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

Abstract: A method can include receiving seismic data responsive to stimulation of an anisotropic formation via a well disposed in the formation; receiving crosswell calibrated velocity model information that spans a depth range of the anisotropic formation; locating a microseismic event generated by the stimulation based at least in part on a portion of the received seismic data and based at least in part on the crosswell calibrated velocity model information; and rendering the located microseismic event to a display with respect to one or more dimensions of the anisotropic formation.

Abstract: A method, downhole tool, and system, of which the method includes deploying a perforation charge into a wellbore, signaling the perforation charge to detonate, deploying a cable into the wellbore, determining a fluid flow rate at a predetermined location in the wellbore using the cable, and determining whether the perforation charge detonated at the predetermined location based on the fluid flow rate.

Abstract: Systems and methods may be used to reconstruct particle velocity wavefields from coupling-calibrated fiber-optic data that subsequently enables physically valid construction of the particle velocity wavefields for a hybrid sensor array including both fiber-optic and particle motion sensors. These systems and methods may be used in a variety of borehole geophysical applications, such as structure and reservoir imaging, impedance inversion, attenuation tomography, micro-seismic fracture imaging, focal mechanism analysis, and so on. The systems and methods may also be used in other applications such as geothermal and CO2 storage monitoring.

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

Abstract: A method can include receiving microseismic data of microseismic events as acquired by sensors during hydraulic fracturing of a geologic region; jointly calibrating sensor orientation of the sensors and a velocity model of the geologic region via an objective function and the microseismic data; and, based at least in part on the jointly calibrating, determining one or more locations of the one or more microseismic events.

Abstract: A seismic system that includes a seismic source configured to generate a first seismic signal and a second seismic signal in a formation adjacent the seismic source. A first downhole sensing device disposed in a first borehole configured to detect the first seismic signal and the second seismic signal in the formation; and a first surface acquisition system is in communication with the first downhole sensing device. The first surface acquisition system is configured to: determine a first reference transit time based at least in part on detection of the first seismic signal by the first downhole sensing device; a first subsequent transit time based at least in part on detection of the second seismic signal by the first downhole sensing device; and whether a synchronization variation is expected to be present based at least in part on the first reference transit time and the first subsequent transit time.

Abstract: A method includes varying a temperature of a treatment fluid. The treatment fluid is pumped into the first wellbore as part of a fluid diversion process or a fluid treatment process after the temperature of the treatment fluid is varied. A first downhole measurement is obtained in the first wellbore using a cable in the first wellbore or a first sensor coupled to the cable concurrently with or after the fluid diversion process or the fluid treatment process. An additional measurement is obtained concurrently with obtaining the first downhole measurement. The first downhole measurement and the additional measurement are combined or compared. A location where the treatment fluid is flowing through perforations in the first wellbore is determined based upon the combining or comparing the first downhole measurement and the additional measurement.

Abstract: A method can include receiving microseismic data of microseismic events as acquired by sensors during hydraulic fracturing of a geologic region; jointly calibrating sensor orientation of the sensors and a velocity model of the geologic region via an objective function and the microseismic data; and, based at least in part on the jointly calibrating, determining one or more locations of the one or more microseismic events.

Abstract: A method includes running a cable into a first wellbore. A fluid diversion process is initiated in the first wellbore. A first downhole measurement is captured in the first wellbore using the cable or a first sensor coupled thereto concurrently with or after the fluid diversion process. An additional measurement is captured concurrently with capturing the first downhole measurement. The first downhole measurement and the additional measurement are compared or combined. A location where fluid is flowing through perforations in the first wellbore is determined based upon the combining or comparing the first downhole measurement and the additional measurement.

Abstract: A method can include receiving an estimated spatial location of a three-component receiver in a borehole; receiving a plurality of spatial locations of sources of seismic energy; receiving incident angles for the three-component receiver at the estimated spatial location for the plurality of spatial locations of the sources of seismic energy; computing orientations for the three-component receiver based at least in part on the incident angles; minimizing an error function for the orientations; and, based at least in part on the minimizing, determining one or more deviation survey parameter values that specify at least a portion of a trajectory for the borehole.

Abstract: A method includes varying a temperature of a treatment fluid. The treatment fluid is pumped into the first wellbore as part of a fluid diversion process or a fluid treatment process after the temperature of the treatment fluid is varied. A first downhole measurement is obtained in the first wellbore using a cable in the first wellbore or a first sensor coupled to the cable concurrently with or after the fluid diversion process or the fluid treatment process. An additional measurement is obtained concurrently with obtaining the first downhole measurement. The first downhole measurement and the additional measurement are combined or compared. A location where the treatment fluid is flowing through perforations in the first wellbore is determined based upon the combining or comparing the first downhole measurement and the additional measurement.

Abstract: A method can include, during a treatment process, receiving vibration data acquired over a length of a fiber cable sensor disposed in a well that includes perforations; filtering the vibration data as to traveling waves to generate filtered data; analyzing the filtered data to generate fluid flow information; and adjusting the treatment process based at least in part on the fluid flow information.

Abstract: A method, downhole tool, and system, of which the method includes deploying a perforation charge into a wellbore, signaling the perforation charge to detonate, deploying a cable into the wellbore, determining a fluid flow rate at a predetermined location in the wellbore using the cable, and determining whether the perforation charge detonated at the predetermined location based on the fluid flow rate.

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: A method can include receiving an estimated spatial location of a three-component receiver in a borehole; receiving a plurality of spatial locations of sources of seismic energy; receiving incident angles for the three-component receiver at the estimated spatial location for the plurality of spatial locations of the sources of seismic energy; computing orientations for the three-component receiver based at least in part on the incident angles; minimizing an error function for the orientations; and, based at least in part on the minimizing, determining one or more deviation survey parameter values that specify at least a portion of a trajectory for the borehole.

Abstract: A method can include, during a treatment process, receiving vibration data acquired over a length of a fiber cable sensor disposed in a well that includes perforations; filtering the vibration data as to traveling waves to generate filtered data; analyzing the filtered data to generate fluid flow information; and adjusting the treatment process based at least in part on the fluid flow information.

Abstract: A seismic system that includes a seismic source configured to generate a first seismic signal and a second seismic signal in a formation adjacent the seismic source. A first downhole sensing device disposed in a first borehole configured to detect the first seismic signal and the second seismic signal in the formation; and a first surface acquisition system is in communication with the first downhole sensing device. The first surface acquisition system is configured to: determine a first reference transit time based at least in part on detection of the first seismic signal by the first downhole sensing device; a first subsequent transit time based at least in part on detection of the second seismic signal by the first downhole sensing device; and whether a synchronization variation is expected to be present based at least in part on the first reference transit time and the first subsequent transit time.

Abstract: A method can include receiving seismic data responsive to stimulation of an anisotropic formation via a well disposed in the formation; receiving crosswell calibrated velocity model information that spans a depth range of the anisotropic formation; locating a microseismic event generated by the stimulation based at least in part on a portion of the received seismic data and based at least in part on the crosswell calibrated velocity model information; and rendering the located microseismic event to a display with respect to one or more dimensions of the anisotropic formation.

Abstract: Systems capable of seismically investigating the earth can include seismic sources and a disposable seismic sensor such as a fiber optic seismic sensor included within a drill string. The fiber optic seismic sensor can include a plurality of fiber Bragg gratings. Related methods can include using the seismic sources and the fiber optic seismic sensor to conduct seismic investigations.