Patent ID: 9121247
Filing Date: 2015-09-01
Classification: E21B

Abstract:
1. An apparatus to provide time-delayed injection of pressurized fluid from a well casing into a geological formation comprising: a housing with openings that allows fluid to pass through the openings to the formation; a mandrel, wherein the mandrel is a one piece design that is configured to carry all of the tensile, compressional and torsional loads of said apparatus; a movable piston configured to cover the openings in a closed position; means for moving the piston to an open position leaving the openings uncovered; means for activating a movement of the piston from the closed position; whereby, as the piston moves from the closed position into a high pressure chamber comprising a hydraulic fluid, the piston is restrained in movement by a passage of the hydraulic fluid from the high pressure chamber into a low pressure chamber through a liquid flow restrictor, and the movement of the piston from the closed position to the open position is delayed by a predetermined metering time.