Abstract: A monitoring system includes a flow line, an optical fiber coupled to the flow line, and a receiver coupled to an end of the optical fiber. The receiver is configured to detect at least one acoustic signal from the optical fiber. In addition, the monitoring system includes processor unit to detect a flow obstruction within the flow line based on the acoustic signal.

Abstract: Some implementations of the present disclosure provide a method that include: accessing a plurality of measurement logs taken from more than one well locations of a reservoir, wherein the plurality of measurement logs encode, for each well location, a plurality of parameters; based on applying a petrophysical model to the plurality of measurement logs, determining the plurality of parameters; based on a portion of the plurality of parameters, calculating a compressional formation slowness and a shear formation slowness; and predicting a fluid type at the more than one well locations of the reservoir based on combining the compressional formation slowness and the shear formation slowness with at least one of the plurality of parameters.

Abstract: A method for collecting data relating to characteristics of a wellbore by generating tube waves within the wellbore using an electro-hydraulic discharge (EHD) source includes generating tube waves that propagate within a fluid column of a wellbore using an EHD source, where the fluid column is defined by a casing string within the wellbore. The method also includes allowing at least a portion of the generated tube waves to interact with acoustic impedance boundaries that act as reflectors within the wellbore, creating reflected tube waves that propagate within the fluid column. The method further includes recording data corresponding to the generated tube waves and the reflected tube waves using a receiver, where the recorded data relate to characteristics of the reflectors within the wellbore.

Abstract: A method of realizing an shear wave propagation velocity anisotropy characterization within a display for a wellbore region including, obtaining a shear wave propagation velocity anisotropy intensity, and a shear wave propagation velocity anisotropy azimuth. A directional line segment is determined to represent the anisotropy for each of a plurality of measured depth points along the wellbore, and plotted on the display as a plurality of directional line segments to produce a 1-dimensional anisotropy characterization plot.

Abstract: A hydrocarbon well includes a wellbore with a surface casing string that couples the wellbore to a wellhead located at the surface and a production casing string that extends through a reservoir within the subsurface. A fluid column is present within the wellbore. The hydrocarbon well also includes a high-frequency tube wave generator that is hydraulically coupled to the wellbore and is configured to generate high-frequency tube waves that propagate within the fluid column. The high-frequency tube waves include a selected waveform containing a specific bandwidth of high-frequency components. The hydrocarbon well further includes a receiver that is hydraulically coupled to the wellbore and is configured to record data corresponding to the generated and reflected high-frequency tube waves propagating within the fluid column, wherein the recorded data relate to characteristics of the wellbore. Moreover, such techniques may also be applied to a pipeline.

Abstract: A method of determining fluid inflow rates within a wellbore comprises determining a plurality of temperature features from a distributed temperature sensing signal originating in a wellbore, determining one or more frequency domain features from an acoustic signal originating the wellbore, and using at least one temperature feature of the plurality of temperature features and at least one frequency domain feature of the one or more frequency domain features to determine a fluid inflow rate at one or more locations along the wellbore.

Abstract: Logging of data by a downhole tool disposed in a borehole may be affected by tool wave effects. The tool waves appear in the first echo of casing wave arrivals and the amplitudes may be much larger than casing wave arrivals. The estimates of casing wave amplitude are biased due to these tool wave arrivals when using conventional cement-bond logging (CBL) processing. An automated adaptive inversion-based array processing for CBL evaluation using a downhole tool provides an improvement in the calculation of a bonding index.

Abstract: A method is described for seismic inversion including receiving a processed seismic image and an enhanced seismic image representative of a subsurface volume of interest; forward modeling the processed seismic image and the enhanced seismic image to generate a first modeled dataset and a second modeled dataset; differencing the first modeled dataset and the second modeled dataset to create a residual dataset; filtering the first modeled dataset to generate an approximation of illumination; preconditioning the residual dataset with the approximation of illumination to generate an adjoint source; back projecting the adjoint source to determine a model update; and applying the model update to an earth model of the subsurface volume of interest.

Abstract: Acoustic waves are obtained from an acoustic logging tool within a borehole passing through a formation. Signal properties in a time domain, frequency domain, or both are determined based on the obtained acoustic waves. A machine learning analysis is used to determine formation slowness based on the determined signal properties and a downhole operational parameter is adjusted based on the determined formation slowness.

Abstract: A method and system for measuring a compressional and a shear slowness. The method may comprise disposing a downhole tool into a wellbore. The downhole tool may comprise a transmitter, wherein the transmitter is a monopole, and a receiver, wherein the receiver is a monopole receiver. The method may further comprise broadcasting the sonic waveform into the formation penetrated by the wellbore, recording a reflected wave on one or more receivers, wherein the reflected wave is a compressional wave or a shear wave, processing the reflected wave into at least one measurement, and applying a validation scheme to the at least one measurement. The system may be a downhole tool comprising a transmitter configured to transmit a sonic waveform into a formation, wherein the transmitter is a monopole, and a receiver configured to record a reflected wave, wherein the receiver is a monopole receiver.

Abstract: An acoustic receiver and method for acoustic logging. The acoustic receiver comprises a housing and a sensor subassembly, which is located within the housing. The sensor subassembly comprises a mount and a cylindrical piezoelectric crystal coupled to the mount. The sensor subassembly also comprises an isolation ring positioned between one of the ends of the cylindrical piezoelectric crystal and the mount. The isolation ring directly engages the crystal and the mount. The method of acoustic logging comprises receiving an acoustic signal using an acoustic receiver, which comprises a cylindrical piezoelectric crystal coupled to a mount without an adhesive material. The method also comprises converting the acoustic signal into an electrical signal by the cylindrical piezoelectric crystal and transmitting the electrical signal to a processor via a conductor coupled to the cylindrical piezoelectric crystal.

Abstract: A method for computing amplitude independent gradient for seismic velocity inversion in a frequency domain includes receiving seismic data associated with a region. The region comprises one or more earth subsurface layers represented by a plurality of points, and each point is associated with a seismic velocity. Seismic velocities at the plurality of points are determined by iteratively updating the seismic velocities based on a plurality of gradient values, where each gradient value corresponds to a point and is determined by evaluating a gradient of an objective function at a location of the point. A seismic image of the one or more earth subsurface layers is displayed based on the determined seismic velocities.

Abstract: The anisotropic media has an anisotropic layer, is disposed between outer isotropic media, causes multiple mode transmission on an elastic wave having a predetermined mode incident into the anisotropic media, and has a mode-coupling stiffness constant not zero. A thickness of the anisotropic layer according to modulus of elasticity and excitation frequency satisfies Equation (2) which is a phase matching condition of elastic waves propagating along the same direction or Equation (3) which is a phase matching condition of elastic waves propagating along the opposite direction, to generate mode conversion Fabry-Pérot resonance, ???kqld?kqsd=(2n+1)?, ??Equation (2) ???kqld+kqsd=(2m+1)?, ??Equation (3) kql is wave numbers of anisotropic media with quasi-longitudinal mode. lqs is wave numbers of anisotropic media with quasi-shear mode. d is a thickness of anisotropic media. n and m are integers.

Abstract: A computer-implemented method and system implementing the method, are disclosed for computing small cave recognition models, using seismic reflection data. User inputs and earth-model data are obtained over points of incidence of a survey region, at various angles of incidence. Various models are then computed that serve for cave identification and take part in preliminary seismic exploration and reservoir characterization. Therefore, the attributes developed by the computer-implemented method and system serve as indicators of low velocity and density cave recognition which are capable of separating the cave events from the normal layer events; identifying caves with size larger than half to one wavelength of the dominant signal; and identifying cave diffractions from caves that contain a local maximal/minimal at around nine degrees in amplitude versus angle models.

Abstract: Systems and methods include a computer-implemented method for presenting interpretation results of synchronized seismic data and fracture treatment times. A standard format seismic dataset of sensor readings obtained from a three-component sensor is generated. Coordinates and recording times corresponding to the sensor readings are added to the standard format seismic dataset. Synchronized seismic data is generated from the standard format seismic dataset by synchronizing seismic recording times with fracture treatment times. Quality-controlled synchronized seismic data is generated by removing dead traces and abnormal data samples from the synchronized seismic data. A time-frequency analysis is performed on the quality-controlled synchronized seismic data, including performing short-time Fourier transforms to analyze variations of Fourier spectra over time. Based on the time-frequency analysis, resonance frequencies are extracted from each frequency spectrum at different time samples.

Abstract: The present disclosure provides a prestack separating method for a seismic wave, including: receiving P-wave, S1-wave and S2-wave of the seismic wave, wherein the P-wave, S1-wave and S2-wave are reflected from different points; projecting the P-wave, S1-wave and S2-wave into a Z-R-T coordinate system, so as to generate a projection matrix, wherein Z is a vertical component, R is a component of a source-to-receiver azimuth and T is a component orthogonal to the R component; forming vectors of the P-wave, S1-wave and S2-wave as a composite vector; transforming the composite vector to an anisotropic wave vector matrix according to base vectors on the vector directions of the P-wave, S1-wave and S2-wave; and performing a rotation transformation of an affine coordinate system on the anisotropic wave vector matrix to generate a wave separation matrix, thereby solving a problem of error prediction result of fracture parameters caused by the “mode leakage” phenomenon.

Abstract: A method and system for producing a Quasi-Static Stoneley Slowness log. The method for producing a Quasi-Static Stoneley Slowness log may comprise recording a pressure wave at a receiver; determining a slowness-frequency range with an information handling system from the pressure wave, processing a frequency-domain semblance, extracting a Stoneley Dispersion, minimizing a misfit between theoretical and the Stoneley Dispersion, and identifying Quasi-Static Stoneley slowness from the Stoneley Dispersion. The well measurement system for producing an Quasi-Static Stoneley Slowness log and shear slowness anisotropy may comprise a downhole tool, a vehicle, and an information handling system.

Abstract: An acoustic receiver and method for acoustic logging. The acoustic receiver comprises a housing and a sensor subassembly, which is located within the housing. The sensor subassembly comprises a mount and a cylindrical piezoelectric crystal coupled to the mount. The sensor subassembly also comprises an isolation ring positioned between one of the ends of the cylindrical piezoelectric crystal and the mount. The isolation ring directly engages the crystal and the mount. The method of acoustic logging comprises receiving an acoustic signal using an acoustic receiver, which comprises a cylindrical piezoelectric crystal coupled to a mount without an adhesive material. The method also comprises converting the acoustic signal into an electrical signal by the cylindrical piezoelectric crystal and transmitting the electrical signal to a processor via a conductor coupled to the cylindrical piezoelectric crystal.

Abstract: A method for generating one or more subsurface stress models. The method may include receiving seismic data. A plurality of first geomechanical property models may be generated based at least partially on the seismic data. A second geomechanical property model may be generated based at least partially on the seismic data. The second geomechanical property model may have a lower resolution than the first geomechanical property models. A stress model, a strain model, or a combination thereof may be generated based on the second geomechanical property model. One or more subsurface stress models may be generated based on the stress model, the strain model, or the combination thereof and the first geomechanical property models.

Abstract: A system for self-tuning sonic transmitters which transmits a plurality of frequencies into a downhole formation, then identifies which of the transmitted frequencies generates the best response from the formation. The system then uses the best frequency identified for subsequent logging of formation data until a subsequent tuning sequence is initiated.

Abstract: Systems and methods for performing focused blind deconvolution of signals received by a plurality of sensors are disclosed. In some embodiments, this may include determining a cross-correlation of first and second signals, obtaining a cross-correlation of a first response function and a second response function based on the cross-correlation of the first and second signals and subject to a first constraint that the first and second response functions are maximally white, and obtaining the first and second response functions based on the cross-correlation of the first and second response functions and subject to a second constraint that the first and second response functions are maximally front-loaded.

Abstract: A method is described for time-lapse seismic imaging that may include detecting moiré patterns in seismic images generated from time-lapse seismic data and identifying geologic features based on the moiré patterns. The method may be executed by a computer system.

Abstract: Apparatus and techniques described herein include receiving information indicative of a first cylindrical shell representing a portion of an acoustic logging tool, receiving information indicative of a second cylindrical shell concentrically surrounding the first cylindrical shell, the second cylindrical shell representing a second portion of the acoustic logging tool, and the second cylindrical shell comprising a fluid metal model including a non-zero density, a non-zero compressional wave propagation velocity, and a shear wave propagation velocity of zero or about zero. Information is determined indicative of an acoustic dispersion comprising a slowness (or other information indicative of a propagation velocity) of a wave propagating along the acoustic logging tool using a model including the first and second cylindrical shells.

Abstract: In accordance with embodiments of the present disclosure, systems and methods for taking acoustic/ultrasonic wave measurements of a wellbore using a downhole tool equipped with microelectromechanical (MEM) transducers are provided. The MEM transducers may include a plurality of MEM transmitters (e.g., MEM speakers) and a plurality of separate MEM receivers (e.g., MEM microphones). These MEM transducers may be disposed in arrays proximate an outer surface of the downhole tool to collect acoustic/ultrasonic wave measurements of the full circumference of a wellbore. Due to their small size, large numbers of MEM transducers may be distributed radially around the downhole tool. Such an arrangement of sensors may enable the downhole tool to perform measurements of the entire wellbore without the downhole tool needing to be rotated, leading to an increased signal-to-noise ratio of the measurements.

Abstract: A technique facilitates monitoring of acoustic signals to measure a velocity vector of a borehole. Acoustic sensors are arranged in a desired acoustic sensor array and positioned along a body of a tool, e.g. a sonic logging tool. The acoustic sensor array is then positioned in fluid along a wall of a borehole formed in a subterranean formation. The acoustic sensors are used to collect acoustic signal data while the acoustic sensors are maintained in a non-contact position with respect to the wall of the borehole. The data may be processed to determine the desired velocity vector.

Abstract: A distributed acoustic sensing system for use in a wellbore can include a shutter positioned between an amplifier and an optical-wave flow controller of the distributed acoustic sensing system for reducing optical noise in the distributed acoustic sensing system. The distributed acoustic sensing system can also include a controller operable to transmit a signal to the shutter to (i) open the shutter for allowing an optical pulse to transmit through the shutter, and (ii) close the shutter for preventing an extraneous optical waveform, that generates at least a portion of the optical noise, from transmitting through the shutter.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire acoustic noise data by one or more receivers, the acoustic noise provided by a passive source comprising a down hole tool body moving within a borehole, and/or a positioning device or a measurement device attached to the tool body. Additional operations may include processing the acoustic noise data to determine receiver calibration parameters, and/or formation properties. Additional apparatus, systems, and methods are disclosed.

Abstract: Methods and systems of barrier evaluation are disclosed. The method includes obtaining vibration measurement data measured in a wellbore having at least one casing. In addition, the method includes determining a boundary definition of the barrier between the casing and a formation, based on the vibration measurement data. Further, the method includes evaluating the barrier based on the one boundary definition. The system includes a vibration sensor located in the wellbore having at least one casing and a vibration source for generating vibrations. The system may also include a data logging system of producing vibration measurement data received with the vibration sensor and a processor for determining at least one boundary definition of barrier between the casing and a formation, based on the vibration measurement data and evaluating the barrier based on the at least one boundary definition.

Abstract: The present techniques are directed to systems and methods for monitoring parameter data from sensors, for example, in a subsea environment. In one method, an electrical signal including data from the subsea unit is converted into an acoustic signal. The acoustic signal is directed through the water column towards a fiber optic cable. The acoustic signal is detected by changes in a light signal carried in the fiber optic cable, and the changes in the light signal are decoded to obtain a data stream representing the parameter data.

Abstract: A system and method for effective estimation of properties of a formation using acoustic array processing is disclosed. An acoustic tool is directed to a zone of interest in the formation and generates a first signal. Real data corresponding to the first signal is then received. One or more basic parameters are provided as input. The basic parameters may include parameters relating to the acoustic tool or parameters relating to the zone of interest. A time semblance shear slowness and a frequency semblance shear slowness are determined using the basic parameters. A mask is then selected using the determined time semblance and frequency semblance shear slowness values and used to isolate a dispersion curve. A shear slowness value is selected from the dispersion curve and quality control is performed on the selected shear slowness value.

Abstract: Conventional computational simulation and inversion of subsurface flow is expensive, which is wasteful in terms of time and energy consumption. The present invention discloses a process for implementation of mathematical techniques such as forward simulation, sensitivity analysis, and inversion to physical microstructure models for subsurface fluid simulation. This process not only offers accurate and reliable results, but also is cost effective.

Abstract: A method for monitoring a subsurface during a 4-dimensional (4D) survey. The method includes obtaining an area of the subsurface that needs to be monitored; identifying receiver and source locations for the area and source frequencies to be emitted into the area based on demigration or inverse ray tracing; performing a light base survey for the area; performing a light monitor survey for the area; and generating an image of the area based on a comparison of (i) the light base survey, and (ii) the light monitor survey for the area.

Abstract: A method of measuring fluid flow conditions in a wellbore includes generating an acoustic probe signal during fluid flow along the wellbore, measuring the performance attribute of the acoustic probe signal within a target frequency range, and of the fluid medium in at least a part of the wellbore based on the measured performance parameters. The target frequency range of the acoustic probe signal encompasses a bubble resonance frequency range for vapor bubbles in the wellbore, for example having frequencies in excess of 20 kHz. An estimated bubble size value may be calculated based on determining a frequency at which the measured probe signal experiences the retardation or peak attenuation.

Abstract: Various micro-sonic density imaging-while-drilling systems and methods are disclosed. In at least some forms, the micro-sonic logging tool is embodied in a drill collar having at least one stabilizer blade. One or more acoustic transmitters are set in a distal face of the stabilizer blade to generate acoustic waves. One or more receivers can also be set in the distal face of the stabilizer blade to detect P-waves and S-waves that have propagated through the formation making up the borehole wall. Processing circuitry measures the velocity or slowness of the acoustic waves and optionally associates the measured values with a spot on the borehole wall as identified. Multiple transmitters can be used if it is desired to obtain compensated measurements. The tool can further include a fluid cell to measure acoustical properties of the borehole fluid, which can be used to convert the formation slowness measurements into density measurements.

Abstract: Various systems and methods are disclosed for implementing and using a multi-axial induction borehole imaging tool that includes emitters that induce, at azimuthally-spaced positions on a borehole wall, a plurality of fields having components in three non-coplanar directions within a formation. The tool also includes directionally sensitive inductive sensors that sense the components caused by each of the one or more inductive emitters, and a downhole controller that processes signals received from the directionally sensitive inductive sensors to provide a set of measurements representative of an impedance tensor at each position.

Abstract: Techniques involve obtaining acoustic data from an acoustic logging tool, where the acoustic data includes waves reflected from the casing, the annular fill material, the formation, and/or interfaces between any of the casing, the annular fill material, and the formation. A crude casing thickness, tool position (e.g., eccentering), mud sound velocity may be estimated using the acoustic data. A specular reflection signal may also be estimated based on the acoustic data. A modeled waveform may be generated using the estimated specular reflection signal and one or more model parameters, such as an estimated crude casing thickness, an estimated tool position, an estimated sound velocity of mud between the acoustic logging tool and the casing, an estimated impedance of the annular fill material, and an estimated impedance of the mud. The modeled waveform may be calibrated in some embodiments.

Abstract: Apparatus and techniques are described, such as for obtaining information indicative of an acoustic characteristic of a formation, including using a transducer assembly, comprising a base plate, a first piezoelectric slab and a second piezoelectric slab. The base plate includes a first region extending axially in a first direction beyond the first and second piezoelectric slabs along a specified axis of the base plate and a second region extending axially in a second direction, opposite the first direction, beyond the first and second piezoelectric slabs. In various examples, a length of the first region along the specified axis is different than a length of the second region to provide an asymmetric configuration. In various examples, an anchoring element is mechanically coupled to the base plate at a location corresponding to a node location of a specified acoustic vibration mode.

Abstract: An example method for displaying sonic logging data associated with a formation surrounding a borehole can include acquiring sonic data at a plurality of depths using an acoustic array located in the borehole and transforming the acquired sonic data from a time-space domain to a frequency-wave number domain at a limited number of discrete frequencies. The method can also include estimating slowness values at the limited number of discrete frequencies from the transformed sonic data, interpolating the estimated slowness values to obtain a projection of one or more slowness-frequency dispersions of the acquired sonic data and displaying the projection of the slowness-frequency dispersions. The projection of the slowness-frequency dispersions can include a plurality of color bands corresponding to each of the limited number of discrete frequencies.

Abstract: A method of performing a stimulation operation for a subterranean formation penetrated by a wellbore is provided. The method involves collecting pressure measurements of an isolated interval of the wellbore during injection of an injection fluid therein, generating a fracture closure from the pressure measurements, generating transmissibility based on the fracture closure and a mini fall off test of the isolated interval during the injection, obtaining fracture geometry from images of the subterranean formation about the isolated interval, and generating system permeability from the transmissibility and the fracture geometry. The method may also involve deploying a wireline stimulation tool into the wellbore, isolating an interval of the wellbore and injecting fluid into the interval with the wireline stimulation tool. The fracture geometry may be obtained by imaging the formation, and fracture geometry may be obtained from core sampling.

Abstract: A method for reducing noise in flouroscopic images by detection of the traits in the curvelet domain, matching of the detected traits and time-domain filtering adapted to the type of coefficients associated with a trait. The method uses the discrete curvelet transforms of the images from a sequence. The denoised coefficients are detected, then transmitted to a step for locally matching the traits, the matched data subsequently undergo a step for time-domain filtering allowing the movement of the objects to be preserved in the image and a step for a 2D IDCT (Inverse Discrete Curvelet Transform) in order to produce the final image.

Abstract: The present disclosure involves a novel way of using drilling vibrations generated by the deformation of a rock formation in response to forces acting on the rock formation, where the forces are related to a drill bit and/or drilling fluid system, to identify the nature and occurrence of fractures, fracture swarms and other mechanical discontinuities (boundaries) such as bedding planes and/or faults that offset or otherwise separate rock formations with different mechanical rock properties.

Abstract: An example method for fracture identification and characterization may include positioning a magnetic dipole transmitter and a magnetic dipole receiver within a borehole in a subterranean formation. At least one of the magnetic dipole transmitter and the magnetic dipole receiver may be tiled with respect to an axis of the borehole. The magnetic dipole transmitter may generate a time-varying electromagnetic (EM) signal. The magnetic dipole receiver may measure a response of the formation to the time-varying EM signal; the response may include at least two depths of a formation and at least two azimuthal orientations of the formation with respect to the axis of the borehole. An image of the formation may be generated based, at least in part, on the response, and at least one fracture characteristic may be determined based, at least in part, on the first image and a synthetic fracture image.

Abstract: Acoustic data acquired in a MWD/LWD system can be compressed for transmission to the surface. The compression technique can include semblance processing acoustic signals received at a plurality of receivers spaced apart from a transmitter to generate a semblance projection at each of a plurality of depths. Peaks of the semblance projection can then be telemetered to the surface, with each peak including a slowness (velocity) value and a coherence (semblance) value. The telemetered values may be processed at the surface to generate logs as a function of depth.

Abstract: A method of simulating a borehole acoustic response in an anisotropic formation of the crust of the earth includes formulating a geometric model of the formation. The geometric model includes a plurality of layers definable in a cylindrical coordinate system defined by an axial direction normal to each of the layers, a radial direction relative to the axial direction, and a circumferential direction relative to the axial direction. The method also includes formulating a computational model of wave propagation in the formation. The computational model includes field variables and a wave equation describing a behavior of the field variables. The field variables are represented as respective Fourier series expansions of Tr-periodic harmonics in the circumferential direction. The method also includes numerically solving the computational model.

Abstract: To construct a reduced order model of a subterranean structure, a model reduction algorithm is applied to produce the reduced order model that is an approximation of a true model of the subterranean structure. The model reduction algorithm uses interpolating frequencies that are purely imaginary to enhance computational efficiency of the algorithm.

Abstract: Methods and systems for investigating a formation surrounding a wellbore. The methods involve a semblance-based analysis of downhole data, for example low frequency downhole data. The semblance-based analysis includes group semblance mapping of the data, followed by single shot semblance map handling, followed by multiple shot data handling. The systems include a seismic source, a seismic receiver, and an electronics system for processing data according to a process including: group semblance mapping, single shot map handling, and multiple shot data handling. The seismic source may generate low frequency signals, and the seismic receiver may be two or more receiver subsystems that include at least two axially spaced-apart hydrophones and at least one multi-component geophone.

Abstract: Cased-hole radial profiling of shear parameters from sonic measurements is disclosed.

Abstract: Systems and methods for the estimating a plurality of anisotropic elastic constants (Cij) using borehole dispersions and refracted compressional headwave velocity at a single logging depth in a vertical, deviated, or horizontal wellbore in a transversely-isotropic with a vertical axis of symmetry (“TIV”) formation. The estimated elastic constants can then be used to calculate near-wellbore stress distributions in the wellbore, which aids in an optimal completion design, such as for shale-gas production in the presence of shale heterogeneity.

Abstract: A non-transitory computer-readable medium stores therein a data storage program causing a computer to execute a process. The process includes obtaining first data by grouping values of spatially discrete distribution points at each of times by each of the spatially discrete distribution points and chronologically sorting the grouped values, obtaining second data by compressing the first data in accordance with at least one of a plurality of compression conditions for each of the distribution points or each group of a plurality of the distribution points, the plurality of compression conditions including a necessity of compression, a compression interval, and a compression algorithm type, and storing the second data in a storage device.

Abstract: The present disclosure relates to methods and apparatuses for evaluating a porous earth formation. The method may include: generating an acoustic wave in a borehole fluid; measuring an attenuation of the acoustic wave; and estimating a permeability of an earth formation acoustically coupled to the borehole fluid using the estimated attenuation and a theoretical attenuation. The method may also include estimating a theoretical attenuation for the borehole fluid using acoustic properties of the borehole fluid. The apparatus for performing the method may include: an acoustic source, an acoustic sensor, and a processor configured to estimate the attenuation of an acoustic wave generated by the acoustic source.