Abstract: A downhole tool, such as a safety valve or a stand-alone nipple, has a tubular housing. An axially extending bore is provided in the wall of the housing. A radially extending recess is provided in the internal bore wall of the housing, encompassing the axially extending bore, and a control fluid pipe is passed through the bore and the recess. A cutting tool is mounted for radial movements in the recess and is actuated by downward jarring forces imparted by an auxiliary tool. The control pipe is severed by the cutting element and the lower severed end portion of the control pipe is concurrently crimped to close such end portion.

Abstract: In a safety valve having an axially shiftable actuating sleeve operable to move a valve head from a closed to an open position, the actuating movement of the actuating sleeve is normally produced by a small diameter piston mounted on an axially extending spindle secured to the valve housing and cooperating with a primary cylinder which is secured to the actuating sleeve by a shiftable latch. A secondary spindle and cooperating cylinder are provided which are supplied with fluid pressure by an entirely separate line. The secondary cylinder, when moved downwardly by fluid pressure, engages the latch to effect a disconnection of the primary cylinder from the actuating sleeve and concurrently effects the connection of the secondary cylinder to the actuating sleeve. The second cylinder may thus release the primary cylinder from the actuating sleeve in any position of the primary cylinder, including the position corresponding to the fully open position of the valve head.

Abstract: A method and apparatus for replacing a defective downhole well safety valve of the full bore type by a wireline valve sealably insertable in the bore of the housing for the defective valve by wireline and operating the wireline inserted safety valve by fluid pressure supplied through an existing control fluid passage provided in the original safety valve housing. An internally projecting integral protuberance is provided in the bore of the original safety valve housing and a connecting fluid conduit is provided between the interior of the protuberance and the existing control fluid passage. A cutting tool is mounted on an axially shiftable sleeve disposed immediately above the protuberance. The axially shiftable sleeve is manipulated by an auxiliary tool temporarily inserted in the bore of the original valve housing and causing the cutting tool to remove the protuberance and thus establish fluid communication for the control fluid with the internal bore of the original safety valve housing.