Regional 3D Geological Modeling and Stress Field Analysis at the CO2 Storage Site of Ketzin, Germany

Abstract

Carbon dioxide capture and storage (CCS) could be used to generally high angles as observed in the seismic surveys indicate a stress state between normal faulting and strike slip regime. reduce the climatic effects of the worldwide emission of greenhouse gases that are emitted by large industrial installations like fossil fuel-fired power plants by 80-90% (Holloway 2007). The more fluid is injected in a geological reservoir, the more important become caprock imperfections like fault zones and fractures which could act as pathways for brines or CO2 to flow upward and contaminate fresh water aquifers or even the surface. Thus, as well as in geothermal explorations, the knowledge about the behavior of the in-situ stresses due to changes in fluid pressure caused by the injection of a fluid like supercritical carbon dioxide is an important aspect for the estimation of the seal integrity and the modeling of leakage scenarios/fluid pathways. In 2004 the research project CO2SINK started to explore an anticlinal structure near the town of Ketzin (about 25 km west of Berlin/Germany) in the Northeast German Basin (NEGB). This site was chosen for a profound monitoring of CO2 sequestration in a saline aquifer. In order to make further investigations about feasibility of longterm CO2 storage CO2SINK is followed by the project CO2MAN that started in 2010. First results from the stress regime analysis show that the minimum horizontal stress Shmin is being equal or increasing 0.62 times the value of the vertical stress Sv (Shmin ? 0,62Sv) and for the maximum horizontal stress is SHmax ? 2.8Sv. SHmax is supposedly in NE-SW direction parallel to the axis of the anicline. Graben structures in the top of the anticline are identified in the baseline 3D seismic. ENE-WSW striking fault planes show a