MULTI-POSITION SLIDING SLEEVE VALVE

摘要

A downhole choke in the form of a sliding sleeve valve operable in a plurality of positions including fully open, fully closed, and positions in between, is disclosed. It features a hydraulic control system that, in one embodiment, provides the motive force to move the sliding sleeve (34) a predetermined amount for a given applied control pressure. Further increments in applied pressure result in further predetermined movements of the sliding sleeve. In another embodiment, the sliding sleeve (34) lands in a series of grooves (86-98) in the surrounding housing depending on the degree of pressure applied to the control system.