GB972582A - Subsurface well tools - Google Patents

Abstract

972,582. Wells. BAKER OIL TOOLS Inc. April 2, 1962 [April 3, 1961], No. 12565/62. Heading E1F. A well packer comprises a body, normally retracted packing on the body, hydraulic means actuated by the hydrostatic head of fluid in the well, means to prevent the head accidentally operating the hydraulic means, and means to counteract the effect of the head on the hydraulic means to permit retraction of the packing. The body, which includes a head 16, a member 13 fixed to the head, a housing 78 fixed to the member 13, a connector 30 slidable on the member 13, and a member 12 fixed to the connector carries the packing 48, a slip expander 44, slips 62, slip ring 65, and a resilient member 73 which are slidable on the members 12, 13. The packer is lowered into a well having two production zones on tubing 10 screwed to the member 30 until an extension of the member 12 seats in a lower packer (not shown) disposed between the zones. A ball 116 is dropped down the tubing 11 and fluid is pumped behind the ball to shear a pin 110 and move a sleeve 106 to open a duct 105, the ball finally falling to the bottom of the well so that the duct is subjected to the head of fluid in the tubing 11 and casing B. The head forces pistons 91 (Fig. 12) upwardly within the housing to move an abutment 75, the member 73, and the slip ring upwardly on the members 12, 13. The slips engage the casing and carry the expander upwardly towards the connector to expand the packing. After the packing has expanded the slips engage the casing and the member 73 is expanded to set the packer. After the packer is set fluid from the lower zone passes upwardly through the extension, the member 12 and tubing 10 to the surface whilst fluid from the upper zone passes through lower tubing 82, the member 13 and the tubing 11 to the surface. The packer is released by pulling on the tubing 11 to release and remove it from the head, by unscrewing the tubing 10 from the connector and pulling it to elevate the head and move the member 13 upwardly within the connector by an amount determined by a stop 37. The upward movement of the member 13 aligns ports 108, 118 so that fluid flows into the air-filled spaces above the pistons to remove the hydrostatic setting force. The parts of the packer may be retracted and the packer removed from the well by continuing to pull the tubing 10 upwardly. In a modification the member 73, which holds the slips against the expander to prevent upward movement of the packer, is dispensed with, the slips are designed to hold the packer against downward movement only, and hydraulically operated grippers are mounted on the head to prevent upward movement of the packer.