The present disclosure provides a small-scale geological anomalous body detection method and device, and relates to the field of small-scale geological anomalous body detection. The method comprises: acquiring diffracted wave shot-gather data collected in a to-be-processed area and determining target single shot data having a distance to the center point, which is a predetermined distance; calculating a first horizontal distance between each shot point in the target single shot data and the center point and calculating a second horizontal distance between the detection point corresponding to each shot point and the center point; constructing a common-diffraction-point gather based on the first horizontal distances and the second horizontal distances; and processing the common-diffraction-point gather by using a correction algorithm of diffracted wave events to obtain a diffracted wave imaging profile.

A system including a sonic source deployed in a first borehole and a fiber optic distributed sensor deployed in a second borehole, both boreholes extending from an earth surface into a formation. The optical fiber is configured to react along its length to incident sonic waves generated by the sonic source and propagating through the first borehole, through the formation, and through the second borehole. The system further includes an optical source to launch optical pulses into the fiber optic distributed sensor while the sonic waves are incident on the fiber optic distributed sensor. The system also includes a data acquisition system coupled to the fiber optic distributed sensor to detect temporal variations in coherent Rayleigh noise (CRN) generated in the fiber optic distributed sensor in response to the optical pulses and the incident sonic waves; and a computer system configured to receive data from the data acquisition system.

Systems and methods for generating seismic images of subterranean features including: receiving raw seismic data of a subterranean formation; selecting a portion of the raw seismic data; transforming the selected portion of the raw seismic data from a first domain to a second domain; generating soft constraint data corresponding to the selected portion of the raw seismic data; calculating at least one weight using the generated soft constraint data; generating a weighted transformed data set by applying at least one weight to the transformed selected portion of the raw seismic data; selecting at least one data point of the generated weighted transformed data set; and removing the selected at least one data point from the weighted transformed data set to generate revised seismic data.

Seismic data from seismic exploration surveys are mapped into a hypercube of bins or voxels in a four-dimensional space (X, Y, Offset, and Azimuth) according to Common Mid-Point (or CMP) between source and receivers. The mapped data from individual voxels or bins is then analyzed by multimodal statistics. Robust estimates of first break picks are obtained from the analysis. The first break picks are then used to as seed inputs for autopicking iteration, which proceeds to convergence. Estimates of confidence levels in the data are provided for re-picking to reduce computer processing time in successive autopicking iterations. Analysis is provided of different seismic attributes such as azimuthal velocity variations indicative of anisotropy, positioning errors of sources/receivers, geometry errors, and three dimensional distribution of inversion residuals. Analysis is also performed of standard deviation of the travel time data useful for estimating data errors in the inversion covariance matrix.

A system and method for forming a seismic image of a subterranean region of interest are provided. The method includes obtaining an observed seismic dataset for the subterranean region of interest and determining a plurality of common-offset sections from the observed seismic dataset. The method further includes determining stochastically migrated common-offset sections for each of the common-offset sections and forming a stochastic image gathers from the plurality of stochastically migrated common-offset sections. The method still further includes forming the seismic image by stacking each of the plurality of stochastically migrated common-offset sections.

Systems and methods are provided to correct seismic data for the undesired effects caused by near surface velocity variations. In one embodiment, a method includes receiving travel time data for a near surface region and estimating an initial velocity model for the near surface region using the travel time data. The method can include updating the velocity model by performing an inversion iteration of including inversion of travel times to estimate slowness. The process can also include calculating at least one long-wavelength static for the near surface region. The long-wavelength statics may be used to correct for undesired effects caused by near surface velocity variations.

A system and method for forming a denoised seismic image of a subterranean region of interest is provided. The method includes obtaining an observed seismic dataset for a subterranean region of interest and forming a plurality of common midpoint gathers having a plurality of traces, each trace having an ordinate series of sample values, a common-midpoint location and a unique value of a secondary sorting parameter. The method further includes, for each of the plurality of common midpoint gathers, selecting a set of spatially adjacent common midpoint gathers using a spatial windowing operator and determining a weighted midpoint gather based on the common midpoint gather and the set of spatially adjacent common midpoint gathers. The method still further includes forming a denoised seismic dataset by combining the weighted midpoint gathers using an inverse spatial windowing operator and forming the denoised seismic image based on the denoised seismic dataset.

A method and a system for implementing the method are disclosed wherein the source wavelet, input parameter models, and seismic input data may be obtained from a non-flat surface, sometimes mild, or foothill topography as well as the shot and receiver lines might not necessarily be straight, and often curve to avoid obstacles on the land surface. In particular, the method and system disclosed, suppresses low wavenumber and low frequency noises, by balancing lateral and vertical amplitudes to produce an image of subsurface reflectors located within a survey area having higher lateral resolutions and wavenumbers, as well as higher high-cut frequencies, and lower low-cut frequencies in complex media, than could otherwise not be achieved by other methods commonly known in the art.

Waves from cement bond logging with a sonic logging-while-drilling tool (LWD-CBL) are often contaminated with tool waves and may yield biased CBL amplitudes. The disclosed LWD-CBL wave processing corrects the first echo amplitudes of LWD-CBL before calculating the BI. The LWD-CBL wave processing calculates a tool wave amplitude and a phase angle difference as the difference of the phases between the tool waves and casing waves. The tool waves are then used to correct the LWD-CBL casing wave amplitude and remove errors introduced from tool waves. In conjunction with the sets of operations described, the LWD-CBL wave processing also include array preprocessing operations. Array preprocessing may employ variation of bandpass filtering and frequency-wavenumber (F-K) filtering operations to suppress tool wave.

A method can include receiving data acquired via survey equipment disposed in an environment; analyzing at least a portion of the data via an iterative adaptive approach that implements matching pursuit to generate analysis results; and identifying at least one feature in the environment based at least in part on a portion of the analysis results.