A method can include receiving microseismic data of microseismic events as acquired by sensors during hydraulic fracturing of a geologic region; jointly calibrating sensor orientation of the sensors and a velocity model of the geologic region via an objective function and the microseismic data; and, based at least in part on the jointly calibrating, determining one or more locations of the one or more microseismic events.

An example method of identifying geologic areas in a formation that are prone to casing deformation includes conducting hydraulic fracturing along a portion of a cased wellbore. The method includes recording microseismic activity occurring within a first threshold distance of the wellbore and establishing stresses on the wellbore casing at one or more points. The method further includes determining, based on the recorded microseismic activity and the stresses on the casing, whether a geologic area in the formation within a second threshold distance of the wellbore is prone to formation relaxation or shear slippage.

Methods and systems including computer programs encoded on a computer storage medium, for utilizing equivalent linear velocity for first arrival picking of seismic refraction. In one aspect, a method includes receiving data for the shot gather record, generating a diving wave equation curve for a particular parameter pair of multiple parameter pairs, and integrating the shot gather record data corresponding to the diving wave equation curve over a selected range of offsets of the shot gather to generate an equivalent linear velocity value for the particular parameter pair and the shot gather record data, selecting, from the equivalent linear velocity values for the plurality of parameter pairs, a greatest equivalent linear velocity value of the equivalent linear velocity values, the greatest equivalent linear velocity value corresponding to a first-arrival parameter pair, and determining, using the first-arrival parameter pair, a set of first-arrival onsets for the selected sub-range of offsets.

A method of performing a fracture operation at a wellsite is disclosed for a wellsite positioned about a subterranean formation having a wellbore therethrough and a fracture network therein. The fracture network includes natural fractures. The method involves generating wellsite parameters of the wellsite comprising seismic measurements, generating smooth fracture parameters of a smooth fracture by solving governing equations based on the wellsite parameters, and generating ledged fracture parameters of a ledged fracture by identifying ledge locations and generating ledged fracture parameters of a ledged fracture at the ledge locations by solving the governing equations based on the wellsite parameters for the ledge locations.

Various aspects described herein relate to a machine learning based detecting of fracture hits in offset monitoring wells when designing hydraulic fracturing processes for a particular well. In one example, a computer-implemented method includes receiving a set of features for a first well proximate to a second well, the second well undergoing a hydraulic fracturing process for extraction of natural resources from underground formations; inputting the set of features into a trained neural network; and providing, as output of the trained neural network, a probability of a fracture hit at a location associated with the set of features in the first well during a given completion stage of the hydraulic fracturing process in the second well.

A method includes receiving over a network from one or more seismic sensors a data set characterizing a seismic event generating a seismic wave. Based on the data set, a time of arrival and intensity of the seismic wave at a predetermined location is calculated. The predetermined location has one or more mitigation devices. Whether the intensity of the seismic wave exceeds a predetermined seismic intensity threshold is determined. If the intensity of the seismic wave exceeds the predetermined seismic intensity threshold, the one or more mitigation devices are activated.

A method can include receiving mechanical information of a geologic environment and location information of natural fractures of the geologic environment; using a model of the geologic environment, calculating at least strain associated with hydraulic fracturing in the geologic environment; calculating at least microseismicity event locations based at least in part on the calculated strain; calibrating the model based at least in part on the calculated microseismicity event locations and based at least in part on measured microseismicity information associated with the geologic environment to provide a calibrated model; and, using the calibrated model, determining an increase in reactivated fracture volume associated with hydraulic fracturing in the geologic environment.

A method of performing oilfield operations at a wellsite is disclosed. The wellsite is positioned about a subterranean formation having multiple wellbores therethrough and a fracture network therein. The fracture network includes natural fractures. The method involves generating fracture parameters including a hydraulic fracture network of a fracture grid for each of the multiple wellbores based on wellsite data including microseismic events and a mechanical earth model, generating reservoir parameters including an updated mechanical earth model of a reservoir grid based on the wellsite data and the fracture parameters, generating integrated wellsite parameters including an integrated earth model by integrating the fracture parameters from the multiple wellbores with the reservoir parameters, and performing production operations at the multiple wellbores based on the integrated wellsite parameters.

Aspects of the subject technology relate to systems, methods, and computer-readable media for detecting and marking events that occur during a fracturing operation. Data related to performance of a fracturing operation in a wellbore during performance of a stage of the fracturing operation can be accessed. An event detection algorithm for detecting a specific event during the fracturing operation can be accessed. The event detection algorithm can be applied to the data to determine whether the specific event actually occurs during at least a portion of the stage of the fracturing operation. As follows, an indication of the specific event occurring during the stage of the fracturing operation can generated if it is determined that the specific event actually occurred during the at least a portion of the stage of the fracturing operation.

Treatment fluid may be injected into a wellbore of a geological formation to stimulate fracturing of the geological formation. A plurality of measurements may be received from one or more sensors on a surface of the geological formation or downhole which measures an indication of change of the geological formation based on the stimulation. A fracture configuration of a fracture in the geological formation may be determined based on an Kalman gain and the plurality of measurement data. Injection of the treatment fluid into the wellbore may be adjusted based on the fracture configuration.