Patent ID: 6601650
Filing Date: 2003-08-05
Classification: E21B

Abstract:
A method for a gate valve mountable onto a wellbore casing, said gate valve being operable for controlling fluid and cutting tubing, comprising:mounting said gate valve on aid well casing for controlling fluid flow in place of at least one BOP on said well casing; mounting a slidable gate within said gate valve, said slidable gate having a first side and a second side opposite said first side; providing first and second seats for said slidable gate; positioning said slidable gate between said first and second seats such that said first side of said gate is adjacent said first seat d said second side of said gate is adjacent said second seat; providing that said first and second seats each have different internal diameters adjacent said slidable gate; forming an aperture through said slidable gate; providing a cutting edge on said slidable gate of said gate valve within said aperture such that said cutting edge defines at least a portion of said aperture.