Injection of 1% O2 in deep aquifer simulated with a pressurized reactor (60bar)

With the injection of biomethane into deep aquifers using as gas storage, a coinjection of oxygen is possible. O2 is used during the sulfide reoxidation process before injection of biomethane into the gas network. The objective of the study is to assess the impact of a gas storage (comprising 1% O2) on the microbial diversity of the aquifer and the storage.Formation water was collected using a down hole sampler from a deep aquifer used for natural gas storage. This formation water (with indigenous microorganisms) was incubated in a deformable reactor maintaining a pressure of 60bar. After 131 days of incubation in conditions mimicking the natural gas storage, 1% O2 was injected into the gas phase. Throughout the procedure, bacterial diversity from the 16S rRNA genes was monitored via sequencing approaches (Illumina, Miseq).