Study of Gas Tracers for CO2 monitoring

AbstractGas tracers have been tested for monitoring and detecting CO2 displacement in the underground and eventually leakages to the upper layers in geological storage sites. Commonly used tracers are perfluorocarbons (PFCs) and sulfur hexafluoride (SF6). In Brazil, we are carrying out gas tracers studies in laboratory for further application in field test facilities. These experiments consist of injecting CO2 with perfluorocarbon (perfluoropropane – PP and perfluormethylcyclopentane – PMCP) at low pressure (ca. 290 psi) in pressurized vessels with different types of sediments and soil samples. After flowing through the sample pores, the tracer is adsorbed into a capillary adsorption tube (CAT) with a specific fiber for perfluorcabon. Then, the tracer is extracted from the CAT through a Thermal Desorption System and subsequently analyzed in a Gas Chromatograph with an Electron Capture Detector (GC -ECD). The objective of these experiments is to evaluate the PFCs as a monitoring tool, analyzing the tracer retention times in different sediments, as well as understanding the CATs adsorption capacity and performance. After laboratory tests, field experiments will be conducted in the course of this project. Several experiments of CO2 injection and controlled leaks will be developed in shallow vertical wells at the project site as a continuity of the experiments started at Ressacada Farm Site (Florianópolis, Brazil). The project aim is to understand the flow and dispersion of CO2 in soil and atmosphere simulating an eventual leakage from a geological reservoir using an automated system with a dedicated module for tracers injection into CO2 stream

An overview of current status of carbon dioxide capture and storage technologies

AbstractGlobal warming and climate change concerns have triggered global efforts to reduce the concentration of atmospheric carbon dioxide (CO2). Carbon dioxide capture and storage (CCS) is considered a crucial strategy for meeting CO2 emission reduction targets. In this paper, various aspects of CCS are reviewed and discussed including the state of the art technologies for CO2 capture, separation, transport, storage, leakage, monitoring, and life cycle analysis. The selection of specific CO2 capture technology heavily depends on the type of CO2 generating plant and fuel used. Among those CO2 separation processes, absorption is the most mature and commonly adopted due to its higher efficiency and lower cost. Pipeline is considered to be the most viable solution for large volume of CO2 transport. Among those geological formations for CO2 storage, enhanced oil recovery is mature and has been practiced for many years but its economical viability for anthropogenic sources needs to be demonstrated. There are growing interests in CO2 storage in saline aquifers due to their enormous potential storage capacity and several projects are in the pipeline for demonstration of its viability. There are multiple hurdles to CCS deployment including the absence of a clear business case for CCS investment and the absence of robust economic incentives to support the additional high capital and operating costs of the whole CCS process

Expert-based development of a standard in CO2 sequestration monitoring technology

Bureau of Economic Geolog

Environmental issues and the geological storage of CO2 : a discussion document

Increasing CO2 emissions will lead to climate change and ocean acidification with severe consequences for ecosystems and for human society. Strategies are being sought to reduce emissions including the geological storage of CO2. Existing studies operate within existing oil and gas regulatory frameworks, but if other non-oil reservoir geological formations are used these existing regulations may not apply. At UK and European levels the potential environmental impacts of uncontrolled CO2 releases from storage sites have been highlighted to be of significance for regulators. Thus a new regulatory framework may be needed. The precautionary principle is likely to be adopted by regulators, so it is important that the effects of acute and chronic exposures of ecosystems to CO2 leakages are evaluated. Consequently, existing regulations are likely to be developed to include specific recommendations concerning leakages. This review shows that many basic data simply do not exist to assist regulators in this process

Marine baseline and monitoring strategies for Carbon Dioxide Capture and Storage (CCS)

The QICS controlled release experiment demonstrates that leaks of carbon dioxide (CO2) gas can be detected by monitoring acoustic, geochemical and biological parameters within a given marine system. However the natural complexity and variability of marine system responses to (artificial) leakage strongly suggests that there are no absolute indicators of leakage or impact that can unequivocally and universally be used for all potential future storage sites. We suggest a multivariate, hierarchical approach to monitoring, escalating from anomaly detection to attribution, quantification and then impact assessment, as required. Given the spatial heterogeneity of many marine ecosystems it is essential that environmental monitoring programmes are supported by a temporally (tidal, seasonal and annual) and spatially resolved baseline of data from which changes can be accurately identified. In this paper we outline and discuss the options for monitoring methodologies and identify the components of an appropriate baseline survey

Thermal effects on geologic carbon storage

The final publication is available at Springer via http://dx.doi.org/10.1016/j.earscirev.2016.12.011One of the most promising ways to significantly reduce greenhouse gases emissions, while carbon-free energy sources are developed, is Carbon Capture and Storage (CCS). Non-isothermal effects play a major role in all stages of CCS. In this paper, we review the literature on thermal effects related to CCS, which is receiving an increasing interest as a result of the awareness that the comprehension of non-isothermal processes is crucial for a successful deployment of CCS projects. We start by reviewing CO2 transport, which connects the regions where CO2 is captured with suitable geostorage sites. The optimal conditions for CO2 transport, both onshore (through pipelines) and offshore (through pipelines or ships), are such that CO2 stays in liquid state. To minimize costs, CO2 should ideally be injected at the wellhead in similar pressure and temperature conditions as it is delivered by transport. To optimize the injection conditions, coupled wellbore and reservoir simulators that solve the strongly non-linear problem of CO2 pressure, temperature and density within the wellbore and non-isothermal two-phase flow within the storage formation have been developed. CO2 in its way down the injection well heats up due to compression and friction at a lower rate than the geothermal gradient, and thus, reaches the storage formation at a lower temperature than that of the rock. Inside the storage formation, CO2 injection induces temperature changes due to the advection of the cool injected CO2, the Joule-Thomson cooling effect, endothermic water vaporization and exothermic CO2 dissolution. These thermal effects lead to thermo-hydro-mechanical-chemical coupled processes with non-trivial interpretations. These coupled processes also play a relevant role in “Utilization” options that may provide an added value to the injected CO2, such as Enhanced Oil Recovery (EOR), Enhanced Coal Bed Methane (ECBM) and geothermal energy extraction combined with CO2 storage. If the injected CO2 leaks through faults, the caprock or wellbores, strong cooling will occur due to the expansion of CO2 as pressure decreases with depth. Finally, we conclude by identifying research gaps and challenges of thermal effects related to CCS.Peer ReviewedPostprint (author's final draft

EOR as sequestration: Geoscience perspective

CO2 Enhanced Oil Recovery (EOR) has a development and operational history several decades longer than geologic sequestration of CO2 designed to benefit the atmosphere and provides much of the experience on which confidence in the newer technology is based. With modest increases in surveillance and accounting, future CO2 EOR using anthropogenic CO2 (CO2-A) captured to decrease atmospheric emissions can be used as part of a sequestration program.Bureau of Economic Geolog

Hydrogeological challenges in a low carbon economy

Hydrogeology has traditionally been regarded as the province of the water industry, but it is increasingly finding novel applications in the energy sector. Hydrogeology has a longstanding role in geothermal energy exploration and management. Although aquifer management methods can be directly applied to most high-enthalpy geothermal reservoirs, hydrogeochemical inference techniques differ somewhat owing to peculiarities of high-temperature processes. Hydrogeological involvement in the development of ground-coupled heating and cooling systems using heat pumps has led to the emergence of the sub-discipline now known as thermogeology. The patterns of groundwater flow and heat transport are closely analogous and can thus be analysed using very similar techniques. Without resort to heat pumps, groundwater is increasingly being pumped to provide cooling for large buildings; the renewability of such systems relies on accurate prediction and management of thermal breakthrough from reinjection to production boreholes. Hydrogeological analysis can contribute to quantification of accidental carbon emissions arising from disturbance of groundwater-fed peatland ecosystems during wind farm construction. Beyond renewables, key applications of hydrogeology are to be found in the nuclear sector, and in the sunrise industries of unconventional gas and carbon capture and storage, with high temperatures attained during underground coal gasification requiring geothermal technology transfer

An International Regulatory Framework for Risk Governance of Carbon Capture and Storage

This essay was prepared as part of a workshop on carbon capture and sequestration held by the International Risk Governance Council (IRGC) in Washington, DC, from March 15–16, 2007. The goal of the workshop was to bring together researchers, practitioners, and regulators from Europe, the United States, and Australia to outline the attributes that an effective regulatory regime for carbon capture and storage should possess. This essay focuses specifically on providing an overview of eight fundamental elements that we believe any effective international and national regulatory structure must address: 1) classification of carbon dioxide (CO2); 2) oversight of CO2 capture and storage; 3) site ownership and storage rights; 4) site operation and management; 5) long-term management and liability; 6) regulatory compliance and enforcement; 7) links to CO2 markets and trading mechanisms; and 8) risk communication and public acceptance. This essay is one of 12 collected for the workshop, and the recommendations herein are the views of the authors and do not reflect the views of their agencies, the IRGC, or specific workshop discussions.carbon sequestration, geologic storage, risk, regulation