Sonic method and apparatus for augmenting fluid flow from fluid- bearing strata employing sonic fracturing of such strata

摘要

A device for fracturing earthen material includes an elongated stem member having a wedging tool attached to the distal end thereof and a sonic oscillator coupled to the top end thereof. The wedging tool has rib means formed on the outer portions thereof, these rib means in one embodiment being spaced around the circumference of the tool at approximately 90° intervals. The stem is lowered into a well to be serviced to stimulate the flow of fluid (generally oil) therefrom. With the tool ribs wedged against the sides of the well, sonic energy is coupled from the sonic oscillator into the stem. This energy may be at a frequency such as to cause resonant elastic vibration of the stem. The tool is fabricated of a hard elastic material, such as steel. The sonic energy is coupled from the wedging ribs of the tool to the earthen formation surrounding the well in a non-isotropic manner, i.e., along particular lines. The sonic energy tends to fracture the earthen formation with the tool being driven down the well by virtue of the bias force applied thereto by virtue of its own weight, the weight of the stem and that of the oscillator structure. As the tool is thus driven down the well, the leading edges of the ribs provide a wedging action which gives good acoustic coupling and engenders a splitting action of the earthen formation to loosen the fluid material contained therein.