Down-Hole Vibrational Oscillator

Abstract

The invention discloses a set of valves that impart hydraulic pressure pulses at specific frequencies that provide oscillatory movement of a shuttle valve within a of a downhole tool operations. These vibrations can lead to pulses for vertical seismic profiling of formations drilled, to check the location of the bit, or to detect the presence of abnormal pore pressure ahead of the bit. The pressure pulses can also be used to enhance drilling and production of wells.

We claim: 
     
         1 . A vibrational oscillator comprising; a shuttle valve assembly disposed along a length of a and within a casing wherein said shuttle valve assembly comprises at least a plunger, a receiving assembly, a cavity, and a valve, within said shuttle valve assembly within which fluid can flow into and out of said shuttle valve assembly and a conduit with an inlet port and an outlet port through which fluid can flow into an upstream section of said oscillator toward and out of a downstream section of said oscillator with at least one fluid passage configured to selectively couple in fluid communication with said inlet port and said outlet port through which fluid passes;
 such that said plunger is capable of receiving fluid and fits into said receiving assembly and said shuttle valve assembly is sealed so as to always allow at least some volume of said fluid to enter or escape said cavity;   and said oscillator includes said plunger that can be at least partially positioned within said receiving assembly to at least partially interrupt fluid flow through said conduit which is in contact with and allows for movement of a fully assembled oscillator component of said oscillator and provides compressive forces that compress at least one spring or set of springs from said receiving assembly and eventually releases said compressive forces when said plunger is removed from said receiving assembly thereby providing for expansion of said springs so that oscillations within said springs located along and/or within said casing are created.   
     
     
         2 . The vibrational oscillator according to  claim 1 , wherein said plunger disposed within said shuttle valve assembly is actuated by pressurized fluid so that said valve can cycle between an opened position and a closed position, such that when in said closed position, said plunger at least partially interrupts a flow of said pressurized fluid through said outlet port; and wherein said plunger reciprocates back and forth between at least a first and a second position during cycling of pressurized fluid into and through said oscillator such that position of said plunger controls fluid into and out of said inlet port of said valve thereby causing a variable force to act on said one or more set of springs resulting in oscillations of said springs. 
     
     
         3 . The vibrational oscillator according to  claim 1 , wherein said oscillations of said springs are along a longitudinal direction and become self-oscillating after an initial oscillation is initiated due to operation of said shuttle valve assembly. 
     
     
         4 . The vibrational oscillator according to  claim 1 , wherein said casing is a cartridge assembly that houses said oscillator. 
     
     
         5 . The vibrational oscillator according to  claim 1 , wherein said oscillator is an agitator in that said oscillator causes vibrations that vibrate within said oscillator causing agitation along at least a portion of a drill string and thereby overcomes static friction downhole. 
     
     
         6 . The vibrational oscillator according to  claim 1 , wherein said valve is a leaky shuttle valve in that said plunger disposed within said cavity of said cartridge includes said leaky shuttle valve that does not fully open or fully close during operation . 
     
     
         7 . The valve of  claim 1 , wherein a plurality of fluid passages include at least one fluid passage configured to divert a flow of pressurized fluid upstream of said outlet port when said plunger is in a closed position, thereby substantially reducing a water hammer effect. 
     
     
         8 . The valve of  claim 1 , wherein said plurality of fluid passages include at least one fluid passage configured to divert a flow of pressurized fluid downstream of said outlet port when said plunger is in an open position, thereby at least partially reducing a water hammer effect. 
     
     
         9 . The valve of  claim 1 , wherein said plunger is coaxially disposed within said oscillator. 
     
     
         10 . The valve of  claim 1 , wherein at least one fluid passage includes:
 (a) a fluid passage through which pressurized fluid is applied to said plunger to cause said plunger to cycle toward a closed position, thereby partially closing said outlet port, when said plunger is in a first position;   (b) the same or a different fluid passage through which pressurized fluid is applied to said plunger to cause said plunger to shift to said second position and;   (c) a same or different fluid passage through which said pressurized fluid is applied to said plunger to allow said plunger to cycle back toward an initial position thereby defining a cycle time of said valve.   
     
     
         11 . The valve of  claim 10 , wherein said cycle time of said valve is a function of a size of said at least one fluid passage. 
     
     
         12 . The valve of  claim 1 , wherein said plunger is configured to move with said receiving assembly when said plunger is in a first position, such that when said plunger moves from an open position to a closed position, a momentum imparted to said plunger facilitates compression of at least a pilot of said shuttle valve shifting toward either said open or said closed position. 
     
     
         13 . The valve of  claim 1 , further comprising a housing in which said valve is disposed. 
     
     
         14 . The valve of  claim 13 , wherein said housing is adapted to be incorporated in a drillstring. 
     
     
         15 . The valve of  claim 14 , wherein said housing is configured to isolate a section of said casing such that an at least partial interruption of pressurized fluid in said casing by said valve generates a negative pressure pulse in said section of casing wherein said negative pulse is isolated. 
     
     
         16 . The valve of  claim 15 , wherein said cycle time required for said plunger to cycle between said open position and said closed position is less than or equal to a two-way travel time of an acoustic pressure wave in a length of said casing. 
     
     
         17 . The valve of  claim 1 , further comprising an on/off mechanism having an on position and an off position, such that when said on/off mechanism is in an off position, said plunger is held in said open position, preventing said valve or said vibrational oscillator from cycling. 
     
     
         18 . The valve of  claim 17 , wherein said on/off mechanism is sensitive to a pressure in said casing, such that said on/off mechanism changes from an off position to an on position after said pressure within said casing reaches a preset level. 
     
     
         19 . The valve of  claim 1 , wherein an at least partial interruption of flow of pressurized fluid by actuation of said valve generates a pressure pulse that propagates away from said valve. 
     
     
         20 . The valve of  claim 1 , further comprising a frequency modulator configured to repeatedly vary a cycle rate of said valve. 
     
     
         21 . The valve of  claim 20 , wherein said frequency modulator comprises a variable volume in fluid communication with a timing shaft, said timing shaft being coupled with said plunger, such that a change in said variable volume produces a corresponding change in a motion of said plunger, thereby changing said cycle rate of said valve. 
     
     
         22 . The valve of  claim 1 , wherein said plunger is a ball, a poppet, or other geometrically symmetrical device that at least partially seals said shuttle valve so that fluid can enter and exit said cavity within said valve. 
     
     
         23 . The oscillating vibrator of  claim 1 , wherein energy from said vibrator is coupled to one or more devices, wherein said devices provide, electrical, mechanical, pneumatic, and/or hydraulic power. 
     
     
         24 . A method for using an oscillating vibrator device comprising;
 (i) allowing fluid to enter an upstream section of at least one fluid cavity within said device through an upstream mechanical stop and flow diverter section attached to an outer casing with an upstream shuttle valve spacer used to provide spacing between an upper section of a shuttle valve and an upstream mechanical stop assembly, wherein said shuttle valve includes a plunger positioned to be activated by forces exerted from an entrance of fluid into said vibrator,   wherein   (ii) said fluid forces said shuttle valve to move in a downstream direction until said shuttle valve plunger engages with a shuttle valve receiving assembly causing an upstream spring located above said shuttle valve assembly to lengthen;   and wherein   (iii) using a downstream spacer for said shuttle valve assembly for spacing at a bottom of said upstream spring is provided so that pressure is building within said shuttle valve receiving assembly, causing downstream directional motion of said shuttle valve receiving assembly and a fully assembled oscillator component portion of said vibrator during compression of a first downhole oscillator spring that allows said shuttle valve plunger to disengage from said shuttle valve receiving assembly, causing said upstream spring for said shuttle valve assembly to return elastically to its initial or starting position;   and wherein;   (iv) a downstream surface of said shuttle valve receiving assembly is connected to at least one downhole spring receiving shaft which runs axially and is aligned with downstream components housing at least said first downhole oscillator spring positioned on either side of a casing mechanical stop and attached to at least a portion of a fully assembled oscillator component portion such that said downhole spring receiving shaft is allowing for movement in a linear fashion based on loading of said at least one downhole oscillator spring and positioning of said shuttle valve plunger in a partially and/or fully engaged or disengaged position with said shuttle valve receiving assembly causing oscillations of said at least one downhole oscillator spring and along a length of said oscillator thereby allowing for agitation due to vibration along a drillstring.   
     
     
         25 . The method of  claim 24 , wherein said oscillations are required to overcome static downhole forces and variability of a loading force on said at least one downhole oscillator spring controls a magnitude of said oscillations and frequency of said vibration allowing for tailoring of said vibration and subsequent seismic pulses utilized downhole. 
     
     
         26 . The method of  claim 24 , wherein said plunger disposed within said shuttle valve assembly is actuated by pressurized fluid so that said valve can cycle between an opened position and a closed position, such that when in said closed position, said plunger at least partially interrupts a flow of said pressurized fluid through said outlet port; and wherein said plunger reciprocates back and forth between at least a first and a second position during cycling of pressurized fluid into and through said oscillator such that position of said plunger controls fluid into and out of said inlet port of said valve thereby causing force to act on one or more set of springs resulting in oscillations of said set of springs. 
     
     
         27 . The method of  claim 24 , wherein said vibrational oscillator is providing oscillations of said springs along a longitudinal direction and become self-oscillating after an initial oscillation is started due to operation of said shuttle valve assembly. 
     
     
         28 . The method of  claim 24 , wherein said casing is a cartridge assembly that houses said oscillator. 
     
     
         29 . The method of  claim 24 , wherein said oscillator is an agitator in that said oscillator causes vibrations within said oscillator causing agitation along at least a portion of a drill string and thereby overcomes static friction downhole. 
     
     
         30 . The method of  claim 24 , wherein said shuttle valve is a leaky shuttle valve in that said plunger disposed within said cavity of said cartridge housing said valve does not fully open or fully close during operation . 
     
     
         31 . The method of  claim 24 , wherein at least one fluid passage is configured to divert a flow of pressurized fluid upstream of said outlet port when said plunger is in a closed position, thereby substantially reducing a water hammer effect. 
     
     
         32 . The method of  claim 24 , wherein said at least one fluid passage is configured to divert a flow of pressurized fluid downstream of said outlet port when said plunger is in a open position, thereby at least partially reducing a water hammer effect. 
     
     
         33 . The method of  claim 24 , wherein said plunger is coaxially disposed within said oscillator. 
     
     
         34 . The method of  claim 24 , wherein at least one fluid passage includes:
 (a) a fluid passage through which pressurized fluid is applied to said plunger to cause said plunger to cycle toward a closed position, thereby partially closing said outlet port, when said plunger is in a first position;   (b) the same or a different fluid passage through which pressurized fluid is applied to said plunger to cause said plunger to shift to said second position and;   (c) a same or different fluid passage through which said pressurized fluid is applied to said plunger to allow said plunger to cycle back toward an initial position.   
     
     
         35 . The method of  claim 24 , wherein a cycle time of said valve is a function of a size of said at least one fluid passage. 
     
     
         36 . The method of  claim 24 , wherein said plunger is configured to move with said receiving assembly when said plunger is in a first position, such that when said plunger moves from said open position to said closed position, a momentum imparted to said plunger facilitates compression of said plunger shifting to a second position. 
     
     
         37 . The method of  claim 24 , further comprising a housing in which said valve is disposed. 
     
     
         38 . The method of  claim 37 , wherein said housing is adapted to be incorporated in a drillstring. 
     
     
         39 . The method of  claim 36 , wherein said housing is configured to isolate a section of conduit, such that an at least partial interruption of pressurized fluid in a conduit adjacent to said valve generates a negative pressure pulse in an isolated section of said conduit. 
     
     
         40 . The method of  claim 24 , wherein a cycle time required for said plunger to cycle between an opened position and a closed position is less than or equal to a two-way travel time of an acoustic pressure wave in a length of a section of said casing. 
     
     
         41 . The method of  claim 24 , further comprising an on/off mechanism having an on position and an off position, such that when said on/off mechanism is in said off position, said plunger is held in said open position, preventing said fully assembled oscillator component portion from cycling. 
     
     
         42 . The method of  claim 41 , wherein said on/off mechanism is sensitive to a pressure in said conduit, such that said on/off mechanism changes from said off position to said on position after pressure within said conduit reaches a predetermined level. 
     
     
         43 . The method of  claim 24 , wherein at least partial interruption of flow of pressurized fluid by actuation of said valve generates a pressure pulse that propagates away from said valve. 
     
     
         44 . The method of  claim 24 , further comprising a frequency modulator configured to repeatedly vary a cycle rate of said oscillating vibrator. 
     
     
         45 . The method of  claim 44 , wherein said frequency modulator comprises a variable volume in fluid communication with a timing shaft, said timing shaft being coupled with said plunger, such that a change in said variable volume produces a corresponding change in a motion of said plunger, thereby changing said cycle rate of said valve and/or said vibrator. 
     
     
         46 . A method for generating pressure pulses within a conduit using a vibrational oscillator comprising at least partially interrupting flow of a pressurized fluid flowing through a casing of said oscillator comprising the steps of:
 (i) introducing a pressure activated flow interruption shuttle valve into said casing said valve being configured to periodically at least partially interrupt a flow of pressurized fluid within said casing;   (ii) allowing flow of said pressurized fluid through said casing; and   (c) directing said pressurized fluid through said valve to actuate said valve, actuation of said valve being implemented by:   (iii) using said pressurized fluid to cause at least a first spring section to compress such that when said valve is in a closed position said at least said first spring section fully compresses thereby also at least partially interrupting a flow of the pressurized fluid in said casing ; and   (iv) using energy stored in said at least first spring when released, is causing oscillatory cycling of pulses within said pressurized fluid.   
     
     
         47 . The method of  claim 46 , further comprising the step of redirecting at least a portion of flow of said pressurized fluid within said conduit such that a step of directing said pressurized fluid through said valve to actuate said valve to at least partially interrupt flow of said pressurized fluid in said casing does not completely interrupt a circulation of said pressurized fluid in said conduit, thereby at least partially reducing a water hammer effect. 
     
     
         48 . The method of  claim 46 , wherein a step of redirecting at least a portion of flow of said pressurized fluid within said casing comprises the step of redirecting at least a portion of the flow of said pressurized fluid upstream of a section of said casing such that said valve at least partially interrupts flow of said pressurized fluid in said conduit. 
     
     
         49 . The method of  claim 46 , wherein energy from said vibrator is coupled to one or more devices, wherein said devices provide, electrical, mechanical, pneumatic, and/or hydraulic power.