completion integrity

The planned research project should contribute to a general understanding of the physicochemical mechanisms and transport properties in porous systems, in particular in cement pores and pipe-cement composites in the presence of hydrogen and formation water.

The behaviour of boundary phase and transport behaviour of hydrogen under real conditions is to be systematically investigated and elucidated within the framework of this project. The planned project focuses on investigations of the hydrogen permeability and chemical-mechanical integrity of porous mineral solids, in particular cements in the presence of pore water-gas systems. The wetting of the inner pore surface with the naturally present aqueous phase induces capillary forces, which can assume high values in very fine-pored systems and contribute to impermeability. In addition to the reservoir conditions of pressure and temperature, the type of gas also plays an important role in the formation of capillary pressure. In the presence of carbon dioxide, for example, rewetting effects have been found that can have a negative impact on the retention capacity. In addition, the lowering of pH can lead to chemical reactions at the rock surface. In pure hydrogen or hydrogen-containing gas mixtures, corresponding investigations on the wetting or phase behaviour are not yet known.

The research report has been published.