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A drilling fluid pulse generator for use above a drill bit to produce pulsations in drilling fluid flow. An autocycling valve briefly interrupts the flow of fluid to bit jets to reduce the effective hydrostatic pressure at the drilling face and to hydraulic energy in the drill string to thoroughly s

A drilling fluid pulse generator for use above a drill bit to produce pulsations in drilling fluid flow. An autocycling valve briefly interrupts the flow of fluid to bit jets to reduce the effective hydrostatic pressure at the drilling face and to hydraulic energy in the drill string to thoroughly scour the hole face when the briefly closed valve reopens. An alternate configuration provides a bypass route for fluid diverted from the bit, and the bypass includes jet nozzles to add energy to the return fluid stream to further reduce the effective hydrostatic pressure at the drilling face.

대표청구항 ▼

A method for increasing the penetration rate of a drill head on a fluid conducting drill string suspended in a well having a drilling face exposed to an effective hydrostatic pressure comprising hydrostatic pressure produced by a drilling fluid column in the well and pressure resulting from impingem

A method for increasing the penetration rate of a drill head on a fluid conducting drill string suspended in a well having a drilling face exposed to an effective hydrostatic pressure comprising hydrostatic pressure produced by a drilling fluid column in the well and pressure resulting from impingement of a stream of drilling fluid ejected from the drill head against the drilling face, the method comprising the steps of: (a) pumping a drilling fluid stream down the bore of the drill string, through a downhole fluid flow resistance means, and ejecting at least part of said drilling fluid stream, from at least one nozzle in said drill head, against the drilling face; (b) periodically increasing the resistance of said downhole fluid flow resistance means to reduce the velocity of said drilling fluid stream ejected from said nozzle to reduce the effective hydrostatic pressure and to store fluid pressure energy in said drill string; and (c) periodically reducing said resistance of said downhole fluid flow resistance means to increase said velocity of said drilling fluid stream ejected from said nozzle; said increasing and said reducing of said resistance being caused to occur alternately and automatically in response to and during constant flow of said drilling fluid stream at a constant flow rate. A method for increasing the penetration rate of a drill head on a fluid conducting drill string suspended in a well having a drilling face exposed to an effective hydrostatic pressure comprising hydrostatic pressure produced by a drilling fluid column in the well and pressure resulting from impingement of a stream of drilling fluid ejected from the drill head against the drilling face, the method comprising the steps of: (a) pumping a drilling fluid stream down the bore of the drill string and ejecting at least part of said drilling fluid stream, from at least one nozzle in said drill head, against the drilling face; and (b) periodically diverting at least part of said drilling fluid stream to the well, outside the drill string through at least one upwardly directed nozzle in the drill string, to periodically reduce the effective hydrostatic pressure at said drilling face; said periodically diverting being caused to occur continually and automatically in response to and during constant flow of said drilling fluid stream at a constant flow rate.