Methods and systems for optical endpoint detection of a sliding sleeve valve

• Main Authors: RICHARD M WILDE, CHRISTOPHER W MAYEU
• Format: Patent
• Language: English
• Published: 26.04.2006
• Subjects: ACTUATING-FLOATS; BLASTING; COCKS; CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES; DEVICES FOR VENTING OR AERATING; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ENGINE PLANTS IN GENERAL; ENGINEERING ELEMENTS AND UNITS; FIXED CONSTRUCTIONS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; STEAM ENGINES; TAPS; THERMAL INSULATION IN GENERAL; VALVES; WEAPONS

Methods and systems for optical endpoint detection of a sliding sleeve valve are disclosed. The system comprises fiber optic cable based sensors (e.g., fiber Bragg gratings or fiber optic coils) positioned in a recess within the valve's housing and affixed proximate to the ends of the cavity in which the sleeve travels. When the sleeve reaches the ends of the cavity, it imparts a stress onto an area of the housing, which preferably constitutes a protrusion within the cavity, which in turn stresses the sensor and changes its reflection profile. This change in reflection profile indicates that the sleeve has traveled to an end point inside the valve, and accordingly that the valve is fully open or fully closed.