SLIDABLE ACCESS CONTROL DEVICE FOR SUBTERRANEAN LATERAL WELL DRILLING AND COMPLETION

摘要

The present invention provides a subterranean structure for controlling tool access to a lateral wellbore extending from a wellbore. The subterranean structure compr ises a bushing that is located in the wellbore and proximate an opening to the lateral well bore and that has an access window therethrough for allowing access by a tool to the lateral well through the opening. The bushing further has a slidable access control device coaxially coupled thereto. Also included is a shifter that is engagable with the slidable access contro l device to cause the slidable access control device to slide between an open position wherein a t ool is allowed to pass through the window and the opening and into the lateral wellbore and a closed position wherein the tool is prevented from passing through the window and the openin g and into the lateral wellbore. The present invention also provides a method of controllin g tool access to a lateral wellbore extending from a wellbore. The preferred method comprises t he steps of: 1)locating a bushing in the wellbore proximate an opening to the lateral wel lbore, the bushing having an access window therethrough for allowing access by a tool to the la teral wellbore through the opening, the bushing further having a slidable access control de vice coaxially coupled thereto; 2)engaging theslidable access control device with a shifter to slide the slidable access control device with respect to the bushing; and 3) sliding t he slidable access control device between an open position wherein a tool is allowed to pass th rough the window and the opening and into the lateral wellbore and a closed position wherein the tool is prevented from passing through the window and the opening and into the later al wellbore.