Patent ID: 8789580
Filing Date: 2014-07-29
Classification: E21B

Abstract:
1. A casing section for positioning in a wellbore at a location where it is desired to form a diverging lateral borehole, the casing section comprising: a generally cylindrical outer sleeve including a proximal end and a distal end, the outer sleeve defining an outer window extending between the proximal end and the distal end; and a generally cylindrical inner sleeve received within the outer sleeve and defining an inner window, the inner sleeve being moveable between a first position in which the inner window is misaligned with the outer window and the inner sleeve substantially closes the outer window, and a second position in which the inner window is aligned with the outer window, wherein the inner sleeve includes an alignment portion that defines an axially-extending slot having cam surfaces extending in a proximal and radial direction, the alignment portion being engageable to move the inner sleeve with respect to the outer sleeve.