Remediation measures are an integral part of regulatory regimes for CCSCarbon dioxide Capture and Storage in all relevant countries and regions where CCSCarbon dioxide Capture and Storage activities are on-going or planned. The comparison shows that most of the regimes are based on similar foundations, closely linking risk assessmentA process intended to calculate or estimate the risk to a given target, part of a risk management system, monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions and remediation measures into one mutually interconnected package. The European and U.S. legislations appear to be the most detailed and most elaborated.
As far as remediation measures are concerned, these can be divided into three categories. The first part, corresponding mainly to wells and wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids intervention techniques, can be based on proven practice of the oil and gas industry. The measures can be used, with or without minor modifications, at CO2Carbon dioxide storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere sites as wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injection of fluids. The second group represents techniques that are common in hydrogeology and pollution control. Here, the technology is either limited to shallow subsurface, i.e., to remediation of CO2Carbon dioxide leakages up to the uppermost parts of the geological profile, or, the techniques need to be used in greater depths, beyond their usual depth limits.
The final group of techniques are the newly developed ones, directed specially at CO2Carbon dioxide storage(CO2) A process for retaining captured CO2, so that it does not reach the atmosphere sites. This group includes, e.g. special materials (special cements, self-healing substances, etc.) or special aquiferAn underground layer of fluid-bearing permeable rock or unconsolidated materials (gravel, sand, or silt) with significant permeability to allow flow management techniques. Due to the fact that remediation techniques for CCSCarbon dioxide Capture and Storage are subject of intensive on-going research and development, further improvements of existing and introduction of new methods and technologies can be expected in the near future.