Disclosed are methods, systems, and computer-readable medium to perform operations including: generating, using a source wavelet and a current velocity model, modeled seismic data of the subterranean formation; applying a pre-condition to a seismic data residual calculated using the modeled seismic data and acquired seismic data from the subterranean formation; generating a velocity update using the source wavelet and the pre-conditioned seismic data residual; updating, using the velocity update, the current velocity model to generate an updated velocity model; determining that the current velocity model satisfies a predetermined condition; and responsively determining that the updated velocity model is the velocity model of the subterranean formation.

Abstract Disclosed is a method for characterising the evolution of a subsurface volume over time. The method comprises providing first and second surveys of the subsurface volume. Each survey comprises seismic data acquired by transmitting seismic signals into the subsurface volume and subsequently detecting some or all of the seismic signals after reflection within the subsurface. The first seismic data of the first survey corresponds to a first time and the second seismic data of the second survey corresponds to a second time. At least some of the first seismic data and the second seismic data is obtained with a non-zero offset. An inversion is performed to obtain estimates of changes having occurred between the first time and the second time in terms of at least one model parameter; wherein for the inversion: the first seismic data and the second seismic data is not processed to be equivalent to zero-offset data prior to the inversion; and it is assumed that the path taken by each received seismic signal between its transmission and reception is the same for the first survey and the second survey

Methods and apparatus are described for performing a 4D monitor marine seismic survey that repeats a previous survey. A number of sources may be used during the 4D monitor survey that differs from a number of sources that were used during the previous survey. Shot points from the previous survey are repeated by the 4D monitor survey, and additional shot points may be produced during the 4D monitor survey that were not produced during the previous survey. Embodiments enable efficiency and data quality improvements to be captured during 4D survey processes, while preserving repeatability.

A method for training a backpropagation-enabled regression process is used for predicting values of an attribute of subsurface data. A multi-dimensional seismic data set with an input dimension of at least two is inputted into a backpropagation-enabled process. A predicted value of the attribute has a prediction dimension of at least 1 and is at least 1 dimension less than the input dimension.

An apparatus, method, and system for determining body wave slowness from guided borehole waves. The method includes selecting a target axial resolution based on the size of a receiver array, obtaining a plurality of waveform data sets corresponding to a target formation zone and each acquired at a different shot position, computing a slowness-frequency 2D dispersion semblance map for each waveform data set, stacking the slowness-frequency 2D dispersion semblance maps to generate a stacked 2D semblance map, and determining a body wave slowness from the extracted dispersion curve. The method may also include generating a self-adaptive weighting function based on a dispersion model and the extracted dispersion curve, fitting the weighted dispersion curve and the dispersion model to determine a body wave slowness that minimizes the misfit between the weighted dispersion curve and the dispersion model. The method can be applied to both frequency-domain and time-domain processing.

A method and system for forming a seismic image of a subterranean region are disclosed. The method includes determining an initial plan for a seismic survey with a value for each member of a set of acquisition parameters and acquiring a first seismic dataset from a first portion of the seismic survey based on the initial plan. The method further includes transmitting the first seismic dataset to a seismic processor, determining a first seismic image from the first seismic dataset by performing expedited seismic processing and determining a first updated plan for the seismic survey based on the first seismic image and acquiring a second seismic dataset from a second portion of the seismic survey based on the first updated plan. The method still further includes transmitting the second seismic dataset to the seismic processor and determining the seismic based on the first seismic dataset and the second seismic dataset.

A computer implemented method for analyzing a reservoir grid modeling a reservoir geological formation is provided in which the reservoir grid corresponds to a 3D grid of cells associated to respective values of at least one geological property. The method includes obtaining a 4D seismic image of the reservoir geological formation. A skeleton of the 4D seismic image is calculated, and the skeleton extends between at least one origin and a plurality of extremities. Each point of the skeleton is associated to a value of the at least one geological property of the reservoir grid. Flow time values are calculated for a fluid flowing from the origin to the extremities along the skeleton, based on the at least one geological property values associated to the points of the skeleton. The reservoir grid is calculated based on the flow time values.

Described herein is a method for acquiring data using a marine vibrator towed by a vessel, the method comprising: obtaining data comprising at least one nominal pre-plot position in a horizontal plane; monitoring a position of the marine vibrator in the and a speed of the vessel; determining an offset between the position of the marine vibrator and the nominal pre-plot position in the towing direction; based on the offset and the vessel speed, adjusting one or more survey parameters and driving the vibrator with a series of one or more sweeps so that a predetermined frequency in the sweep or a subsequent sweep is emitted when the position of the vibrator is within a maximum distance of the nominal pre-plot position.

The present disclosure provides a method and a system for high-resolution seismic fault detection by means of an adversarial neural network, including following steps of: training a target adversarial neural network based on a preset training sample set, so as to obtain a trained target adversarial neural network, wherein the preset training sample set includes seismic data and fault labels, the target adversarial neural network includes: a segmentation module, a feature fusion module, and a discriminator module, the segmentation module is a module configured for obtaining a fault feature based on the preset training sample set, and the feature fusion module is a module configured for fusing the fault feature and the seismic data into a global feature map; and performing seismic fault detection on a target seismic image based on the trained target adversarial neural network.

System and methods for predicting time-dependent rock properties are provided. Seismic data for a subsurface formation is acquired over a plurality of time intervals. A value of at least one rock property of the subsurface formation is calculated for each of the plurality of time intervals, based on the corresponding seismic data acquired for that time interval. At least one of a trend or a spatio-temporal relationship in the seismic data is determined based on the value of the at least one rock property calculated for each time interval. A value of the at least one rock property is estimated for a future time interval, based on the determination. The estimated value of the at least one rock property is used to select a location for a wellbore to be drilled within the subsurface formation. The wellbore is then drilled at the selected location.