Method and system for determining and controlling position of a valve

摘要

Apparatuses and methods for accurately determining the position of a sliding or rotational sleeve valve in real time are disclosed. The apparatus comprises fiber optic cable based sensors which are either linearly or circumferentially arrayed in the housing (2) that surrounds the sleeve (1) and which can comprise bare cable or cable having fiber Bragg gratings (FBGs). As the sleeve slides or rotates within the housing, the sensors in the arrays are deformed, and this deformation can be correlated to sleeve position by assessing the sensor's reflectivity profiles. Deformation of the sensors is achieved by various mechanical and/or magnetic schemes incorporated into the sleeve.