Description

Designed for you, if you are...

• A professional with a geoscience background

How we build your confidence

• Practical examples of data and computer simulations
• Theoretical concepts are explained and illustrated on case studies
• You will go through several exercises
• Case studies

The benefits from attending

• Use or request the appropriate processing technique
• Design an array for passive seismic (surface or downhole) monitoring to meet your targets
• Determine uncertainties of locations for microseismic events in microseismic monitoring arrays
• Orient downhole geophones from a perforation or calibration shot
• Quality check locations of microseismic events: estimate approximate distance and depth of a recorded microseismic event on a downhole array
• Build a velocity model (P- and S-wave) from a sonic log or check shot measurement suitable for microseismic monitoring
• Calibrate a velocity model for both surface and downhole arrays
• Estimate the source mechanism from surface microseismic monitoring
• Manage and mitigate hazards resulting from induced seismicity
• Take into account the uncertainties in the results of microseismic monitoring
• Effectively use the information provided by microseismicity
• Understand how the stress is constrained by microseismic events

Topics

• Introduction
  - Definition of microseismicity, induced / triggered seismicity
  - A brief review of microseismicity outside the oil industry: water reservoirs, mining and geothermal
  - Induced seismicity by reservoir production
  - Historical review of microseismicity during reservoir production
  - Historical review of microseismicity by hydraulic fracturing (M-site, Cotton Valley, Barnett, etc.)
  - Principles of hydraulic fracturing and geomechanics
• Earthquakes
  - Instrumentation for passive seismic
  - Earthquake location techniques
  - Relative locations
  - Microseismic location techniques and exercises
• Downhole location technique
  - Single well monitoring technique
  - P-wave and S-wave polarisation
  - P-wave only location from downhole arrays
  - Picking strategies for microseismic data
  - Optimal design of downhole monitoring array
  - Orientation of downhole geophones
  - Velocity model calibration
  - Inclined / dual and multi-well monitoring techniques
• Surface monitoring technique
  - Vertical component only, uncertainty associated from P-wave locations: depth vs. origin time
  - Detection uncertainty and signal-to-noise ratio
  - Frequency content, attenuation and detection
  - Design of surface monitoring array
  - Calibration shots / velocity model building: isotropic vs. anisotropic velocity
  - Relative locations
  - Downhole and surface location case study
  - Near surface amplification
• Source mechanisms
  - Concept of source mechanism, definition of dip, strike and rake for shear source
  - Description of shear, tensile, volumetric, CLVD source through moment tensor
  - Inversion for source mechanisms from single monitoring borehole / multiple monitoring boreholes / surface P-only data
  - Source mechanisms of microseismic events
• Source characterisation
  - Magnitude local and moment
  - Magnitude and energy
  - B-value and magnitude of completeness
  - Stress drop, source dimensions
• Anisotropy
  - Introduction to anisotropy
  - Effect of anisotropic media on S-waves: shear wave splitting
  - Shear wave splitting observed in microseismic data
  - Inversion of anisotropic media from P and S-waves using microseismic events
  - P-wave anisotropy on surface monitoring data
  - Time-lapse changes in anisotropy
• Reservoir simulations
  - Current use of microseismicity in the oil industry
  - Diffusion model for pressure triggering of microseismic events
  - Discrete fracture networks constrained by microseismicity
  - Reservoir simulations and history matching
• Seismicity in the vicinity of oil or gas reservoirs
  - Theory and history of induced felt seismicity
  - Seismic moment and total injected volume
  - Blackpool case study as an example of induced seismicity
  - DFW seismicity case study
  - Social issues related to hydraulic fracturing
• Case studies and conclusions
  - Recent important case studies: locations and source mechanisms
  - Relationship between microseismicity and hydraulic fracturing
  - Summary of the class
  - The most important things to remember about microseismicity