Abstract: Implementations described and claimed herein provide systems and methods for isolation detection. In one implementation, an axial acoustic signal is obtained. The axial acoustic signal is captured using an axial sensor deployed in a structure in a subterranean surface. The axial acoustic signal is separated into a first wave region and a second wave region by applying velocity filtering. An axial symmetry of a portion of the structure is determined based on at least one of the first wave region or the second wave region.

Abstract: A method is disclosed that includes obtaining a seismic data set and a seismic wave propagation velocity model and approximating the seismic wave propagation velocity model as a plurality of layers each bounded by a first and second bounding depth. For each of the plurality of layers, the method includes: simulation of the propagation of a seismic wave through the layer using a two-way seismic wave propagation simulator; forming an over-determined system of linear equations relating at least one mono-frequency component of the seismic wave at the first depth to one mono-frequency component at the second depth; and determining a plurality of one-way seismic wave propagation operators by inverting the over-determined system of linear equations. The method further includes processing the seismic data set using the one-way seismic wave propagation. A system and a non-transitory computer readable medium for implementing the method are also disclosed.

Abstract: Embodiments presented provide for a fully automated method of high-resolution interval velocity estimation for vertical seismic profile-type data.

Abstract: A vibratory source for generating seismic signals includes a baseplate, and a lift and hydraulic actuator system configured to actuate the baseplate to impart seismic waves into the ground. The baseplate includes plural individual plates for contacting the ground.

Abstract: Methods and systems for processing seismic data are presented. Primary wave (P) seismic data (PP data) and shear wave (P) seismic data (PS data) are jointly inverted as part of a nonlinear tomography process which adheres to one or more co-depthing constraints.

Abstract: A method is disclosed for radiaiiy profiling shear velocities of flexural wave modes in a formation. The method includes establishing sensitivity kernels with two non-dimensionalized parameters and using said sensitivity kernels to perform an inversion for radial shear wave velocity profiles. This method may be used for LWD, MWD, or wireline logging operations.

Abstract: A method for establishing a geostress field distribution of slopes in canyon areas includes: obtaining a persistence ratio of a fracture surface based on a structural plane trace length and a rock bridge length of the fracture surface, and then obtaining a fracture stage of a crack according to progressive failure characteristics of rock mass, combining a character of the fracture surface to obtain magnitude and direction of a maximum principal stress, and establishing the geostress field distribution. The method is simple to operate, does not need to carry out geostress testing, does not need a large amount of manpower and material resources, does not need redundant fund investment, and can simply and effectively obtain geostress field data. Moreover, combining with the geostress field inversion technology, a large-scale geostress field distribution condition can be obtained, which can provide a basis for engineering site selection and engineering rock mass stability determination.

Abstract: Disclosed are a method and apparatus for estimating S-wave velocities by learning well logs, whereby the method includes a model formation step of forming an S-wave estimation model to output S-wave velocities corresponding to measured depth when the well logs are input based on train data sets including train data having values of multiple factors included in the well logs, the values being arranged corresponding to measured depth, and label data having S-wave velocities corresponding to measured depth as answers, and an S-wave velocity estimation step of inputting unseen data having values of multiple factors included in well logs acquired from a well at which S-wave velocities are to be estimated, the values being arranged corresponding to measured depth, to the S-wave estimation model to estimate S-wave velocities corresponding to measured depth.

Abstract: First time-based data, indicative of a first parameter, varies in value with respect to time and is associated with a drilling operation utilized to construct a well extending into a subterranean formation. A moving window transform of second time-based data is performed to generate a three-dimensional expression of frequency and amplitude of the first parameter or a second parameter. The second time-based data is based on the first time-based data. The second parameter varies in value with respect to time and is dependent upon the first parameter. The drilling operation is assessed based on the expression.

Abstract: Marine seismic data can be processed to remove or reduce two or more source side acquisition effects jointly when 1) the effects are placed in the same data domain as the received data and 2) the effects are described using the same basis functions which may signify representing the received data and the effects in the same chosen transform domain. The data effects may include source signature removal, source radiation pattern removal, residual shot noise suppression and data regularization, multi-channel reconstruction or regularization, prediction of sea surface multiples, separation of simultaneous sources etc. The joint processing can use iterative or non-iterative inversion technique, where the iterative inversion technique may be a matching pursuit technique.

Abstract: A method can include receiving values of an inversion based at least in part on seismic amplitude variation with azimuth (AVAz) data for a region of a geologic environment; based at least in part on the received values, computing values that depend on components of a second-rank tensor aij; selecting a fracture height for fractures in the geologic environment; selecting an azimuth for a first fracture set of the fractures; based at least in part on the values for the second-rank tensor aij, the fracture height and the selected azimuth, determining an azimuth for a second fracture set of the fractures; and generating a discrete fracture network (DFN) for at least a portion of the region of the geologic environment where the discrete fracture network (DFN) includes fractures of the first fracture set and fractures of the second fracture set.

Abstract: A method for minimizing the risk of induced seismicity from injection of fluids into a naturally fractured reservoir uses a meshless particle-based simulation to quantify the heterogeneity in energy storage within the reservoir. In particular, this methodology creates an equivalent fracture model from data on the natural fracture density, regional stress, pore pressure and elastic properties of the reservoir, in which points in the reservoir have a fracture length and fracture orientation. A meshless particle-based method is then employed to simulate the geomechanical interaction between regional stress and natural fractures to estimate the stress anisotropy and strain (e.g., differential stress and shear strain). The induced seismicity potential is then calculated at points in the reservoir based on the estimated stress anisotropy and strain. A zone for injection of fluids into the reservoir can be selected by identifying a large area of the reservoir having low induced seismicity potential.

Abstract: A system and method to predict rock strength by directly inverting for petrophysical properties. In one embodiment, seismic data is received or obtained from a seismic survey (step 101). The seismic data are then conditioned (step 103) in order to prepare them for an inversion process (step 105). The inversion process has an embedded rock physics model that allows the inversion to be formulated based upon, and thereby outputting or calculating (step 107), petrophysical properties. Rock strength data may then be calculated from the petrophysical properties (step 109).

Abstract: Method and system for ongoing monitoring for underground structure at or near a production wellpad is provided. The system includes a sparse acquisition grid and utilizes information obtained from Rayleigh waves to monitor subsurface structures.

Abstract: An inspection system to measure the condition of at least a wall of a ground opening, the inspection system having a head unit for lowering into a borehole during a data collection phase wherein at least one set of test data is collected concerning one or more physical characteristics of the borehole during the data collection phase, the head unit having an internal measurement system and a sensor arrangement with a plurality of sensors facing radially outwardly of a head axis that is generally parallel to at least a portion of a borehole axis, the plurality of sensors allowing the head unit to be moved during the data collection phase without rotation about the head axis, the plurality of sensors at least partially producing the at least one set of test data collected during the data collection phase.

Abstract: A method for using an offset vector tile gather to image a subsurface defines an offset vector tile gather by selecting a plurality of seismic traces from recorded seismic data. Each seismic trace in the offset vector tile includes reflections from subsurface reflectors and reflection points at depths below the surface of the subsurface. Each reflection point is in a given seismic trace, and each given seismic trace extends from a seismic source to a seismic receiver. The reflection points define an offset vector tile having a source line span and a receiver line span. The source line span is equal to or greater than a distance between adjacent seismic receiver lines, and the receiver line span is less than a distance between adjacent seismic source lines. The offset vector tile gather is used to produce a three dimensional image of the subsurface.

Abstract: Desirable completion zones can be identified using closure stress in combination with one or more other attributes such as porosity. One computer-based well placement method includes using the computer to: process a seismic data volume to map the spatial distribution of a seismic-based CSS attribute; acquire logs from one or more boreholes in the subsurface region; derive from the logs a relationship between CSS and a minimum in-situ stress; apply the relationship to the CSS attribute map to produce a landing map that highlights desirable completion zones; and place one or more wells in the desirable completion zones. The borehole logs may include direct measurements of minimum in-situ stress (acquired via microfracture testing), sonic tool measurements of P-wave and S-wave velocity, and density tool measurements of bulk formation density.

Abstract: A method. In one embodiment there is provided a method in which a direction from a sensor position to a noise source is determined. A coordinate rotation is applied to a first set of signal values, wherein each signal value of the first set of signal values is based on an output of a corresponding component of a three-component particle motion sensor at the sensor position. The applying generates a rotated set of signal values. The coordinate rotation comprises a coordinate rotation transforming a first set of coordinate axes to a second set of coordinate axes, wherein the first set of coordinate axes has each coordinate axis aligned with a corresponding component of the three-component particle motion sensor at the sensor position, and the second set of coordinate axes comprises a first axis pointed in a direction opposite the direction from the sensor position to the noise source.

Abstract: The present disclosure provides a system and method for estimating fracture density within a subsurface formation from S-wave seismic data. In one embodiment, the S-wave seismic data is separated into fast (“S1”) and slow (“S2”) data. A computer is used to compute local similarity of the S1 and S2 data and to compute a cumulative time-difference by which the S2 data lags the S1 data from the local similarity. Based on the computed cumulative time-difference, the fracture density of a subsurface formation is estimated.

Abstract: Seismic data acquired by independent simultaneous sweeping (ISS®) techniques are processed is to attenuate random uncompressed cross-talk signals and improve the resolution of the pre-stack migrated time image. A frequency-varying mean filter is applied on cross-spread offset-azimuth gathers of the data. The frequency-space domain filter may vary its window size according to the characteristics of the cross-talk.

Abstract: Control device (100) controlling a drilling operation and methods by which the dynamics of the continuum in question can be divided into superimposed waves, of which the wave traveling in the direction of the actuator and/or drive (10) is compensated by the actuator. This prevents reflection of the energy on the actuator. By using two sensors (30, 40) the wave traveling towards the actuator (10) and the wave traveling away from the actuator (10) can be calculated separately from one another, so that both the parameters of the wave traveling toward the actuator and the parameters of the wave traveling away from the actuator can be determined in order to be able to perform a control of the driving device of the drill string (20) on this basis.

Abstract: A system and method for investigating rock formations outside a borehole are provided. The method includes generating a first compressional acoustic wave at a first frequency by a first acoustic source; and generating a second compressional acoustic wave at a second frequency by a second acoustic source. The first and the second acoustic sources are arranged within a localized area of the borehole. The first and the second acoustic waves intersect in an intersection volume outside the borehole. The method further includes receiving a third shear acoustic wave at a third frequency, the third shear acoustic wave returning to the borehole due to a non-linear mixing process in a non-linear mixing zone within the intersection volume at a receiver arranged in the borehole. The third frequency is equal to a difference between the first frequency and the second frequency.

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

Abstract: A method of conducting multiple source, multiple signal seismic surveys in a marine environment are provided.

Abstract: An ultrasound system comprises an ultrasound probe for transmitting transmit beams and receiving receive beams. A processor controls the ultrasound probe to direct the transmit beams in a first direction to acquire a first incidence frame of data and a second direction to acquire an second incidence frame of data, wherein the first and second directions are different with respect to each other. A tissue characterization module compares the normal and oblique incidence frames of data to determine at least one property parameter of a scanned medium based on amplitude differences between the receive beams.

Abstract: A monopole acoustic transmitter for logging-while-drilling comprising as a ring that comprises one or more piezoelectric arc segments. The ring is oriented in a plane whose normal is essentially coincident with the major axis of a logging tool in which it is disposed. The ring disposed within a recess on the outer surface of a short, cylindrical insert. The insert is inserted into a drill collar, rather than into the wall of the collar. The ring can comprise a continuous ring of piezoelectric material, or alternately arc segments or active ring segments of piezoelectric ceramic bonded to segments of other materials such as alumina to increase the frequency or heavy metals such as tungsten to reduce the frequency. The material and dimensions of the material used in-between the piezoelectric segments is chosen to alter the frequency of the ring.

Abstract: A subterranean mapping system may include at least one electrically conductive element associated with a subterranean formation having a passageway therein. The subterranean mapping system may also include a radiofrequency (RF) source coupled to the at least one electrically conductive element to generate an electromagnetic (EM) field in the subterranean formation. The subterranean mapping system may also include a subterranean mapping device configured to be carried along a path of travel within the passageway and while sensing the EM field versus time.

Abstract: A subterranean mapping system may include a pair of spaced electrically conductive well pipes in a subterranean formation containing a hydrocarbon resource. The pair of electrically conductive well pipes may include a fluid inlet pipe and a fluid outlet pipe. The subterranean mapping system may further include a radiofrequency (RF) source coupled to the pair of electrically conductive well pipes to generate an electromagnetic (EM) field in the subterranean formation. The subterranean mapping system may further include a subterranean mapping device configured to be carried along with a fluid flow along a path of travel from the fluid inlet pipe to the fluid outlet pipe and while sensing the EM field versus time.

Abstract: Disclosed herein is a method of delineating a second wellbore from a first wellbore. The method includes, emitting acoustic waves from a tool in the first wellbore, receiving acoustic waves at the tool reflected from the second wellbore, and determining orientation and distance of at least a portion of the second wellbore relative to the tool.

Abstract: An approach is provided for a multi-component seismic data processing that separates P-type and S-type seismic waves in an affine coordinate system. A method for separating and composing seismic waves comprises: determining base vectors of the seismic waves; transforming and separating the seismic wave in an affine coordinate system; and obtaining a signal with true amplitudes and eliminating a mode leakage phenomenon. Therefore, the method achieves the wave separation and recovers the amplitudes of separated waves simultaneously, which reduces noises to provide more precisely seismic data and to satisfy the requirement of seismic data analysis and processing.

Abstract: A seismic survey system for surveying a subsurface. The system includes a volumetric land source buried underground for generating P-waves; a non-volumetric land source buried underground for generating P- and S-waves; plural receivers distributed about the volumetric and non-volumetric land sources and configured to record seismic signals corresponding to the P- and S-waves; and a controller connected to the volumetric land source and the non-volumetric land source and configured to shot them in a given pattern.

Abstract: The present invention provides a technique to separate compressional seismic waves from shear seismic waves and to determine their direction of propagation to enhance the seismic monitoring oil and gas reservoirs and the seismic monitoring of hydrofracturing in oil and gas wells. The invention utilizes various combinations of multi-component linear seismic sensors, multi-component rotational seismic sensors, and pressure sensors. Sensors are jointly deployed in arrays of shallow monitoring wells to avoid the complicating effects of the free surface of the earth. The emplacement of sensors in the shallow monitoring wells may be permanent. The method has a wide range of application in oil and gas exploration and production. This abstract is not intended to be used to interpret or limit the claims of this invention.

Abstract: A method for estimating principal stresses of a subterranean formation from seismic data. In one embodiment, rock strength parameters from seismic data of the formation is first determined to calculate the anisotropic elastic properties of the formation. The three principal stresses of the formation: vertical stress, minimum horizontal stress, and maximum horizontal stress, is determined using at least the calculated anisotropic elastic properties and the rock strength parameters of the formation. From the estimated principal stresses, the differential ratio of the maximum and minimum horizontal stresses can be determined to indicate optimal zones for hydraulic fracturing. In another embodiment, a tectonic strain term is introduced to calibrate the estimated principal estimated stress to a known reference point. In yet another embodiment, hoop stress is incorporated to estimate the fracture initiation pressures.

Abstract: A method to generate images of acoustic contrasts for structures located between at least one acoustic source and at least one receiver, said structures converting a part of the compressional energy to shear.

Abstract: A vibration sensor system for contacting the surface of a solid medium for detecting horizontally polarized shear waves and compressional waves. At least two contact points interface between a vibration sensor array and the solid medium to provide uninterrupted contact with the medium during detection of dynamic motions in the medium. A single vibration sensor is mounted on at least two adjacent contact points to convert detected dynamic motions to corresponding electrical signals. The single vibration sensor mounted on the two adjacent contact points forms a sub-array. The vibration sensor system has at least two sub-arrays. A conditioning and combining member treats sensor electrical signals from at least two sub-arrays to form a composite output signal for the system.

Abstract: A method is described for identifying anisotropic regions in unconventional hydrocarbon reservoirs, such as in shale formations. Anisotropy can be indicative of a zone of fracturing, which may represent a “sweet spot” for drilling a productive well. Seismic amplitude data from receivers is recorded along two orthogonal lines radiating from a seismic source. After time-migration, the equations for each orthogonal direction may be summed to obtain values for A and (Biso+0.5*Bani) which are independent of azimuth angle. Since Biso is normally constant or slow varying over a shale formation, anisotropic regions may be identified by looking for anomalous values of (Biso+0.5*Bani).

Abstract: Methods and systems for estimating the residual static terms for multi-component land datasets are described. A one-pass estimation simultaneously using P-P pre-stack data and P-S pre-stack data for generating common source residual statics for the P-P data and the P-S data and separate receiver residual statics for the P-P data and the P-S data. A series of iterations are performed using either a linear or a non-linear simulation to converge on acceptable residual statics.

Abstract: Methods and apparatus to combine monopole and multipole acoustic logging measurements to determine shear slowness are disclosed. An example method to determine shear slowness of a formation from acoustic logging data disclosed herein comprises determining a plurality of mixed coherence values corresponding to a respective plurality of possible shear slowness values, each mixed coherence value determined by combining a monopole coherence value determined from monopole logging data and a multipole coherence value determined from multipole logging data, the monopole and multipole coherence values each being determined for a particular possible shear slowness value corresponding to the mixed coherence value, and using the particular shear slowness value corresponding to a maximum mixed coherence value in the plurality of mixed coherence values to represent the shear slowness of the formation.

Abstract: A 4D seismic technique, where a base seismic trace is measured at a first time in a region of the subsoil, and then a monitor seismic trace corresponding to the base seismic trace is measured at a second time. To interpret the 4D measurements, assumptions are made about the variation of elastic parameters in permeable layers at predefined positions in one direction between the first and the second time. Elastic parameters include the density (?) and the speed of propagation of the pressure waves (VP) in the permeable layers. Numerical evaluation is performed for a capability of each assumption about the variation of elastic parameters to give an account of a change between the measured base seismic trace and the measured monitor seismic trace, and the variation of the elastic parameters is estimated in accordance with an assumption of optimum capability.

Abstract: A radial shear velocity profile of an earth formation is obtained by using dipole and/or cross-dipole measurements. The non-uniqueness in the inversion is addressed by using a constraint based on the fact that high-frequency dipole shear waves are mostly sensitive to the near-borehole shear velocity.

Abstract: Method for aligning converted wave seismic reflection data (PS data) with conventional PP seismic reflection data so that both data types may be used to more accurately image the subsurface for hydrocarbon exploration or field development. Amplitude vs. angle (AVA) or amplitude vs. offset (AVO) attributes of PP and PS seismic data are identified and defined, which attributes are theoretically expected to be in phase and optimize seismic resolution in the data. In one embodiment of the invention, such attributes are calculated (310), then the same horizons are identified in a series of PP attributes and in a series of PS attributes, then the second series is aligned with the first at the horizon locations (316, 320), then a time transfer function is generated and applied to the PS mode data (322), and the aligned joint-mode data are inverted (326) using, for example, AVA attributes.

Abstract: A system and method of processing seismic data obtained using a plurality of towed single-component receivers in a marine environment is described, the towed single-component receivers configured to measure compressional P waves. The method comprises retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data, wherein the P-P data and shear mode data were both received at the towed single-component receivers configured to measure compressional P waves to generate the seismic data. The method further comprises processing the seismic data to extract SV-P shear mode data and generating shear mode image data based on the extracted shear mode data.

Abstract: The present disclosure relates to methods and systems for evaluating potential hydrocarbon prospect locations within a subsurface formation. First and second opposite polarity directional seismic signals are propagated from a seismic source through the subsurface formation and recorded. A pure shear wave record is derived from the recorded signals and compared to a compression wave record for at least one potential hydrocarbon reservoir location within the formation.

Abstract: A measurement method for a granular compaction pile 10 using a crosshole seismic test. The measurement method includes forming first to fifth measurement holes around the granular compaction pile, injecting grouting material into the first to fifth measurement holes and inserting casings into the first to fifth measurement holes, respectively, and installing an oscillator and a detector of a crosshole seismic tester in the first to fifth holes and detecting a velocity of a shearing wave, thereby measuring a diameter of the granular compaction pile according to a construction depth thereof. The shape and the diameter of the granular compaction pile are easily checked without causing damage to the granular compaction pile.

Abstract: A vibration sensor system for contacting the surface of a solid medium for detecting horizontally polarized shear waves and compressional waves. At least two contact points interface between a vibration sensor array and the solid medium to provide uninterrupted contact with the medium during detection of dynamic motions in the medium. A single vibration sensor is mounted on at least two adjacent contact points to convert detected dynamic motions to corresponding electrical signals. The single vibration sensor mounted on the two adjacent contact points forms a sub-array. The vibration sensor system has at least two sub-arrays. A conditioning and combining member treats sensor electrical signals from at least two sub-arrays to form a composite output signal for the system.

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

Abstract: A system and method of acquiring and processing full elastic waveform data from a vertical-force source comprises providing seismic waves into the earth from the vertical-force source, sensing reflections of the seismic waves at multi-component geophones placed along the surface of the earth, and processing the reflections of the seismic waves to generate full elastic waveform data.

Abstract: A logging system for measuring anisotrophic properties of the materials penetrated by a borehole. A downhole or “logging tool” element of the system comprises a source section that comprises either a unipole or a dipole acoustic source. The receiver section comprises a plurality of receiver stations disposed at different axial spacings from the acoustic source. Each receiver station comprises one or more acoustic receivers. The system requires that the source and receiver sections rotate synchronously as the logging tool is conveyed along the borehole. Receiver responses are measured in a plurality of azimuthal angle segments and processed as a function of rotation angle of the tool. The logging system can be embodied as a logging-while-drilling system, a measurement-while-drilling system, and a wireline system that synchronously rotates source and receiver sections. All embodiments require that the acoustic source operate at a relatively high frequency.

Abstract: Methods and apparatus facilitating measurement of anisotropy are disclosed. According to some aspects, anisotropy can be determined while drilling. Monopole/quadrupole interactions, as well as monitoring dipole excitations and other methods, may be used to find the principal shear directions of a formation while drilling or during wireline or other operations.

Abstract: An approach is provided for a multi-component seismic data processing that separates P-type and S-type seismic waves in an affine coordinate system. A method for separating and composing seismic waves comprises: determining base vectors of the seismic waves; transforming and separating the seismic wave in an affine coordinate system; and obtaining a signal with true amplitudes and eliminating a mode leakage phenomenon. Therefore, the method achieves the wave separation and recovers the amplitudes of separated waves simultaneously, which reduces noises to provide more precisely seismic data and to satisfy the requirement of seismic data analysis and processing.