Systems and methods are disclosed for generating subsurface property data as a function of position and time. Exemplary implementations may include obtaining a first initial subsurface property model and a first set of subsurface property parameters, obtaining training input data and a first training subsurface property dataset, generating a first conditioned subsurface property model, and storing the first conditioned subsurface property model.

A device, computer program and related method for processing a first seismic signal that includes identifying one portion of a second seismic signal and determining a length of a seismic wavelet. It is also possible to train a neural network by using a plurality of sub-portions of said portion a input variables and at least one second piece of information as a target variable. Said sub-portions of the portion have a length dependent on the length of the seismic wavelet determined. Finally, the method includes determining at least one first piece of geological information based on the first seismic signal using said trained neural network.

A computer-implemented method for determining rock and fluid parameters of a subsurface region from measured seismic reflection data, said method including: generating, with a computer, a geophysical data volume by combining a plurality of angle stacks obtained from the measured seismic reflection data and geophysical property data obtained from a full wavefield inversion of the measured seismic reflection data; for each point of the geophysical data volume, determining, with a computer, a petrophysical model that is a probability of a rock state based on initial values of the rock and fluid parameters and the geophysical data volume; iteratively determining, using a computer, updated values for the rock and fluid parameters, wherein the iteratively determining includes determining a petrophysical parameter estimate for the rock and fluid parameters from the petrophysical model as constrained by the geophysical data volume and the initial values of the rock and fluid parameters, minimizing a misfit between the geophysical data volume and synthetic data generated from a forward modeling of the initial values of the rock and fluid parameters using a cost function that includes the petrophysical parameter estimate of the rock and fluid parameters, and repeating the iteratively determining until a predetermined stopping criteria is satisfied and final values for the rock and fluid parameters are generated, and each subsequent iteration of the iteratively determining replaces the initial values for the rock and fluid parameters with the updated values for the rock and fluid parameters from a previous iteration; determining, with a computer, uncertainty in the final values for the rock and fluid parameters; and exploring for or producing hydrocarbons using the final values for the rock and fluid parameters and there uncertainty.

Method for building a subsurface model of velocity or other elastic property from seismic reflection data using tomography. The method uses velocity scans to pick a focusing velocity model at each image point (40). The focusing velocities are used to pick depth errors from tables (60) generated using a tomographic inversion matrix (30) and a suite of different velocity models (10). The depth errors are then reconstructed at each image point from the velocity scans based on the difference between the base velocity model and the most coherent velocity from the scan (70). The reconstructed depth errors are used to compute the velocity model update (80).

Disclosed herein are methods for predicting pore pressure in geological environments. Aspects of the disclosure describe details relating to performing geomechanical modeling for a target location in order to obtain a surrogate stress at the target location and predicting pore pressure by coupling velocity data (e.g., seismic and/or sonic) with the surrogate stress. Aspects of the disclosure can be used to obtain improved predictions of pore pressure in subsurface environments, especially in basins with complex geologic histories, and in practice to improve the safe design of casing, wellbore trajectory, and overall borehole stability.

A downhole tool for operation within a wellbore and including a transmitter array and first and second receiver arrays. The transmitter array includes a plurality of transmitters azimuthally distributed around a longitudinal axis of the downhole tool at a first axial location of the downhole tool. The first receiver array includes a plurality of first receivers azimuthally distributed around the longitudinal axis at a second axial location axially offset from the first axial location. The second receiver array includes a plurality of second receivers azimuthally distributed around the longitudinal axis at a third axial location axially offset from the first and second axial locations.

An acoustic signal is transmitted from a downhole tool positioned within a wellbore.

Amplitudes and travel times of the acoustic signal received at different azimuthal locations of the downhole tool are measured. Correction factors, each corresponding to a different one of the measured amplitudes, are determined based on the travel times measured at each of the different azimuthal locations. Corrected amplitudes are each determined based on the corresponding measured amplitude and the corresponding correction factor.

Method for multi-parameter inversion using elastic inversion. This method decomposes data into offset/angle groups and performs inversion on them in sequential order. This method can significantly speed up convergence of the iterative inversion process, and is therefore most advantageous when used for full waveform inversion (FWI). The present inventive approach draws upon relationships between reflection energy and reflection angle, or equivalently, offset dependence in elastic FWI. The invention uses recognition that the amplitudes of small angle (near offset) reflections are largely determined by acoustic impedance alone (1), independent for the most part of Vp/Vs. Large angle (middle and far offset) reflections are affected by Ip, Vp/Vs (2) and other earth parameters such as density (3) and anisotropy. Therefore, the present inventive method decomposes data into angle or offset groups in performing multi-parameter FWI to reduce crosstalk between the different model parameters being determined in the inversion.

A roadmap for a field development strategy for optimal recovery is provided in a high quality 3D geological model. This geological model combines geological attributes, pore and rock properties for an optimum 3D representation of the reservoir thousands of feet beneath the surface. The model is based on the pertinent geological facies, derived from well core description and detailed studies of rock, as well as fluid and pore properties (Full Pore System) obtained from laboratory analyses of core material and well log data. These data differentiate various important pore throat and pore body regions and relationships, i.e., macroporosity and microporosity. Understanding hydrocarbon volumes in the various pore type groups and then establishing proper recovery techniques through focused laboratory studies yields a field development strategy that can significantly increase hydrocarbon recovery from a reservoir.

Global inversion of multi-vintage seismic data uses simulated annealing to minimize a cost function simultaneously for all vintages and all angle stacks to yield values of geophysical properties. Each vintage is generated from an independent seismic survey of a subsurface structure conducted over a distinct period of time and includes seismic traces and angle stacks. An initial model of the subsurface structure is used and includes values for geophysical properties and time shift maps between vintages. The time shift map contains shifts in the seismic trace between vintages. The cost function includes a time shift map term for the difference between the time shift map and a calculated time shift of the seismic trace between vintages and is based on a proposed perturbation to at least one of the geophysical properties. The time shift map is also used as a global constraint on proposed perturbations of subsurface properties.