Crosswell Microseismic System for Anisotropic Formation Monitoring
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Solution Overview
Problem
Current reflection seismology methods face challenges in accurately interpreting seismic data from anisotropic formations, particularly in locating microseismic events generated by stimulation processes, due to limitations in velocity modeling and data interpretation.
Innovation Solution
A method and system that receive seismic data from anisotropic formations, utilize crosswell calibrated velocity model information to locate microseismic events, and render these events on a display, enhancing the accuracy of event location and interpretation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional reflection seismology methods are used to interpret seismic data from anisotropic formations, then the interpretation process is simplified, but the accuracy of microseismic event location deteriorates
Solution Approach 1:
The system performs preliminary crosswell seismic surveys to calibrate velocity models before conducting production seismic monitoring. This advance preparation establishes accurate anisotropic velocity parameters that are then used during stimulation operations, eliminating the need for complex real-time velocity modeling and improving event location accuracy.
Solution Approach 2:
The patent introduces crosswell seismic data as an intermediary to bridge the gap between surface seismic data and subsurface anisotropic properties. This intermediate measurement provides direct velocity calibration information that simplifies the interpretation of production seismic data from monitoring wells.
2Measurement precision
If crosswell calibrated velocity model information is used to locate microseismic events, then the event location accuracy is improved, but the data processing complexity increases
Solution Approach 1:
Velocity models are calibrated using crosswell seismic data before production monitoring begins. This preliminary calibration stores anisotropic velocity parameters that are then directly applied during stimulation event location, avoiding complex real-time calculations and reducing processing complexity during operations.
Solution Approach 2:
The system uses the same monitoring wellbore infrastructure to serve dual purposes: both as a seismic source for stimulation and as a receiver for event location. This self-service approach eliminates the need for separate calibration surveys and reduces overall data processing complexity.
3Reliability
If conventional velocity modeling is used for anisotropic formations, then the processing workflow is simpler, but the interpretation reliability deteriorates
Solution Approach 1:
Crosswell seismic surveys serve as an intermediary measurement that directly probes anisotropic velocity properties in the target formation. This intermediate data provides reliable velocity calibration that accounts for anisotropy, improving interpretation reliability without requiring complex theoretical modeling.
Solution Approach 2:
The system changes the velocity model parameters by incorporating anisotropic corrections based on crosswell calibration data. This parameter adjustment transforms the velocity model from a simple isotropic assumption to a calibrated anisotropic model, significantly improving interpretation reliability for microseismic event location.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves the accuracy of microseismic event location and interpretation, enabling better understanding of fracture geometry and stress changes in anisotropic formations, thereby optimizing hydraulic fracturing operations.
Implementation Method 1
receiving seismic data responsive to stimulation of an anisotropic formation via a well disposed in the formation; locating a microseismic event generated by the stimulation based at least in part on a portion of the received seismic data
Data Source
AI summary
A method can include receiving seismic data responsive to stimulation of an anisotropic formation via a well disposed in the formation; receiving crosswell calibrated velocity model information that spans a depth range of the anisotropic formation; locating a microseismic event generated by the stimulation based at least in part on a portion of the received seismic data and based at least in part on the crosswell calibrated velocity model information; and rendering the located microseismic event to a display with respect to one or more dimensions of the anisotropic formation.