CCS research by the Hydrothermal Laboratory

Weighing out starting material for borehole cement and impurities study.

Filling a gold reaction cell.

Led by Keith Bateman as part of the Hydrothermal Laboratory.

The Hydrothermal Laboratory staff all have an academic chemical background, as well as strong practical skills. Properly understanding the processes going on in the experiments involves close collaboration between the experimental staff, analytical chemists and mineralogists. As well as collaboration with other fluid processes researchers — Helen Taylor-Curran in the Gas Monitoring Facility, Simon Gregory in the Geomicrobiology Laboratory, Chris Rochelle in the Hydrates and Ices Laboratory and Caroline Graham in the Transport Properties Research Laboratory.

The areas of CCS that this laboratory is working on are outlined below.

Subsurface storage of CO2

In the hydrothermal laboratory, we can simulate the conditions typical of the upper few kilometres of the Earth's crust, to conduct experiments at in situ conditions. The focus of our CCS research is on the geochemical interactions between CO2, groundwaters and a range of rock types at elevated temperatures (25°C to 400°C using incubators, ovens and heating jackets) and pressures that range from ambient to over 500 atmospheres.

We have different types of pressure vessels: static 'batch reactors', mixed flow reactors and flow-through reactors. Many items of equipment have been designed by laboratory staff and manufactured within the BGS workshops.

The hydrothermal laboratory is assessing the chemical and mineralogical changes caused by stored CO2 on reservoir rocks (e.g. sandstones and limestones) and caprocks (e.g. clays and evaporites), and how these contribute to long-term safe storage. Reactions are tracked in various ways, including visual observations, monitoring fluid chemical changes and detailed mineralogical analysis of the reacted solids. Additionally, we can derive the fundamental data on reaction processes and rates that underpin predictive geochemical modelling of how the rocks will react on a longer timescale. This allows us to investigate the feasibility of storing CO2 in this way in different formations, under different conditions.

Projects for this laboratory include:

  • Ultimate CO2 (Understanding the Long-Term Fate of Geologically Stored CO2) — we are studying the effects of acidic impurities (hydrogen sulphide (H2S), sulphur dioxide (SO2) and nitrogen dioxide (NO2)) present in the CO2 upon the reservoir rock.
  • ECO2 (Sub-seabed CO2 Storage: Impact on Marine Ecosystems) — we are studying the effects of CO2 on seabed sediment
  • CO2 Care (Site Closure Assessment Research) — we conducted experiments that studied the impact of stored CO2 on borehole infrastructure (i.e. borehole steel and cement), and how this might impact borehole sealing and the potential for CO2 release, as well as studying the effects of acidic impurities (H2S, SO2 and NO2) present in the injected CO2
Preparing a large volume pressurised mixed flow vessel.
Sampling a high temperature, rocking pressure vessel.
Setting up the ECO2 project laboratory work — pressurised CO2-fluid-rock reactions at colder temperatures (10°C).