Passive sampler for monitoring of CO2 leakage
The objective of the project was to develop a sorbent-based offshore monitoring technology to detect CO2 leakage during CO2-EOR operations.
The project work plan was divided into the following activities:
1) Identification of passive samplers
2) Building of experimental setup for sea bed conditions
3) Determination of tracer uptake rate
4) Determination of phase distribution of tracer candidate.
PFCs (perfluorocarbons) were selected as tracers. CAT (Capillary Absorption Tube) material placed inside the PES (polyethersulphone) membrane was tested and chosen to be the passive sampler combination.
A flow through experimental setup was built, optimized and tested for performing tracer uptake rate experiments. In addition, one desorption unit was built to quantify the absorbed tracer after the experiments. The developed passive sampler combination proved to be successfully absorbing the PFC tracer. A slim tube setup was used to investigate the phase distribution of tracer candidates. It was shown that the PFCs have a shorter travel time through the system than CO2 and thus will provide early warning of leakage from the reservoir.