Abstract: There is disclosed a subsurface tubing safety valve comprising a body having ports therein connecting the bore of the body with the annulus thereabout, a sleeve for reciprocating in the body between positions opening and closing the ports, and a piston which reciprocates within the sleeve, and a pair of coil springs, a first of which acts between the piston and sleeve and a second of which acts between the sleeve and body. When the sleeve is raised to its open position, the piston may be caused to move upwardly within the sleeve in response to a predetermined increase in pressure differential acting upwardly across the piston so as to compress and generate energy in both springs. As the piston moves up, the sleeve is connected to it for downward movement therewith in response to a predetermined decrease in the pressure differential across the piston to a position in which the sleeve is released by an expandable end of a bellows in response to a predetermined drop in the pressure of the well fluid.

Abstract: There is disclosed apparatus for use in controlling flow within a well bore wherein each of two or more well tubing strings are suspended from the head of the well, and a mandrel connected as a part of each string, in a position spaced vertically of the other mandrel connected to the other string, has a side pocket to one side of its bore to receive a fluid pressure responsive, flow controlling tool which is run into and out of the pocket on a wireline, as well as a second bore which receives a section of the other string for vertical movement with respect to the one string.