Abstract: A downhole injection valve for selectively opening and closing the bore of a tubing string to permit the passage of chemical treatment fluid at a preselected flow rate to a downhole tool comprises a first annular valve element mounted in a valve housing which is connected in a tubing string above the downhole tool. A slip joint is connected between the valve housing and the downhole tool to permit relative upward and downward movement of the valve housing with respect to the tool. A second annular valve element is disposed in surrounding relationship to a support rod which is inserted in the tubing string and supported at its bottom end by the downhole tool. Upward movement of the tubing string effects contact of the first and second annular valve elements to close all fluid flow through the bore of the tubing string. Conversely, downward movement of the tubing string will effect axial separation of the valve elements to permit fluid flow through the tubing string to the downhole tool.

Abstract: A downhole injection valve for selectively opening and closing the bore of a tubing string to permit the passage of chemical treatment fluid to a downhole tool comprises a first annular valve element mounted in a valve housing which is connected in a tubing string above the downhole tool. A slip joint is connected between the valve housing and the downhole tool to permit relative upward and downward movement of the valve housing with respect to the tool. A second annular valve element is disposed in surrounding relationship to a support rod which is inserted in the tubing string and supported at its bottom end by the downhole tool. Upward movement of the tubing string will then effect contact of the first annular valve element carried by the valve housing with the second annular valve element carried by the support rod, and thus move such elements into engagement and close all fluid flow through the bore of the tubing string.

Abstract: An injection tool for use in injecting fluids through perforations in the well bore of an oil or gas well is mechanically set and mechanically releasable. Fluid can be injected between upper and lower packing elements into a selected perforation. The upper and lower packing elements on opposite sides of the perforation into which fluid is injected are retractable, and any pressure differential across the upper packing elements or across the lower packing elements can be separately equalized.