Energy Technologies: How They Work and Their Induced Seismicity Potential - Induced Seismicity Potential in Energy Technologies - page 78

BOX 3.8 Continued

Injection history

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

Figure 3 CO 2 injection history at Statoil's Sleipner, Snøhvit, and In Salah fields. SOURCE: Eiken et al. (2011).

formations. Pressure management was deemed an important issue with downhole pressure gauges of great
importance (Eiken and Ringrose, 2011).
Prior to the start of all three projects, extensive monitoring was conducted to establish baseline condi-
tions, including any microseismic activity. Monitoring during CO 2 injection for possible leakage and induced
seismicity has occurred in all three projects. At both offshore projects, monitoring methods have included
measurements of wellhead pressure and temperature, downhole pressure, gravity, and time-lapse seismic.
At In Salah, monitoring data have included time-lapse seismic; pressures, rates, and gas chemistry at the
wellhead; cores, logs, and fluid samples from the subsurface; one microseismic well, five shallow aquifer
wells, and an appraisal well; satellite surveys to measure surface deformation; and surface measurements
to monitor for potential leakage or rock strain. Monitoring from pilot wells at this location has shown detect-
able microseismic events related to CO 2 injection. Shallow wells with three-component seismic detectors are
emerging as the preferred deployment solution to give more extensive areal coverage of the field.

SOURCES: Eiken and Ringrose (2011); Eiken and Ringrose (personal communication, June 4, 2012); Ringrose
and Eiken (2011); NPD (2011); Helgesen (2010); Statoil (2009); Arts et al. (2008); and “Sleipner Vest”
(available at www.statoil.com/en/TechnologyInnovation/ProtectingTheEnvironment/CarboncaptureAndStor-
age/Pages/CarbonDioxideInjectionSleipnerVest.aspx).