Reliable and cost-effective monitoring, verification and accounting (MVA) techniques are an important part of making geologic sequestration a safe, effective, and acceptable method for greenhouse gas control. MVA of geologic storage sites is expected to serve several purposes, including addressing safety and environmental concerns; inventory verification; project and national accounting of greenhouse gas emissions reductions at geologic storage sites; and evaluating potential regional, national, and international greenhouse gas reduction goals.
The goal of our program area is to develop and demonstrate a broad portfolio of technologies, applications, and accounting requirements that can demonstrate 99 percent retention of CO2 through geologic carbon storage. The MVA program area is testing multiple technologies (atmospheric monitoring, remote sensing and near-surface monitoring, subsurface monitoring, and intelligent monitoring networks and protocols) in several geologic storage projects worldwide. Each geologic storage site varies significantly in risk profile and overall site geology, including target formation depth, formation porosity, permeability, temperature, pressure, and seal formation.
MVA technologies selected for commercial-scale projects are tailored to site-specific characteristics and geological features. General goals for MVA for geological storage are to:
- Improve understanding of storage processes and confirm their efficiency and effectiveness.
- Evaluate the interactions of CO2 with formation solids and fluids.
- Assess environmental, safety, and health impacts in the event of a leak to the atmosphere or shallow aquifer.
- Evaluate and monitor any required remediation efforts should a leak occur.
- Provide a technical basis to assist in legal disputes resulting from any impact of sequestration technology (groundwater impacts, seismic events, crop losses, etc.)
Geologic storage of CO2 requires pre-operation, operation, closure, and post-closure monitoring activities at the storage site, as well as risk assessment and development of flexible operational plans, and mitigation strategies that can be implemented should a problem arise. Effective application of monitoring ensures the safety of carbon capture and storage projects with respect to both human health and the environment and provides the basis for establishing accounting protocols for greenhouse gas registries and carbon credits on trading markets for stored CO2, if necessary. Additional details about DOE's MVA program and projects can be found on NETL's website.