CO2Carbon dioxide and CO2Carbon dioxide-bearing fluids might have various effects in the deep underground, in drinking-water aquifers, in the shallow subsurface and in the aboveground environment. The impact of the CO2Carbon dioxide differs depending on its concentrations, the compartment affected and also the location. Thus, two major challenges in evaluating the risks posed by released CO2Carbon dioxide are:
- estimating the spatial and temporal distribution of CO2Carbon dioxide fluxes entering spaces or objects that should be protected;
- predicting ambient CO2Carbon dioxide concentrations resulting from given CO2Carbon dioxide fluxes.
Depending on the characteristics of the leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column pathways, a surface release may be concentrated and spot-like or diffuse and widespread over a broad area. High flux densities (mass flow per area and time) could occur in the vicinity of leaking wells (including blow-outs), resulting in high concentrations in the affected locations. However, the evaluation of the riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event depends largely on the released quantity and, if direct damage occurred, it would be restricted to the vicinity of the leak. In contrast, a diffuse leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column of large quantities over large areas might result in low flux densities that may not be noticed for a while. In either case, a significant riskConcept that denotes the product of the probability of a hazard and the subsequent consequence of the associated event to humans or the environment may or may not be created depending on the amount of CO2Carbon dioxide that has leaked out, the flux density and the resulting concentrations (Benson, 20062006 - S.M. BensonAssessment of Risks from Storage of Carbon Dioxide in Deep Underground Geological Formationssee more). The latter example of a diffuse flux highlights the necessity of comprehensive monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions plans.
The leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column of large quantities of CO2Carbon dioxide might be detected, e.g. by monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids pressures, wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids before CO2Carbon dioxide will reach the surface or build-up to detectable geochemical anomalies in shallow groundwater. At such first indications of leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column, measures can be taken to prevent negative effects on protected goods at the surface. In addition, monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions at the surface and of the shallow subsurface may be intensified in order to detect and quantify possible diffuse fluxes.
The quantification of risks includes predictions of magnitude and impact of CO2Carbon dioxide on the surrounding environment. Natural CO2Carbon dioxide release is a frequent phenomenon in various regions, world-wide. These sites can be used to establish magnitude-impact relations for various environments (Roberts et al., 20112011 - Jennifer J Roberts, Rachel A Wood, R Stuart HaszeldineAssessing the health risks of natural CO2 seeps in Italysee more). Field measurements demonstrate a wide range of fluxes that results from CO2Carbon dioxide ascending through various crustal rocks. Natural sites can be used to validate monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions methods at different surface conditions in the storage(CO2Carbon dioxide) A process for retaining captured CO2Carbon dioxide, so that it does not reach the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) area and to test concepts for different magnitudes expected. Because of the natural variability, various methods are required for site-specific monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions of CO2Carbon dioxide leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column risks.
Though the total release or flux rates are proportional to possible impacts, for human health and safety the actual concentrations in the breathing air are critical. In poorly ventilated rooms low fluxes may accumulate over time to hazardous concentrations, while in open air conditions turbulent mixing can maintain concentrations in tolerable ranges, even in the surroundings of a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids blow-out(well) Refers to catastrophic failure of a well when the petroleum fluids or water flow unrestricted to the surface (Ferrara and Stefani, 19771977 - G. C. Ferrara, G. StefaniCO2 distribution in the atmosphere and noise survey after blow-out in Allina I well, northern Latium, Italysee more).
Thus, depending on the monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions purpose, various monitoringMeasurement and surveillance activities necessary for ensuring safe and reliable operation of a CGS project (storage integrity), and for estimating emission reductions parameter have to be recorded:
- total release for emission trading,
- flux for operators and regulators decisions about corrective measures,
- ambient concentrations for human safety.