Hydraulic impulse generator and frequency sweep mechanism for borehole applications

Apparatus for at least partially interrupting flow of a pressurized fluid that is circulating though a conduit, comprising:

• (a) a housing;
• and
• (b) a valve substantially enclosed by said housing, said valve comprising;
• (i) an inlet port configured to couple in fluid communication with the conduit through which the pressurized fluid is circulating;
• (ii) an outlet port configured to couple in fluid communication with the conduit through which the pressurized fluid is circulating;
• (iii) a plurality of fluid passages configured to selectively couple in fluid communication with said inlet port;
• (iv) a first member that is actuated by the pressurized fluid to cycle between an open position and a closed position, such that when in said closed position, said first member at least partially interrupts a flow of the pressurized fluid through the outlet port;
• and
• (v) a second member disposed within said first member, the second member being reciprocated back and forth between first and second positions during each cycle by the pressurized fluid, a position of said second member determining which of said plurality of fluid passages is coupled in fluid communication with said inlet port.

A method for generating pressure pulses within a conduit by at least partially interrupting flow of a pressurized fluid circulating through the conduit, comprising the steps of:

• (a) introducing a pressure activated flow interruption valve into the conduit, the valve being configured to periodically at least partially interrupt a flow of the pressurized fluid in the conduit;
• (b) circulating the pressurized fluid through the conduit;
• and
• (c) directing the pressurized fluid through the valve to cyclically actuate the valve, actuation of the valve being implemented by:
• (i) using the pressurized fluid to cause a first valve member to cycle between an open position and a closed position, such that when in the closed position, the first valve member at least partially interrupts a flow of the pressurized fluid through the valve, thereby at least partially interrupting a flow of the pressurized fluid in the conduit;
• and
• (ii) using the pressurized fluid to cause a second valve member disposed within the first valve member to reciprocate between a first position and a second position, a position of the second valve member controlling the cycling of the first valve member by the pressurized fluid.

A method for generating pressure pulses within a conduit by at least partially interrupting flow of a pressurized fluid circulating through the conduit, comprising the steps of:

• (a) introducing a pressure activated flow interruption valve into the conduit, the valve being configured to periodically interrupt a flow of the pressurized fluid in the conduit, a flow of the pressurized fluid through the valve causing the valve to cycle between an open position and a closed position, such that when in the closed position, the valve at least partially interrupts a flow of the pressurized fluid through the conduit;
• (b) circulating the pressurized fluid through the conduit;
• and
• (c) directing the pressurized fluid through the valve to cyclically actuate the valve, such that:
• (i) a first valve member is actuated by the pressurized fluid to cycle between a first position and a second position, such that when in the second position, the first valve member at least partially interrupts a flow of the pressurized fluid through the valve, causing the valve to be in the closed position;
• and
• (ii) a second valve member disposed within the first valve member is reciprocated back and forth between another first position and another second position during each cycle by the pressurized fluid, the second valve member controlling actuation of the first valve member by the pressurized fluid.

A method for generating pressure pulses within a conduit by at least partially interrupting flow of a pressurized fluid circulating through the conduit, comprising the steps of:

• (a) coupling a pressure activated flow interruption valve to the conduit, the valve being configured to periodically interrupt a flow of the pressurized fluid in the conduit, a flow of the pressurized fluid through the valve causing the valve to cycle between an open position and a closed position, the pressure activated flow interruption valve comprising:
• (i) a poppet that is actuated by the pressurized fluid to cycle between an open position and a closed position, such that when in the closed position, the poppet at least partially interrupts a flow of the pressurized fluid through the valve;
• and
• (ii) a pilot disposed within the poppet, the pilot being reciprocated back and forth between first and second positions during each cycle by the pressurized fluid, such that a position of the pilot controls the pressurized fluid that actuates the poppet;
• (b) circulating the pressurized fluid through the conduit;
• and
• (c) directing the pressurized fluid through the valve to cyclically actuate the valve, thereby periodically interrupting a flow of the pressurized fluid in the conduit as the valve cycles between the open position and the closed position.