Hydrocarbon exploration and extraction can be facilitated using machine-learning models. For example, a system described herein can receive seismic data indicating locations of geological bodies in a target area of a subterranean formation. The system can provide the seismic data as input to a trained machine-learning model for determining whether the target area of the subterranean formation includes one or more types of geological bodies. The system can receive an output from the trained machine-learning model indicating whether or not the target area of the subterranean formation includes the one or more types of geological bodies. The system can then execute one or more processing operations for facilitating hydrocarbon exploration or extraction based on the seismic data and the output from the trained machine-learning model.

A device for assigning to the unknown onset of a signal in a noisy time series a probability of that onset having a signed excursion away from the trace mean including one or more means arranged to: define a polarity at a given time sample by reference to the sign of the amplitude difference between the extrema immediately before and after the given time sample in the time series; define a positive and a negative polarity probability density function; take the respective products of the positive and negative polarity probability density functions with an onset probability density function defining the probability that the onset of the signal occurs at a given time sample; and marginalize the respective products of the positive and negative polarity probability density functions with the onset probability density function over time to estimate final probabilities that the onset has a positive or a negative polarity.

A system for processing DAS VSP surveys is provided. The system includes a DAS data collection system coupled to at least one optical fiber at least partially positioned within a wellbore and configured to either activate or passively listen to a seismic source of energy for one or more times. The system further includes an information processing system connected to the DAS data collection system. A seismic dataset is received from the DAS data collection system recorded in a spatiotemporal domain. The seismic dataset is converted into intercept-time ray-parameter domain dataset. Local apparent slope is determined for each seismic signal in the received seismic dataset. Amplitude correction is performed for the received seismic signals by using the slowness profile and the determined local apparent slope in the intercept-time ray-parameter domain dataset. The corrected intercept-time ray-parameter domain dataset is converted back into the spatiotemporal domain.

A method is described for identifying source rocks in a subsurface volume of interest. The method may include generating a trend-normalized reflectivity seismic attribute and calculating the location, thickness, organic richness and thermal maturity of the potential source rocks based on seismic data. The method may be executed by a computer system.

Systems and methods for identifying anomalies in a subterranean formation based on seismic attributes include: receiving a seismic cube and a seismic surface, wherein the seismic cube includes traces recorded at receivers deployed to collect seismic data, and the seismic surface is picked on the seismic cube; extracting seismic wavelets with a selected length from the seismic cube along an intersection with the seismic surface for each spatial coordinate associated with the seismic surface; determining a population trend of the seismic wavelets; and generating a attribute map based on comparing each of the seismic wavelets to the population trend.

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 or 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.

Disclosed are methods, systems, and computer-readable medium to perform operations including: receiving seismic data acquired by at least one receiver of a geologic survey system configured to perform a geologic survey of a subterranean formation, wherein the seismic data is associated with reflected acoustic signals generated by at least one source of the geologic survey system; calculating a ground force signal by stacking the acoustic signals generated by the least one source; calculating, using the ground force signal, a time and depth variant quality factor (Q) of the subterranean formation; and compensating, based on the time and depth variant Q, attenuation in the seismic data.

The disclosure provides methods and systems for characterizing depositional features. The methods and systems include accessing data encoding seismic waves as seismic traces reflected from cells at various locations within a particular stratum in response to a seismic source. The cells are classified into multiple non-overlapping groups according to the amplitude values or other seismic attributes of the seismic waves reflected from the various locations within the particular stratum. One or more subgroups of adjacent cells are identified. A subgroup area metric is calculated for each subgroup of cells by combining individual area metrics from adjacent cells in a given subgroup and subsequently assigning the calculated subgroup area metric to each cell of the given subgroup. One or more depositional features within the stratum are characterized based at least in part on the variation map based on the subgroup area metric of each cell.

Methods and devices for seismic exploration of an underground formation including an orthorhombic anisotropic medium or a tilted transverse isotropic medium are provided. Isotropic-type processing techniques use effective elastic parameter values calculated based on elastic parameter values, anisotropy parameter values and azimuth angle values for the orthorhombic anisotropic medium. For the tilted transverse isotropic medium, the effective elastic parameter values depend also on the tilt angle thereof.

A method of evaluating processing imprint on seismic signals includes receiving a first and a second seismic dataset of a reservoir. A first and a second synthetic dataset are generated, where the second synthetic dataset is generated by multiplying at least a portion of data in the first synthetic dataset by a scaling factor. A first and a second combined dataset are generated by adding the respective seismic dataset and the respective synthetic dataset. A first and a second processed dataset are generated by applying a seismic processing step on the first and the second combined dataset, respectively. A difference factor between the first and the second processed dataset is calculated. Based on the difference factor and the scaling factor, it is determined whether the seismic processing step is able to preserve signal amplitude changes between the first and the second seismic dataset.