Downhole fluid supercharger

Abstract

An apparatus for directing 'supercharged,' i.e., high velocity streams of drilling fluid upward around a reduced area between the apparatus and the borehole. These high velocity 'supercharged' streams, by virtue of the Bernoulli effect become very low in static fluid pressure. These high velocity, low pressure streams decrease the hydrostatic pressure at the drill bit and accomplish a more efficient drilling by the bit. What is provided is a main tool body positioned along the drill string intermediate a section of drill pipe and the drill bit. The tool further comprises lower an external body portion which is rotated at a rotational velocity three times slower than the rotation of the velocity of the drill string. There is further provided a fluid jetting and diffuser system allowing the fluid or a portion of the fluid to be jetted out of the wall of the sub at a high velocity exterior to the sub in a reduced area between the sub and wall of the borehole whereby hydrostatic pressure is isolated and the pressure is reduced in that area around the drill bit thus reducing the hydrostatic pressure around the bit, for more efficient drilling. Upon further rotation of the external body portion, a porting system interrupts fluid flow to diffuser ports and allows flow back down into the drill bit area for the necessary washing away of the cuttings as the bit drills into the earth. Simultaneously, the reduced annular area is enlarged, allowing unobstructed passage of drill cuttings.