US Patent 10428621 Choke

A choke controlling fluid flow in a well has a conduit with an inlet and an outlet, and a flow restrictor comprising first and second choke members (10,20), one of which (20) rotates relative to the other (10) to choke or promote flow. The first and second choke members (10,20) are axially spaced from one another, and have mating faces that are optionally planar, and are axially stacked in the choke. The choke is operated by a shifting tool (50), which grips the inner surface of the rotating choke member (20), and rotates it relative to the other (10), in order to vary the flow.