and outer tubulars.

Abstract: The present invention relates to apparatus and methods for remotely actuating a downhole tool. In one aspect, the present invention provides an apparatus for activating a downhole tool in a wellbore, the downhole tool having an actuated and unactuated positions. The apparatus includes an actuator for operating the downhole tool between the actuated and unactuated positions; a controller for activating the actuator; and a sensor for detecting a condition in the wellbore, wherein the detected condition is transmitted to the controller, thereby causing the actuator to operate the downhole tool. In one embodiment, conditions in the wellbore are generated at the surface, which is later detected downhole. These conditions include changes in pressure, temperature, vibration, or flow rate. In another embodiment, a fiber optic signal may be transmitted downhole to the sensor. In another embodiment still, a radio frequency tag is dropped into the wellbore for detection by the sensor.

Abstract: The present invention, in one embodiment, has a valve body within which is mounted a stem support; a plunger with a stem which is movably mounted for movement in the stem support to move a rounded head of the plunger to sealingly contact a sealing surface within the valve body thereby preventing flow through the valve; a piston recess in the stem which receives and holds a top portion of a piston; the piston (or some part connected thereto or formed integrally thereof) held immobile by one or more holding devices (e.g. bars, plates, pins, rods, etc.) which, in one embodiment extend through the piston and into the stem support or into a piston housing and which are frangible, erodible, degradable or destroyable either by action of a hydrostatic head of fluid on a bottom surface of the piston or by chemical or thermal attack and degradation.