Disclosed herein are various embodiments of a technique to monitor hydro-fracturing in oil and gas wells by use of active seismic sources and arrays of monitoring sensors. The invention utilizes combinations of seismic sources such as vertical vibrators in anti-phase pairs. The invention utilizes combinations of multi-component rotational seismic sensors, and/or multi-component linear sensors, and/or pressure sensors. Sensors are jointly deployed in arrays on the surface and/or in shallow monitoring wells to avoid the complicating effects of the free surface of the earth. The emplacement of sensors on the surface or in the shallow monitoring wells may be permanent. Fractures are monitored by combinations of physical effects such as propagation time delays, shear reflections, birefringent shear wave splitting, and amplitude variations. 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.

A method includes receiving seismic data for a geologic region of the Earth; building a velocity model of the geologic region of the Earth; selecting at least one mode of multiple and corresponding travel time data from a data storage where the travel time data correspond to at least one complex ray signature in the geologic region of the Earth and are based at least in part on the velocity model; performing migration on the seismic data using at least the selected travel time data to generate processed seismic data; and rendering an image of the geologic region of the Earth to a display where the image includes at least a multiple image.

Data from crosswell seismic surveys is processed to provide crosswell time-lapse data to map fluid changes in a reservoir where time-lapse or 4D seismic data is unavailable or unreliable, such as in onshore reservoirs. The resultant processing results provide quantitative information for history matching purposes using a probabilistic approach to take in account uncertainties in the geological model and reduce uncertainties in reservoir production forecasts.

Production capability of cased hole perforations in a cased completed well lined with a casing in an under-pressured gas producing reservoir is tested. A sonde of a dipole shear or array sonic (full waveform) acoustic well logging tool is moved in a well bore of the cased completed well in the reservoir across a depth interval of interest, which covers cased hole perforations zones in the reservoir. The well logging sonde has in it an acoustic energy source and acoustic energy receivers. Responses are logged at depth intervals of interest to the transit of Stoneley waves along the casing walls from the acoustic energy source to the acoustic energy receivers. Measures of characteristics (e.g., travel time and attenuation) of the Stoneley wave are obtained. The responses are then processed to indicate production capability of the cased hole perforations.

A method is described for seismic modeling implemented on a computer system including multiple computer nodes, which includes receiving, at a computer processor, a 4D speed of sound in water library and a marine seismic survey geometry; creating, via the computer processor, a full survey 3D Earth model for each seismic shot time based on the 4D speed of sound in water library to generate a set of dynamic 3D Earth models; simulating 4D seismic shots for the set of dynamic 3D Earth models by simulating multiple shots on each node to generate a set of 4D seismic shot gathers; and outputting the 4D seismic shot gathers.

A method for echo detection may comprise recording one or more reflected waveforms, segmenting the one or more reflected waveforms based at least in part on a firing pulse length, applying a shaped filter to each segment of the one or more reflected waveforms, decoupling the one or more reflected waveforms into a time-frequency energy map, extracting a firing frequency band time domain plot from the decoupled time-frequency map, identifying a maximum amplitude in the extracted firing frequency band of the one or more reflected waveforms as an excitation, and identifying a second maximum amplitude in the extracted firing frequency band of the one or more reflected waveforms as an echo. A system for echo detection may comprise a digital signal processor, a transmitter, a transducer, a receiver, an analog to digital converter configured to digitize the measurement, and an information handling system.

A method for identifying a location of a distributed acoustic system channel in a distributed acoustic system. The method may comprise generating a two or three dimensional layer model interface with an information handling system, preparing a P-wave first arrival pick time table, estimating an initial model layer properties, estimating a location of the distributed acoustic system channels, preparing an overburden file of layer properties, running an anisotropic ray tracing, defining an upper and a lower limits for model parameters, specifying parameters for the inversion, running an inversion, selecting a solution based at least in part on stored error predictions, and calculating a mean and a standard deviation of an inverted model parameter.

A method for generating acoustic images corrected for distortions caused by attenuation of the ultrasonic signal by the mud may comprise disposing a downhole tool into a borehole, transmitting a pressure pulse from at least one transducer into the borehole, recording an echo with the at least one transducer, measuring a travel time, measuring an amplitude, determining a geometry of the borehole, determining a location of the downhole tool in the borehole, calculating an incident angle, mapping a mud attenuation, and correcting an image. A system for generating acoustic images corrected for distortions caused by attenuation of the ultrasonic signal by the mud comprising a downhole tool that may comprise a measuring assembly, wherein the measuring assembly comprises at least one transducer and wherein the at least one transducer is configured to emit a pressure pulse and record an echo. The system may further comprise an information handling system.

Methods, systems, and computer program products for characterizing materials in a wellbore having multiple casing strings uses well completion data and instantaneous frequency, instantaneous phase, and/or amplitude attributes, including waveform amplitude and instantaneous amplitude, of an acoustic waveform to determine material densities, acoustic velocities and acoustic travel distances for the materials between the various stages of casings.

The invention discloses an omnidirectional vector seismic data processing method and apparatus, a computer readable storage medium and a device, applied to an omnidirectional vector geophone. Wherein the method comprises: collecting omnidirectional vector seismic data of the omnidirectional vector geophone, and performing a pre-processing operation on the omnidirectional vector seismic data; performing pressure and shear waves separation operation on the omnidirectional vector seismic data after the data is subject to the pre-processing operation, to obtain pressure wave data and shear wave data; sequentially performing space vector calculation, a wave field recovery operation and an imaging operation on the pressure wave data and the shear wave data, and then performing modeling to obtain a pressure wave velocity model and a shear wave velocity model. The invention solves the problem of the existing seismic exploration technology that cannot measure and process divergence data and curl data of seismic wave field, so as to improve construction, lithology, fluid exploration accuracy and reliability and promote seismic exploration to be developed from structural exploration to lithology exploration and fluid exploration.