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. A fluid is flowed through an inlet passageway into a biasing mechanism. A fluid flow distribution is established across the biasing mechanism. 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 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 can take various forms such as a widening passageway, contour elements along the biasing mechanism, or a curved section of the biasing mechanism passageway. The biasing mechanism can include hollows formed in the passageway wall, obstructions extending from the passageway wall, fluid diodes, Tesla fluid diodes, a chicane, or abrupt changes in passageway cross-section.

主权项

1. A method for autonomously controlling flow of a fluid in a wellbore extending through a subterranean formation, the fluid having a characteristic which autonomously changes over time, the fluid flowing through an inlet passageway, a flow biasing mechanism defining a widening passageway narrower at the upstream end and wider at the downstream end, wherein the downstream end of the biasing mechanism defines two sides which connect to corresponding first and second sides of a fluidic switch assembly, corresponding first and second departure angles defined at the connections, and, wherein the first departure angle is shallower than the second departure angle, and a variable flow resistance assembly, the method comprising the following steps:
communicating the fluid between the wellbore and the subterranean formation by flowing the fluid out of the subterranean formation and into the wellbore, or out of the wellbore and into the subterranean formation; flowing the fluid through the inlet passageway; resisting flow of the fluid with at least first and second walls of the flow biasing mechanism having dissimilar predefined shapes such that resistance to the dissimilar predefined shapes of the first and second walls establishes a first fluid flow distribution across an outlet of the flow biasing mechanism; then autonomously altering the first fluid flow distribution to a second flow distribution across the outlet of the flow biasing mechanism in response to an autonomous change in the fluid characteristic and in response to an associated change in the resistance to the dissimilar predefined shapes of the first and second walls of the flow biasing mechanism; and changing the fluid flow resistance of the variable flow resistance assembly in response to the altering of the distribution of flow from the outlet of the flow biasing mechanism.