The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 26, 1982
Filed:
Feb. 20, 1980
Charles H McLaurin, Wichita Falls, TX (US);
Wayne F Nelson, Waxahachie, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
A tool is disclosed for shifting the sleeve of a port collar in a well casing, to open and close the ports in the collar. The basic tool is made up of a housing having a double piston assembly mounted slideably in a transverse bore in the housing. The transverse bore is intersected by a lengthwise bore in the housing. Fluid is carried into the housing from a tubing string connected into the lengthwise bore. The double piston assembly has an outside face in contact with fluid in the well casing, and an inside face in contact with fluid inside the housing bore. In addition, the outside face has a larger surface area than the inside face. This differential in the piston surface area allows the piston assembly to be held in a 'retract' position by applying fluid pressure to the outside face. Alternatively, the piston assembly can be moved laterally to engage the port collar sleeve by applying fluid pressure to the inside face. Pulling the tubing string upwardly shifts the sleeve to a position which opens the collar ports. Setting weight on the tubing string moves the sleeve downwardly to close the collar ports.