A method for extracting a downgoing wavelet and attenuation parameters from VSP data, comprising: performing upgoing and downgoing P-waves separation processing on VSP data to obtain downgoing P-wave data; performing a FFT on seismic data with a preset time window length starting from the P-wave first arrival time and cut from the downgoing P-wave data to obtain FFT transformed downgoing P-wave data and a multi-trace downgoing P-wave log spectrum; subtracting a downgoing wavelet log spectrum from the multi-trace downgoing P-wave log spectrum to obtain a wavelet-corrected multi-trace downgoing P-wave log spectrum; performing, based on parameters of the wavelet-corrected multi-trace downgoing P-wave log spectrum, a correction and an inverse FFT on the FFT transformed downgoing P-wave data to obtain a downgoing wavelet; and obtaining attenuation parameters based on P-wave first arrival time and the parameters of the wavelet-corrected multi-trace downgoing P-wave log spectrum. The method can extract a downgoing wavelet and attenuation parameters with high accuracy. Also provided are an apparatus for extracting a downgoing wavelet and attenuation parameters from VSP data, a computer device, and a computer-readable storage medium.

A method or system is configured for determining a seismic attenuation quality factor Q for intervals of subsurface formations by performing actions including receiving vertical seismic profile traces. The actions include filtering the vertical seismic profile traces with an inverse impulse response of a downhole receiver. The actions include transforming the vertical seismic profile data from the particle motion measured by the downhole receiver to the far-field particle motions represented by the source wavelet. The actions include determining a ratio of the spectral amplitudes of the direct arrival event of the transformed vertical seismic profile data and the source Klauder wavelet. A quality factor Q is generated representing an attenuation of the seismic signal between the source at ground level surface and the downhole receiver.

The present invention provides an intelligent geophysical data acquisition system and acquisition method for shale oil and gas optical fiber. A pipe string is arranged in a metal casing, and an external armored optical cable is fixed outside the metal casing; an, internal armored optical cable is fixed outside the pipe string; the external armored optical cable comprises a downhole acoustic sensing optical cable, two multi-mode optical fibers, a strain optical cable and a pressure sensor array, and further comprises horizontal ground acoustic sensing optical cables arranged in the shallow part of the ground according to an orthogonal grid, and artificial seismic source excitation points arranged on the ground according to the orthogonal grid.

A seismic source is positioned at the surface of a geologic formation and a plurality of seismic receivers is positioned in a wellbore of the geologic formation. Seismic wavefield data is obtained based on the seismic source outputting seismic energy into the wellbore and the plurality of seismic receivers receiving the seismic energy. A velocity profile is determined along the wellbore based on the seismic wavefield data. P and S wave data in a downgoing direction is separated from the seismic wavefield data based on an inversion and the velocity profile. The P and S wave data in the downgoing direction is adaptively subtracted from the seismic wavefield data to form residual wavefield data. The P and S wave data in a upgoing direction is separated from the residual wavefield data based on the inversion and an updated velocity profile. The P and S wave data in the upgoing and downgoing direction is output.

A seismic attenuation quality factor Q is determined for seismic signals at intervals of subsurface formations between a seismic source at a marine level surface and one or more receivers of a well. Hydrophone and geophone data are obtained. A reference trace is generated from the hydrophone and geophone data. Vertical seismic profile (VSP) traces are received. First break picking of the VSP traces is performed. VSP data representing particle motion measured by a receiver of the well are generated. The reference trace is injected into the VSP data. A ratio of spectral amplitudes of a direct arrival event of the VSP data and the reference trace is determined. From the ratio, a quality factor Q is generated representing a time and depth compensated attenuation value of seismic signals between the seismic source at the marine level surface and the first receiver.

A distributed acoustic sensor is positioned within a wellbore of a geologic formation. Seismic waves are detected using the distributed acoustic sensor. A raw seismic profile is generated based on the detected seismic waves. Resonant noise is identified and reduced in seismic data associated with the raw seismic profile.

A method for performing a formation-related operation based on corrected vertical seismic profile (VSP) data of an earth formation includes performing a VSP survey and applying a normal moveout (NMO) correction equation to the survey data that is a function of source offset to wellhead. The method also includes solving the NMO correction equation using a simulated annealing algorithm having an object function that is a coherence coefficient of semblance analysis of an NMO corrected reflection event within a time window to provide NMO corrected data. The method further includes performing the formation-related operation at at least one of a location, a depth and a depth interval based on the VSP NMO corrected data.

A seismic attenuation quality factor Q is determined for seismic signals at intervals of subsurface formations between a seismic source at a marine level surface and one or more receivers of a well. Hydrophone and geophone data are obtained. A reference trace is generated from the hydrophone and geophone data. Vertical seismic profile (VSP) traces are received. First break picking of the VSP traces is performed. VSP data representing particle motion measured by a receiver of the well are generated. The reference trace is injected into the VSP data. A ratio of spectral amplitudes of a direct arrival event of the VSP data and the reference trace is determined. From the ratio, a quality factor Q is generated representing a time and depth compensated attenuation value of seismic signals between the seismic source at the marine level surface and the first receiver.

Methods and systems of measuring acoustic signals via a borehole wall are disclosed. One or more non-contact magneto-dynamic sensors are configured or designed for deployment at at least one depth in a borehole. The magneto-dynamic sensor comprises a coil excited by an electric current and a circuitry for outputting a signal corresponding to a time-varying impedance of the coil. A processor is configured to perform signal processing for deriving at least one of a magnitude or a frequency of vibration of the borehole wall based on the output signal from the circuitry.

A technique facilitates monitoring of acoustic signals to measure a velocity vector of a borehole. Acoustic sensors are arranged in a desired acoustic sensor array and positioned along a body of a tool, e.g. a sonic logging tool. The acoustic sensor array is then positioned in fluid along a wall of a borehole formed in a subterranean formation. The acoustic sensors are used to collect acoustic signal data while the acoustic sensors are maintained in a non-contact position with respect to the wall of the borehole. The data may be processed to determine the desired velocity vector.