GB924708A - Well devices - Google Patents

Abstract

924,708. Oil wells. J. V. FREDD. Aug. 10, 1959, No. 27331/59. Class 85. A device for anchoring and supporting well devices, e.g. a length of extension tubing 75, or temperature or pressure recorders, at a predetermined position in a well flow conductor, comprises locking means which are positively held in locking position by a longitudinally movable member which itself is releasably locked in locking position. The device consists of a mandrel 10 having an upper section 11, a lower section 12 and a central bore 13. Positioning and locking keys 16 are carried by a member 15 which consists of top and bottom rings 17 connected by ribs 18. The keys 16 are urged outwardly by springs 24 and are shaped to project into correspondingly shaped grooves 38, 39 when the device, being run into the flow conductor, is arrested by shoulders 41 on the keys reaching a shoulder 34 on the landing nipple 40. Each of the keys has lateral apertures 29, 44 and an inclined drain aperture 45a. To lock the device against upward movement from its located position, dogs 45 are mounted on the upper section 11 of the mandrel and are forced into a locking groove 46 in the nipple 40 by the camming action of a sleeve 57 when it is forced down by jars from the running-in tool. The dogs 45 project through windows in a cage 49 screwed at 14 on to the mandrel section 11. The dogs have hooked ends 47 which extend into a groove 48 in the cage 49, and the camming action is effected by the bevelled ends 55 of the strips between the windows of the sleeve 57 sliding over inclined surfaces 54 on the dogs which are held in the locking groove 46 by further downward movement of the sleeve 57 to bring the enlarged portion 61 into contact with the surfaces 54a of the dogs 45. When the sleeve 57 is fully depressed, an inwardly projecting detent 68 on the cage 49 snaps into a groove 69 in the sleeve 57 and prevents unintentional upward movement thereof. The running tool is released from the device by downward jars which shears a retaining pin, and is then removed. The device is removed by a retrieving tool which engages under the flange 74 and pulls up the sleeve 57, the detent 68 yielding to permit this; the dogs 45 being thus released and the device being pulled up, the bevelled surface 31 of the keys 16 forcing them inwardly when necessary. In a modification, the dogs 45, separate from the keys 16, are dispensed with, and the keys are shaped to land on a circular ledge and to move outwardly into the locking groove in the landing nipple. They are retained positively in the locking groove by the camming action of a sleeve, corresponding with the sleeve 57, which is forced down by jars from the running tool, which first breaks a shear pin, and is releasably locked in its lowest position by a spring-pressed detent. The device is removed, as before, by upward pulling with a retrieving tool.