Adjustable choke device for a production tube

Variable flow, internally adjustable choke (100) configured to be incorporated into a production tubing (200) of a subterranean well (300). The internally adjustable choke (100) includes a cylindrical choke body (102) having a longitudinal centerline (104); a cylindrical flow adjustment sleeve (110) concentrically and interiorly located with respect to the body (102); a plurality of fluid inlets (120) into the body (102) that establish fluid communication from outside the body (102) to an inlet annular reservoir (122) within the body (102); a pair of cylindrical, longitudinally aligned annular rings (130, 132), each ring (130, 132) having a plurality of longitudinally oriented flow ports 140 therethrough; an outlet annular reservoir (160) within the body (102); and a plurality of open ports (170) through the sleeve (110), each at least partially radially aligned with the outlet annular reservoir (160) and open thereto for fluid communication therewith.