Abstract: A method for fluid identification (water, oil, gas or CO2) and saturation estimation in subsurface rock formations using the prestack inverted seismic data by calculating the target fluid saturation (Sfl)(114) in a reservoir given the magnitude obtained from the P- to S-wave velocity ratio (Vp/Vs) (103), and acoustic impedance (AI) (102) extracted from the seismic data inversion, comprising the following steps: a) obtaining wireline log data within a zone of interest in a nearby well (101) and determining the suitable cementation and mineralogy factors by calibrating the background water-bearing sand trend with the reference 0% (or 0 fraction) Sfl curve onto the acoustic impedance-Vp/Vs ratio plane (110), b) calibrating Sfl computed from the acoustic impedance-Vp/Vs ratio curves with Sfl obtained from a conventional method by iterating P-wave velocity (Vpfl) and density (?fl) of the target fluid (111), c) obtaining inverted seismic data in the form of Acoustic Impedance (AI) (102) and Vp/Vs ratio (103) cubes,

Abstract: A system for downhole communication includes a roll stabilized platform and a mud pulse generator in communication with the roll stabilized platform. The mud pulse generator generates pressure pulses in a pattern that includes encoded data. A receiver receives the pressure pulses and the encoded data is decoded. The receiver is located at any location capable of receiving pressure pulses.

Abstract: A device for generating pressure pulses includes a valve member disposed in a fluid passageway, the fluid passageway including a restriction, the valve member movable by an actuator relative to the restriction to generate a pressure pulse in a fluid in the fluid passageway based on varying a relative position between the valve member and the restriction and creating a differential pressure across the fluid passageway, the differential pressure applying a first force on the valve member. The device also includes a piston member in hydraulic communication with the differential pressure, the differential pressure applying a second force on the piston member, the piston member having a locomotive mechanical connection to the valve member.

Abstract: An oscillating shear valve of a continuous pulse generator comprises a rotator and a stator which are coaxially mounted, valve orifices are formed on the rotator and the stator, each of the valve orifices comprises a circular arc line, two straight line segments and two fillets, and is designed by establishing polar coordinate equations of the circular arc line, the straight line segments and the fillets and calculating a mud throttling area formed when the oscillating shear valve moves and determining parameters of structures of the valve orifices by a correlation coefficient index of the fluid differential pressure and a standard sinusoidal wave.

Abstract: A plugging tool includes an elongated inner housing allowing a first fluid to flow through a hollow interior of the inner housing, a retractable plunger positioned within the inner housing and operable to obstruct the flow of the first fluid into a discharge chamber and resume the flow of the first fluid into the discharge chamber based on a pressure exerted by the first fluid on the retractable plunger, and at least one pressure release valve (PRV) operable to open and release at least a portion of the first fluid from the inner housing based on a pressure exerted by the first fluid on the at least one PRV, wherein operation of the retractable plunger and the at least one PRV generates pulses of the first fluid used to deposit a sealing plug at a target interval of a wellbore.

Abstract: A mud pulse telemetry valve and method including a flow tube having at least one upper hydraulic opening extending from an inner surface and at least one lower hydraulic opening extending from an inner surface, a flow restriction member positioned in the flow tube and defining an orifice, an orifice housing connected to the flow tube and supporting the flow restriction member, and a screen defining a flow path from a first end of the screen to the orifice. The orifice housing has at least one inlet port in fluid communication with the upper hydraulic opening upstream of the flow restriction member, and the screen has a plurality of filter openings positioned between the flow path and the at least one inlet port. The mud pulse telemetry valve further has a control valve assembly and a pilot valve assembly.

Abstract: A pressure pulse communication system and method during gas drilling are provided. The system includes a downhole solenoid valve module and a sensor module, where the downhole solenoid valve module includes a valve body, a gas inlet, a piston micro-hole, a moving piston, a piston return spring, a piston cylinder, a gas outlet, a piston pressure relief hole, a solenoid valve spring, a solenoid valve, a battery, a pressure balancer, and a rubber seal. The pressure pulse communication system and method generate pressure pulses by changing the internal pressure of a drill pipe, such that a surface pressure sensor continuously receives the pressure pulses, thereby achieving the purpose of acquiring downhole temperature, pressure, and well inclination angle data.

Abstract: A setting module for setting a packer assembly in a wellbore can include a motor, a sensor, and an electronic control device. The sensor can detect pressure of fluid from a surface of the wellbore in an inner diameter of the setting module and output detected pressure to an electronic control device. The electronic control device can detect a triggering pressure sequence of the fluid from the surface and can, in response to detecting the triggered pressure sequence, output a command to the motor to drive a pump to cause a slip to move for setting the packer assembly.

Abstract: A set of instructions stored on at least one non-transitory computer readable medium running on a computer system having at least one processor. The set of instructions extract outputs from sensors of a measurement while drilling system of a drilling rig; enable a transmitter to transmit a first data stream having at least one data series including drilling data, the first data stream having an interruptible portion encompassing at least a portion of the drilling data; detect a trigger event during transmission of the first data stream; and cease transmission of the first data stream.

Abstract: A mud pulse telemetry valve assembly and method including a mud valve sub and a mud pulse telemetry valve. The mud pulse telemetry valve having a flow tube positioned within the mud valve sub in a way that at least a portion of an outer surface of the flow tube is spaced a distance from at least a portion of an inner surface of the mud valve sub to form a hydraulic passageway having an upstream end and a downstream end. The mud pulse telemetry valve further having a control valve assembly and a pilot valve assembly.

Abstract: An apparatus obtains measurements from a seismic sensor, wherein the seismic measurements include a set of seismic waves having at least a subset of seismic multiples and a machine-readable medium having program code executable by a processor to cause the apparatus to determine seismic measurements of the seismic waves, fit reflectivity model based on a set of reflectivity models using a nonlinear scheme to the seismic measurements, and identify a subset of the seismic measurements corresponding to the subset of seismic multiples. The apparatus also includes program code to cause the apparatus to generate a set of reduced-noise seismic measurements based on attenuation of the subset of the seismic measurements.

Abstract: Digital signal processing for mud pulse telemetry utilizes a variety of “On/Off” keying based modulation schemes, such as pulse width modulation (PWM) and pulse position modulation (PPM), to encode and/or decode information. A combination of PPM and PWM is disclosed that increases a bit rate while keeping a chip rate unchanged. The combination of PPM and PWM comprises determining a drilling condition and forming a message based on the drilling condition, forming a string of symbol values comprising the message, identifying a pulse width and a pulse start for the pulse based on a symbol value, providing a first pulse at a selected chip location, providing subsequent pulses to form the pulse width, and forming a quiet period at the end of the pulse width.

Abstract: The present embodiments relate to detecting instances of individuals being in peril within an independent or assisted living environment. According to certain aspects, with an individual's permission or affirmative consent, a hardware controller (such as a smart or interconnected home controller, or even a mobile device) may receive and analyze sensor data detected within the independent or assisted living environment to determine whether an individual may be in peril. In this circumstance, the hardware controller may generate a notification that indicates the situation and may communicate the notification to a proper individual, such as a family member or care giver, who may be in a position to mitigate or alleviate any risks posed by the situation. The foregoing functionality also may be used by an insurance provider to generate, update, or adjust insurance policies, premiums, rates, or discounts, and/or make recommendations to an insured individual.

Abstract: A method of determining the condition of a drill string includes receiving, by a processing device and from one or more sensors coupled to a portion of a drill string at or near a surface of a wellbore, noise information. The noise information represents drilling vibrations of the drill string during drilling of the wellbore. The method also includes determining, by the processing device based on the noise information, multiple vibration modes of the drill string. The method also includes comparing, by the processing device, the vibration modes to at least one vibration mode threshold. The method also includes determining, by the processing device based on the comparison of the vibration modes to the at least one vibration mode threshold, a condition of the drill string.

Abstract: An apparatus for monitoring deployment of filtration media at least partially surrounding a tubular disposed in a borehole penetrating the earth includes a carrier configured to be conveyed through the tubular, a low-frequency acoustic wave source disposed on the carrier and configured to transmit acoustic waves in a frequency that is less than 3000 Hz into the tubular, and an acoustic wave receiver disposed on the carrier a distance from the low-frequency acoustic wave source and configured to receive acoustic waves transmitted by the low-frequency acoustic wave source. The apparatus also includes a controller configured to compare data characterizing the received acoustic waves to reference data characterizing acoustic waves with the filtration media not deployed.

Abstract: A method includes comparing a natural frequency of a tubular with a frequency of each of at least two pulse generating devices positioned adjacent each other on the tubular, the tubular and the at least two pulse generating devices comprising an energy system; adjusting the frequency of at least one of the at least two pulse generating devices when the frequency is equal to the natural frequency of the tubular and obtaining an adjusted frequency different from the natural frequency; calculating an energy distribution in the energy system based on the natural frequency and the adjusted frequency of the at least one of the at least two pulse generating devices; and determining a new location on the tubular for positioning one or more of the at least two pulse generating devices such that energy introduced into the energy system is less than energy dissipated from the energy system.

Abstract: A flow-off telemetry system and method of communicating information from a downhole location in a borehole to a surface location while fluid circulation is off. A string is conveyed in the wellbore to define an inner bore and an annulus. During a flow-off condition, an inner bore sealing element closes the inner bore to create a first standing column of fluid in the inner bore, and an annulus sealing element closes the annulus to form a second standing column of fluid in the annulus. A bypass valve in the string at a downhole location between the first standing column of fluid and the second standing column of fluid is activated to generate a pressure pulse including information for performing an action. The pressure pulse is received at a pressure sensor at the surface location and a controller performs an action in response to the information in the pressure pulse.

Abstract: A method includes operating a downhole acquisition tool in a wellbore in a geological formation and performing formation testing using the downhole acquisition tool in the wellbore to determine at least one measurement associated within the geological formation, the wellbore, or both. The downhole acquisition tool includes one or more sensors that may detect the at least one measurement and the at least one measurement includes formation pressure, wellbore pressure, or both. The method also includes using a processor of the downhole acquisition tool to obtain a response characteristic associated with the formation, the wellbore, or both based on oscillations in the at least one measurement and determining at least one petrophysical property of the geological formation, the wellbore, or both, based on the response characteristic. The petrophysical property includes permeability, mud filter cake permeability, or both.

Abstract: Apparatus and methods pertaining to a processing system operable to determine a change to an operation of a well construction system based on an indication of a quality of transmitted communication between downhole equipment of the well construction system in a wellbore and surface communication equipment of the well construction system transmitted during the operation, a projected effect of the operation on future communication between the downhole equipment and the surface communication equipment, downhole data related to one or more conditions in the wellbore, or a combination thereof. The processing system is operable to cause the change to the operation of the well construction system to be implemented.

Abstract: A mud pulse telemetry valve assembly and method including a mud valve sub and a mud pulse telemetry valve. The mud pulse telemetry valve having a flow tube positioned within the mud valve sub in a way that at least a portion of an outer surface of the flow tube is spaced a distance from at least a portion of an inner surface of the mud valve sub to form a hydraulic passageway having an upstream end and a downstream end. The mud pulse telemetry valve further having a control valve assembly and a pilot valve assembly.

Abstract: A technique includes receiving data representing a measurement acquired by a tool motion sensor of a downhole sonic measurement tool; and receiving data representing a measurement acquired by a pressure sensor of the sonic measurement tool. The technique includes modifying the measurement acquired by the pressure sensor based at least in part on the measurement acquired by the tool motion sensor to attenuate tool borne noise.

Abstract: A telemetry method transmits data from a downhole location to a surface location. During transmission an event is detected that makes it desirable to change a transmitted data stream. A downhole processor processes the detected event in combination with a predefined event database and downhole measurement data using a frame building algorithm to compute a digital data stream. Synchronization markers are added to the data stream to obtain a synchronized data stream in which the synchronization markers identify the detected event. The synchronized data stream is transmitted to the surface location using a downhole telemetry tool and received at the surface location to obtain a decoded data stream. A surface processor processes the synchronization markers to identify the detected event and further processes the detected event in combination with a predefined event database and the decoded data stream using the frame building algorithm to obtain the downhole measurements.

Abstract: A method of drilling a subterranean wellbore using a drill string includes injecting a drilling fluid into the subterranean well bore via the drill string and removing the drilling fluid from an annular space around the drill string (the annulus) via an annulus return line, oscillating a pressure of the drilling fluid in the annulus, determining a wellbore storage volume and a wellbore storage coefficient for each drilling fluid pressure oscillation, and using the wellbore storage volume and wellbore storage coefficient to determine a proportion by volume of gas and a proportion by volume of liquid in the annulus during that drilling fluid pressure oscillation. The wellbore storage volume is a change in a measured flow rate over a time period. The wellbore storage coefficient is the wellbore storage volume divided by a pressure change over the time period.

Abstract: A fluid pressure pulse generator apparatus for a telemetry tool comprising a stator and a rotor. The stator comprises a stator body and a plurality of radially extending stator projections spaced around the stator body and the spaced stator projections define stator flow channels extending therebetween. The rotor comprises a rotor body and a plurality of radially extending rotor projections spaced around the rotor body. The rotor projections are axially adjacent the stator projections and the rotor is rotatable relative to the stator such that the rotor projections move in and out of fluid communication with the stator flow channels to create fluid pressure pulses in fluid flowing through the stator flow channels. At least one of the rotor projections and at least one of the stator projections has a standard outer diameter. At least one of the rotor projections and/or at least one of the stator projections has a reduced outer diameter.

Abstract: A method and system of communicating with a device by controlling the flow rate of a fluid. The method comprises transmitting an encoded message with a flow control device by controlling the flow rate of a fluid and generating a signal indicative of the flow rate with a receiver. The method also comprises decoding the message by analyzing the signal using amplitude shift-keying. The system comprises a flow control device, a receiver, and a controller. The flow control device is in fluid communication with a tubular string and transmits an encoded message by controlling the flow rate of the fluid flowing through the tubular string. The receiver generates a signal indicative of the flow rate of the fluid in the tubular string. The controller is in communication with the receiver and decodes the message by analyzing the signal using amplitude shift-keying.

Abstract: A vibration while drilling acquisition and signal processing system include a sensor assembly affixable to a drill string in a drilling unit and a sensor for detecting vibrations in the drill string. A first processor is in signal communication with the sensor and is programmed to digitally sample signals from the sensor. A transmitter in signal communication with the first processor communicates the digitized signals to a device disposed apart from the drill string. The first processor is programmed to operate the signal. An electric power source provides power to the sensor, the first processor and transmitter. Either or both the first processor and a second processor associated with the device is programmed to calculate properties of rock formations using only detected vibration signals from the drill string.

Abstract: An example system for detecting mud pump stroke information comprises a distributed acoustic sensing (DAS) data collection system coupled to a downhole drilling system, a stroke detector coupled to a mud pump of the downhole drilling system configured to detect strokes in the mud pump and to generate mud pump stroke information based on the detected strokes, and a fiber disturber coupled to the stroke detector and to optical fiber of the DAS data collection system configured to disturb the optical fiber based on mud pump stroke information generated by the stroke detector. The system further comprises a computing system comprising a processor, memory, and a pulse detection module operable to transmit optical signals into the optical fiber of the DAS data collection system, receive DAS data signals in response to the transmitted optical signals, and detect mud pump stroke information in the received DAS data signals.

Abstract: A Sagnac loop coherent phase modulated RF photonic link employing an ACP-OPLL linear phase demodulator was presented. This structure demonstrated stable signal transmission over a 1-km long coherent RF photonic link.

Abstract: Drilling communication systems employ a Wi-Fi wet connect to communicate information from one downhole subsystem to another. In some implementations, the subsystems are disposed within drilling callers making-up a bottom hole assembly (BHA). The Wi-Fi wet connect may communicate information obtained by a first downhole subsystem for storing or transmission by the second downhole subsystem.

Abstract: In accordance with some embodiments of the present disclosure, systems and methods for a feedback based toolface control system for a rotary steerable drilling tool is disclosed. The method includes determining a desired toolface of a drilling tool, calculating a toolface error, calculating a correction to correct the toolface error by: estimating, using a model, an output of each of a plurality of states of the model based on an input to each of the states of the model and determining a desired input to each of the plurality of states, beginning at the toolface, based on a desired output of at least one of the plurality of states connected to a particular state, transmitting the signal to the input component of the drilling tool such that the signal adjusts the current toolface based on the correction, and drilling a wellbore with a drill bit oriented at the desired toolface.

Abstract: An apparatus and system for generating pressure pulses for enhancing and completing a well bore within a coiled tubing assembly including: a CT-MWD-FTD tool longitudinally and axially positioned within the center of a main valve assembly including a main valve. The drilling fluid is subsequently split into both an inlet main fluid stream and a pilot fluid stream, wherein the pilot fluid stream subsequently flows such that the pilot fluid recombines with the main flow stream to become a main exit fluid flow. The main exit fluid flow then proceeds toward a motor housing wherein one or more annular pressure sensors measure the pressure of fluid flow with sensors that send signals to a Digital Signal Processor (DSP) that controls flow throttling devices which generate controllable, large, rapid and measurable energy pulses.

Abstract: Systems and methods for digital signal processing are provided. A method includes mapping a symbol in a pulse sequence by using a pulse width and a pulse start in the symbol, reading a message using a symbol value for each symbol in a string of symbols, and modifying a drilling configuration according to the message. A device configured to perform the above method is also provided.

Abstract: Techniques for improving implementation of a downhole tool string to be deployed in a borehole formed in a sub-surface formation. In some embodiments, a design device determines a model that describes expected relationship between properties of the downhole tool string, the borehole, the sub-surface formation, and mud cake expected to be formed in the borehole; determines calibration locations along the borehole based on properties of the borehole; determines candidate spacer configurations based on contact force expected to occur at contact points between the downhole tool string and the mud cake when deployed with each of the candidate spacer configuration via the model; and determines a final spacer configuration to be used to attach one or more spacers along the downhole tool string based on expected head tension to move the downhole tool string when deployed in the borehole with each of the candidate spacer configurations via the model.

Abstract: A method for automatically selecting a frequency band for transmission of a telemetry signal includes transforming acquired measurements from a time domain to a frequency domain to obtain a spectrum of measurements. The spectrum of measurements is processed to compute a total energy in band and a standard deviation of the power spectral density in band for a plurality of frequency bands. A ratio of the total energy in band to the standard deviation acquiring a plurality of measurements of transmitted telemetry signals and of the power spectral density in band is computed for at least two of the plurality of frequency bands. The frequency band having the highest computed ratio is selected and automatically downlinked to a downhole transmitter.

Abstract: A manufacturing system that manufactures a downhole tool string, which includes a model that describes relationship between properties of the downhole tool string, properties of a borehole, properties of a formation, and properties of a mud cake formed on a surface of the borehole and a design device that iteratively determines contact parameters that describe one or more contact points expected between the downhole tool string and the mud cake based at least in part on the model, in which the contact parameters comprise contact force expected at each of the contact points, adjusts the properties of the downhole tool string to add a spacer at one of the contact points associated with highest contact force, and indicates location, type, or both of the spacer to enable the manufacturing system to attach the spacer to the downhole tool string before deployment of the downhole tool string in the borehole.

Abstract: A method for transmitting data from a MWD system at the BHA of a drill string may include transmitting the data in a MWD signal from the MWD system. The MWD signal may be modulated at a position closer to the surface onto a mud pulse modulated signal. The mud pulse modulated signal may be generated by a downhole friction reducing device. The downhole friction reducing device may include a mud motor. The mud motor may create pressure pulses based on its speed of rotation. The downhole friction reducing device may include a modulating valve. The modulating valve may be electromechanically or mechanically operated. The modulated signal may be detected at the surface by a receiver using one or more pressure or flow sensors. The receiver may use one or more harmonics of the modulated signal to receive the data.

Abstract: A flow bypass sleeve for a fluid pressure pulse generator of a downhole telemetry tool. The fluid pressure pulse generator comprising a stator having one or more flow channels or orifices through which drilling fluid flows and a rotor which rotates relative to the stator to move in and out of fluid communication with the flow channels or orifices to create fluid pressure pulses in the drilling fluid flowing through the fluid pressure pulse generator. The flow bypass sleeve is configured to attach to a drill collar which housing the telemetry tool and comprises a body with a bore therethrough which receives the fluid pressure pulse generator. The body includes at least one longitudinally extending bypass channel comprising a groove longitudinally extending along an internal surface of the body or an aperture longitudinally extending through the body.

Abstract: Methods, apparatuses, and computer readable medium including computer program products, are provided for determining the depth of water in a well. A method may include coupling a signal onto a cable connected to a submersible well pump. The method may further include monitoring the cable to determine a first time corresponding to a first reflection of the signal caused by the cable entering a water column between a water surface and the submersible pump. The method may further include monitoring the cable to determine a second time corresponding to a second reflection of the signal caused by an impedance mismatch between the cable surrounded by water and a motor in the submersible well pump. The method may further include determining a water height between the submersible pump and the water surface from the first time and the second time.

Abstract: The present disclosure provides systems and methods for expanded mud pulse telemetry. Certain methods provided include measuring pressure proximate at least one of first and second pressure control modules along a drilling apparatus and telemetering the measured pressure to a surface controller. A command is transmitted from the surface controller to at least one of the first and second pressure control modules or one of first and second controllable flow restrictors via mud pulse telemetry while mud is not being pumped through a main standpipe.

Abstract: An electromagnetic telemetry system adjusts telemetry parameters which may include carrier frequency, signal amplitude and/or data encoding protocol to achieve reliable data transmission and to conserve power. In some embodiments, sweep signals transmit a range of carrier frequencies and the parameters are determined in part by analyzing the received sweep signals. In some embodiments, different parameters are selected automatically based on a mode of drilling.

Abstract: The disclosure is directed to method and apparatus for communication through a fluid. The method includes measuring signals in the fluid at at least two spaced apart positions; estimating a subset of a separation matrix; and using the estimated subset and the signals to estimate a signal sent by the message source. The apparatus may include a message source on a bottom hole assembly; sensors disposed at least two spaced apart locations; and at least one processor configured to: estimate a subset of a separation matrix based on the signals and use the subset to estimate a message signal set by the message source.

Abstract: Apparatus, systems, and methods may operate to determine the rotating magnetic tool face associated with a rotating section of a drillstring, to determine angular displacement between the rotating section of the drillstring and a substantially fixed section housing the rotating the section, and to determine the magnetic tool face of the substantially fixed section by combining the rotating magnetic tool face and the angular displacement. Additional apparatus, systems, and methods may operate in a similar manner to determine tool face locations.

Abstract: An apparatus includes a first structure having a cavity containing a first coupler portion, and a first cover to sealably cover the cavity. In addition, a second structure for engaging the first inductive structure has a cavity containing a second coupler portion. A second cover is sealably covers the cavity of the second structure.

Abstract: One embodiment includes a method comprising receiving an acoustic signal that is propagated along a drill string. The method also includes correlating the acoustic signal to a first stored acoustic signal representing a first symbol, wherein the first stored acoustic signal is acquired from a propagation along the drill string in an approximately noise free environment.

Abstract: Disclosed are a method and an apparatus for decoding a signal sent from a measurement-while-drilling tool. In order to decode the signal, a decoder implementation that is communicative according to a decoder implementation protocol and that is configured to decode the signal into a decoded signal is instantiated. The decoder implementation protocol is then conformed to a transmission protocol. The signal is sent to the decoder implementation according to the transmission protocol. Because the decoder implementation protocol has been conformed to the transmission protocol, the decoder implementation can receive the signal and can decode it. One way in which the decoder implementation protocol can be conformed to the transmission protocol is through the use of a translation layer between the module that sends the signal to be decoded and the decoder implementation.

Abstract: A fluid pressure pulse generator comprising a stator and rotor that can be used in measurement while drilling using mud pulse or pressure pulse telemetry is disclosed. The stator comprises a stator body with a circular opening therethrough and the rotor comprises a circular rotor body rotatably received in the circular opening of the stator body. One of the stator body or the rotor body comprises one or more than one fluid opening for flow of fluid therethrough and the other of the stator body or the rotor body comprises one or more than one full flow chamber. The rotor is rotatable between a full flow configuration whereby the full flow chamber and the fluid opening align so that fluid flows from the full flow chamber through the fluid opening, and a reduced flow configuration whereby the full flow chamber and the fluid opening are not aligned.

Abstract: A rotary shutter valve 500 is used for geothermal reservoir stimulation. The valve 500 includes a pressure chamber 520 for holding a working fluid (F) under pressure. A rotatable shutter 532 is turned with a powering device 544 to periodically align one or more windows 534 with one or more apertures 526 in a bulkhead 524. When aligned, the pressurized working fluid (F) flows through the bulkhead 524 and enters a pulse cavity 522, where it is discharged from the pulse cavity 522 as pressure waves 200. The pressure wave propagation 200 and eventual collapse of the bubbles 202 can be transmitted to a target rock surface 204 either in the form of a shock wave 206, or by micro jets 208, depending on the bubble-surface distance. Once cavitation at the rock face begins, fractures are initiated in the rock to create a network of micro-fissures for enhanced heat transfer.

Abstract: Provided is a power supply system capable of being used in a well over a long period of time. A power supply system for a well according to the present invention includes a secondary battery having an operating temperature range including a temperature of the inside of a well and supplying power to a device installed in the well; and a charge-discharge mechanism for charging and discharging the secondary battery, and is installed in the well. The secondary battery to be used in the power supply system may be a molten salt battery, and may include a sensor and communication apparatus.

Abstract: A casing string is augmented with one or more variable flow resistance devices or “vibrating tools” to facilitate advancement of the casing and distribution of the cement in the annulus once the casing is properly positioned. The method includes vibrating the casing string while advancing the casing down the wellbore or while the cement is pumped into the annulus, or both. After the cementing operation is completed, the devices may be drilled out to open the casing string for further operations. The casing string assembly may include a vibrating tool at the end in place of a conventional float shoe or float collar. Multiple vibrating tools can be employed in the casing string, and they may be combined with conventional float shoes and collars. Additionally, vibrating tools in the form of plugs can be pumped down and landed inside the casing string.

Abstract: An apparatus for communicating electrical power and data between downhole devices. The apparatus includes a wellbore tubular having a wall. An electrical device is positioned in a wellbore region to an exterior of the wellbore tubular. A first acoustic coupling element is positioned to the exterior of the wellbore tubular and is electrically connected to the electrical device. A second acoustic coupling element is positioned to an interior of the wellbore tubular. The second acoustic coupling element is operable to transmit electrical power to and receive data from the first acoustic coupling element through communication of acoustic signals through the wall of the wellbore tubular.