Abstract: Methods of controlling a downhole tool in a well are disclosed wherein pressure change signals are introduced into a column of fluid standing in the well. The command signal includes at least one high level pressure change applied to the column of fluid. The high level pressure change includes a change from a first value to a second value, with the second value being at least about 1,000 psi above hydrostatic pressure of the column of fluid in the well, and with pressure being maintained at the second value for an interval of time corresponding to information stored in a control system of the downhole valve. A number of suitable command signal formats are disclosed, particularly including pressure drop signals.

Abstract: A method for establishing production of oil or gas from a secondary production zone which is above a primary production zone in a well in which a settable material is placed in the annulus between the casing and the tubing above the secondary production zone and allowed to set up, and the secondary zone is then perforated with a through-tubing perforating gun.

Abstract: A sleeve valve assembly featuring a cylindrical housing within which a sleeve valve is axially slidable within a radially expanded section of the housing. The radially expanded section of the housing presents an inwardly extending stop shoulder at one point along its length and an annular expansion notch at another point. The sleeve valve includes a radially projecting chamfered boss about its circumference. A portion of the sleeve valve is longitudinally slotted so as to form collets. An outwardly biased C-ring is disposed about the sleeve valve within the radially expanded section. The C-ring is initially disposed to be free to travel axially along the radially expanded section between the boss and the stop shoulder. As the sleeve valve is moved toward an open position, the boss, C-ring and stop shoulder engage each other such that the sleeve valve is releasably snagged against further axial movement toward the open position. A significant axial force upon the sleeve valve is required to effect unsnagging.

Abstract: A method and apparatus for establishing a fluid plug within a well bore which can then be substantially destroyed upon demand to permit reestablishment of the well within a short period of time thereafter. Increased pressure actuates a plug rupture mechanism which destroys the integrity of the plug and allows the plug to be substantially eliminated from the wellbore within a short period of time thereafter. In described preferred embodiments, the plug is comprised of a salt and sand mixture which is highly resistant to fluid compressive forces but is subject to destruction under shear tension forces. The plug may be encased within a plug sleeve which is, in turn, encased within a plug housing which may be disposed within the well bore. The sleeve is associated within the housing so that fluid may be displaced about the plug sleeve as the housing is disposed into the well bore.

Abstract: A gun hanger for emplacement through a tubing string into a casing string, comprising an inner mandrel, a setting means slidably received on said mandrel, said setting means including a plurality of spaced apart, extendable slips mounted thereon such that operation of said setting means causes said slips to extend and engage the casing string, a slip release means slidably received on said mandrel such that operation of said slip release means causes said slips to retract and disengage from the casing string, said setting means and said release means having diameters less than the inside diameter of the tubing string when said slips are retracted, a centralizer mounted on and extending axially from the hanger, said centralizer comprising a stem and a plurality of evenly circumferentially spaced longitudinal bow springs flexibly mounted thereon, said bow springs being longitudinally spaced along said stem such that each spring longitudinally clears its preceding and succeeding springs when said springs are com

Abstract: The inventive apparatus for remotely handling bar-like components which define a longitudinal direction includes a gripper mechanism for gripping the component including first and second gripper members longitudinally fixedly spaced from each other and oriented parallel to each other in planes transverse to the longitudinal direction. Each gripper member includes a jaw having at least one V-groove with opposing surfaces intersecting at a base and extending radially relative to the longitudinal direction for receiving the component in an open end between the opposing surfaces. The V-grooves on the jaw plate of the first and second gripper members are aligned in the longitudinal direction to support the component in the first and second gripper members.

Abstract: A diaphragm with an inflatable torus-shaped perimeter is used to seal at least one end of a stack so that debris that might be hazardous will not be released during removal of the stack. A diaphragm is inserted and inflated in the lower portion of a stack just above where the stack is to be cut such that the perimeter of the diaphragm expands and forms a seal against the interior surface of the stack.