ALEXANDRIA, Va., Aug. 20 -- United States Patent no. 12,392,220, issued on Aug. 19, was assigned to GRANT PRIDECO INC. (Houston).
"Valve and method for multi-stage well stimulation" was invented by Paul David Busengdal (Ikornnes, Norway), Tom Rune Koloy (Sandnes, Norway) and Vijay Kumar Keerthivasan (Sandnes, Norway).
According to the abstract* released by the U.S. Patent & Trademark Office: "A valve for use in a wellbore for facilitating a multi-stage stimulation method includes a first sleeve configured to move to open the valve. In addition, the valve includes a second sleeve configured to move to close the valve. The first sleeve and the second sleeve are both movable in a first direction. Movement of the first sleeve a first distance...