METHOD AND APPARATUS FOR CONTROLLING FLUID FLOW IN AN AUTONOMOUS VALVE USING A STICKY SWITCH

摘要

APPARATUS AND METHODS ARE DESCRIBED FOR AUTONOMOUSLY CONTROLLING FLUID FLOW IN A TUBULAR IN A WELLBORE (12). A FLUID IS FLOWED THROUGH AN INLET PASSAGEWAY INTO A BIASING MECHANISM (140). A FLUID FLOW DISTRIBUTION IS ESTABLISHED ACROSS THE BIASING MECHANISM (140). THE FLUID FLOW DISTRIBUTION IS ALTERED IN RESPONSE TO A CHANGE IN THE FLUID CHARACTERISTIC OVER TIME. IN RESPONSE, FLUID FLOW THROUGH A DOWNSTREAM STICKY SWITCH (160) ASSEMBLY IS ALTERED, THEREBY ALTERING FLUID FLOW PATTERNS IN A DOWNSTREAM VORTEX ASSEMBLY. THE METHOD “SELECTS” BASED ON A FLUID CHARACTERISTIC, SUCH AS VISCOSITY, DENSITY, VELOCITY, FLOW RATE, ETC. THE BIASING MECHANISM (140) CAN TAKE VARIOUS FORMS SUCH AS A WIDENING PASSAGEWAY (142), CONTOUR ELEMENTS (200) ALONG THE BIASING MECHANISM (140), OR A CURVED SECTION (222) OF THE BIASING MECHANISM (140) PASSAGEWAY. THE BIASING MECHANISM (140) CAN INCLUDE HOLLOWS FORMED IN THE PASSAGEWAY WALL, OBSTRUCTIONS EXTENDING FROM THE PASSAGEWAY WALL, FLUID DIODES, TESLA FLUID DIODES, A CHICANE (214), OR ABRUPT CHANGES IN PASSAGEWAY CROSS-SECTION.