Abstract: A wireline operated overshot is disclosed. In the illustrated embodiment, the overshot includes a grapple which is located internally of a sleeve telescoped about it having a tapered internal shoulder. The grapple engages and disengages a fish. In the event the overshot becomes stuck on a fish, it can be released by downwardly jarring movement which shears a pin. The pin is located to permit a limited range of telescoping movement between the grapple and telescoped external sleeve. A spring is incorporated which forces the grapple downwardly against the tapered sleeve. The apparatus includes a latching mechanism which overcomes the spring to move the parts to a released position.

Abstract: A tubing pressure test apparatus which comprises an elongate hollow body is disclosed. A fishing neck on a sliding mandrel carrying a check valve on the bottom end is received an upper outer hollow mandrel which has an internal valve seat. Fluid communication from the exterior of the mandrel to an internal passage is controlled by the check valve on the upper mandrel. The check valve is received in the seat below lateral passages to the exterior. The axial internal passage communicates through the bottom of the tool to enable the tool to be pulled upwardly in the tubing string through a column of liquid. The upper outer mandrel is threaded to a central pipe which supports an expandable resilient element. The pipe is slidably connected to an outer lower mandrel which has a taper which forces the expandable element radially outwardly when a compressive force is applied to the top of the tool.

Abstract: A collar locating apparatus is disclosed. It is a wire line tool adapted to be run in a tubing string to count the number of collars and thereby determine depth. It incorporates an elongate body. It has a pair of caliper arms which are spring loaded to flare outwardly. The device is run to the bottom of the tubing string and is jar operated to sever a shear pin whereupon the caliper arms are released to deflect outwardly. The extent of deflection of the arms is determined by an adjustable nut below the arms which slides downwardly on the body and releases the arms for controlled outward deflection. The arms are pivoted and clamped at a common collar above the arms to enable them to pivot.

Abstract: A setting and retrieval device for down-hole equipment which includes a solid mandrel tapered at its bottom to a larger diameter which cooperates with a set of surrounding collet fingers which have a shoulder and gripping threads thereon to engage a fish or a tool to be set down hole. The apparatus is used as a running tool and a retrieval tool. The collet fingers slide relative to the taper at the urging of a compressible spring arranged between a slidable thimble which supports the collet fingers. It is locked in the up position by serrations which face one another.