Adaptive 4d seismic survey design for monitoring of carbon storage sites

A computing system, comprising:

• one or more processors;
• and
• a memory system comprising one or more non-transitory computer-readable media storing instructions that, when executed by at least one of the one or more processors, cause the computing system to perform operations, the operations comprising:
• simulating a seismic experiment using a baseline model, wherein the seismic experiment comprises a simulated pressure propagation of seismic wavefields and/or a simulated particle velocity propagation of the seismic wavefields in the baseline model;
• generating a set of synthetic data for a range of source locations and a range of receiver locations that correspond to an identified source location and an identified receiver location that respectively are configured to be used in a monitor survey;
• perturbing the baseline model to produce one or more perturbed baseline models, wherein the baseline model is perturbed with a constant slowness to produce a first perturbed baseline model, and/or with a localized perturbation representative of a defined target to produce a second perturbed baseline model;
• selecting a plurality of candidate acquisition geometries to probe the one or more perturbed baseline models, wherein the candidate acquisition geometries comprise a subset of the identified source location and the identified receiver location;
• extracting a set of simulated data from the simulated seismic experiment that corresponds to the candidate acquisition geometries, wherein the set of simulated data comprises shot gathers and/or receiver gathers that each correspond to the identified source location and the identified receiver location in the candidate acquisition geometries;
• and
• executing a model probing exercise for the extracted set of simulated data for each candidate acquisition geometry and each of the one or more perturbed baseline models.

A non-transitory computer-readable medium storing instructions that, when executed by one or more processors of a computing system, cause the computing system to perform operations, the operations comprising:

• simulating a seismic experiment using a baseline model, wherein the seismic experiment comprises a simulated propagation of seismic wavefields that may be extracted as a pressure or a particle velocity measurement in the baseline model;
• generating a set of synthetic data for a range of source locations and a range of receiver locations that correspond to an identified source location and an identified receiver location that respectively are configured to be used in a monitor survey, wherein the identified source location and the identified receiver location are each modelled first shot gathers or first receiver gathers, wherein the first shot gathers and/or the first receivers gather respectively correspond to a single set or a multicomponent set of seismic data;
• perturbing the baseline model to produce one or more perturbed baseline models, wherein the baseline model is perturbed with a constant slowness to produce a first perturbed baseline model, and with a localized perturbation representative of a defined target to produce a second perturbed baseline model, wherein the baseline model is perturbed with a slowness value from about 0.5% to about 3% of an inverse P-wave velocity of the baseline model, wherein the baseline model is perturbed with the localized perturbation that corresponds to an expected elastic property change in a subsurface formation after injection of carbon dioxide (CO2), wherein the expected elastic property change is generated through reservoir modelling, and wherein the baseline model is perturbed in parallel with simulating the seismic experiment;
• selecting a plurality of candidate acquisition geometries to probe the one or more perturbed baseline models, wherein the candidate acquisition geometries comprise a subset of the identified source location and the identified receiver location;
• extracting a set of simulated data from the simulated seismic experiment that corresponds to the candidate acquisition geometries, wherein the set of simulated data comprises second shot gathers and/or second receiver gathers that each correspond to the identified source location and the identified receiver location in the candidate acquisition geometries;
• executing a model probing exercise for the extracted set of simulated data for each candidate acquisition geometry and each of the one or more perturbed baseline models, wherein the model probing exercise comprises:
• determining a data residual from the simulated seismic experiment and the one or more perturbed baseline models, wherein the data residual comprises a difference between an output of the simulated seismic experiment and the corresponding set of synthetic data generated in the one or more perturbed baseline models;
• and
• determining a full-waveform inversion gradient based upon the data residual, wherein the full-waveform inversion gradient is indicative of how the candidate acquisition geometries illuminate and recover a target perturbation;
• conducting a statistical analysis of a selected number of metrics from the model probing exercise, wherein the statistical analysis comprises computing a mean and a standard deviation of the metrics, and wherein the metrics comprise a percentage of a target region illuminated by the candidate acquisition geometries, a root mean square difference between the target perturbation and a recovered perturbation, a cross-correlation coefficient between the target perturbation and the recovered perturbation, an estimated cost of the candidate acquisition geometries, or a combination thereof;
• calculating a confidence value for each candidate acquisition geometry based upon the statistical analysis and/or the metrics;
• and
• ranking each of the candidate acquisition geometries based on the calculated confidence values.