Abstract: A method for acoustic geosteering in directional drilling is provided. The method includes measuring a response from a fiber-optic distributed acoustic sensor disposed on a bottom hole assembly and determining a location of the bottom hole assembly from seismic waves received from surface sources. A subterranean layer structure proximate to the bottom hole assembly is determined from reflections of a locally generated soundwave. Adjustments to geosteering vectors for the bottom hole assembly are determined based, at least in part, on the location and the subterranean layer structure.

Abstract: A method and apparatus for single-trip casing cutting and pulling for well abandonment and slot recovery. Perforations (28) are made in the casing (12) at a maximum depth using a punch tool (18) and a pulsed fluid circulated through the perforations (28) to determine a return at surface. In the event of a return at surface being detected, the casing (12) is cut and then pulled with assisted vibratory action. When no return is detected, perforations (28) are made at increasingly shallower depths until a return is detected and the casing (12) is then cut and pulled. This ensures the maximum length of casing (12) is cut and pulled on a single trip in the well bore.

Abstract: A method and apparatus for single-trip casing cutting and pulling for well abandonment and slot recovery. Perforations (28) are made in the casing (12) at a maximum depth using a punch tool (18) and fluid circulated through the perforations to determine a return at surface. In the event of a return at surface being detected, the casing (12) is cut and pulled. When no return is detected, perforations are made at increasingly shallower depths until a return is detected and the casing (12) is then cut and pulled. This ensures the maximum length of casing (12) is cut and pulled on a single trip in the well bore (10).

Abstract: A method includes simultaneously injecting a chemical agent, through an injector, into a perforated wellbore section of a well in a hydrocarbon reservoir, and generating an acoustic wave with an acoustic tool in the wellbore section. The injector and acoustic tool are moved to and fro in synchronization. The acoustic tool includes at least one of a sonotrode and a shock wave tool. A downhole tool assembly comprises the injector, the acoustic tool, and a movable cable hose connected to the injector and the acoustic tool for moving the injector and acoustic tool to and fro in synchronization. The cable hose comprises a wire for supplying power to the acoustic tool and having a conduit for supplying the chemical agent to the injector.

Abstract: A smart device includes a scaffold that responds to an applied stimulation and an encapsulating structure that encapsulates the scaffold. The scaffold is formed from at least one smart material that responds to the applied stimulation. The encapsulating structure is formed from a material that yields to the response of the scaffold.

Abstract: Apparatus and adapter are usable for aligning downhole torch apparatuses and cutting devices, including axial pyro torches, circulating pyro torches, and radial cutting and perforating torches, within a wellbore for removal of one or more downhole obstructions. The torch and/or cutting apparatus comprises a body having a nozzle adapted to project a fuel load, such as molten thermite or molten thermite with a polymer, in a direction aligned with the obstruction. The adapter comprises protruding elements for eliminating or diminishing damage to the area surrounding the obstruction, including the inner walls of the wellbore and/or casing, and can further comprise centralizers for alignment of the apparatus with the obstruction, within the wellbore.

Abstract: A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability.

Abstract: An apparatus for estimating an ambient environment at which organic scale will form in a downhole fluid includes a stress chamber disposed in a borehole in a production zone at a location of maximum pressure and configured to receive a sample of the fluid from the production zone and to apply an ambient condition to the sample that causes the formation of organic scale. A sensor is configured to sense formation of organic scale within the chamber and an ambient environment sensor is configured to sense an ambient environment within the chamber at which the formation of organic scale occurs. The apparatus further includes a processor configured to receive measurement data from the organic scaling sensor and the ambient environment sensor and to identify the ambient environment at which the formation of organic scale occurs using the organic scaling sensor measurement data and ambient environment sensor measurement data.

Abstract: Various embodiments disclosed relate to compositions including a plurality of capsules each independently comprising an outer wall and an inner compartment, the inner compartment independently comprising at least one of a first hardenable resin, a first hardener or activator, and a solvent, self-healing hardened resins formed from the same, and methods of using the same. In various embodiments, the present invention provides a method of treating a subterranean formation including placing the composition in a subterranean formation, and forming a selfhealing hardened resin in the subterranean formation from the composition.

Abstract: This invention relates to the oil and gas industry and can be used for intensifying the production of well fluids. The present downhole acoustic apparatus comprises an upper head for attachment to a logging cable or coiled tubing, an acoustic emitter and a lower guiding head. The emitter consists of a body with piezoelectric transducers, comprised of piezoceramic discs, arranged perpendicular to the axis of the body. Emitter bodies are formed in the shape of cylinders from a metal with a milled surface and are connected to each other by means of a rubber-plastic filler. This provides an increase in the acoustic power of radiation in a radial direction and makes it possible to treat horizontal and lateral wells.

Abstract: A method to dislodge debris from a pump system in which the pump system includes a down-hole pump coupled by a rod string to an above-ground pump actuator, which is coupled to a controller configured to operate the pump system. The method also includes determining that the pump system should begin operating in a pump clean mode, and implementing the pump clean mode configured in the controller. The method also includes impressing a preset vibration frequency during a portion of a pump stroke of at least one pump cycle. Further, the method calls for determining that the pump clean mode is complete, and returning the pump system to a normal operation mode.

Abstract: A probe for generating seismic waves, includes at least: a tubular body (10) having a first end linked to an electrical power cable, a capacitor bank arranged within the body, a spark gap installed at a second end of the body and linked to the capacitor bank, suitable for generating a seismic wave upon the release of the energy stored by the capacitor bank, wherein: the capacitor bank is formed from cylindrical capacitors (621) including bases each having a different polarity, the capacitors are mounted coaxially to each other, parallel to the main axis of the body, and the capacitors are electrically linked into at least two groups of capacitors connected in parallel, each group of capacitors having a positive pole and a negative pole, the groups being arranged in the body such that the facing poles of two adjacent groups are of the same polarity.

Abstract: Enhanced method for borehole mining comprising: drilling a borehole using a low-frequency pulsing sonic, hydraulic mining system including a pulsed jet assembly; inserting casing into the borehole above target deposit depth; inserting and rotating assembly into the casing with a sub-coupling and a shoe rock bit positioned below the casing; pumping fluid into the borehole; evaluating slurry at surface; fracturing and disaggregating materials at target deposit with pulsing jets from the sub-coupling and rock bit causing light slurry to flow upwardly to the annulus between the borehole casing and the downhole assembly, then upwardly through the annulus to the surface of the borehole thereby causing heavy slurry to concentrate in a sump, located below the pulse jet rock bit; continuing to form cavity at target location; removing pulsed jet assembly from borehole; running core barrel to extract heavy slurry from sump; analyzing slurry to determine whether to continue with operation.

Abstract: There is taught herein a method of inducing micro fractures and fracture slip in formations thereby creating new dislocations in pre-existing fractures during hydraulic fracturing operations. An embodiment uses multi-component generated signals from multiple seismic signal generators located on or below the surface; and rotating the generated signals such that their vectors of propagation can be varied and optimized for inducing the micro-seismic and fracture slip events for highest cumulative hydrocarbon extraction considering the mechanical properties and direction of the stresses and pre-existing fractures. Embodiments relate to methods for inducing additional seismic events and fracture slip during hydraulic fracturing, particularly micro-seismic events and fracture slip which improve the short and long term production from the reservoir formation.

Abstract: A method for the recovery of hydrocarbon from a reservoir includes arranging a chamber in fluid communication with the reservoir via at least one conduit. The chamber includes first and second wall parts movable relative to each other. An impact pressure is provided in the fluid to propagate to the reservoir via the conduit, where the impact pressure is generated by a collision process between an object arranged outside of the fluid and the first wall parts for the first wall part to impact on the fluid in the chamber. The chamber is arranged to avoid a build-up of gas-inclusions where the first wall part impacts on the fluid. This may be obtained by arranging the conduit in or adjacent to the zone where the gas-inclusions naturally gather by influence of the gravitational forces, or by placing the first wall part impacting on the fluid away from this zone.

Abstract: A device for hydrocarbon resource recovery from at least one well in a subterranean formation may include a radio frequency (RF) source, a solvent source, and a double-wall structure coupled to the RF source to define an RF antenna within the at least one well to provide RF heating to the subterranean formation. The double-wall structure may absorb heat from adjacent portions of the subterranean formation. The double-wall structure may also include inner and outer walls defining a solvent passageway therebetween coupled to the solvent source. The outer wall may have a plurality of openings therein to eject solvent into the subterranean formation. The double-wall structure may transfer heat to the solvent so that the ejected solvent is in a vapor state.

Abstract: An apparatus for generating of vibrations for enhancing of forming at least one fracture having a required width r and length L in the formation surrounding a wellbore in the regime of resonance by means of applying vibrations to the formation which is undergoing pressurizing exceeding the fracture gradient pressure of the formation.

Abstract: Acoustophoretic devices for separating particles from a non-flowing host fluid are disclosed. The devices include a substantially acoustically transparent container and a separation unit, with the container being placed within the separation unit. An ultrasonic transducer in the separation unit creates a planar or multi-dimensional acoustic standing wave within the container, trapping particles disposed within the non-flowing fluid and causing them to coalesce or agglomerate, then separate due to buoyancy or gravity forces.

Abstract: A well tool (10) for use in a well pipe comprises a housing (11) and a pulse generator (14) provided within the housing (11). The pulse generator (14) comprises an inductor (Ls), and a power supply device (HV, c) for supplying electrical power to the inductor (L) and thereby providing that an electromagnetic pulse is generated, in such a way that the electromagnetic pulse is providing physical vibrations in the well pipe. A cross sectional gap area (Agap) of an annular gap between a median of the inductor (Ls) and an inner surface of the well pipe is substantially equal to an inner cross sectional area (Ainner) of the inductor (Ls) up to the median diameter (d) of the inductor.

Abstract: A cleaning tool that includes an acoustic cavitation duct that cleans particles within a continuous flow of slurry. In one embodiment, the acoustic cavitation duct includes an elongated fluid passageway for carrying the flow of slurry. A number of ultrasonic transducers are spaced from one another along the length of the passageway and induce cavitation into the slurry as it travels through the duct. The cavitation promotes the cleaning of the slurry particles. In one example, the transducers operate at differing frequencies.

Abstract: A method for heating hydrocarbon resources in a subterranean formation may include positioning a tubular conductor within a wellbore in the subterranean formation and slidably positioning a radio frequency (RF) transmission line within the tubular conductor so that a distal end of the transmission line is electrically coupled to the tubular conductor. The method may also include supplying RF power, via the RF transmission line, to the tubular conductor so that the tubular conductor serves as an RF antenna to heat the hydrocarbon resources in the subterranean formation.

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: A method and assembly for recovering oil using elastic vibration energy involves placing a downhole apparatus in a well, which downhole apparatus is connected to aboveground power supply units and contains an ultrasonic transducer that provides for the generation of high frequency elastic vibrations, exciting elastic vibrations of different frequencies and then repeatedly applying the elastic vibrations to the oil formation, wherein both high and low frequency vibrations are applied to the formation. The low frequency vibrations are generated with the aid of an electric pulse device which is connected to an aboveground power supply and includes the following electrically interconnected components: a charger, a unit of energy storage capacitors, a discharge unit with electrodes, and two switching devices. The method and assembly make it possible to recover oil from depths of over 2000 meters and to act effectively on the formation being treated.

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: A system is provided for communicating within a borehole using controlled vibrations. A movement mechanism uses mechanical energy provided by a mechanical energy source to enable translational movement of a first surface relative to a second surface to allow the first surface to repeatedly impact the second surface to produce a plurality of vibration beats. The vibration beats will occur whenever the mechanical energy is provided by the mechanical energy source at one of at least three impact levels. A vibration control mechanism selectively controls an amplitude of the plurality of vibration beats to encode information therein. The amplitude of a vibration beat is selectively controlled by regulating the impact of the first surface and the second surface to one of the at least three impact levels.

Abstract: A method for cleaning a casing of an oil well is disclosed. Operational parameters for a cleaning tool may be defined based, at least in part, on results of a survey of the well. The cleaning tool may include a discharge head to generate electrical discharges between a pair of electrodes, the electrical discharges causing shock waves to remove deposits from the casing. The cleaning tool may be lowered into the casing. The cleaning tool may generate shock waves in accordance with the defined operational parameters to clean a predetermined target portion of the casing. The cleaning tool may be withdrawn from the casing.

Abstract: A system usable with a well includes a waveform generator for enhancing fluid recovery from a reservoir by controlling a production pump or an injection pump downhole in the well with waveform signals to create a pressure wave which propagates into the reservoir and enhances the recovery of the fluid.

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 downhole tool with a feedback arrangement including a tool having one or more fluid outflow ports that exhaust fluid during normal operation of the tool. A feedback arrangement in operable communication with the fluid exhausted from the one or more fluid outflow ports during operation of the tool. The feedback arrangement interacting with exhausting fluid to produce a signal receivable at a remote location indicative of proper tool operation. A method for confirming operation of a downhole tool is included.

Abstract: A well system and associated method can include an acoustic generator which can be used to excite a formation with acoustic waves transmitted from the acoustic generator. Another well system and associated method can include an acoustic generator which can transmit acoustic waves into cement surrounding a casing. Another well system and associated method can include an acoustic generator which can be used to transmit acoustic waves into an annulus surrounding a well screen during or after a gravel packing operation. Another well system and associated method can include an acoustic generator which can be connected in a drill string in close proximity to a drill bit, with the acoustic generator transmitting acoustic waves into a formation ahead of the bit.

Abstract: Acoustic radiators for coal bed methane or shale gas production are configured to be strategically placed on drillstrings within gas production exhaust boreholes and hydraulically powered so they will radiate intense harmonic sonic waves to shake the solid media immediate to the wall areas. The gas volume output that can be realized by an exhaust well depends highly on the permeability of the media, especially at inside faces of the borehole. The shaking half-opens up fractures and pores in the solid media. Thus the permeability of the media to gas improves under such shaking and gas collection efficiencies are improved. The beneficial effects can be increased by locating two or more acoustic radiators proximate to one another in a phased relationship.

Abstract: An ultrasonic device and system is provided for specific application to unloading non-gaseous production (typically mineralized water which may or may not be associated with produced solids and/or hydrocarbon liquids) from gas producing wells. In one embodiment, the system comprises an ultrasonic particle generator bank, including a transformer as needed (geometry of bank varies depending on down hole configurations) with multiple ultrasonic sources for redundancy/longevity and particle formation rate control. The multiple ultrasonic sources may be powered electrically from the surface, or by other means, with a length management conveyance system. The ultrasonic sources may be buoyed at substantially optimal depth below the surface of the non-gaseous production being particlized.

Abstract: A system and method are provided for producing controlled vibrations within a borehole. In one example, the system includes a movement mechanism and a vibration control mechanism. The movement mechanism is configured to use mechanical energy provided by a mechanical energy source to enable translational movement of a first surface relative to a second surface to allow the first surface to repeatedly impact the second surface to produce a plurality of vibration beats, where the vibration beats will occur whenever the mechanical energy is provided by the mechanical energy source unless the provided mechanical energy is dampened to prevent the translational movement. The vibration control mechanism is configured to selectively control an amplitude of the vibration beats to encode information therein, where the amplitude of a vibration beat is selectively controlled by dampening the provided mechanical energy to regulate the impact of the first surface and the second surface.

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 method and system for stimulating production of a natural resource (e.g., Oil, gas or water) producing well using vibrational energy delivered to the geological formation through a downhole type apparatus that maybe permanently installed, and continuously or periodically operated even during recovery of the natural resource. The apparatus is constructed to resist corrosion and provides one or more heat sink chambers for controlling heat dissipation during operation. The system is capable of monitoring production, adapting stimulation parameters based on user input and other pertinent parameters.

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: A method of inducing fracture in at least a portion of a geologic structure includes inducing acoustic waves into a fluid medium present in a borehole extending at least partially into the structure. Embodiments may include preheating or pressurizing the fluid medium prior to inducing the acoustic wave therein.

Abstract: A system and method for managing a well site having a subterranean formation. The method comprises determining a first spectral attenuation of a first seismic wave measured from a first location, determining a second spectral attenuation of a second seismic wave measured from a second location, determining a reservoir attenuation anisotropy from a comparison of the first spectral attenuation to the second spectral attenuation, and determining at least one fracture parameter of the subterranean formation from a comparison of the first seismic wave to the second seismic wave.

Abstract: A downhole device with compressive layer at the surface thereof. Such devices may be particularly well suited for survivability in the face of potentially long term exposure to a downhole environment. Techniques for forming protective compressive layers at the surfaces of such devices may include positioning devices within a chamber for bombardment by high frequency particles. As a manner of enhancing the compressive layer thickness and effectiveness, low temperature conditions may be applied to the device during the high frequency treatment.

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: Methods, apparatus and systems for controllably mobilizing, flowing and maneuvering the flow of hydrocarbon-containing materials within and about a subterranean reservoir. The system comprises selectively positioning at a ground surface level above a subterranean reservoir containing hydrocarbon-containing materials, at least three seismic apparatus spaced apart in a triangulated configuration. The system is provided with an electronic seismic control device configured to controllably communicate with and cooperate with each of the seismic apparatus to concurrently modulate the amplitudes and frequencies of the vibrational energies produced therefrom. The system is provided with a sensing apparatus configured to detect and monitor changes in the fluidity and movement of the hydrocarbon-containing materials about the subterranean reservoir.

Abstract: An ultrasonic fracking system and methods of using the same to extract hydrocarbons from underground geological formations (e.g., oil shale, coal beds, etc.) are disclosed. The system includes piezoelectric devices that are used to produce ultrasonic mechanical vibrations and induce fractures in the geological formations. In one embodiment, a system for extracting underground hydrocarbons comprises a plurality of piezoelectric devices capable of producing mechanical waves sufficient to fracture oil shale and other geological formations, a system of delivery for innocuous proppants to create a path of least resistance for enhanced hydrocarbon flow, and a vacuum pump connected to the fractures created by the piezoelectric devices to assist in removing the hydrocarbons.

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: A method of deep acid stimulation for a zone to be treated in an underground formation using an acidizing tool, the method including the steps of introducing the acidizing tool into the well bore, introducing the acid formulation onto the well bore wall at the treatment zone and introducing ultrasound energy into the underground formation at the treatment zone. The subsequent acid penetration depth is deeper than the initial acid penetration depth. A method of stress fracturing a portion of an underground formation includes the steps of introducing the acidizing tool into a well bore and introducing the acid formulation and the ultrasound energy at the focused treatment point. The weakened acidized spots in combination with the stress on the underground formation causes oriented stress-induced fractures to form that are fluidly coupled with the well bore. An acidizing tool includes an acid delivery system and an ultrasonic transmitter.

Abstract: The method and apparatus for producing shock waves in a well wherein a device connected to the bottom of the tubing string in the borehole of the well filled by liquid and containing the upper and lower plungers movably arranged within corresponding cylinders for compressing a liquid inside the compression chamber and discharging the liquid into the borehole on upstroke thereby generating a shock wave. In addition, providing an exit of the lower plunger out of the lower cylinder at the top of upstroke of pumping unit on the distance ? determined by the following formulae: ? ? ( D 1 2 - D 2 2 ) ? A sw ? H Ed r 2 , where D1 and D2 are the outside diameters of the lower and upper plungers, Asw is the amplitude of generated shock wave, H is a depth of the lower plunger at the top of upstroke, E is modulus of elasticity of the sucker rod's material, dr is the diameter of sucker rods.

Abstract: A hydraulic pulse valve for use in downhole tools includes a split ring seal to limit the fluid flow available to shift a poppet in the valve from an open position to a closed position. The split ring seal provides relatively long and repeatable pressure pulses, which improve the effectiveness of the hydraulic pulse valve for borehole applications.

Abstract: A downhole apparatus including a pressure pulse generator and a pulse reflector is provided. The pulse reflector reflects at least a portion of an incident pressure pulse from the generator as a reflected pressure pulse. The apparatus is configured to provide the reflected pressure pulse with a phase shift with respect to the incident pressure pulse. A method of transmitting pressure pulses downhole by generating a pressure pulse and reflecting at least a portion of an incident pressure pulse at a pulse reflector as a reflected pressure pulse is also provided. A phase shift of the reflected pressure pulse with respect to the incident pressure pulse is controlled.