Abstract: A stage valve with particular use in cementing a well bore annulus where the stage valve has pressure operated valve member for opening a flow passage in the stage valve and the valve member has differential pressure areas which maintain the valve member open while a fluid moves through the flow passage in one direction and which can be closed by fluid moving in an opposite direction. The flow passage has a choke to develop a pressure differential from the flow of fluid. Spring members can be used with the valve member to close the flow passage when the pressure differential of the fluid flow in one direction is insufficient to maintain the valve member in an open position.

Abstract: A method of packing a well, particularly an oil, gas or water well. A particle/liquid slurry is injected into the wellbore, the particle density to liquid density ratio of which is no greater than about 2 to 1. The particles are substantially free of surface adhesive. The particles are strained out of the slurry in the wellbore, so as to produce a packed mass of the particles adjacent the formation. The packed mass is such as to allow flow of fluids therethrough between the formation and the wellbore, while substantially preventing particulate material from the formation passing therethrough and into the wellbore. The well may be deviated. The fluid density is preferably about 0.8 to about 1.2 g/cm.sup.3.

Abstract: A tool is disclosed for controlling flow of treating fluid from a tubing string into an earth formation, in which the bottom hole pressure is less than the hydrostatic pressure of the fluid in the string. In another application, the tool is used in conjunction with a wash tool to wash sediment out of casing perforations and slotted liners. Before the downhole operation is commenced, a slidable piston in this tool closes off fluid outlet ports, to prevent the fluid from "gravity flowing" out of the tubing string. The piston is held in the closed position by the co-action of an adjusting bolt and a compression spring. The fluid is released from the tubing string by applying sufficient fluid pressure against the piston to overcome the spring load and thus move the piston downwardly past the fluid outlet port.

Abstract: The invention is an elongated tool for detachably connecting a sand screen and liner assembly to a tubing string. The tool comprises a releasing housing sleeve, a hookup nipple section which partly telescopes within the releasing housing sleeve with the telescoped end closed by a removable hookup nipple plug. A movable hollow piston having a ball valve seat at one end and a cross bore extending through its other end part fits within the other end of the releasing housing sleeve with the cross bore aligned with longitudinally extending slots in the releasing housing sleeve.The hookup nipple has circumferentially extending grooves near its upper end which each mate with an array of bores extending through the releasing housing sleeve. Ball detent elements are disposed in the bores and grooves.