By-pass valve mechanism and method of use hereof

A method for by-passing well fluid past a packer element of a well treatment tool having a treatment fluid passage during conveyance of the well treatment tool within the well casing, comprising:

• connecting a by-pass valve mechanism to the well treatment tool, said by-pass valve mechanism having a by-pass valve body defining a flow passage being in communication with said treatment fluid passage and having at least one by-pass port for communicating said flow passage with an annulus between the well treatment tool and the well casing, said by-pass valve mechanism having a valve element being moveable within said by-pass valve housing between an open position permitting by-pass flow of well fluid through said at least one by-pass port and a closed position blocking by-pass flow of well fluid through said at least one by-pass port;
• connecting said by-pass valve body with a string of conveyance and treatment fluid supply tubing;
• retaining said valve element at said open position during running of said well treatment tool and by-pass valve mechanism and permitting by-pass of fluid between said treatment fluid passage and said annulus;
• releasing said valve element from said open position responsive to fluid pressure;
• and
• causing pressure responsive movement of said by-pass valve element from said open position to said closed position.

A by-pass valve mechanism in combination with a well treatment tool having at least one packer element for sealing within the well casing of a well, permitting by-pass of well fluid past the packer element of the well treatment tool during conveyance of the well treatment tool within the well casing, comprising:

• a by-pass valve housing being connected with a well tool and defining an internal flow passage in communication with a tubing string and having at least one by-pass port establishing communication of the internal flow passage with an annulus between said by-pass valve housing and the well casing, said by-pass valve housing defining an annular internal valve receptacle and an annular internal valve seat;
• a tubular valve element being moveable within said annular internal valve receptacle between an open position permitting flow of well fluid through said at least one by-pass port and a closed position establishing sealing with said annular internal valve seat and blocking the flow of well fluid through said at least one by-pass port and permitting the flow of fluid through said internal flow passage;
• at least one shear element being mounted to said by-pass valve housing and having retaining engagement with said tubular valve element and securing said valve element at said open position permitting fluid by-pass during tool running and being sheared and releasing said valve element for closing movement responsive to predetermined fluid pressure.