3D geomechanical modeling for CO2 geological storage in faulted formations. A case study in an offshore northern Adriatic reservoir, Italy

Abstract One of the six CO2 carbon capture and storage (CCS) demonstration projects recently selected within the European Energy Programme for Recovery (EEPR) is located in Italy. In the framework of the feasibility study, the selection of a geological formation suitable to store the required 1 Mt/yr of CO2 over 10 years and the safety of the CO2 disposal are two major issues. In the present modeling study, we investigate the role played by geomechanics in assessing the maximum CO2 amount that can be sequestered into a 2000 m deep multi-compartment reservoir seated in the off-shore northern Adriatic sedimentary basin. We use a three-dimensional finite element–interface element geomechanical model to simulate the possible mechanical failure in both the injected formation and caprock, the fault reactivation, and the ground surface displacement. The faulted geological structure is reproduced based on detailed seismic surveys, with petrophysical/geomechanical properties based on the several well-logs available from several oil/gas explorations in the area. The pore pressure distribution due to two injection wells is provided by a fluid-dynamic simulator and a sensitivity analysis is carried out to investigate the role of the major uncertainties in the geomechanical setting. The modeling results suggest that a safe and permanent containment may be secured over a few years only. Afterwards, mechanical failure by shear stress is likely to be experienced by a significant portion of reservoir's injected compartments. Shear failure and fault reactivation can occur much before attaining the hydraulic fracturing pressure, hence represent two major issues in assessing the maximum allowable CO2 injection overpressure.

[1]  Nicola Castelletto,et al.  Thermo‐hydro‐mechanical modeling of fluid geological storage by Godunov‐mixed methods , 2012 .

[2]  Carlo Janna,et al.  Numerical modelling of regional faults in land subsidence prediction above gas/oil reservoirs , 2008 .

[3]  Carlo Janna,et al.  Simulation of ground failure due to groundwater pumping , 2010 .

[4]  Ben A. Eaton,et al.  Fracture Gradient Prediction and Its Application in Oilfield Operations , 1969 .

[5]  Giuseppe Gambolati,et al.  Land uplift due to subsurface fluid injection , 2011 .

[6]  S Pacala,et al.  Stabilization Wedges: Solving the Climate Problem for the Next 50 Years with Current Technologies , 2004, Science.

[7]  Julio Friedmann,et al.  Seal integrity and feasibility of CO2 sequestration in the Teapot Dome EOR pilot: geomechanical site characterization , 2008 .

[8]  Zhishen Wu,et al.  Numerical simulation on crust deformation due to CO2 sequestration in deep aquifers , 2002 .

[9]  G. Gambolati,et al.  Anthropogenic Land Subsidence , 2006 .

[10]  Giuseppe Gambolati,et al.  Water–gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea , 2000 .

[11]  C. Tsang,et al.  Estimating maximum sustainable injection pressure during geological sequestration of CO2 using coupled fluid flow and geomechanical fault-slip analysis , 2006 .

[12]  Donald L. Katz,et al.  Threshold pressure phenomena in porous media , 1968 .

[13]  Domenico Baù,et al.  Basin-scale compressibility of the northern Adriatic by the radioactive marker technique , 2002 .

[14]  David R. Cole,et al.  CO2 Sequestration in Deep Sedimentary Formations , 2008 .

[15]  D. Vasco,et al.  Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria , 2010 .

[16]  J. Cosgrove,et al.  Prediction of fracture-induced permeability and fluid flow in the crust using experimental stress data , 1999 .

[17]  Domenico Baù,et al.  Interpretation of Radioactive Marker Measurements To Evaluate Compaction in the Northern Adriatic Gas Fields , 2003 .

[18]  Federica Donda,et al.  CO2 storage potential of deep saline aquifers: The case of Italy , 2010 .

[19]  Giuseppe Gambolati,et al.  Finite element analysis of land subsidence above depleted reservoirs with pore pressure gradient and total stress formulations , 2001 .

[20]  Richard R. Hillis,et al.  Estimating fault stability and sustainable fluid pressures for underground storage of CO2 in porous rock , 2004 .

[21]  Don W. Vasco,et al.  Satellite‐based measurements of surface deformation reveal fluid flow associated with the geological storage of carbon dioxide , 2010 .

[22]  L.G.H. van der Meer,et al.  Geomechanical modeling of surface uplift around well KB-502 at the in Salah CO2 storage site , 2011 .

[23]  J. Prévost,et al.  Coupled multi-phase thermo-poromechanical effects. Case study: CO2 injection at In Salah, Algeria , 2011 .

[24]  Y. Le Gallo,et al.  A Sequential Splitting Strategy for CO2 Storage Modelling , 2006 .

[25]  G. Gambolati,et al.  Multiphysics modeling of CO2 sequestration in a faulted saline formation in Italy , 2013 .

[26]  Nicola Castelletto,et al.  Numerical Modeling of Rock/Casing Interaction in Radioactive-Marker Boreholes of the Northern Adriatic Basin, Italy , 2010 .

[27]  J. Nauroy,et al.  3D geomechanical modelling for CO2 geologic storage in the Dogger carbonates of the Paris Basin , 2009 .

[28]  Massimo Rossi,et al.  Sedimentary and tectonic evolution in the eastern Po-Plain and northern Adriatic Sea area from Messinian to Middle Pleistocene (Italy) , 2010 .

[29]  Nicola Castelletto,et al.  Geomechanical response to seasonal gas storage in depleted reservoirs: A case study in the Po River basin, Italy , 2011 .

[30]  Jonny Rutqvist,et al.  Impact of CO2 geological sequestration on the nucleation of earthquakes , 2011 .

[31]  J. Geertsma,et al.  Land subsidence above compacting oil and gas reservoirs , 1973 .

[32]  Jonny Rutqvist,et al.  The Geomechanics of CO2 Storage in Deep Sedimentary Formations , 2012, Geotechnical and Geological Engineering.

[33]  Peter Wriggers,et al.  Computational Contact Mechanics , 2002 .

[34]  James P. Verdon,et al.  Linking microseismic event observations with geomechanical models to minimise the risks of storing CO2 in geological formations , 2011 .

[35]  A. W. Bishop,et al.  The Principle of Effective Stress , 1959 .

[36]  Matthew C. Gerstenberger,et al.  Induced seismicity and its implications for CO2 storage risk , 2011 .

[37]  E. Fjaer,et al.  Petroleum Related Rock Mechanics , 1992 .

[38]  Giuseppe Gambolati,et al.  Groundwater pumping and land subsidence in the Emilia‐Romagna coastland, Italy: Modeling the past occurrence and the future trend , 2006 .

[39]  Alvaro Maia da Costa,et al.  Risks And Mitigation Problems In a CO2 Injection Project For a Petroleum Onshore Field In Brazil , 2010 .

[40]  B. Müller,et al.  The tectonic regime in Italy inferred from borehole breakout data , 2003 .

[41]  G. Gambolati,et al.  Geomechanical issues of anthropogenic CO2 sequestration in exploited gas fields , 2010 .

[42]  A. Cooper.  The classification, recording, databasing and use of information about building damage caused by subsidence and landslides , 2008, Quarterly Journal of Engineering Geology and Hydrogeology.

[43]  Eric Tenthorey,et al.  Geomechanical analysis of the Naylor Field, Otway Basin, Australia: Implications for CO2 injection and storage , 2010 .