SC10 Microseismic Monitoring in Oil or Gas Reservoirs

Sponsored by: SEG

Thursday, 23 June – Friday, 24 June 2022, 8:00 a.m.–5:00 p.m.  |  

Who Should Attend

Entry and Intermediate levels - The course is designed to be followed by anyone with a broad geoscience background: no specific detailed foreknowledge is required, although a familiarity with geophysical terminology will be useful.

Objectives

• Design an array for passive seismic (surface or downhole) monitoring and estimate uncertainties of locations for microseismic events
• Orient downhole geophones from a perforation or calibration shot, estimate approximate distance and depth of a recorded microseismic event
• Build a velocity model (P and S-wave) from a sonic log or check shot measurement suitable for microseismic monitoring
• Estimate source mechanism from surface microseismic monitoring
• Design a monitoring array that would allow avoiding of significant (felt) seismic events induced by hydraulic fracturing (traffic light system)

Course Content

• Introduction: Why do we perform microseismic monitoring? Definition of microseismicity, induced/triggered seismicity, a brief review of microseismicity outside of oil industry: water reservoirs, mining, geothermal. Oil reservoir production induced seismicity. Historical review of microseismicity in oil industry with focus on hydraulic fracturing (M-site, Cotton Valley, Barnett, etc.). Principles of the hydraulic fracturing and geomechanics.
• Earthquakes: number of unknowns, differences from active seismic. Instruments suitable for measuring earthquakes and their optimal parametrization. Earthquake location techniques. Relative locations. Location techniques.
• Downhole location technique: single well monitoring acquisition. S-P wave time and P-wave polarization technique location, P-wave and S-wave polarization. P-wave or S-wave only location from a single monitoring borehole. Horizontal monitoring boreholes. Picking strategies for downhole microseismic data. Optimal design of downhole monitoring array. Magnitude and detection. Orientation of downhole geophones/deviation surveys/velocity model calibration. Inclined/dual and multi well monitoring techniques. Check list for downhole monitoring.
• Surface monitoring technique: Why do surface and near-surface microseismic monitoring? Imaging of microseismic event using P-wave migration. Uncertainty associated with P-wave only 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 through cross-correlations and using S-wave from surface monitoring. Downhole and surface location case study. Near surface amplification. Check list for surface monitoring.
• Source mechanisms: concept of source mechanism and why do we care about source mechanisms. Definition of the dip, the strike and the rake for a 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. Radiation pattern of typical source mechanisms.
• Advanced source characterization: Vp/Vs ratio and amplitudes from point source, Seismic moment and Magnitude, Energy of seismic events and moment, Intensity, relative magnitudes. What is the b-value and how can we use it. Stress drop and 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 in surface monitoring data. Time-lapse changes in anisotropy.
• Engineering applications of microseismicity: Current use of microseismicity in oil industry and implementation of microseismicity into modeling. Microseismic based completions evaluation. Diffusion model for pressure triggering of microseismic events. Discrete Fracture Networks constrained by microseismicity. Stimulated reservoir volume. Microseismic and production, 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. Oklahoma seismicity triggered by salt water disposal. Hazard assessment and mitigation.
• Review of recent important case histories. Summary of microseismic pros and cons, applications pros and cons. Business considerations – microseismic timelines, deliverables, minimum standard. Relationship between microseismicity and hydraulic fracturing. The road ahead. Most important things to remember about microseismicity.

Fees

Pricing:

Members - $500

Non-Members - $600

Students - $250

Room Assignment:

George R. Brown Convention Center

Attendee Limit:

30 People

Education Credits:

1.6 CEU

Venue

Website Map

Instructor

Leo Eisner President Czech Academy of Sciences, Czech Republic

Leo Eisner graduated from the Charles University in 1995 (MSc) and Caltech in 2001 (Ph.D.). Leo spent six years as a Senior Research Scientist with Cambridge Schlumberger Research where he filed five patents and issued numerous publications. He joined MicroSeismic, Inc. in 2008 and was promoted to the Chief Geophysicist in 2009. In 2010 he has accepted honorary position of Purkyne Fellow at the Academy of Sciences of the Czech Republic in Prague. He is founder and president of seismic service company Seismik s.r.o. His peer reviewed articles (30+) and extended abstracts (50+) cover a broad range of subjects, including the seismic ray method, finite-difference methods, seismological investigations of local and regional earthquakes, induced seismicity and microseismicity, etc.