Abstract: An apparatus is described for controlling flow of fluid in a subterranean formation based on a selected characteristic of fluid flow, such as viscosity, velocity or density, as that characteristic varies over time. A pathway-dependent resistance assembly, such as a vortex chamber having two inlets and an outlet, provides varying resistance to fluid flow based on the ratio of flow from the inlets, the direction of flow as directed by the inlets, and the characteristic of the fluid. The incoming flow ratio is preferably determined by flowing fluid through a plurality of passageways having differing flow rate responses to fluid having differing characteristics. Fluid of a selected characteristic will encounter lesser resistance to flow across the system, while fluid of an un-favored characteristic will encounter greater resistance to flow. Thus, flow of well fluids can be autonomously restricted as the fluid characteristics change over time.

Abstract: Apparatus and methods for controlling the flow of fluid, such as formation fluid, through an oilfield tubular positioned in a wellbore extending through a subterranean formation. Fluid flow is autonomously controlled in response to change in a fluid flow characteristic, such as density or viscosity. In one embodiment, a fluid diverter is movable between an open and closed position in response to fluid density change and operable to restrict fluid flow through a valve assembly inlet. The diverter can be pivotable, rotatable or otherwise movable in response to the fluid density change. In one embodiment, the diverter is operable to control a fluid flow ratio through two valve inlets. The fluid flow ratio is used to operate a valve member to restrict fluid flow through the valve.

Abstract: Apparatus and methods for controlling the flow of fluid, such as formation fluid, through an oilfield tubular positioned in a wellbore extending through a subterranean formation. Fluid flow is autonomously controlled in response to change in a fluid flow characteristic, such as density or viscosity. In one embodiment, a fluid diverter is movable between an open and closed position in response to fluid density change and operable to restrict fluid flow through a valve assembly inlet. The diverter can be pivotable, rotatable or otherwise movable in response to the fluid density change. In one embodiment, the diverter is operable to control a fluid flow ratio through two valve inlets. The fluid flow ratio is used to operate a valve member to restrict fluid flow through the valve.

Abstract: An apparatus is described for controlling flow of fluid in a tubular positioned in a wellbore extending through a subterranean formation. A flow control system is placed in fluid communication with a main tubular. The flow control system has a flow ratio control system and a pathway dependent resistance system. The flow ratio control system has a first and second passageway, the production fluid flowing into the passageways with the ratio of fluid flow through the passageways related to the characteristic of the fluid flow. The pathway dependent resistance system includes a vortex chamber with a first and second inlet and an outlet, the first inlet of the pathway dependent resistance system in fluid communication with the first passageway of the fluid ratio control system and the second inlet in fluid communication with the second passageway of the fluid ratio control system.