Patent ID: 9194205
Filing Date: 2015-11-24
Classification: E21B

Abstract:
1. In combination, a pipe; a plug of a removable material seated in said pipe to seal an upper volume of said pipe from a lower volume of said pipe; at least one bypass channel in said pipe communicating said upper volume of said pipe with said lower volume of said pipe, said bypass channel including an axially disposed chamber; and a closing body disposed in said axially disposed chamber for axial movement between a first position maintaining said upper volume of said pipe and said lower volume of said pipe in fluid communication with each other and a second position closing communication between said upper volume of said pipe and said lower volume of said pipe, and wherein said closing body is a piston having an upper enlarged piston part in sealed relation to said bypass channel, a lower enlarged piston part in sealed relation to said bypass channel, and an intermediate piston part between said upper enlarged piston part and said lower enlarged piston part spaced circumferentially from said bypass channel.