Abstract: A fluidic oscillator is disclosed for providing oscillating flow to outlet ports (172, 173). The fluid oscillator (100) in one embodiment has no fluid communication between a pair of diverging diffuser legs (163, 164) downstream of the upstream edge (169) of a splitter (165) and no fluid communication between a chamber (162) and either of the diverging diffuser legs downstream of the splitter edge. In other embodiments, a turbulent flows generator is formed by use of bump step (202), pins (220, 230), surface discontinuities (250) or a combination thereof.

Abstract: In accordance with illustrative embodiments of the present invention, a well perforation cleaning tool includes a fluidic oscillator that creates pressure pulsations which induce cyclical stresses in the walls of the perforations and causes damaged skins thereon to disintegrate in order to improve the productivity of the well. The output passages of one embodiment of the fluidic oscillator are connected to respective internal storage cavities and each cavity is communicated with the annulus by a pair of outlet passages. In other embodiments, relatively short length external cavities communicate with the output passages to provide means by which the pressure pulsations are conveyed to the well annulus. Cylindrical filter tubes having a plurality of sets of axially spaced slots are adjustably mounted at the upper and lower ends of the tool may, if desired, be used to provide resistances which substantially confine the pressure pulsations to the immediate vicinity of the tool body.

Abstract: In accordance with an illutrative embodiment of the present invention, a fluidic oscillator includes a transverse vacuum port which extends between the diffuser legs a predetermined distance below the leading edge surface of the splitter. When flow is down one leg, a slight negative pressure condition is created in the port and transmitted thereby to the other leg, which causes switching of the flow to such other leg. The process then repeats in response to negative pressure in the one leg to cause switching of the flow back thereto. Fluid flow thus is switched back and forth between the legs at a resonant frequency, so that continuously fluctuating pressures are applied to the surrounding medium.

Abstract: In accordance with an illustrative embodiment of the present invention, a well perforation cleaning tool includes a fluidic oscillator that creates pressure changes which induce cyclical stresses in the damaged skins of the perforations and causes the skins to disintegrate in order to improve the productivity of the well. Cylindrical filter tubes having a plurality of sets of slots are adjustably mounted at the upper and lower ends of the tool to provide resistances which confine the pressure changes to the immediate vicinity of the perforated interval.