Abstract: A method is described for generating a subsurface model using stochastic full waveform inversion by receiving a seismic dataset representative of a subsurface volume of interest; performing stochastic full waveform inversion of the seismic dataset to generate a long wavelength subsurface model; and performing full waveform inversion of the seismic dataset using the long wavelength subsurface model as a starting model to generate an improved subsurface model. The method may further include performing seismic imaging of the seismic dataset using the improved subsurface model to generate a seismic image and identifying geologic features based on the seismic image. The method may be executed by a computer system.

Abstract: A multi-frequency signal may be used to induce voltage difference across a portion of a pipe. The voltage difference may be induced to take multi-frequency measurement of impedance characteristics of fluid inside the pipe. The multi-frequency measurement of the impedance characteristic of the fluid inside the pipe may be used to determine a characteristic of the fluid inside the pipe. This may be achieved by active integration of experimental data with high-resolution multi-frequency electrical impedance tomography (MFEIT) modeling.

Abstract: A method for determining placement of MFEIT sensors in a horizontal well for detecting producing stages of the horizontal well. Embodiments involve computationally modeling the underlying physics of a well system and performing inversion to identify the MFEIT parameters (locations and conductivity) from electrical impedance measurements.

Abstract: A multi-frequency signal may be used to induce voltage difference across a portion of a pipe. The voltage difference may be induced to take multi-frequency measurement of impedance characteristics of fluid inside the pipe. The multi-frequency measurement of the impedance characteristic of the fluid inside the pipe may be used to determine a characteristic of the fluid inside the pipe. This may be achieved by active integration of experimental data with high-resolution multi-frequency electrical impedance tomography (MFEIT) modeling.

Abstract: A method is described for subsurface hydrocarbon reservoir characterization including receiving a time-lapse electromagnetic (EM) dataset and a flow dataset; inverting the time-lapse EM dataset using a parametric inversion that models steel well casings to determine a volume of fluid-changed reservoir; inverting the time-lapse EM dataset and the flow dataset using a joint inversion that honors the volume of the fluid-changed reservoir to determine relative permeability and capillary pressure; and characterizing flow characteristics in the volume of the fluid-changed reservoir. The method may be executed by a computer system.

Abstract: A method is described for subsurface hydrocarbon reservoir characterization including receiving a time-lapse electromagnetic (EM) dataset and a flow dataset; inverting the time-lapse EM dataset using a parametric inversion that models steel well casings to determine a volume of fluid-changed reservoir; inverting the time-lapse EM dataset and the flow dataset using a joint inversion that honors the volume of the fluid-changed reservoir to determine relative permeability and capillary pressure; and characterizing flow characteristics in the volume of the fluid-changed reservoir. The method may be executed by a computer system.

Abstract: Systems and methods for training a model that uses probabilities of lithologies as prior information in an inversion are disclosed. Exemplary implementations may: obtain training data, the training data including (i) subsurface map data sets, and (ii) known lithologies; obtain an initial seismic mapping model; generate a conditioned seismic mapping model by training the initial seismic mapping model; store the conditioned seismic mapping model; obtain a target subsurface map data set; apply the conditioned seismic mapping model to generate a classified lithology map data set; apply an inversion to the classified lithology map data set to generate volumes of lithologies; generate an image that represents the volumes of lithologies; display the image.

Abstract: A method is described for deriving high-resolution reservoir properties for a subsurface reservoir. The method may include receiving a seismic dataset; inverting the seismic dataset to generate an ensemble of coarse-scale seismic parameters, wherein the inverting may use one of Bayesian models with Markov Chain Monte Carlo (MCMC) sampling, simulated annealing, partial swarm, or analytic Bayes formulations; receiving fine-scale lithotype models; developing deep learning neural networks based on transfer learning using the fine-scale lithotype models to generate a conditional probability distribution of high-resolution reservoir parameters; generating an ensemble of high-resolution reservoir parameters using the deep learning neural network to condition the ensemble of coarse-scale seismic parameters; and displaying, on a user interface, the ensemble of high-resolution reservoir parameters. The method is executed by a computer system.

Abstract: Systems and methods for training a model that uses probabilities of lithologies as prior information in an inversion are disclosed. Exemplary implementations may: obtain training data, the training data including (i) subsurface map data sets, and (ii) known lithologies; obtain an initial seismic mapping model; generate a conditioned seismic mapping model by training the initial seismic mapping model; store the conditioned seismic mapping model; obtain a target subsurface map data set; apply the conditioned seismic mapping model to generate a classified lithology map data set; apply an inversion to the classified lithology map data set to generate volumes of lithologies; generate an image that represents the volumes of lithologies; display the image.

Abstract: Embodiments of a method for detecting well integrity failure are disclosed herein. In general, embodiments of the method utilize seismic signals for detection. In particular, embodiments of the method may use recording of passive or active seismic signals. Further details and advantages of various embodiments of the method are described in more detail in the application.

Abstract: A method and system for characterizing subsurface hydraulic fractures, specifically the effective permeability thereof, are disclosed. One method includes transmitting electromagnetic signals from an electromagnetic source toward a subsurface hydraulic fracture location, capturing electromagnetic signal measurements of a subsurface hydraulic fracture on the Earth's surface above the subsurface hydraulic fracture location at a plurality of electromagnetic receivers, and associating characteristic hydraulic flow parameters with the electromagnetic signal measurements to determine one or more fracture zones. The method further includes determining an effective permeability of the one or more fracture zones, thereby determining an effectiveness of hydraulic fracturing in the subsurface hydraulic fracture location.

Abstract: A method and system for characterizing subsurface hydraulic fractures, specifically the effective permeability thereof, are disclosed. One method includes transmitting electromagnetic signals from an electromagnetic source toward a subsurface hydraulic fracture location, capturing electromagnetic signal measurements of a subsurface hydraulic fracture on the Earth's surface above the subsurface hydraulic fracture location at a plurality of electromagnetic receivers, and associating characteristic hydraulic flow parameters with the electromagnetic signal measurements to determine one or more fracture zones. The method further includes determining an effective permeability of the one or more fracture zones, thereby determining an effectiveness of hydraulic fracturing in the subsurface hydraulic fracture location.

Abstract: A surface electromagnetic survey system and method for detecting a fracture or fracture zone in a rock formation are provided. The system includes an electromagnetic source configured to generate an electromagnetic field in the vicinity of or at a surface of the rock formation. The electromagnetic source includes one or more electric dipole sources that are arranged so as to generate a substantially vertical electric field. The system also includes an electromagnetic receiver associated with the electromagnetic source, the electromagnetic receiver being configured to measure a component of the electromagnetic field at the surface of the rock formation; and a processor configured to convert the measured component of the electromagnetic field measured at the electromagnetic receiver into an electromagnetic field response per unit moment of the electromagnetic source. The electromagnetic field response provides information about characteristics parameters of the fracture or fracture zone.

Abstract: Embodiments of a method for detecting well integrity failure are disclosed herein. In general, embodiments of the method utilize seismic signals for detection. In particular, embodiments of the method may use recording of passive or active seismic signals. Further details and advantages of various embodiments of the method are described in more detail in the application.

Abstract: A system and a method for time lapse monitoring of a target feature within a rock formation are provided. The system includes a data weighted electromagnetic source configured to generate an electromagnetic field in vicinity or at a surface of the rock formation; and an electromagnetic receiver configured to measure a component of the electromagnetic field generated by the source. The data weighted electromagnetic source includes a plurality of electromagnetic sources and an electromagnetic field contribution from each electromagnetic source is weighted so as to enhance the component of the electromagnetic field measured by the electromagnetic receiver.

Abstract: A system and a method for estimating a reservoir parameter are provided. The method includes calculating a plurality of priors using a Markov random field, the plurality of priors comprising probability distributions of a plurality of litho-types; calculating posterior distributions based on the priors, the posterior distribution depending upon measured geophysical data, geophysical attributes and reservoir parameters; and determining at least a portion of litho-types in the plurality of litho-types that correlate most with the measured geophysical data.

Abstract: A system and a computer implemented method for determining a best well location from a plurality of possible well locations are described herein. The method includes drawing a plurality of earth models from a posterior distribution, wherein the posterior distribution is generated by stochastic inversion of existing data; calculating a well production at a plurality of proposed well locations within an earth model in the plurality of earth models using a relationship between the well production and earth parameters; calculating from the plurality of earth models, cost distributions using the relationship between well cost and the earth parameters; and calculating probability weighted values for the proposed well locations using probabilities from location dependent stochastic inversions as weights.

Abstract: A system and a computer implemented method for determining a value of information are described herein. The method includes drawing a plurality of synthetic prior earth models from one or more prior distributions for a plurality of well locations and generate from each prior distribution synthetic data; and drawing a plurality of posterior earth models from a posterior distribution for the plurality of well locations, the posterior distribution being generated through stochastic inversion from the synthetic data and the plurality of posterior models are drawn from each of the plurality of prior earth models. The method further includes calculating a difference or a ratio between a weighted value prior and a weighted value posterior and calculating a sum over a plurality of well locations of the difference or the ratio to obtain the value of information.

Abstract: A system and a method for estimating a reservoir parameter are provided. The method includes calculating a plurality of priors using a Markov random field, the plurality of priors comprising probability distributions of a plurality of litho-types; calculating posterior distributions based on the priors, the posterior distribution depending upon measured geophysical data, geophysical attributes and reservoir parameters; and determining at least a portion of litho-types in the plurality of litho-types that correlate most with the measured geophysical data.

Abstract: A method and a system for providing electromagnetic measurement in a rock formation are provided. The system includes a borehole casing having a plurality of casing segments. At least two casing segments of the plurality of casing segments are electrically isolated from each other. The system further includes an electromagnetic source positioned on a surface of the earth. The electromagnetic source is connected to the at least two casing segments. The electromagnetic source is configured to energize the at least two casing segments so as to generate an electromagnetic field in the rock formation around the borehole casing.