Patent ID: 8256514
Filing Date: 2012-09-04
Classification: E21B

Abstract:
1. An apparatus for holding and launching down-hole actuation devices into a well, comprising: (a) a body with a bottom end, a top end and a long bore that extends from the bottom end to the top end, the bottom end formed for connection above a well head to place the long bore in fluid communication with the well head; (b) a first retainer and a second retainer each of the first and the second retainer being extendable into a blocking position in the long bore, and retractable from the blocking position in the long bore, the first and second retainers being spaced apart along the long bore defining there between a first down-hole actuation device retaining space and a second down-hole actuation device retaining space between the second retainer and the top end, the first retainer being moveable into and out of its blocking position independently of the second retainer to hold or allow release of a down-hole actuation device from the long bore; (c) a removable cap on the top end engageable in a sealing position to fluidly seal the long bore from the apparatus outer surface but permitting access to the long bore from the outer surface when removed and a fluid inlet opening to the long bore adjacent the top end to provide an access for a flow of the fluid to the long bore when the cap is in the sealing position; and, (d) a hydraulic drive mechanism for driving extension of the first retainer into the long bore to a blocking position and for driving retraction of the first retainer out of the long bore to a release position, the hydraulic drive mechanism including (i) a cylinder for driving the first retainer, the cylinder including a hydraulic fluid inlet for communicating hydraulic fluid to a retraction drive side of the cylinder and a hydraulic fluid outlet for allowing evacuation of fluid from the cylinder during retraction, (ii) a valve on the hydraulic fluid outlet and (iii) a lock that permits retraction of the first retainer only when communication of a hydraulic drive pressure to the hydraulic drive mechanism is sensed, the lock including a sensor to monitor hydraulic pressure in the hydraulic fluid inlet and a communicator between the sensor and the valve that opens the valve when the sensor senses a hydraulic drive pressure in the hydraulic fluid inlet.