Abstract: The present study aims to summarize the state of knowledge concerning the effects of sulphur compounds and odorants in underground gas storage facilities (UGS). It is motivated by increasing amounts of biogas in the German gas grid, potentially followed by residence of mixed odorized gases in UGS. The effects of these compounds on reservoirs are heterogeneously described by theoretical geochemical publications, laboratory results and the experiences of operating French and German UGS. An increase of the formation of H2S that coincide with risks for storage integrity, capacity and well productivity is not known from operation practice. Pore blockage and reduction in permeability in consequence of mercaptans or THT contaminations are not published. The same can be stated for any increased flow resistance, blockage and corrosion processes in well completions. However, increased technological requirements are expected during injection of odorized gas concerning the processing or disposal of reservoir fluids charged with sulphur compounds and odorants as well as contaminated brines during releaching. Thus, no immediate safety requirements to UGS arise due to the storage of odorized biogas. However, technical operation must be surveyed for additional effects. The number of relevant publications available on the topic is limited so that a significant number of questions related to particular storage sites remains unclarified.

This literature study was written to survey the effect of CO2 in underground gas storage. In the context of an increase of the proportion of renewable energies, biogas is inferred to increase CO2 amounts compared to the current CO2 level in natural gas (