Self calibrating toe valve

Abstract

A toe valve () comprising; a housing () having an interior and exterior; a sliding sleeve (); a counter mechanism () comprising a cylinder, a ratchet piston () with first and second ends, and a ratchet shaft () connected to the second end; a trigger assembly () comprising a trigger housing, and a release piston (), wherein the trigger assembly () is arranged between the counter mechanism () and the sliding sleeve (), and wherein the release piston () is configured to activate the sliding sleeve (), and the ratchet shaft () is configured to activate the release piston (), wherein the toe valve () further comprises; a closed chamber () enclosing the ratchet shaft () and defined at least partly by the cylinder comprising a chamber fluid with a chamber pressure (P); an inlet pressure port () configured to be in communication with a wellbore fluid with a wellbore pressure (P), and wherein the first end of the ratchet piston () is in fluid communication with the inlet pressure port (), wherein the ratchet piston () is configured to move towards the trigger assembly () to a new position and compress the chamber fluid when the wellbore pressure (P) is larger than the chamber pressure (P); a retaining mechanism () configured to retain the ratchet shaft () in the new position; and a valve mechanism interconnecting the first and second ends of the ratchet piston () and configured for equalizing the pressure across the ratchet piston ().