Monitoring techniques of C02 geological storage and its application analysis

Key words:  carbon dioxide  geological storage  reservoir monitoring  gas tracer  monitoring techniques

Abstract:

The purpose and importance of various monitoring methods that can be used in different stages of the C02 storage process were addressed. Different monitoring mechanisms and corresponding techniques were described. The monitoring on COj storage can be applied to different systems including reservoir, sub-surface and surrounding environment, and various techniques such as 4D seismic, gravity metering, soil gas sampling, well fluid sampling and gas tracers can be used. The advantages and limitations of these techniques were analyzed along with field application experience. The results show that gas tracer, well fluid sampling and logging can be used to track the fluid migration and C02 state in conjunction with verifying well & reservoir integrity，while soil gas and atmosphere measurements are effective to monitor the C02 leakage and subsurface environment. The selection of monitoring techniques should take the purpose of monitoring and reservoir conditions into consideration. Technically effective, safe and economic monitoring programs can be designed based on the techniques currently available and field experience gained from previous and current demonstration projects.