Abstract: Implementations described and claimed herein provide systems and methods for isolation detection. In one implementation, recorded data is obtained. The recorded data includes radial acoustic waves transmitted and received using a radial sensor of an acoustic logging tool deployed in a wellbore. Clockwise waves are separated from counterclockwise waves by converting the recorded data from a time domain to a frequency domain. The clockwise waves are shifted into shifted clockwise waves, and the counterclockwise waves are shifted into a shifted counterclockwise waves. A forward wave is generated by combining the shifted clockwise waves, and a reflected wave is generated by combining the shifted counterclockwise waves. One or more isolation regions are identified in the wellbore using the forward wave and the reflected wave.

Abstract: A seismometer with high sensitivity, broadband and all-dip is provided, The which relates to the technical field of seismometer, including a first force feedback module, an insulator, a top cover, a terminal post, an upper leaf spring, a mass block, a casing, a sealing ring, an insulation gasket, a guide spring, a wire frame, a magnetic shoe, a compensation ring, a lower leaf spring, a bottom cover, a second force feedback module and a third force feedback module. It provides the broadband seismometer technology based on dynamic force balance feedback and the all-dip broadband seismometer technology based on dip angle perception, which breaks through the limitations of conventional seismometers in sensitivity, frequency band, and dip angle, and truly realizes a seismometer with high sensitivity, broadband, and all-dip.

Abstract: An untethered downhole tool includes a first body, a second body, a logging sensor, a motor, and a controller. Each of the first and second bodies includes a housing that defines an inner volume and a magnetic anchor configured, in an active state, to attach the body to a wellbore tubular. The motor is attached to one of the first or second bodies and coupled to a spooler. The controller is communicably coupled to the motor and the first and second magnetic anchors. The controller is configured to adjust one of the first or second magnetic anchors from the active state to an inactive state; and activate the motor to operate the spooler to spool the cable from the spooler to increase a length of a portion of the cable between the spooler and the detached first or second body.

Abstract: An acoustic isolator and methods to the same. The acoustic isolator may comprise a body, one or more annular chambers formed inside the body of the acoustic isolator and positioned along a longitudinal axis of the acoustic isolator, an annular groove formed on an outer surface of the body of the acoustic isolator, and a passage disposed between the one or more annular chambers and the annular groove. The method may comprise transmitting an acoustic wave from a transmitter disposed on an acoustic logging tool into a subterranean formation, receiving an acoustic signal from the subterranean formation with a receiver disposed on the acoustic logging tool, and attenuating a second acoustic wave that moves between the transmitter and the receiver and through an acoustic isolator.

Abstract: A system for estimating a property of a region of interest includes an acoustic measurement device including a transmitter configured to emit an acoustic signal having at least one selected frequency configured to penetrate a surface of a borehole in an earth formation and produce internal diffuse backscatter from earth formation material behind the surface and within the region of interest, and a receiver configured to detect return signals from the region of interest and generate return signal data. The system also includes a processing device configured to receive the return signal data, process the return signal data to identify internal diffuse backscatter data indicative of the internal diffuse backscatter, calculate one or more characteristics of the internal diffuse backscatter, and estimate a property of the region of interest based on the one or more characteristics of the internal diffuse backscatter.

Abstract: Accelerometers are described herein that have RMS outputs. For instance, an example accelerometer may include a MEMS device and an ASIC. The MEMS device includes a structure having an attribute that changes in response to acceleration of an object. The ASIC determines acceleration of the object based at least in part on changes in the attribute. The ASIC includes analog circuitry, an ADC, and firmware. The analog circuitry measures the changes in the attribute and generates analog signals that represent the changes. The ADC converts the analog signals to digital signals. The firmware includes RMS firmware. The RMS firmware performs an RMS calculation on a representation of the digital signals to provide an RMS value that represents an amount of the acceleration of the object.

Abstract: The present disclosure discloses a seismic vibrator, a vibration device and a driving apparatus for the same. The seismic vibrator comprises: a base; a mounting plate; a first spring configured to connect the base and the mounting plate, so that the mounting plate reciprocates relative to the base; a coil fixed with the base; a magnet having one end fixed with the mounting plate, and the other end stretched into the coil; a magnetic steel fixed with the magnet, wherein a gap for accommodating the coil is provided between the magnetic steel and the magnet; and a counterweight fixed with the mounting plate. The vibration device comprises the above seismic vibrator and an adjustable base. Compared with the traditional electromagnetic controllable seismic vibrator, the structure of the seismic vibrator provided by the present disclosure is simpler.

Abstract: The disclosed embodiments include a method of downhole leak detection. The method of downhole leak detection includes obtaining physical signals detected by at least one physical sensor traveling along a wellbore. Additionally, the method includes detecting correlated sequences from the physical signals and constructing a covariance matrix based on the correlated sequences. The method also includes computing a spatial spectrum indicative of a location of a leak based on the covariance matrix.

Abstract: A method for characterizing a bond between a first tubular disposed in a borehole and a structure outside of the tubular, the method includes transmitting a signal into and through the first tubular using a signal transmitter conveyed through the borehole and detecting a return signal using a return signal receiver conveyed through the borehole to provide return signal information in a time domain. The method also includes transforming the return signal information in the time domain to return signal information in a frequency domain using a transform and determining a difference between the return signal information in the frequency domain and reference frequency domain return signal information. The method further includes characterizing the bond of the first tubular to the structure outside of the first tubular using the difference to provide a characterization of the bond.

Abstract: Data is received downhole from a downhole logging tool to produce received data. The received data is processed to produce processed data. A binary formatting option is selected from a group of binary formatting options, wherein applying the selected binary formatting option to the processed data produces fewer bits than applying any other binary formatting option of the group of binary formatting options to the processed data. The selected binary formatting option is applied to the processed data to produce binary data. The binary data is transmitted uphole. The binary data is received uphole. The received binary data is decompressed to produce uncompressed data. The uncompressed data is processed uphole.

Abstract: An apparatus for use in acoustically assessing a wellbore, comprises a tubular body, an acoustic transmitter supported on the body, first and second acoustic receivers supported on the body with the second receiver being farther from the transmitter, wherein at least one of the inner and outer body surfaces includes a helical groove between the acoustic transmitter and the first acoustic receiver and the helical groove is filled with a composite material. The body may include a second helical groove that has the same pitch as the first helical groove and is diametrically opposite the first helical groove and may further include a third helical groove between the first and second receivers. At least one of the grooves may an opening width that is less than the maximum groove width and may have a cross-sectional area that includes a neck. The composite material may comprise tungsten particles in rubber.

Abstract: An apparatus includes a central body having a longitudinal axis and a first extended member attached to the central body, wherein the first extended member extends away from the longitudinal axis. The apparatus also includes a first mechanically sensitive sensor mechanically coupled to the first extended member.

Abstract: A method for estimating a borehole condition using a Stoneley measurement is provided. The method comprises recording acoustic waveforms obtained from one or more receivers, applying a time window to the acoustic waveforms to extract Stoneley components, computing energies of the Stoneley components within a frequency band, and obtaining at least one of borehole conditions based on the energies of Stoneley components.

Abstract: A detection panel, a display apparatus, a method for driving the detection panel, and a method for manufacturing the detection panel are provided. The detection panel includes an upper electrode layer, a piezoelectric material layer and a conductive backing layer which are sequentially stacked. The piezoelectric material layer is configured to change an electric field between the upper electrode layer and the conductive backing layer under an ultrasonic wave, and generate an ultrasonic wave under an electric field. The conductive backing layer includes a plurality of noise elimination members, and each of the noise elimination members has a dimension in a direction parallel to the detection panel that gradually decreases in a direction distal to the piezoelectric material layer.

Abstract: A method for identifying one or more imaging properties. The method may comprise identifying one or more candidate mud constants, taking one or more measurements from a borehole with a downhole tool to form an image log, inputting into a machine learning model one or more inputs such that the machine learning model outputs one or more estimated imaging properties, and inputting into a forward model at least the one or more estimated imaging properties and the one or more candidate mud constants such that the forward model outputs one or more reconstructed tool responses. The method may further comprise computing a misfit between the one or more reconstructed tool responses and the one or more measurements, picking a mud candidate from the one or more candidate mud constants based at least in part on the misfit, and producing one or more imaging properties from the picked mud candidate.

Abstract: A system for inspection includes an ultrasound transmitter, an ultrasound receiver, an isolator, and a control system. The ultrasound transmitter, the ultrasound receiver, and the isolator are coupled to an exterior of a metal pipeline. The control system is configured to provide an input signal to the ultrasound transmitter; receive a received signal using the ultrasound receiver; and provide a result based at least in part on the received signal.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: Apparatus includes a plurality of geological subsurface electrical line sensors spaced apart from each other proximate a predetermined geological subsurface region of interest, with at least one of the electrical line sensors situated as a line source to produce a multi-frequency electrical impedance tomography source signal, and with at least one of the electrical line sensors situated as a line detector to receive the multi-frequency electrical impedance tomography response signal associated with the source signal that propagates through the predetermined geological subsurface region of interest, and a controller including a processor and a memory configured with instructions that, when executed by the processor, cause the processor to determine an electrical mapping over the predetermined geological subsurface region of interest based on the multi-frequency electrical impedance tomography source signal, response signal, and the spatial positions of the geological subsurface electrical line sensors.

Abstract: A wellbore communication system includes a section of downhole tubing positionable within a wellbore and a track mechanically coupleable to the section of downhole tubing. The wellbore communication system also includes a downhole communication device and an actuator mechanically coupleable to the downhole communication device and the track. In operation, the actuator is able to move the downhole communication device along the track.

Abstract: A downhole tool that has a plurality of arm assemblies. Each of the arm assemblies has an arm configured to expand and retract and an actuator. A hydraulic bus in fluid communication with the plurality of arm assemblies. A plurality of flow control devices. The flow control devices are configured to selectively isolate one or more arm assemblies of the plurality of arm assemblies from the hydraulic bus while maintaining the other arm assemblies of the plurality of arm assemblies in communication with the hydraulic bus.

Abstract: A device for centering a sensor assembly in a bore comprises a first support member and a second support member axially spaced apart along a longitudinal axis of the device, and a plurality of arm assemblies connected between the first and second support members. Each arm assembly comprises a first arm pivotally connected to the first support member by a first pivot joint having a first pivot axis, a second arm pivotally connected to the second support member by a second pivot joint having a second pivot axis, a third arm connected between the first and second arms, the third arm pivotally connected to the first arm by a third pivot joint having a third pivot axis, and the third arm pivotally connected to the second arm by a fourth pivot joint having a fourth pivot axis.

Abstract: A method includes obtaining physical signals detected by a physical sensor traveling along a wellbore. The method also includes performing a first and second frame decomposition operations on a first and second set of physical signals detected by the physical sensor at first and second locations to obtain first and second pluralities of virtual signals associated with first and second arrays of virtual sensors. Each virtual sensor of the first and second arrays of virtual sensors is located at a virtual distance relative to the first and second locations, and the virtual distance corresponds to a physical distance. Additionally, the method includes computing first and second direction of arrival estimates of the first and second locations of the single physical sensor relative to a location of a downhole leak. Further, the method includes triangulating the first and second direction of arrival estimates to estimate the location of the downhole leak.

Abstract: A technique includes receiving data acquired by an acoustic measurement tool in a well, where the data represents multiple acoustic modes, including a first order formation flexural acoustic mode and a higher order formation flexural acoustic mode. The technique includes processing the data to identify the higher order formation flexural acoustic mode; and determining a shear slowness based at least in part on slowness values that are associated with the identified higher order formation flexural acoustic mode.

Abstract: Downhole fiber optic interrogation systems are described. The systems include a fiber optic control system, a first sensing system, a second sensing system, an optical fiber disposed within a well, and an optical switch arranged between the optical fiber and the first and second sensing systems, wherein the fiber optic control system performs time division multiplex control of the optical switch wherein the first sensing system is operably connected to the optical fiber and the second sensing system is not connected to the optical fiber, and further controls the optical switch such that the second sensing system is operably connected to the optical fiber and the first sensing system is not connected to the optical fiber.

Abstract: An apparatus comprising a stacked node configured to be positioned within a subterranean opening and comprising a plurality of separate receivers oriented end-to-end and each configured to independently detect subterranean activity, and a transmission medium configured to transmit data from the stacked node, wherein the data is representative of subterranean activity detected by the plurality of separate receivers.

Abstract: A leak-detecting assembly can include an array of hydrophones. The array can be moved within a hydrocarbon well. A variation in the Doppler shift caused by a stationary acoustic source (such as a leak) while the array moves towards and away from that source can be determined based on information from the array of hydrophones. The assembly can be associated with a passive system that captures acoustic signals directly from the source or leak and estimates a location of the source or leak based on measurement of Doppler shift in each receiver.

Abstract: One example of an acoustic signal attenuator for LWD/MWD logging systems can be implemented as an acoustic well logging tool positionable in a wellbore. The tool includes a longitudinal tool body. An acoustic signal transmitter and an acoustic signal receiver are mounted in the tool body and spaced longitudinally apart from each other. An acoustic signal attenuator which includes multiple slots formed in an outer surface of a portion of the tool body is positioned between the transmitter and the receiver. Each slot includes multiple protrusions extending from an inner surface of the slot into the slot. In operation, the multiple protrusions in each slot operate to attenuate an acoustic signal propagating from the transmitter to the receiver through the tool body.

Abstract: A system and method for rheology measurements. The system may comprise a conduit; an ultrasound transmitter positioned to direct ultrasound pulses into the conduit; an ultrasound receiver positioned to receive sound waves from the conduit; a pump fluidically coupled to the conduit; and a heat exchanger fluidically coupled to the conduit. The method may comprise drawing a sample of a treatment fluid into the rheology measurement system; pressuring the sample of the treatment fluid; adjusting temperature of the treatment fluid; directing ultrasound pulses into the treatment fluid while the treatment fluid is flowing through the rheology measurement system; measuring sound waves reflected by the treatment fluid; and determining a velocity profile of the treatment fluid based at least on the measured sound waves.

Abstract: An asynchronous top-mounted pulser system for a measurement while drilling tool uses hydraulic flow, an obstruction, a piston-balance system, and an orifice, to create pressure pulses in drilling fluid, using hydraulic pressure on an obstruction in a main pulser to assist in closing the obstruction. A valve poppet is set above (upstream of) the orifice and is pushed by fluid flow towards a closing position. The piston-balance system, connected to the poppet and located downstream of the orifice in the main pulser, responds to net pressures on the upstream and downstream sides of the piston to move the poppet. The piston also responds to a spring assembly urging the piston downstream, and tending to move the valve poppet to a closed position. A servo pulser, located downstream of the main pulser, opens and closes a rotary shear servo valve-controlled bypass flow path to control the net pressures on the piston.

Abstract: The disclosed embodiments include leak detection systems and methods of downhole leak detection. In one embodiment, the method includes obtaining physical signals measured by at least one physical sensor traveling along a wellbore. The method also includes performing a frame decomposition operation on the physical signals of a first of the at least one the physical sensor to obtain a plurality of virtual signals associated with an array of virtual sensors, each virtual sensor of the array of virtual sensors being located at a virtual distance relative to the first physical sensor, the virtual distance corresponding to a physical distance. The method further includes synchronizing the virtual signals of the array of virtual sensors. The method further includes computing a spatial spectrum indicative of a location of a leak based on the synchronized virtual signals.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method for estimating in real time the geomechanical properties using drilling data and an accurate drilling model. An initial structural framework and initial distribution of the geomechanical and other rock properties is adjusted in real time by estimating accurately the corrected mechanical specific energy (CMSE), which is then used to estimate the geomechanical and other rock properties. For example, the updated geomechanical model can be used to geosteer the well toward the brittle zones that will achieve the best stimulation when using hydraulic fracturing in unconventional wells.

Abstract: A method and system of mud pulse telemetry uses a preamble having a number of periods of a synchronization sequence followed by a single period of a channel estimation sequence. The synchronization may be characterized by a generally flat frequency spectrum, and the channel estimation sequence may be characterized by a low cross-correlation with said synchronization sequence. The sequences may be generated from a set of nonrepeating discrete sequences. The preamble may be suitable for both sequence detection and channel estimation, satisfy all the physical and/or electronic constraints of the system, and allow for fast convergence of an adaptive channel tracking or equalization system.

Abstract: A method and apparatus for measuring a property of settling of a first phase in a second fluid phase of a mixture. In order to measure the property of settling, the mixture may be contained in a chamber, an acoustic wave may be repeatedly passed vertically through the mixture, a transit time may be measured for each acoustic wave to traverse the mixture, and the property of settling using a change in the transit times of the acoustic waves may then be determined. In various embodiments, the property of settling can be a degree of settling.

Abstract: A well tool can include an outer housing and a vibratory transmitter disposed in the outer housing. The vibratory transmitter transmits a vibratory signal to an optical line disposed in the outer housing. A well system can include an optical line extending in a wellbore, and at least one well tool secured to the optical line and including a vibratory transmitter which transmits a vibratory signal to the optical line. The optical line conveys the well tool into the wellbore. A method of telemetering data from a well tool to an optical line can include securing the well tool to the optical line without optically connecting the well tool to the optical line, and conveying the well tool in a wellbore on the optical line.

Abstract: A seismic sensor device includes an elongated housing for placement at least partially into an earth surface. A plurality of particle motion sensors are contained in the elongated housing to measure translational data in a first direction, where plural pairs of the particle motion sensors are spaced apart along a second, different direction along a longitudinal axis of the elongated housing. A communication interface communicates the measured translational data to a computer system configured to compute a gradient based on respective differences of the measured translational data of the corresponding plural pairs of the particle motion sensors, and compute one or more of rotation data and divergence data using the gradient.

Abstract: In the present invention that considerable advantage is to be gained in the provision of apparatus and methods for spectral noise logging that exhibit improved frequency resolution and thus sensitivity over those systems known in the art since this would allow for improved detection and characterization of fluid flow through, or behind, a casing of a well penetrating subsurface formations.

Abstract: A flange bolt cutter for separating two connected flanges. The flange bolt cutter contains a circular saw blade connected to an flange mount which can be vertically adjusted relative to the flange mount and/or includes two arms which can be pivotally adjusted relative to each other.

Abstract: A downhole signal transmission system provides electric radiofrequency signals that are coupled to electrically conductive or non-conductive fluids through electrical insulators. A plurality of signal repeaters are tuned to the frequencies of the radiofrequency signals, and a plurality of transmission lines terminated by resonance circuits are also provided such that the terminating resonance circuits resonate on the frequencies of the electric radiofrequency signals. The plurality of signal repeaters and plurality of transmission elements are arranged to be redundant such that a failure of one or more of the signal repeaters or a failure of one or more of the transmission elements does not substantially affect the operation of the data transmission system. The signal repeaters and transmission elements also are arranged such that a failure of any of the signal repeaters or a failure of any of the transmission elements is communicated to the surface.

Abstract: A system for drilling at least one well of interest proximate a reference well comprises at least one sensor in a drill string in the at least one well of interest to detect at least one parameter of interest related to a distance and a direction to the reference well. A controller is operatively coupled to the at least one sensor to determine the distance and the direction from the sensor to the reference well based at least in part on the at least one detected parameter of interest. A steerable assembly is operatively coupled to the controller to receive commands from the controller to adjust the path of the at least one well of interest being drilled based at least in part on the distance and direction from the sensor to the reference well.

Abstract: A tool for monopole and multipole sonic logging includes an acoustic source section, an acoustic receiver section, and an isolator section disposed therebetween. The tool may include a mandrel having integrally formed alternating first portions having a first outer diameter and second portions having a second outer diameter. The second outer diameter is smaller than the first outer diameter, which allows the portions to function acoustically as a mass and spring system. The isolator section sufficiently mutes or delays extensional and flexural modes intrinsic to the logging tool itself. Thus, the effects of the tool presence on the measurements are minimized. In addition, a plurality of axially oriented grooves are defined in an outer surface of the acoustic receiver section, and each groove is configured for receiving an acoustic receiver module that includes a sensor, an amplifier, an A/D converter, and a digital multiplexer.

Abstract: A seismic sensor cable 10 for lowering into a subterranean well 15 for acquiring information about seismic, microseismic and mechanical vibration incidents in the subterranean well 15, where the device comprises a first portion 20 that is elongate and has a first length with a proximal end and a distal end that are to be lowered down into a lower part of the subterranean well 15, the first portion 20 having a plurality of electric or electromechanical multicomponent seismic sensors 25 that are connected and distributed over large parts of its first length, and wherein the seismic profiling device 10 further comprises a second portion 30 that is elongate and has a second length with a proximal end that is to be held above the subterranean well 15 and a distal end that is to be lowered down into the upper part of the subterranean well 15, said second portion 30 comprising an optical fiber 35 that runs along large parts of said second portion 30, and an electric cable 40 for conducting electric power from the pr

Abstract: The disclosure addresses multiple embodiments of an acoustic isolator, and an acoustic logging tool which incorporates the acoustic isolator. The acoustic isolator is configured to minimize acoustic transmissions which could otherwise adversely affect acoustical measurements being made by an acoustic receiver. The described acoustic isolators include a plurality of longitudinally arranged mass members coupled to a central supporting structure, in a configuration to reduce acoustic transmissions in at least selected frequency ranges.

Abstract: A method for revealing anomalous discontinuity interfaces in pore pressures in non-drilled geological formations and an implementing system.

Abstract: A downhole tool that has a plurality of arm assemblies. Each of the arm assemblies has an arm configured to expand and retract and an actuator. A hydraulic bus in fluid communication with the plurality of arm assemblies. A plurality of flow control devices. The flow control devices are configured to selectively isolate one or more arm assemblies of the plurality of arm assemblies from the hydraulic bus while maintaining the other arm assemblies of the plurality of arm assemblies in communication with the hydraulic bus.

Abstract: A method and apparatus for normalizing an acoustic wellbore tool by correcting measured sector acoustic signals due to changes in pressure and temperature downhole, the method and apparatus comprising an acoustic wellbore tool having at least one monopole transmitter and monopole receiver, and one or more sector transmitters and receivers disposed along the longitudinal axis of the tool, determining the attenuation values of received monopole and sector acoustic signals, determining a correction ratio using an average sector attenuation value and a theoretical attenuation value, and correcting the sector acoustic signals using the correction ratio.

Abstract: An apparatus and method for simultaneously obtaining quantitative measurements of vertical and horizontal resistivity and permittivity formation parameters by firing, using at least one transmitter in each of a horizontally and vertically polarized array on opposite sides of a drill collar, signals in the direction of a downhole formation, the fired signals from the transmitters in the arrays being fired simultaneously and engaging the downhole formation. The apparatus and method continues by receiving, using at least one receiver in each of the arrays, signals associated with the fired signals after the fired signals have engaged the downhole formation, where the received signals represent apparent formation data. The apparatus and method further involves determining, using the measured apparent formation data, the true formation data including one or more vertical and horizontal formation parameters.

Abstract: An ultrasound probe assembly includes a transducer configured to transmit and receive ultrasound signals in relation to a structure, and a delay line coupled to the transducer. The delay line is configured to change shapes between an uncompressed state and a compressed state. In at least one embodiment, the changing shape of the delay line changes a shape of the ultrasound signals.

Abstract: A shock sleeve is positioned above a UBHO sleeve, and both are received inside a substantially tubular sub collar. The shock sleeve is free to reciprocate with respect to the UBHO sleeve and sub collar. A mud pulse transmitter valve is received into the shock sleeve. The shock sleeve is interposed between upper and lower shock springs, which provide compensating compression spring bias to dampen the transmitter valve (as received in the shock sleeve) from vibration or shock forces experienced by the sub collar. At least one shock absorbing compression ring interposed between mating portions of the shock sleeve and transmitter valve also dampens the transmitter valve against vibration or shock. An optional mud filter received over the shock sleeve removes particulate matter from drilling fluid before it encounters the shock sleeve.

Abstract: Various systems and methods for implementing and using a variable stiffness downhole tool housing include cylindrical segments positioned along a common axis, with a pair of segments each coupled to a bulkhead and positioned at either axial end of the tool housing. The housing also includes a flexible cylindrical sleeve, positioned along the common axis between two of the plurality of cylindrical segments, that includes a first and second region with an outer diameter no larger than a common segment inner diameter and a third region located between the first and second regions and with an outer diameter no larger than a common segment outer diameter (the first and second regions each at least partially inserted into an end of one segment). A stiffness controller controls the stiffness of the tool housing by controlling at least part of an axial force exerted between the two segments.