INDUCED SEISMICITY IN PETROLEUM FIELDS: RESERVOIR CHARACTERIZATION, SEISMIC RISK ASSESSMENT AND MANAGEMENT M. Nafi Toksöz Earth Resources Laboratory, Massachusetts Institute of Technology Cambridge, MA February, 2006

INVESTIGATORS MIT: KUWAIT: Prof. M. Nafi Toksöz KISR- Dr. Dhari Al-Ajmi (seismologist, team leader) (Kuwait team leader) Prof. Bradford Hager (geomechanics) Kuwait Oil Company- Prof. Thomas Herring (GPS network, inSAR) Dr. Adel Al-Abbasi Prof. Frank Dale Morgan (geotechnical, gravity) Kuwait University- Investigators Prof. Kenneth Oye (policy, risk management) to be nominated by the university Prof. Andrew Whittle (soil mechanics) and the Kuwait team

Induced Seismicity Often accompanies fluid injection and production in Oil and gas fields; geothermal reservoirs; hydraulic fracturing. Oil and gas fields; geothermal reservoirs; hydraulic fracturing.Causes? Pore pressure changes Pore pressure changes Stresses due to volume changes. Stresses due to volume changes.

Why is it Important? GIVES INFORMATION ABOUT RESERVOIR PROPERTIES AND FLUID PRESSURE CHANGES POTENTIAL FOR DAMAGING EARTHQUAKES AND RISK TO: Surface facilities Surface facilities Wells and casings Wells and casings Fault seals Fault seals Environment Environment Public acceptance Public acceptance

Seismic Event Locations

Bou-Rabee, F. and R., M.,Abdel-Fattah, Kuwait J., Sci., Eng v. 31.

Al-Awadhi, J., V. Midzi, Seism. Res. Lett., V:72, N:4, 2001.

PROPOSED TASKS Analyze existing seismic and other data relevant to induced seismicity. Densify the existing seismic network to provide a good coverage over the southern and northern oil fields. Include three deep seismic stations and three strong motion instruments at each region. Install continuous GPS stations at each of the two regions to determine three-component surface deformations. Initiate the inSAR analysis to determine subsidence or other deformations. Initiate a reservoir characterization and dynamics (compaction, pore fluid characterization). Do an initial probabilistic earthquake hazard assessment using the existing data. Calculate ground motions and site effects. Develop a plan for the management of potential seismic hazard. Update steps 7 and 8 with new data.

USGS Fact Sheet , December 2003

THANK YOU

SOULTZSOULTZ Early Experimental Phase In The Upper Reservoir Exploration of the Deep Reservoir Downhole seismic network

(a) Vertical view and (b) top view of the seismicity associated with the stimulation in 2003

Hydraulic Experiment Soultz,1993 JHD Collapsing

PS fracture Example of multiplet Time

Aligned waveforms of the master and the slave after adjusting the time delay P wave master slave

Relocated Clusters - Vertical View Well GPK3 (Injection) Well GPK2 (Production)

(a) Azimuth (b) Dip in degrees of the planes deduced by planarity analysis

Distribution of the events around the GPK3 well (200m around the well). Two major microseismic zones are observed: one at app m TVD and the other one at app. 4900m TVD. If we compare that with the major flow exits, we find a good correlation between the location of these events and the increases of flow.

Rutledge J. and Phillips S., 2002 – Upper Cotton Valley, TX