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.

A method of exploring for hydrocarbons in a region, including the steps of obtaining seismic data for the region corresponding to two or more different times and analyzing the seismic data corresponding to the two or more different times to determine whether there are any changes in the seismic data.

A method for determining a thermal maturity image of a subterranean region and a non-transitory computer readable medium, storing instructions for executing the method, are disclosed. The method includes, obtaining a seismic dataset for the subterranean region of interest, obtaining a thermal maturity value for a plurality of core samples taken from different positions within the subterranean region, and obtaining a plurality of well log types from the core sampling location. The method further includes determining a calibrated rock physics model based on the plurality of well log types, determining a pore fluid type based on the calibrated rock physics model, and determining a thermal maturity model based on the plurality of core samples, on the pore fluid type, and on the plurality of well logs. The method still further includes determining the thermal maturity image of the subterranean region based on the seismic dataset and thermal maturity model.

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.

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.

Methods and mediums for estimating stimulated reservoir volumes are disclosed. Some method embodiments may include obtaining microseismic event data acquired during a hydraulic fracturing treatment of the formation, the data including event location and at least one additional attribute for each microseismic event within the formation; filtering the microseismic events based on the at least one additional attribute; determining a density of filtered microseismic events; weighting the filtered microseismic events based on the density; and determining a stimulated reservoir volume estimate based on filtered and weighted microseismic events.

A method for mapping remaining hydrocarbon resources in a subsurface reservoir, includes obtaining a map of seismic amplitude difference over a time period based on a survey of the subsurface reservoir, generating an expected trend dataset for the reservoir based on one or more non-water saturation effects detected over the time period by one or more wellbore surveillance techniques at one or more locations in the reservoir, correcting the map of seismic amplitude difference, at least in part, on the expected trend dataset to generate a corrected seismic amplitude map, and using the corrected seismic amplitude difference map to generate a map representative of remaining hydrocarbon resources in the reservoir. Embodiments include a system for performing the method and a medium containing computer executable software instructions for performing the method.

A method of performing single trace inversion to characterize changes in a subsurface region includes obtaining a base seismic trace and a monitor seismic trace of the subsurface region at different respective times. The method includes generating a predicted monitor seismic trace from the base seismic trace by a process including applying a time shift to the base seismic trace, the time shift being derived from estimated velocity perturbations occurring between the base seismic trace and the monitor seismic trace, compensating for amplitude changes between the base seismic trace and the monitor seismic trace, wherein the time shift is applied to the amplitude changes, and minimizing a difference between the predicted monitor seismic trace and the monitor seismic trace by iteratively estimating the velocity perturbations to obtain final estimated velocity perturbations. Changes of at least part of the subsurface region may be characterized using the final estimated velocity perturbations.

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.

A system and method for seismic monitoring of large area subsurface reservoirs, for instance, the system comprising: multiple electro acoustic technology assemblies comprising seismic sensing elements, electronic circuits for converting the seismic sensing signals to frequencies, amplification circuitry to amplify the frequencies, an acoustic source that converts the amplified frequencies to an acoustic frequency signal; a fiber optic acoustic sensing system comprising a fiber optic cable deployed in a subsurface reservoir, where the multiple electro acoustic technology assemblies are proximate to and/or acoustic coupled with the fiber optic cable of the fiber optic acoustic sensing system, and a surface based distributed acoustic sensing interrogator connected to the fiber optic cable.