Abstract: A system includes a discharge tool positioned within a wellbore and configured to generate an electrical discharge that interacts with a rock formation proximate to the discharge tool, wherein the interaction of the electrical discharge with the rock formation vaporizes a portion of the rock formation to generate a discharge plasma. The system further includes an optical emission spectroscopy (OES) sub-system configured to determine an elemental composition of the portion of the rock formation based on optical emission generated by the discharge plasma, wherein at least a portion of the OES sub-system is positioned within the wellbore.

Abstract: A vibratory casing recovery bottom hole assembly and a method of recovering casing in a wellbore. The vibratory casing recovery bottom hole assembly includes a casing spear, a flow modifier and a dynamic amplification tool. The flow modifier produces cyclic variations in fluid pressure through the assembly at a first frequency and the bottom hole assembly is configured to have a natural or resonant frequency when vibrated to be near or at the first frequency. The dynamic amplification tool induces vibration in the bottom hole assembly while ensuring the dynamic amplification factor of the system is greater than one so as to transmit maximum vibration to the casing at the casing spear. Embodiments of dynamic amplification tools are described.

Abstract: Method for the prevention and/or removal of biofilm and sediment formation in borehole tubes or distribution tubes, with the following steps: (i) mounting one or more ultrasonic transducers (9, 9?) on an aboveground part of the tube; (ii) sending the ultrasonic waves whereby both the power and the frequency of the ultrasonic waves are varied in time, with a frequency between 20 and 60 kHz and a power between 1 and 6 Watt for smaller tubes and between 6 and 40 Watt for larger tubes; (iii) sending the varying ultrasonic waves through the water that flows or is pumped through the tube; (iv) providing an automatic interruption of the effect of the ultrasonic waves when the flow of the water through the tube stops, either by shutting off the transducers, or by the automatic operation of a non-return valve which interrupts the water column between the transducer and the underlying mass of water.

Abstract: A method of deliquification of production wells includes placing an artificial lift tool in a gas wellbore, where the artificial lift tool includes a rack and multiple piezoelectric transducers. The rack includes multiple trays. Each piezoelectric transducer of the multiple piezoelectric transducers is positioned on a respective tray of the multiple trays. The method further includes providing, by a pump, a liquid on surfaces of the multiple piezoelectric transducers and providing, by a signal source, an electrical signal to the multiple piezoelectric transducers. The method also includes generating, by the multiple piezoelectric transducers, acoustic waves from the electrical signal, where at least some of the liquid provided to the multiple piezoelectric transducers is atomized by the acoustic waves.

Abstract: A downhole acoustic stimulation tool comprises: a sealed chamber containing a liquid; a pair of electrodes located in the chamber; at least one transducer arranged to generate an acoustic field between the electrodes thereby inducing cavitation in a volume of the liquid between the electrodes; and at least one capacitor configured to apply a pulse voltage across the electrodes when discharged, thereby causing the cavitating volume of liquid to form a plasma which collapses to form a shockwave. The at least one transducer constitutes a first energy source, and the at least one capacitor back and electrodes constitute a second energy source. Alternative forms and arrangements of the first and second energy sources are also disclosed.

Abstract: A power condition system is disclosed for conditioning power for charging of at least one capacitive element of a pulse power electrode, where the electrical power is received from at least one of a downhole alternator or generator. The received electrical power is rectified and controlled for both voltage and current amplitude. The electrical power is then split into two parallel square wave signals. The electrical power is then transformed, using parallel high frequency high voltage transformers, to a high voltage signal. The high voltage signals are rejoined and rectified to produce a high voltage DC signal. The DC signal is smoothed at a high capacity inductor and output via a switching element to at least one capacitive element of the pulse power electrodes.

Abstract: Systems and methods for improving injectivity of a hydrocarbon reservoir include: identifying a restriction of flow from an injection well into the hydrocarbon reservoir; transmitting a series of acoustic waves from an injection well into a formation that includes the hydrocarbon reservoir, wherein the series of acoustic waves are transmitted continuously for at least one day; transmitting a series of seismic waves from the injection well into the formation after the series of acoustic waves are transmitted into the hydrocarbon reservoir, wherein the series of seismic waves are transmitted continuously for at least one week; and injecting water into the injection well to cause hydrocarbon of the hydrocarbon reservoir to flow from the hydrocarbon reservoir to a production well after the series of acoustic waves are transmitted into the hydrocarbon reservoir.

Abstract: A system and apparatus for plasma blasting comprises a borehole, with a novel blast probe, the probe comprising a high voltage electrode and a ground casing tube separated by a dielectric separator except for an evacuated area where the plasma blast occurs, wherein the opening in the ground casing and the dielectric separator constitute a sliced and elliptical probe shape. The sliced and elliptical shape of the opening focuses a plasma blast in a specific direction and contours, wherein at least a portion of the high voltage electrode and the ground electrode are submerged in the blast media. The blasting media comprises water alone or in combination with other materials. The sliced and elliptical blast probe permit directional aiming of the blast.

Abstract: A method and system for downhole pulse generation determines an optimal frequency and, in some embodiments, amplitude of axial pressure pulses to maximize the rate of penetration. Specifically, one or more sensors may be disposed on or near an axial oscillation tool that provides near real-time raw sensor data relating to speed, velocity, and acceleration of the tool. With this sensor data, an optimal set of parameters, namely an optimal frequency and, in some embodiments, amplitude may be determined based on the hydraulic conditions and frictional forces of the actual drilling environment. An optimizing control system may directly communicate these parameters to the axial oscillation tool or pass the parameters to an axial oscillation tool control system that controls the operation of the tool. Advantageously, frictional forces may be substantially reduced, the rate of penetration may be substantially enhanced, and power consumption may be intelligently managed.

Abstract: A method, system and apparatus for plasma blasting comprises a borehole for water, oil or gas extraction, an in hole capacitor bank for powering a blast probe, the probe comprising a high voltage electrode and a ground electrode separated by an insulator, wherein the high voltage electrode and the insulator constitute an adjustable probe tip, and an adjustment unit coupled to the adjustable probe tip, wherein the adjustment unit is configured to selectively extend or retract the adjustable probe tip relative to the ground electrode and a blasting media, wherein at least a portion of the high voltage electrode and the ground electrode are submerged in the blast media. The blasting media comprises water. The adjustable tip permits fine-tuning of the blast.

Abstract: A method for extracting gas by fracturing a coal seam through a combination of hydraulic slotting and multi-stage combustion impact wave comprises cutting slots in an impact borehole using a hydraulic slotting equipment to perform pressure relief and permeability enhancement on a coal seam and enlarge a N2 (nitrogen gas) or CO2 (carbon dioxide gas) storage space, injecting a large amount of N2 or CO2 into the borehole by means of a high pressure gas cylinder and a pressure reducing valve through a gas injection and extraction pipe, then injecting a certain amount of methane and dry air into a high-temperature and high-pressure combustion chamber by means of the high pressure gas cylinder and the pressure reducing valve, so that the gases are mixed and combusted to form high-temperature and high-pressure impact wave to push a piston to compress the N2 or CO2, thereby generating a large number of factures on the coal seam around the impact borehole under guiding action of the slots.

Abstract: The group of inventions relates to the oil-and-gas extraction industry, in particular to equipment for removing deposits of asphaltenes, resins, paraffins, hydrates, calcium salts, etc. from tubing strings of oil and gas wells without extracting said tubing strings from the wells. This instrument can also be used for cleaning water-extracting wells and other wells. The internal surface of a tubing string is cleaned by a combined action (ultrasonic, mechanical, heat) on contaminants. Owing to the fact that operation of a well does not stop, dirt atomized by the combined action is raised to the surface and removed from the well by a stream of fluid. A system for ultrasonic cleaning of a tubing string consists of an ultrasonic generator and a downhole ultrasonic scraper, which comprises a converter converting electrical vibrations into mechanical vibrations, which is placed into a protective casing and is connected to a vibration transformer, which boosts the amplitude of vibrations of ultrasonic transducers.

Abstract: A method, system and apparatus for plasma blasting comprises a borehole for oil or gas extraction, an in hole capacitor bank for powering a blast probe, the probe comprising a high voltage electrode and a ground electrode separated by a dielectric separator, wherein the high voltage electrode and the dielectric separator constitute an adjustable probe tip, and an adjustment unit coupled to the adjustable probe tip, wherein the adjustment unit is configured to selectively extend or retract the adjustable probe tip relative to the ground electrode and a blasting media, wherein at least a portion of the high voltage electrode and the ground electrode are submerged in the blast media. The blasting media comprises water. The adjustable tip permits fine-tuning of the blast.

Abstract: A permeability enhancement method for coalbed methane wells by using electric pulse detonation fracturing technology is applicable to exploitation of coalbed methane wells in coal beds with low permeability. Firstly, a positive electrode coalbed methane wellbore and a negative electrode coalbed methane wellbore are constructed from the ground surface to a coal bed. A fixed platform installed with a positive electrode and a high-voltage pulse device are placed, by using a derrick, downwards to a predetermined permeability enhancement portion of the coal bed in the positive electrode coalbed methane wellbore, and another fixed platform installed with a negative electrode is placed, by using a derrick, downwards to a predetermined permeability enhancement portion of the coal bed in the negative electrode coalbed methane wellbore.

Abstract: A device is for perforation of a downhole formation. The device has an electronically induced acoustic shock wave generator; and an acoustic shock wave focusing member. The device is adapted to focus generated acoustic shock waves onto an area of a borehole in order to disintegrate the downhole formation within said area. The device is adapted to generate a plurality of consecutive focused acoustic shock waves in order to gradually excavate a perforation tunnel, or to improve an already existing perforation tunnel, extending from said borehole and into said formation.

Abstract: Some embodiments include a plasma source. The plasma source includes: (i) a plasma emitter having a first electrode and a second electrode defining an electrode gap therebetween; (ii) stands disposed adjacent to the electrode gap and the plasma emitter; (iii) emitter openings configured such that shockwaves generated by the plasma source are directed through the emitter openings and radially from the plasma emitter, wherein adjacent emitter openings of the emitter openings are separated from each other by at least one stand of the stands; (iv) an enclosure housing at a distal end of the plasma emitter and having a delivery device configured to introduce a conductor through an opening in the second electrode and into the electrode gap; and a device housing at a proximal end of the plasma emitter and having a transformer, a capacitor unit, and a contactor. Other embodiments of related systems and methods are also disclosed.

Abstract: Provided herein are systems and methods for real time processing of signals from an array of transducers for detecting transient elastic waves originating from unknown locations in a body, which may propagate in a dispersive fashion. The systems and methods allow real time combination and analysis of signals, including decisions regarding storage as new data is received. The methods described herein include designing arrays of detectors and methods for processing signals in real time given the constraints of the body under test determining whether to store the set of information while a new set of information is received for processing within a real time environment. The methods described herein include methods which result in the determination or small time shifts which place all signals into a coherent time base which are then combined achieving a composite waveform that possesses an increased signal-to-noise ratio over any single element.

Abstract: A bridge plug for a well includes an actuator member that moves from a first position such that the bridge plug is in a retracted position and a second position such that the bridge plug is in a deployed position. The bridge plug includes a slip section comprising one or more slips that grip a surface radially outward of the bridge plug in the deployed position and a petal section positioned downward of and adjacent to the slip section, the petal section comprising a plurality of petals that fan radially outward from the bridge plug in the deployed position to catch a slurry. The bridge plug also includes a centralizer section positioned downward of and adjacent to the pedal section, the centralizer section having a plurality of centralizers that ramp outwardly in an upward direction in the deployed position for centralizing the bridge plug.

Abstract: Methods of assessing asphaltene inhibitor/dispersant efficiency are disclosed. Also disclosed are methods of assessing solvent/dispersant/cleaner efficacy for remediating asphlatene deposition. The methods are useful in facilitating the production, transportation, storage, and separation of crude oil and natural gas, and more particularly, for preventing the undesired deposition of asphaltene from crude oil.

Abstract: In some embodiments, a plasma source can comprise a plasma emitter comprising a first electrode and a second electrode, the first electrode and the second electrode defining an electrode gap. In some embodiments, the plasma source can further comprise an enclosure housing attached to a distal end of the plasma emitter, the enclosure housing can comprise a delivery device configured to introduce a metal conductor through an axial opening in the second electrode and into the electrode gap and a device housing attached to a proximal end of the plasma emitter, the device housing can comprise a high voltage transformer electrically coupled to a capacitor unit. In some embodiments, the capacitor unit electrically can be coupled to a contactor, and the contactor can be electrically coupled to the first electrode. Other embodiments of related methods and systems are also provided.

Abstract: A magnesium alloy is suitable for use as a corrodible downhole article, wherein the alloy includes: (a) 2-7 wt % Gd, (b) 0-2 wt % Y, (c) 0-5.0 wt % Nd, and (d) at least 80 wt % Mg, and has an elongation as measured by ASTM B557M-10 of at least 22%.

Abstract: A device (20) for stimulation of wells, includes a tool (200) including a capacitive element (205) and a stimulation head (210). The device further includes switching elements capable of placing the tool (200) in at least two states: i) a charging state in which the capacitive element and the stimulation head are electrically in series between the first terminal and the second terminal of the tool, in such a way that the electrical source charges the capacitive element through the stimulation head (210), and ii) a discharging state in which the capacitive element discharges through the stimulation head (210). Also, a diagnostic method for such a device (20) for stimulation of wells.

Abstract: A magnesium alloy is suitable for use as a corrodible downhole article, wherein the alloy includes: (a) 11-15 wt % Y, (b) 0.5-5 wt % in total of rare earth metals other than Y, (c) 0-1 wt % Zr, (d) 0.1-5 wt % Ni, and (e) at least 70 wt % Mg. It has been surprisingly found by the inventors that by increasing the Y content of the alloy to the range specified above, increased age hardening response and hence increased 0.2% proof stress can be achieved.

Abstract: A method, system, and electrode assembly are disclosed that maximizes the lifetime of electrodes for high energy electrical discharges in water by arranging the electrodes in concentric rings or a stack of concentric rings. The radii and the thickness of the ring electrodes are optimized for electrical reliability, low jitter, and minimal erosion. In one embodiment, the electrode assembly is configured to be disposed in a subterranean dielectric medium, receive an electric current pulse having a length of time greater than 100 microseconds, and form an electric arc between the first electrode and the second electrode, thereby producing a pressure pulse axially away from the insulator.

Abstract: A downhole tool is disclosed herein that has an inlet for receiving fluid into a housing of the downhole tool. The downhole tool further includes a vibratory apparatus at least partially disposed within the housing of the downhole tool, the vibratory apparatus having an operational flow path disposed therein to operate the vibratory apparatus when fluid flowing through the operational flow path is above a predetermined pressure. Furthermore, the downhole tool has a bypass passageway disposed in the housing for providing an additional flow path for fluid through the downhole tool to prevent fluid from reaching the predetermined pressure in the operational flow path of the vibratory apparatus, the bypass passageway selectively blockable such that fluid in the operational flow path is increased above the predetermined pressure to activate the vibratory apparatus when the bypass passageway is blocked. A method of using the downhole tool is also disclosed.

Abstract: A piezoelectric power generation system includes a housing defining an opening therethrough and a support structure disposed within the housing, the support structure comprising a plurality of portions. The piezoelectric power generation system also includes one or more piezoelectric elements disposed between two of the plurality of portions of the support structure within the housing. Movement or vibration in the support structure compresses the one or more piezoelectric elements, wherein the one or more piezoelectric elements generate electric energy when compressed. The piezoelectric power generation system further includes one or more exciters coupled to the support structure, wherein the exciters move or vibrate when acted on by a flow of fluid, wherein the motion of vibration of the one or more exciters is translated to the support structure and ultimately to the one or more piezoelectric elements.

Abstract: A repeater for use downhole in an oil or other well for detecting a sound or other signal that originates further downhole and generating a signal or indication perceptible uphole or at or above the rig floor. The signal may be a change in the weight of the rig measured at the rig floor caused by driving a counterweight against a stop at the repeater.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate control the operation of a fluid pulse source using drilling fluid to excite vibrations in a shock sub, increasing the axial vibration in a drill string to reduce static friction between the drill string and a formation surrounding the drill string. The vibrations are excited at a fundamental frequency that is outside of the operational communications frequency range of an associated acoustic telemetry communications system. Additional apparatus, systems, and methods are disclosed.

Abstract: Disclosed is a method for restoring, maintaining, or increasing well productivity or reducing a water cut. The method comprises positioning an acoustic device in a well located within the geological formation and performing an acoustic treatment impacting a muddled zone in cycles comprising one or more manipulated waves of ultrasonic pressure on the muddled zone. The cycles comprising treatment comprise a Fourier transformation of a periodic function, wherein the transformation determines a rate at which an acoustic treatment pressure of each cycle rises from a value of zero to a maximum value. This rate is directly proportional to a force of an impact on the formation, and the greater the rate, the greater the impact. A cycle frequency is determined and designed based on particular formation parameters and particular treatment parameters obtained by sensors positioned on the acoustic device. The treatment is repeated until well productivity is restored.

Abstract: A method for improving and maintaining well productivity is disclosed. The method comprises placing acoustic devices within wells of a geological formation, measuring parameters for initial pulsed acoustic impact, and continuing to measure parameters in order to change impact parameters during production to optimize the acoustic effect. The method may be used to restore, maintain, or increase the productivity of an entire geological formation (oil or gas), and to reduce the water cut in the formation.

Abstract: A plasma source for generating nonlinear, wide-band, periodic, directed, elastic oscillations in a fluid medium. The plasma source includes a plasma emitter having two electrodes defining a gap, a delivery device for introducing a metal conductor into the gap, and a high voltage transformer for powering the plasma emitter. A system and method for stimulating wells, deposits, and boreholes through controlled periodic oscillations generated using the plasma source. The system includes the plasma source, a ground control unit, and a support cable. In the method, the plasma source is submerged in the fluid medium of a well, deposit, or borehole and is used to create a metallic plasma in the gap. The metallic plasma emits a pressure pulse and shockwaves, which are directed into the fluid medium. Nonlinear, wide-band, periodic and elastic oscillations are generated in the fluid medium, including resonant oscillations by passage of the shockwaves.

Abstract: A method for determining position of a wellbore in the Earth's subsurface includes actuating a plurality of seismic energy sources each disposed at a known geodetic position. Seismic energy from the sources is detected at a selected location along the wellbore. The geodetic position at the selected location is determined from the detected seismic energy. A corresponding method includes actuating a seismic energy source at a selected position within the wellbore. The seismic energy is detected at a plurality of known geodetic positions. The geodetic position of the source is determined from the detected seismic energy.

Abstract: An apparatus includes a body shaped to deform a wellbore tool in a predetermined manner. A vibration device applies a vibration to the body to reduce a frictional force caused when the body deforms the wellbore tool. In one arrangement, the vibration devices imparts a resonant wave motion to a swaging apparatus that is being pushed through a passage of a wellbore tubular. A swaging body vibrates at a resonant frequency along the long axis of the wellbore tubular and/or normal to long axis of the wellbore tubular. The relative motion between the swaging body and the tubular member reduces the force required to expand the wellbore tubular. Optionally, a controller operatively connected to the vibration device adjusts the operation of the vibration device in response to the sensor measurements of the vibrations in the swage body.

Abstract: An apparatus for use in a wellbore is provided that in one embodiment may include at least one transmitter configured to generate acoustic signals in the wellbore, at least one receiver configured to receive acoustic signals from a formation surrounding the wellbore in response to the transmitted acoustic signal and also configured to provide electrical signals representative of the received acoustic signals, a circuit configured to apply a time-variable gain to the electrical signals to amplify the electrical signals, and a processor configured to process the amplified electrical signals and provide a property of interest.

Abstract: Selected designs for reciprocating pumps and down-hole well-stimulation equipment reflect disparate applications of identical technical principles (relating to, e.g., the vibration spectrum of an impulse). In certain of these designs, the vibration spectrum is controlled, suppressed and/or damped using tunable components to limit destructive excitation of resonances; in others the vibration spectrum is tuned at its source for maximum resonance excitation. For example, tunable fluid ends control valve-generated vibration to increase fluid-end reliability. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized. Subsequent damping and/or selective attenuation of vibration likely to excite one or more predetermined (and frequently localized) fluid end resonances represents further optimal use of fluid end vibration-control resources.

Abstract: A method of determining an azimuthal orientation of a well tool relative to a line in a well can include connecting at least one acoustic source to the well tool, the acoustic source having a known azimuthal orientation relative to the well tool, and detecting at least one acoustic signal transmitted from the acoustic source to an acoustic sensor, the acoustic sensor having a known azimuthal orientation relative to the line. A system for determining an azimuthal orientation of one or more lines relative to a well tool in a wellbore can include at least one acoustic source having a known azimuthal orientation relative to the well tool, and an optical waveguide connected to a distributed acoustic sensing instrumentation, the waveguide having a known azimuthal orientation relative to the lines, and in which the distributed acoustic sensing instrumentation detects acoustic signals transmitted from the acoustic source to the waveguide.

Abstract: Disclosed herein is an autonomous and consistently active acoustic rehabilitation technology for wells, reservoirs, and extraction of natural resources using a borehole method. The invention can be used in oil, gas, mining, geological exploration industries, and in extraction technologies for oil and gas, including shale. It is especially useful for improvement of oil and gas output from wells and stimulation of production for maximizing recovery from reserves. The invention is applicable to areas including, but not limited to, well reserves using pumps, layer pressure supporting wells, and offshore-bed wells.

Abstract: A technique employs the use of oscillations downhole to facilitate a desired functionality of a downhole tool. According to this technique, a tool is initially conveyed downhole and operated to perform a function that relates to a downhole application. The operational efficiency of the tool is improved by creating oscillating forces which vibrate the tool to achieve a desired result, e.g. freeing the tool from a stuck position.

Abstract: A hydrodynamic pulse tool and method for cleaning, stimulation and production enhancement of oil, gas and injection wells by propagating successive pressure waves through the wellbore and/or the producing/injecting formation in a directional or vectored manner. The tool comprises a resonance chamber defined by a generally cylindrical hollow tubular member adapted for connection to conventional coiled or jointed tubing, and at least one hydraulically driven pulse generator rotatably disposed within the resonance chamber. The hydraulic force of pressurized fluid pumped through the tool drives the rotation of the at least one pulse generator, which generates successive sequential hydraulic pressure pulses in a sequential, sequential offsetting and/or sequential reinforcing manner.

Abstract: A radio frequency heater is disclosed including a vessel for containing material to be heated and a radio frequency radiating surface. The vessel has a wall defining a reservoir. The radio frequency radiating surface at least partially surrounds the reservoir. The radiating surface includes two or more circumferentially spaced petals that are electrically isolated from other petals. The petals are positioned to irradiate at least a portion of the reservoir, and are adapted for connection to a source of radio frequency alternating current. A generally conical tank or tank segment having a conically wound radio frequency applicator is also contemplated. Also, a method of heating an oil-water process stream is disclosed. In this method a radio frequency heater and an oil-water process stream are provided. The process stream is irradiated with the heater, thus heating the water phase of the process stream.

Abstract: The method and apparatus for enhancing fluid removal from a fracture in a geologic formation by applying periodic/cyclic shock waves to the fracture in a formation surrounding a wellbore which has undergone fracturing. In accordance with the invention, the method includes the steps of arranging a device attached to an end of a tubing string inside a wellbore in a vicinity of said fracture for generating shock waves, providing a liquid via the tubing string into the device for generating shock waves with the amplitude Pa of shock waves determined by a following expression: 0.3 MPa?Pa?1.4Pp?0.8?gH, where Pp is a formation pore pressure, ? is a formation density, g is a gravity acceleration, H is a depth of said fracture, Pa is an amplitude of the shock wave.

Abstract: The invention provides an apparatus and method for stimulating a borehole of a well. The invention provides an apparatus that generates low-frequency seismic type elastic waves that propagate to the geologic formation and in order to enhance the movement of fluids in the geologic formation toward a well. The apparatus may operate automatically driven by a power source that may be located on the ground surface. The regime of operation may be determined by user input. Operation of the apparatus may carried out while production of a natural resource is ongoing.

Abstract: The invention is directed to a hydraulic actuated pump system which lifts production fluids and re-circulating hydraulic fluid from a petroleum well. Additives may be added to the hydraulic fluid to apply direct chemical treatment to the production formation. A sonic stimulator may be included to stimulate and produce the same liquids from the horizontal section of the well.

Abstract: A system and method are provided for producing controlled vibrations within a borehole. In one example, the system includes an encoder plate, an anvil plate, and a movement mechanism configured to enable rotational and translational movement of the encoder plate relative to the anvil plate to allow the encoder plate to repeatedly impact the anvil plate to create vibrations. The system also includes a vibration control mechanism configured to control an amplitude of the vibrations.

Abstract: According to some embodiments, a borehole deployable apparatus is described that can be used to generate strong vibrations in a subterranean rock formation. In some embodiments, the apparatus accelerates a mass using mechanisms built into the tool and causes the mass to strike the borehole wall. The mechanisms can control the mass acceleration, and the frequency of strikes. In some embodiments, the apparatus is designed for use in the field of petroleum recovery where the vibrations are used to create or re-establish a flow rate for the fluids in the formation.

Abstract: Temperature and pressure measurements that are made downhole are used to predict a compressional wave velocity for pure water under downhole conditions. The predicted velocity and a measured compressional velocity of a formation brine are used in a non-iterative method to estimate a value of the formation brine salinity that is between 0 and 1.

Abstract: A sonic oil recovery apparatus for use in a well has an injector tubing extending interior of the casing of the well, and a resonator tube affixed to or within the injector tubing. The resonator tube has an interior flow pathway so as to allow a fluid to flow therethrough from the injector tubing. The resonator tube is suitable for transmitting an acoustic signal approximately equal to the resonate frequency of a formation in the well. The resonator tube can have a plurality of orifices plates formed therein such that the fluid flowing through the resonator tube generates the acoustic signal. The resonator tube can alternatively be a solid state acoustic resonator therein.

Abstract: A treatment device for treating liquids in oil, gas or water wells comprises an ultrasonic treatment device (1). The ultrasonic treatment device (1) includes a resonator (2), a transducer (9) and a matching transformer (10) for transferring a maximum of power from an ultrasonic generator to the transducer (9) through a long cable (11). The cable (11) has a considerable length of at least 3 km and is attached to a generator (5).

Abstract: A method of generating an axial shear wave in a formation surrounding a wellbore comprising urging a clamp pad into contact with a wall of the wellbore, and applying an axial force to the clamp pad to impart a shear force into the wall of the wellbore to generate a shear wave in the formation.

Abstract: The method and apparatus for enhancing fluid removal from a fracture in a geologic formation by applying periodic/cyclic shock waves to the fracture in a formation surrounding a wellbore which has undergone fracturing. In accordance with the invention, the method includes the steps of arranging a device attached to the end of tubing inside the wellbore in the vicinity of said fracture for generating shock waves, providing a liquid via tubing into the device for generating shock waves with the amplitude Pa of shock waves determined by following expression: 0.3 MPa?Pa?1.4Pp?0.8?gH, where Pp is the formation pore pressure, ? is the formation density, g is a gravity acceleration, H is the depth of said fracture, Pa is the amplitude of the shock wave.