Geomechanical Aspect of Seismicity Induced by Subsurface Fluid Injection and Production S. Mehran Hosseini, Ph.D. Student Fracture Tip Stress Trajectory USC Induced Seismicity Consortium Meeting Fracture Tip Stress Field July 02, 2013 Outline Application Coulomb Stress Transfer Analytical Solutions Numerical Solutions Data and Software Requirement Along Deliverables Methodology: Project Schedule and Milestones References 2 Applications • Oil and Gas Production • Hydraulic Fracturing • CO2 Sequestration • Geothermal Reservoirs • Enhanced Oil Recovery • Waste Injection Methodology 4 Coulomb Stress Transfer Coulomb stress transfer is an interaction criterion that promises a deeper understanding of earthquake occurrence, and a better description of probabilistic hazard. http://www.youtube.com/watch?v=CDdHPDdPpYE&feature=player_embedded Coulomb stress change can happen as result of pore pressure diffusion in a poroelastic medium (reservoir) as well as stresss change and displacement associated with hydraulic fracturing and faulting. Why should we be concerned? USGS seismic hazard map speaks for itself. USGS Seismic Hazard Map USC Induced Seismicity Consortium Meeting S. Mehran Hosseini, July 02, 2013 Risk Quantification and Management Earthquakes have happened in the past and will happen in the future. The main question is how much subsurface production and injection can increase or decrease the risk, If any. In the case of increased risk what solutions can be followed to decrease the risk. The results of the study will be included in the hazard mitigation tool. 6 Similar Analytical Solutions: Fracture Network Characterization Based on Seismic Event Front Failure in the intact rock Failure along the planes of weakness Hosseini and Aminzadeh [2013] Event Front Hosseini and Aminzadeh [2013] ΔP m β Fault or Fracture Orientation Numerical Solution: Coulomb Stress Change Due to Subsurface Injection and Production USGS Coulomb Software: One can calculate static displacements, strains, and stresses caused by fault slip, magmatic intrusion or dike expansion. Problems such as how an earthquake promotes or inhibits failure on nearby faults, or how fault slips are germane to Coulomb. Calculations are made in an elastic halfspace with uniform isotropic elastic properties following Okada [1992]. This software is used in several studies which are published in Nature and other distinguished journals. 8 Data and Software Requirement Along Deliverables Required Data Triaxial test results Geology data Micorseismic data Stress data Image log Sonic log More specific data needs will be updated along the way Required Software USGS Coulomb Software (Free) ABAQUS (Dassault Systems) Jewel Suite (Baker Hughes) Mangrove (Schlumberger) CMG Deliverables Results will be conveyed through quarterly meeting presentations and reports. The results upon client agreement will be included in S. Mehran Hosseini’s Ph.D. dissertation. Results upon client agreement will be published in related journals and conference proceedings. 9 Project Schedule and Milestones After Aminzadeh et al. [2013]; Yellow Areas shows my personal contribution plan References Aminzadeh, F., Jafarpour, B., Sammis, C., Ghanem, R., Strack, K., Karrenbach, M. 2012. Quantifying Seismic Hazard from Subsurface Fluid Injection and Production (SFIP) for Shale Gas and Oil Reservoirs. REPSEA RFP2012UN001. Hosseini, S.M., Aminzadeh, F. 2013. A New Model for Geomechanical Seismicity Based Reservoir Characterization Including Reservoir Discontinuity Orientations. Paper SPE 166485 presented at the SPE Annual Technology conference and exhibition, New Orleans, LA, 30 September-2 October. Okada, Y. 1992. Internal deformation due to shear and tensile faults in a half-space, Bull. Seismol. Soc. Amer., 82 (2), 1018-1040. Richards-Dinger, K., Stein, R.S., and Toda, S. 2010, Decay of aftershock density with distance does not indicate triggering by dynamic stress, Nature, 467, 583-586, doi:10.1038/nature0940. Thank You Questions? Paper # • Paper Title • Presenter Name