Abstract: A technique facilitates enhanced microseismic monitoring. The technique may be applied to source mechanism identification under, for example, ill-conditioned receiver coverage to enhance the resolvability for microseismic monitoring. The microseismic monitoring may be used in hydraulic fracturing monitoring, induced seismicity monitoring, CO2 injection monitoring, other injection monitoring, mining, and/or other techniques which cause microseismic events.

Abstract: A technique facilitates enhanced microseismic monitoring. In a variety of applications, the technique may be used to enhance the resolvability of moment tensor inversion for ill-conditioned seismic receiver coverage. As a result, microseismic monitoring technique enhances the capability for monitoring many types of naturally occurring and created seismic events. For example, the technique may be employed to enhance hydraulic fracturing monitoring, induced seismicity monitoring, CO2 injection monitoring, other injection monitoring, mining, and/or other techniques which cause microseismic events.

Abstract: Analysis of a seismic event, such as a microseismic event caused by hydraulic fracturing, comprises measuring seismic waves emitted by the event and converting the measurements into two values for magnitude of explosion or implosion and for magnitude of displacement discontinuity at a plane, together with two directions, a direction of a normal to the plane and a direction of displacement; where the two values and the two directions compose the moment tensor describing the seismic event. The measurements may be converted into the moment tensor and decomposed into the values and directions. The values and directions associated with several seismic events may be displayed concurrently on a graphic display as a graphic representation of multiple events, where each event may be depicted with magnitude of expansion or contraction represented by a volume and the plane represented as a laminar object.

Abstract: A technique facilitates enhanced microseismic monitoring. In a variety of applications, the technique may be used to enhance the resolvability of moment tensor inversion for ill-conditioned seismic receiver coverage. As a result, microseismic monitoring technique enhances the capability for monitoring many types of naturally occurring and created seismic events. For example, the technique may be employed to enhance hydraulic fracturing monitoring, induced seismicity monitoring, CO2 injection monitoring, other injection monitoring, mining, and/or other techniques which cause microseismic events.

Abstract: A technique facilitates enhanced microseismic monitoring. The technique may be applied to source mechanism identification under, for example, ill-conditioned receiver coverage to enhance the resolvability for microseismic monitoring. The microseismic monitoring may be used in hydraulic fracturing monitoring, induced seismicity monitoring, CO2 injection monitoring, other injection monitoring, mining, and/or other techniques which cause microseismic events.

Abstract: Methods and systems for processing microseismic waveforms. The methods and systems provide determining a measure of waveform fit in the frequency-domain comprising constructing, in the frequency-domain, at least one of an amplitude misfit functional and a cross phase functional between arrivals; and estimating source parameters and/or model parameters.

Abstract: A technique facilitates performance of seismic profiling, such as three-dimensional vertical seismic profiling. A downhole acquisition system is provided with acoustic receivers designed to receive acoustic source signals. The firing of acoustic source signals is synchronized with the downhole acquisition system. Additionally, the firing of two or more acoustic source signals is controlled to provide simultaneous or nearly simultaneous timing of one acoustic source signal with respect to another acoustic source signal. A processing system is used to acquire and process a data stream of the initial shot and a data stream of the additional shot occurring simultaneously or nearly simultaneously.

Abstract: A technique includes receiving first seismic data acquired by one or more receivers in response to energy produced by one or more seismic sources interacting with a subsurface feature. The first seismic data is indicative of measured reflection coefficients for image points for the subsurface feature, the measured reflection coefficients are associated with incidence angles, and a range of the incidence angles varies with respect to an image point position. The technique includes processing the first seismic data in a machine to generate second data indicative of a normal incidence reflection coefficient for at least one of the image points not associated with a normal angle of incidence.

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: 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: Analysis of a seismic event, such as a microseismic event caused by hydraulic fracturing, comprises measuring seismic waves emitted by the event and converting the measurements into two values for magnitude of explosion or implosion and for magnitude of displacement discontinuity at a plane, together with two directions, a direction of a normal to the plane and a direction of displacement; where the two values and the two directions compose the moment tensor describing the seismic event. The measurements may be converted into the moment tensor and decomposed into the values and directions. The values and directions associated with several seismic events may be displayed concurrently on a graphic display as a graphic representation of multiple events, where each event may be depicted with magnitude of expansion or contraction represented by a volume and the plane represented as a laminar object.

Abstract: Methods and systems for processing acoustic measurements related to subterranean formations. The methods and systems provide receiving acoustic waveforms with a plurality of receivers, deriving slowness of the formation based on the acoustic waveforms, and modeling dominant waveforms in the acoustic waveforms based on the formation slowness, wherein deriving the formation slowness comprises parametric inversion for complex and frequency dependent slowness and the derived complex slowness has real and imaginary parts.

Abstract: A method for the detection and localization of microseismic events is proposed which operates in real-time. It provides hypocenters in three spatial dimensions 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. The method combines and improves two existing approaches. For detection and localization purposes the method makes use of the generalized beam-forming and forward modeling properties defined in the “CMM” algorithm. For location refinement, the method uses a stabilized version of the generalized “Geiger” approach.

Abstract: A technique includes receiving first seismic data acquired by one or more receivers in response to energy produced by one or more seismic sources interacting with a subsurface feature. The first seismic data is indicative of measured reflection coefficients for image points for the subsurface feature, the measured reflection coefficients are associated with incidence angles, and a range of the incidence angles varies with respect to an image point position. The technique includes processing the first seismic data in a machine to generate second data indicative of a normal incidence reflection coefficient for at least one of the image points not associated with a normal angle of incidence.

Abstract: A technique facilitates performance of seismic profiling, such as three-dimensional vertical seismic profiling. A downhole acquisition system is provided with acoustic receivers designed to receive acoustic source signals. The firing of acoustic source signals is synchronized with the downhole acquisition system. Additionally, the firing of two or more acoustic source signals is controlled to provide simultaneous or nearly simultaneous timing of one acoustic source signal with respect to another acoustic source signal. A processing system is used to acquire and process a data stream of the initial shot and a data stream of the additional shot occurring simultaneously or nearly simultaneously.

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 the detection and localization of microseismic events is proposed which operates in real-time. It provides hypocenters in three spatial dimensions 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. The method combines and improves two existing approaches. For detection and localization purposes the method makes use of the generalized beam-forming and forward modeling properties defined in the “CMM” algorithm. For location refinement, the method uses a stabilized version of the generalized “Geiger” approach.

Abstract: Methods and systems for processing acoustic measurements related to subterranean formations. The methods and systems provide receiving acoustic waveforms with a plurality of receivers, deriving slowness of the formation based on the acoustic waveforms, and modeling dominant waveforms in the acoustic waveforms based on the formation slowness, wherein deriving the formation slowness comprises parametric inversion for complex and frequency dependent slowness and the derived complex slowness has real and imaginary parts.

Abstract: Methods and systems for processing microseismic waveforms. The methods and systems provide determining a measure of waveform fit in the frequency-domain comprising constructing, in the frequency-domain, at least one of an amplitude misfit functional and a cross phase functional between arrivals; and estimating source parameters and/or model parameters.

Abstract: A method of applying an effective velocity model to vertical seismic profile (VSP) seismic data comprises correcting for offset using a non-hyperbolic effective velocity model so as to take account of the earth's layering and anisotropy. One preferred non-hyperbolic model for the relationship between offset and travel time is: formula (I) where t is the travel time of seismic energy from the source to the receiver, x is the offset between the source and the receiver, and z is the depth of the receiver.