Apparatus for generating vibrational energy in a borehole
AssigneeOil & Gas Consultants International, Inc.
InventorJames F. Brett
Life of this patent
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Abstract
An apparatus for generating vibrational energy in a borehole including an elongated mass having a surface of diameter less than the borehole, a rotary source for suspending the cylindrical mass in a borehole and a system to cause frictional contact between the surface of the mass and the borehole wall, the cylindrical mass being rotatable about its rotational axis in one direction to cause the mass to backward whirl in the opposite direction within the borehole, the cylindrical force of the whirling mass serving to generate vibrational energy in the borehole.
Claims39
For use in a borehole having a generally cylindrical wall, an apparatus for generating vibrational energy comprising:
- a mass having a surface of dimension less than the borehole and having a rotational axis;
- means to position said mass in a borehole;
- means to rotate said mass about its rotational axis within the borehole in a selected direction of rotation;
- and
- means to cause said surface of said mass to establish frictional contact with the borehole wall to thereby cause said mass to backward whirl in the direction opposite to said direction of rotation of said mass, centrifugal force of the whirling mass serving to generate vibrational energy in the borehole.
For use in a borehole having a generally cylindrical wall, an apparatus for generating vibrational energy comprising:
- a rotary source positionable within a borehole and having a bottom end having a rotatable shaft extending therefrom;
- means to removably suspend said rotary source to a selected position in a borehole;
- means to retractably and non-rotatably secure said rotary source at said selected position in a borehole;
- a mass having an axis of rotation and having a surface of dimensions less than the borehole and having a rotational axis;
- and
- flexible coupling means connecting said mass to said rotary source shaft whereby said mass may be rotated about said axis of rotation by the rotary source in a selected direction of rotation to cause said mass surface to establish frictional contact with the borehole to thereby cause said mass to backward whirl in the direction opposite to said direction of rotation, centrifugal force of the backward whirling mass serving to generate vibrational energy in the borehole.
For use in a borehole having a generally cylindrical wall, an apparatus for generating vibrational energy, comprising:
- a housing of external diameter less than that of the borehole, the housing having a portion thereof providing an internal cylindrical surface;
- means to removably suspend said housing to a selected position in the borehole;
- means to retractably and non-rotatably secure said housing at said selected position in a borehole;
- a rotary source positioned with and supported to said housing and having a retractable shaft extending therefrom;
- a mass having an external surface of dimension less than said internal cylindrical surface of said housing and having an axis of rotation;
- flexible coupling means connected between said rotary source shaft and said mass whereby said mass may be rotated about its axis of rotation in a selected direction of rotation to cause said mass surface to establish contact with said housing internal cylindrical surface to cause said mass to backward whirl in the direction opposite to said direction of rotation, centrifugal force of the backward whirling mass serving to generate vibrational energy in said housing, which vibrational energy is transferred to the borehole.
A system for generating vibrational energy in a drill string in which the drill string has a cylindrical interior surface extending downwardly to a drill bit at the lower end thereof, the drill string and bit being positioned in a borehole, comprising:
- a rotary source positionable within the cylindrical interior of a drill string and having a bottom end having a rotatable shaft extending therefrom;
- a mass having an axis of rotation and having a surface of dimension less than the borehole and having a rotational axis;
- flexible coupling means connecting said mass to said rotary source shaft whereby said mass may be rotated about said axis or rotation in a selected direction of rotation to cause said mass surface to establish frictional engagement with the drill string cylindrical interior surface to thereby cause said mass to backward whirl in the direction opposite to said direction of rotation, centrifugal force of the backward whirling mass serving to generate vibrational energy in the drill string.
A method of obtaining information indicative of the earth's structure adjacent a borehole that extends from the earth's surface, the borehole having a generally cylindrical wall, comprising:
- positioning a mass having a rotational axis in a borehole, the mass having an external surface of dimension less than the borehole;
- rotating the mass about its rotational axis in a selected direction in the borehole and causing the surface of the mass to contact the borehole wall to thereby cause the mass to backward whirl in the borehole in the direction opposite to said direction of rotation of the mass, centrifugal force of the backward whirling mass serving to generate vibrational energy that is radiated in the earth as a seismic signal;
- positioning at least one geophone in contact with the earth at a location remote from said rotating mass for receiving a seismic signal resulting from vibrational energy generated by the backward whirling mass;
- collecting data generated by said at least one geophone;
- and
- processing the collected data to provide information indicative of the earth's structure adjacent the borehole.
Dependencies are inferred from the claim text.