Abstract

The IMPACTS project investigated how impurities affect the design and operation of CO2 transport and storage processes. Experimental work and modelling have advanced the state of the art in the areas of how impurities in CO2 affect thermo-physical properties, fluid flow, corrosion, and reservoir chemical reactivity. High-quality experimental thermodynamic data were obtained to develop new reference equations of state for exhaust gases (EOS-CG). Parts of the results have been distributed as the publicly available TREND 2.0 software. The software enables modelling the true behaviour of impure CO2 mixtures, thereby increasing the fidelity of the simulations. IMPACTS also provided recommendations that relate results from parts of the CCS chain into results that relate to the entire CCS chain. They cover such areas as trade-offs between impurity levels and CCS system costs, optimized CO2 quality on a case-by-case basis for CCS chains, and design/operation of pipelines. New methodologies have been suggested for selecting the design criteria for operation of CO2 pipelines to avoid two-phase flow and running ductile fractures. This can help limit over-specifying design and reduce costs. For example, IMPACTS has shown how 4% of impurities in the CO2 can increase the power consumption for compression and processing by 50%. IMPACTS has generated a large amount of new knowledge and is an example of how a wide-reaching research program with several groups investigating different aspects of the same topic has brought the knowledge base forward while ensuring that the results are aligned. © 2016 Elsevier Ltd

Abstract

In this study we probe the ultimate potential Underground Gas Storage (UGS) capacity of the Netherlands by carrying out a detailed feasibility study on inflow performances of all onshore natural gas reservoirs. The Netherlands is one of the largest natural gas producers in Western Europe. The current decline of its national production and looming production restrictions on its largest field of Groningen -owing to its induced seismicity- have recently made necessary to upgrade the two largest UGS of Norg and Grijpskerk. The joined working volume of these two UGS is expected to replace the swing capacity of the Groningen field to continue guaranteeing the security of supply of low calorific natural gas. The question is whether this UGS configuration will provide the expected working storage capacity unrestricted by issues on reservoir performances and/or induced seismicity. This matter will be of paramount importance in the near future when production restrictions and/or the advance state of depletion of the Groningen field will turn the Netherlands into a net importer of high calorific natural gas. By then, the question will be whether the available UGSs will still be economically attractive to continue operating, or if additional or alternative UGSs will be needed?. Hence the characterization and ranking of the best potential reservoirs available today is of paramount importance for future UGS developments. We built an in-house automated module based on the application of the traditional inflow performance relationship analysis to screen the performances of natural gas reservoirs in onshore Netherlands. Results enable identifying the 72 best candidates with an ultimate total working volume capacity of 122±30 billion Sm 3 . A detailed sensitivity analysis shows the impact of variations in the reservoir properties or wellbore/tubing configurations on withdrawal performances and storage capacity. We validate our predictions by comparing them to performances of the UGSs currently operating in the Netherlands. Our results show that although Norg and Grijpskerk stand midst the best candidates, their working:cushion gas volume (wv:cv) ratios appear amongst the lowest. We found many other reservoir candidates with higher wv:cv ratios ("1) and working volumes between 3 and 10 billion Sm 3 geographically distributed across the Netherlands. Any of the current and future UGSs will have to compete with economically more attractive means of gas import via pipelines and liquefied natural gas. We suggest that only the strategic development of a network of efficient underground gas storages with wv:cv ratios "1, could increase its economical attractiveness. This can reduce future dependence on foreign gas supply for cases of import disruption or shortages during peak demand in winter periods. Future political and economic decisions and societal acceptance will determine the role that UGS will play in the security of supply of natural gas in the Netherlands and Western Europe.