Current challenges at CO 2 Sites Ola Eiken et al., Statoil R&D Force seminar on injection safety 4 th December 2013 Offshore Sleipner Onshore In Salah Sub-sea Snøhvit 1 - Classification: External 2010-09-23
Snøhvit Sleipner In Salah 2 - Classification: External 2010-09-23
Pressure [bar] 1 10 100 1000 10000 solid liquid vapor -60-40 -20 0 20 40 60 80 100 Temperature [ o C] 3 - Classification: External 2010-09-23
Sleipner Permeability 1 10 100 1000 In Salah Snøhvit 0 0.1 0.2 0.3 0.4 Porosity 4 - Classification: External 2010-09-23
Accumulated injected CO2 [million tons] 12 11 10 9 8 7 6 5 4 3 2 1 0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Year 5 - Classification: External 2010-09-23
Sleipner CO 2 injection 6 Wellhead pressure 60 62 64 66 68 70 72 74 76 78 80 13-1996 15-1997 14-1997 16-1998 15-1998 17-1999 16-1999 17-2000 16-2000 18-2001 17-2001 19-2002 18-2002 20-2003 19-2003 20-2004 19-2004 21-2005 20-2005 22-2006 21-2006 23-2007 22-2007 23-2008 22-2008 24-2009 Date Wellhead pressure (bar)
Utsira formation 7- Classification: Internal 2011-05-25
Utsira Formation Sand wedge Nordland Shale Utsira Fm Hordaland Fm Ref. SACS project (SINTEF) 8 - Classification: Internal 2011-05-25
Top Utsira Fm. time map Sleipner A Deep Shallow CO 2 injection point Domal trap. Low relief. Sleipner A protected. 9 - Classification: Internal 2011-05-25
Time-lapse seismic data 1994 Sleipner CO 2 injection Utsira Fm. 2001 CO 2 plume in map view 2008 2008-1994 10 - Classification: Internal 2011-05-25
Gravity monitoring 2002, 2005, 2009, 2013 Further monitoring at Sleipner Seafloor mapping 2006 In-situ CO 2 density: 720 +/- 80 kg/m 3 Maximum dissolution rate: 1.8% per year 11 - Classification: External 2010-09-23
12 - Classification: External 2010-09-23 Fracture in block 16/4
The In Salah CO 2 storage site Gas from other fields Amine C0 2 removal Gas production (5 wells) CO 2 injection (3 wells) Cretaceous sequence (900m) Carboniferous mudstones (950m) 13 - Classification: Internal 2011-05-25
14 In Salah Surface Deformation Japex/JGI Study Comments: Period 2004 to 2008 Japan Geophysics Institute; Onuma & Ohkawa (2008) Based on Differential (DInSAR) method Subsidence seems to follow subsurface fault pattern Uplift pattern is clearly centered on injection wells with elongation in NW-SE stress direction 2007/3/3 2006/12/23 2006/7/1 2006/2/11 2005/9/24 2005/6/11 2005/2/26 2004/12/18 2004/10/9 2004/7/31 No explanation of calibration or reference point given
Geomechanical modelling at In Salah Extensively studied as part of a Joint Industry Project (2007-2013). InSAR monitoring data provided a unique opportunity to understand pressure propagation and rock mechanical deformation Key published papers include: Vasco et al. (2008, 2010) Ringrose et al. (2009, 2013) Mathieson et al. (2010) Rutqvist et al. (2010) Bissel et al. (2011) Gemmer et al. (2012) Oye et al. (2013) Map of surface uplift May 2009 20mm uplift Modelled rock strain (section) Injection Unit 15 Classification: Internal 2012-05-08
Lawrence Berkeley analysis of InSAR Vasco et al. (2008, 2010) developed a geophysical inversion method infer subsurface pressure and flow from InSAR surface deformation data Their model required a vertical tensile source at 1.8 km [3.5 km long and 100 m vertically], which turned out to be an excellent prediction of subsequent observations They also showed that variation in elastic moduli is important for a good prediction Observation vs. prediction from Vasco et al., 2010 Longitude (Degrees) Longitude (Degrees) 16 Classification: Internal
Snøhvit CO 2 injection 17 - Classification: Internal 2011-05-25
10m Snøhvit injection well 2km Depth map of base Tubåen Fm. Perforated zones 18 - Classification: External 2010-09-23
Cumulative injection 700 000 Cumulative injected mass (tons) 600 000 500 000 400 000 300 000 200 000 100 000 0 17.4.2008 17.7.2008 16.10.2008 15.1.2009 17.4.2009 17.7.2009 16.10.2009 16.1.2010 17.4.2010 Date 19 - Classification: Internal 2011-05-25
368 358 Estimated downhole shut-in pressure 800 000 700 000 348 600 000 Pressure [bar] 338 328 318 500 000 400 000 300 000 308 200 000 298 100 000 288 17.4.2008 17.7.2008 16.10.2008 15.1.2009 17.4.2009 17.7.2009 16.10.2009 16.1.2010 17.4.2010 Date 0 20 - Classification: Internal 2011-05-25
Snøhvit CO 2 monitoring CO 2 injection well CO 2 injection well 600 000 Pressure 10 bar 4D seismic acquisition 4 months Time 500 000 400 000 300 000 200 000 Cumulative injected mass [tons] Top Fuglen Fm. Base Tubåen Fm. baseline 2003 repeat 2009 difference Amplitude changes Modelled CO 2 saturation and pressure increase Increasing amplitude 0.5 km 21 - Classification: External 2010-09-23
Is there enough room for CO 2 storage? Ehlig-Economides & Economides (2010) concluded for a closed volume: the volume of liquid or supercritical CO 2 to be disposed cannot exceed more than about 1% of pore space. [And that this] renders geologic sequestration of CO 2 a profoundly non-feasible option for the management of CO 2 emissions. This provoked a strong reaction from the proponents of CCS that large-scale geological CO 2 storage is feasible. Most people agree that you cannot inject very much fluid into a confined box. There are three important limiting factors: 1. The size of the box (the storage unit) 2. The properties of the box boundaries (faults and shale sealing units) 3. The ability of the box to absorb increased pressure (rock and fluid compressibility). Zhou et al. (2008) concluded that: Storage efficiency is ~0.5% for closed systems But that a semi-closed system with a seal permeability of 10-17 m 2 (0.01 md) or greater behaves essentially as an open system with respect to pressure buildup (due to brine leakage). 22
Conclusions In highly varable and complex reservoirs, single wells have injected several hundred thousand tons of CO 2 per year. Surface geophysical and well pressure monitor data give rich information on the storage behaviour. Dynamic modelling to match the data is still challenging, and there is room for further model improvement. The actual plume development has been strongly controlled by geological factors which we learned about during injection. High-quality monitor data lowers the detection threshold for any potential leakage. At Sleipner and Snøhvit 4D seismic monitoring is of sufficient quality to confirm that there are no signs of leakage into the overburden. At In Salah, In SAR data has proven particularly valuable in monitoring pressure distribution. We expect detailed site characterization, monitoring and well solutions to increase the storage capacity on a case by case basis, as the site specific knowledge develops. 23 - Classification: External 2010-09-23
Thank you Current challenges at CO 2 sites Ola Eiken oei@statoil.com, tel: +47 90 17 19 43 www.statoil.com 24 - Classification: External 2010-09-23