CO2 storage in East Brandenburg:  Implications for synergetic geothermal energy production and conceptual design of an early warning system against groundwater salinization

Duration:  01.05.2010 to 30.04.2013

Work package 7:  Investigation of weak zones and saltwater upwelling regions with electromagnetic methods

Project leader WP7:  Prof. Dr. rer. nat. R. Herd

Program:  BMBF Special Program GEOTECHNOLOGIES

Overall project objectives:
Storage of carbon dioxide in deep saline aquifers will lead to a corresponding displacement of the pore water due to the pressure increase in the reservoir rocks. The effects of this displacement process, especially on the overlying lithological units, have been insufficiently studied so far. Therefore, the BRINE project will investigate whether saltwater migration from deep saline aquifers could lead to a threat (salinization) of the drinking water aquifers in the upper rock strata. Furthermore, it is to be examined whether pressure relief wells that may be required are suitable for geothermal energy production. A potential storage structure in eastern Brandenburg was selected as the study site. The main objective of the joint project is the conceptual development of an early warning system to detect upward saltwater migration processes.

Monitoring methods such as electrical resistivity tomography, magnetotellurics and electromagnetics will be used to detect a possible saltwater upwelling. These methods take advantage of the different conductivity of fresh and salt water. Furthermore, the development of coupled numerical models is planned in order to identify the main controlling factors of a possible saltwater migration. The results will be used to derive suitable measures to counteract a possible salinization of the drinking water. Should the pressure in the reservoir formation reach a critical point above which a breakthrough of the saline pore water is to be expected, boreholes could be drilled to relieve the pressure. A further objective of the consortium is therefore to examine the geothermal potential of a possible pressure relief measure within the framework of a study.