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 includes a semi-doughnut-shaped wall contour element formed along one side. |