Abstract: Downhole seismic receiver systems that may be compatible with measurement-while-drilling systems. The downhole seismic receiver systems may be integrated into drill-string components, including drill collars of a bottom hole assembly. The downhole seismic receiver systems include one or more receiver subsystems which in turn include at least two or more same-type seismic sensors. The downhole seismic receiver systems are compatible with low frequency seismic sources and may be useful in determining orientation and location of bed boundaries around a wellbore and ahead of a drill-bit. The downhole seismic receiver systems can be operated with a downhole or surface source. Methods for downhole seismic, including single well and cross-well seismic. The methods may include analyzing data acquired by the receiver systems to obtain seismic information around the wellbore and ahead of the drill bit.

Abstract: Downhole seismic sources that may be compatible measurement-while-drilling systems. The downhole seismic sources are integrated into drill string components, including drill collars of the bottom hole assembly. The downhole seismic sources may generate a low swept frequency signal suitable for imaging around the drill-string and ahead of the drill bit. Integrated downhole seismic systems including a downhole seismic source, receivers and optionally data processing capabilities. The integrated systems may be configured to determine the distance and orientation of bed boundaries, including ahead of the drill bit up to about 200 m to 500 m in depth. Methods for downhole seismic, including single well and cross-well seismic. The methods may include obtaining seismic information ahead of the drill bit.

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: Slowness dispersion characteristics of multiple possibly interfering signals in broadband acoustic waves as received by an array of two or more sensors are extracted without using a physical model. The problem of dispersion extraction is mapped to the problem of reconstructing signals having a sparse representation in an appropriately chosen over-complete dictionary of basis elements. A sparsity penalized signal reconstruction algorithm is described where the sparsity constraints are implemented by imposing a l1 norm type penalty. The candidate modes that are extracted are consolidated by means of a clustering algorithm to extract phase and group slowness estimates at a number of frequencies which are then used to reconstruct the desired dispersion curves. These estimates can be further refined by building time domain propagators when signals are known to be time compact, such as by using the continuous wavelet transform.

Abstract: A system for locating an interface between a first material and a second material including one or more acoustic sensing elements operatively arranged to measure a characteristic of one or more acoustic signals at a plurality of locations along a length thereof. An instrumentation unit is coupled with the one or more acoustic sensing elements, and arranged to determine a difference between at least a first value of the characteristic measured at a first location and a second value of the characteristic measured at a second location of the plurality of locations for identifying the interface between the first material and the second material as being located between the first and second locations if the difference is greater than a preselected threshold amount. A method of locating an interface is also included.

Abstract: The present disclosure relates to increasing the output power of a clamped seismic or acoustic source disposed in a wellbore without damaging the borehole/casing/cement. One or more sources are provided and carried on a conveyance mechanism. The conveyance mechanism may be a wireline, a coiled tubing, or a drill pipe. The one or more sources are run into and/or out of the wellbore and temporarily disposed at various locations within the wellbore. The one or more sources are temporarily clamped to the wellbore at the various locations using distributed clamping, and a source signal is generated by the distributed clamped source. The distributed clamping device may have multiple clamping mechanisms along an increased length of the source or a continuous clamping mechanism along an increased length of the source.

Abstract: A system for detecting subterranean voids includes a sensor array disposed in a subterranean location, an energy emitting device disposed on a position on a surface of terrain, the energy emitting device operative to emit wave patterns that propagate in a subterranean region proximate to the energy emitting device, and a control system communicatively connected to the sensor array, the control system operative to receive signals from the sensor array indicative of the direction and intensity of wave patterns emitted from the energy emitting device and output an indication to a user indicative of the location of a subterranean void.

Abstract: Devices, systems and methods for land seismic. The devices include an above-ground storage tank in which an acoustic energy source is immersed in liquid. The above-ground storage tank may be portable, reusable, self-supporting and may lay flat when empty of liquid and rise on its own when being filled with liquid. The systems include the seismic source-storage tank device, one or more sensors for recording signals that are generated when the source is activated, and a processor for analyzing the recorded signals for geophysical information. The methods involve methods of inducing seismic waves using the seismic source-storage tank devices, and methods of conducting seismic surveys using the seismic source-storage tank devices.

Abstract: The present disclosure relates to making seismic measurements using a seismic source disposed in a wellbore. One or more seismic sources are provided and carried on a conveyance mechanism. One or more seismic receivers are provided and placed on or near the earth's surface, in the same wellbore as the seismic sources, or in another wellbore. The one or more seismic sources are run into and/or out of the wellbore using a controller or sequencer. The one or more seismic sources are positioned, manually or automatically, at one or more locations in the wellbore, using a set of computer-controlled instructions. Seismic measurements are made at the one or more locations by activating the one or more seismic sources and detecting a seismic source signal using the seismic receivers. The receivers may be carried on a conveyance mechanism and their position controlled, manually or automatically, using the set of computer-controlled instructions.

Abstract: Methods for in-situ reservoir investigation by borehole seismic methods are provided using receiver(s) and a downhole source. The downhole source may be a microseismic event, and may be located relative to the receiver(s) in any configuration. The downhole source may also be a controlled source that is positioned in a reverse vertical seismic profile (RVSP) geometry with respect to the receiver(s). The methods may involve locating the receiver(s) in a first well (which may have any orientation, including vertical or horizontal), and locating the source in a monitoring well (which may have any orientation, including vertical or horizontal), such that the source in the monitoring well is positioned at a greater depth in the formation than the receivers in the first well.

Abstract: An apparatus and a method for characterizing parts of a reservoir surrounding a borehole are provided including using at least one transmitter to emit a probing signal into the borehole and at least one receiver to receive a signal representing a response of the formation to the probing signal, with the distance separating the transmitter and the receiver being variable while suspended in the borehole using for example an apparatus which can be decoupled in the borehole into a stationary and a mobile section, carrying transmitter and receiver.

Abstract: Systems, methods, and software can be used to determine a confidence value for a fracture plane. In some aspects, a subset of microseismic events associated with a fracture treatment of a subterranean zone are selected. Confidence in associating the selected subset of microseismic events with a common fracture plane is determined. The confidence can be determined, for example, based on the number of microseismic events in the subset, a location uncertainty for each microseismic event in the subset, a moment magnitude for each microseismic event in the subset, a distance between each microseismic event and a fracture plane fitted to the microseismic events, an orientation of the fracture plane fitted to the microseismic events, or a combination of these and other factors.

Abstract: Systems, methods, and software can be used to analyze microseismic data from a fracture treatment. In some aspects, fracture planes are identified based on microseismic event data from a fracture treatment of a subterranean zone. Each fracture plane is associated with a subset of the microseismic event data. Confidence level groups are identified from the fracture planes. Each confidence level group includes fracture planes that have an accuracy confidence value within a respective range. A graphical representation of the fracture planes is generated. The graphical representation includes a distinct plot for each confidence level group.

Abstract: Disclosed is a method for estimating downhole lateral vibrations a drill tubular disposed in a borehole penetrating the earth or a component coupled to the drill tubular. The method includes rotating the drill tubular to drill the first borehole and performing a plurality of measurements in a time window of one or more parameters of the drill tubular at or above a surface of the earth during the rotating using a sensor. The method further includes estimating the downhole lateral vibrations using a processor that receives the plurality of measurements.

Abstract: Methods and apparatus for generating borehole seismic surveys are disclosed. The methods and apparatus enable more accurate surveys than previous surveying systems. In some embodiments, firing of remote seismic sources is synchronized with data recording in a borehole. In some embodiments, the synchronization is based on a universal time standard. In some embodiments, GPS positioning technology is used to predict firing times and synchronize firing times with downhole and surface recording.

Abstract: A method for estimating formation porosity and lithology on a real time basis during a logging while drilling operation using measured values of formation attenuation attributes for compression and/or shear.

Abstract: A system and method of performing a microseismic fracture operation for a wellsite having a subterranean formation with a complex fracture network therein are provided. The method involves describing a relationship between microseismic events to determine the complex fracture network of the subterranean formation, generating a fault volume by extracting faults from the fracture network based on the relationship between the microseismic events, generating a discrete fracture network comprising discrete fractures from the complex fracture network by extracting fracture planes from the obtained fault volume, and simulating fracture geometry and proppant placement.

Abstract: Presented are systems and methods for dampening vibrations transmitted to a sensor assembly based on well drilling operations. Vibration isolators are distributed around a sensor assembly and retained in their desired location. The sensor assembly and retained vibration isolators are inserted in a shrinkable thin-walled tube and the thin-walled tube is shrunk to constrict the inner surface of the thin-walled tube, and the retained vibration isolators against the outer surface of the sensor assembly. Additionally, the constricted thin-walled tube restrains a wiring harness associated with the sensor assembly in a wire well traversing the axial direction of the sensor assembly.

Abstract: The disclosure provides devices, systems and methods for obtaining unaliased wavefield data despite using spatial sampling distances that are higher than conventional techniques and temporal sampling rates that are lower than conventional techniques. The devices can include an array of sensors for sampling a desired wavefield and at least one of its derivatives. The systems can include a multi-level array of such sensor configurations. The methods can include lowering such an array into a borehole and sampling data at distances that are greater than suggested by conventional theory, or lowering a multi-level array into a borehole and simultaneously gathering data at different depth levels.

Abstract: The disclosure provides neutrally-buoyant tools for seismic data collection. The tools may range from several hundred meters to several kilometers in length and have integrated sensors which move along with the borehole fluid in response to a passing seismic wave. The disclosure also provides methods of deploying neutrally-buoyant tools, which includes using a tractor, adding a weight or both to the tool in order to overcome the difficulty of lowering a neutrally buoyant tool into a borehole, and optionally occasionally clamping the tool to the borehole to alleviate tension in the tool. This disclosure also provides methods of acquiring seismic data, which involves positioning a neutrally-buoyant tool in a borehole such that the tool is able to move relatively freely along with the borehole fluid in response to a seismic wave passing through the fluid, firing a seismic source, and using the sensors to collect seismic data generated thereby.

Abstract: A tool is described for seismic data collection which may have sensors mounted along its entire length to sample both geophysical signal and noise including at least one of acoustic noise, system noise, and noise resulting from the interaction between the two. Systems and methods for acquiring borehole seismic data are also described. In contrast to conventional systems which attempt to avoid introducing noise into the collected data stream, the present systems include a sufficient type, number, and spacing of sensors to intentionally sample at least one source of noise. The methods include operating a borehole seismic acquisition system to sample both a target signal and at least one source of noise and using a processor with machine-readable instructions for separating the noise from the signal.

Abstract: A method of determining an azimuthal orientation of a well tool relative to a line in a well can include connecting at least one acoustic source to the well tool, the acoustic source having a known azimuthal orientation relative to the well tool, and detecting at least one acoustic signal transmitted from the acoustic source to an acoustic sensor, the acoustic sensor having a known azimuthal orientation relative to the line. A system for determining an azimuthal orientation of one or more lines relative to a well tool in a wellbore can include at least one acoustic source having a known azimuthal orientation relative to the well tool, and an optical waveguide connected to a distributed acoustic sensing instrumentation, the waveguide having a known azimuthal orientation relative to the lines, and in which the distributed acoustic sensing instrumentation detects acoustic signals transmitted from the acoustic source to the waveguide.

Abstract: A fiber optic distributed vibration system for detecting seismic signals in an earth formation is provided. The system includes a fiber optic cable deployed in a borehole that extends into the earth formation and which is configured to react along its length to a seismic wave incident on the fiber optic cable from outside the borehole. An optical source launches an optical signal into the fiber optic cable while the seismic wave is incident thereon. A receiver detects coherent Rayleigh noise (CRN) produced in response to the optical signal. A processing circuit processes the detected CRN signal to determine characteristics of the earth formation.

Abstract: Methods and systems for the detection and localization of microseismic events are proposed which operate in real-time. Hypocenters in three spatial dimensions are provided along with an estimate of the event origin time. Sensor positions may be distributed in 3D space, and are not confined to linear arrays in vertical wells. A location of the event is approximated and a grid search, based on the approximate location of the event, is used to derive a residual function over a finer sampling followed by a gradient search of the residual function to optimize the location of the event.

Abstract: A method for updating an earth model with fractures or faults using a microseismic data using mechanical attributes of an identified faults or fracture by matching a failure criterion to observed microseismic events for an identified fault or fracture.

Abstract: A system performs production optimization for oilfields using a mixed-integer nonlinear programming (MINLP) model. The system uses an offline-online approach to model a network of interdependent wells in an online network simulator while modeling multiple interdependent variables that control performance as an offline MINLP problem. The offline model is based on production profiles established by assuming decoupled wells in the actual network of wells. In one example, an amount of lift-gas to inject and settings for subsurface chokes are optimized. An offline solver optimizes variables through the MINLP model. Offline results are used to prime the online network simulator. Iteration between the offline and online models results in a convergence, at which point values for the interdependent variables are communicated to the real-world oilfield to optimize hydrocarbon production.

Abstract: A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation.

Abstract: A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation.

Abstract: A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation.

Abstract: An acoustic logging while drilling tool includes an acoustic transmitter and a linear array of acoustic receivers. At least one of the transmitter and the linear array of receivers is deployed on a blade having an outer diameter greater than that of the tool body. In preferred embodiments the transmitter and linear array are each deployed on a distinct blade. Deployment of the transmitter and/or the receivers on a blade reduces the standoff distance to the borehole wall which tends to improve the signal strength of received guided waves without an increase in transmitter power or receiver sensitivity.

Abstract: Microseismic mapping using buried arrays with the integration of passive and active seismic surveys provides enhanced microseismic mapping results. The system is initially set up by recording seismic data with the buried array installation while shooting a significant portion of the 3D surface seismic survey. The 3D surface seismic survey provides the following data: shallow 3D VSP data from the buried arrays; P-wave and converted wave data for the area covered by the buried array that benefits from the planned data integration processing effort; and microseismic data and associated analysis.

Abstract: A seismic survey system for performing offset borehole seismic survey measurement operations. The system may include a first seismic survey subsystem having a first wireless digital communication device and a second seismic survey subsystem having a second wireless digital communication device and remotely located from the first seismic survey subsystem. The first and second digital communication devices may be configured to provide a digital communication link for transporting digital information between the first seismic survey subsystem and second seismic survey subsystem. The system may be configured to enable a user at the first seismic survey subsystem to remotely modify at least a portion of a first plurality of operating parameters associated with at least one source signal device located at the second seismic survey subsystem. The system may also be configured to utilize GPS information in order to improve accuracy of source signal firing timing synchronization.

Abstract: A method for estimating formation permeability from measured sonic wave Stoneley attributes and particularly the Stoneley attributes of slowness (DTst) and attenuation (ATTst), taking into consideration the existence of a heavy walled drill collar at the end of the drill string and the relative lack of borehole mud cake during a drilling operation. In the subject LWD application a real-time qualitative indication for fracture and permeable zones is estimated from Stoneley measurements. This information is useful to a driller to make important timely decisions about drilling and completion programs.

Abstract: A method for determining an acoustic anisotropy of a subterranean formation includes measuring acoustic wave slownesses at three or more toolface angles while rotating a logging while drilling tool in a borehole. Compressional, shear, and/or guided wave slownesses may be measured. The measured slownesses are fit to a mathematical model to obtain maximum and minimum slownesses. The maximum and minimum slownesses are processed to determine the acoustic anisotropy of the formation.

Abstract: Systems and method described herein provide for obtaining information which can be used to create a seismic image of a portion of the earth surrounding a well. A device for obtaining information for creating a seismic image proximate a well includes at least one set of acoustic transducers mounted to an exterior surface of a well tubing and configured to transmit at least one acoustic signal, at least one set of hydrophones mounted to the exterior surface of the well tubing and configured to receive at least one reflected acoustic signal; and a cable configured to convey information to and from the at least one set of acoustic transducers and the at least one set of hydrophones.

Abstract: Methods and systems for acoustically determining reservoir parameters of subterranean formations. A tool comprising at least one seismic source or seismic receiver mounted thereon; a conveyance configured for movement of the acoustic tool in a borehole traversing the subterranean formations; and a source retainer configured or designed for permanent deployment in the borehole to removably retain the acoustic tool in the borehole. The source retainer when deployed provides acoustic coupling with the borehole and removably retains the acoustic tool in the borehole so that, over multiple deployments, the acoustic tool is repeatedly deployed at the same predetermined location and orientation relative to the subterranean formation, and with the same acoustic coupling to the borehole.

Abstract: A system includes a plurality of sensor assemblies that are adapted to be deployed in a wellbore and acquire sensor data indicative of microseismic activity due to a hydraulic fracturing operation in the wellbore. At least one of the sensor assemblies includes a command interface and at least one sensor and is adapted to use the command interface to identify a command stimulus that is communicated downhole and initiate an acquisition by the sensor in response to identifying the command stimulus.

Abstract: A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation.

Abstract: A method of passive surveying comprises generating one or more detected signals by passively detecting a signal generated within a subsurface earth formation due to a seismoelectric response or an electroseismic response in at least one porous subsurface earth formation containing at least one fluid, and processing the one or more detected signals to determine at least one property of the subsurface earth formation.

Abstract: A system and method for steering a relief well to intersect a previously drilled wellbore. In one embodiment, a system includes a drill string disposed in the relief well and a surface processing system. The drill string includes a plurality of sections of wired drill pipe connected end-to-end, and a bottom hole assembly disposed at a downhole end of the drill string. The bottom hole assembly includes a drill bit, a steering tool configured to direct the drill bit towards a target, and an acoustic sensing tool. The acoustic sensing tool includes a plurality of acoustic sensors configured to detect acoustic signals emanating from fluid flow in a target wellbore. The surface processing system is coupled to the uphole end of the drill string, and is configured to determine a direction to the target wellbore based on the acoustic signals detected by the acoustic sensors.

Abstract: A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprises a) transmitting an optical signal into a fiber optic cable (14) that includes a sensing apparatus (20) comprising a plurality of substantially parallel fiber lengths (24), b) collecting from the sensing apparatus a plurality of received optical signals, each received signal comprising a portion of the transmitted signal that has been reflected from a different segment of a cable length, wherein the different segments are each in different cable lengths and correspond to a single selected location along the sensing cable, and c) processing the collected signals so as to obtain information about an acoustic signal received at the different segments. The cable may be ribbon cable and the lateral distance between the different segments may be less than 10 meters.

Abstract: Disclosed is a system for detecting seismic events, the system including a plurality of seismic receivers, at least one of the receivers in the plurality adapted for: monitoring seismic activity, providing an alert to at least another of the receivers in the plurality upon detection of a seismic event, and triggering the monitoring in the at least another of the receivers in the plurality. A method and computer program product for monitoring seismic events is also disclosed.

Abstract: This invention provides a method for characterizing natural fracture networks or other textural networks in an Earth formation when using microseismic monitoring of a hydraulic fracturing job. The method comprises receiving (120) microseismic data from a hydraulic fracturing event, identifying a data subset (153) comprising components of the microseismic data associated with the one or more hydraulic fractures; and obtaining a remainder dataset (156) of the microseismic data by removing the subset from the microseismic data. One approach for identifying the data subset, after removing high uncertainty microseismic events, is to create a Voronoi diagram of a plurality of cells each associated with one of the microseismic events, determine a density for each cell, create a connectivity matrix of the high density cells and identify event clusters in the connectivity matrix which are aligned with a main growing direction of the hydraulic fracture.

Abstract: Methods and related systems are described relating to processing subsurface sonic and seismic data. The described techniques use anisotropy estimates derived from a walkaway VSP to calibrate elastic properties derived from sonic logs. An empirical relationship between the sonic derived anisotropy parameters is modified until the upscaled elastic properties from the sonic log data best matches the anisotropy parameters measured with the walkway VSP. The result is a set of elastic constants consistent with the walkaway VSP measurements.

Abstract: The present invention relates to wellbore surveillance system for obtaining fluid reservoir information data, such as the position and amount of gas, oil and/or water, while draining hydrocarbons from an oil or gas field via a casing in a wellbore in a formation, the casing having a vertical part near a top of the casing and an inner face, the system comprising a first sensor for measuring a content of gas, oil and/or water in the formation, and a second sensor for measuring a content of gas, oil and/or water in the formation.

Abstract: Methods and apparatus to determine slowness of drilling fluid in an annulus are described. An example method of determining slowness of drilling fluid in an annulus of a borehole in a formation includes obtaining a first slowness of the drilling fluid in the annulus and measuring with a downhole tool slownesses of the formation based on the first slowness. The example method also includes determining a first compressibility of the formation based on the slownesses of the formation and a first density of the formation and calculating a second density and a second compressibility of the drilling fluid in the annulus based on the first density and the first compressibility. The method also includes calculating a second slowness of the drilling fluid in the annulus based on the second density and the second compressibility.

Abstract: The present disclosure relates to methods and apparatuses for estimating a parameter of interest of an earth formation. The method may include using an acoustic sensor azimuthally positioned relative to a monopole acoustic source to reduce at least one high-order mode due to the monopole acoustic source. The monopole acoustic source may include one or more acoustic elements. The method may include generating a monopole acoustic pulse. The apparatus may include at least one acoustic source element and at least one acoustic sensor disposed on a housing configured for conveyance in a borehole. The at least one acoustic sensor may be azimuthally positioned relative to the at least one acoustic source to reduce at least one high-order mode.

Abstract: An acoustic energy source for imparting acoustic energy into the Earth's subsurface includes an electrically driven transducer coupled to a source of swept frequency alternating current. A tunable Helmholtz resonator is disposed proximate the transducer. In one example, the resonator has a tuning device configured to maintain a resonant frequency substantially equal to an instantaneous frequency of the alternating current. The tuning device includes an actuator coupled to a sleeve, wherein the sleeve is disposed over selected numbers of openings in a wall of a tube on the resonator. The transducer and the resonator are disposed in a wellbore drilled through rock formations. The wellbore has a plurality of layers of fluid therein, each layer thereof having a different density and/or viscosity.

Abstract: The subject disclosure relates to sonic logging while drilling. A transmitter and at least one receiver are mounted on a drill collar for performing sonic investigations of the formation traversing a borehole.

Abstract: A seismic survey system for performing offset borehole seismic survey measurement operations. The system may include a first seismic survey subsystem having a first wireless digital communication device and a second seismic survey subsystem having a second wireless digital communication device and remotely located from the first seismic survey subsystem. The first and second digital communication devices may be configured to provide a digital communication link for transporting digital information between the first seismic survey subsystem and second seismic survey subsystem. The system may be configured to enable a user at the first seismic survey subsystem to remotely modify at least a portion of a first plurality of operating parameters associated with at least one source signal device located at the second seismic survey subsystem. The system may also be configured to utilize GPS information in order to improve accuracy of source signal firing timing synchronization.