Abstract: An apparatus for restricting fluid flow includes: a ball receiving element disposed in a fluid conduit and configured to receive a ball that has been advanced through the fluid conduit and at least partially restrict fluid flow, the fluid conduit having a longitudinal axis; and at least one feature disposed at the fluid conduit and configured to at least one of reduce a rate of deceleration of the ball due to actuation of the apparatus and reduce pressure waves generated by an impact between the ball and the ball receiving element.

Abstract: A vibratory tool for downhole use is capable of letting a wireline or other tools pass a passage therethrough that can be subsequently closed by landing a plug on a seat. The dump valve is disposed annularly about the central passage so that cycling the tool does not cause it to be slammed against a seat. Since only a plug is delivered to a passage the functioning parts already in the housing are made stronger to improve reliability. Additional power is delivered per stroke from modular stacked piston units. The tool can be run in a manner where the high amplitude low frequency oscillating forces are delivered to the stuck fish without impacts of the pistons on the housing.

Abstract: An assembly for milling a window in a tubular features a layout that keeps a restorative force normal to the whipstock slope acting on the window mill to help it track the whipstock ramp long enough for making an exit at the desired location. A string mill assembly is made long enough to allow such a restorative force to be created on the window mill as it advances down the ramp. The bearing or cutting structures on the string mill are positioned with respect to the window mill so that either the top of the string mill or at least the first bearing structure above the window mill presents at the top of the window as the window mill arrives at the position where it is desired that it make an exit. The lower bearing structure of the string mill also preferably has a rounded profile to facilitate its entrance on to the whipstock ramp without getting in a bind on the tubular wall adjacent the top of the window.

Abstract: A vibratory tool for downhole use is capable of letting a wireline or other tools pass a passage therethrough that can be subsequently closed by landing a plug on a seat. The dump valve is disposed annularly about the central passage so that cycling the tool does not cause it to be slammed against a seat. Since only a plug is delivered to a passage the functioning parts already in the housing are made stronger to improve reliability. Additional power is delivered per stroke from modular stacked piston units. The tool can be run in a manner where the high amplitude low frequency oscillating forces are delivered to the stuck fish without impacts of the pistons on the housing.

Abstract: An apparatus for applying a force to a stuck object in a wellbore comprises a work string extending in the wellbore. A vibrating string has a vibrator engaged with the stuck object. The vibrator drives the vibrating string to impart the force to the stuck object. An isolator associated with the work string and the vibrating string decouples a portion of a motion of the vibrating string from the work string. A method of applying a force to a stuck object in a wellbore comprises extending a work string in the wellbore from a surface location. A vibrating string is engaged with the stuck object. The vibrating string is driven at a frequency to apply the force to the stuck object. The work string is isolated from the vibrating string such that a portion of the motion of the vibrating string is decoupled from the work string.

Abstract: A method of imposing a simple harmonic wave of bidirectional vibration on an object stuck in sand in a well bore, where vibrations are imposed in close proximity to the stuck location, and where the harmonic wave has sufficient amplitude and frequency to create soil liquefaction at the surface of the stuck object, thereby reducing the amount of overpull necessary to free the object from the sand.