Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers

Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where CO2 storage capacity is evaluated both volumetrically (with “open” and/or “closed” approaches) and through flow modeling. These examples show that the “open aquifer” CO2 storage capacity estimation can strongly exceed the cumulative CO2 injection from the flow model, whereas the “closed aquifer” estimates are a closer approximation to the flow-model derived capacity. An analogy to oil recovery mechanisms is presented, where the primary oil recovery mechanism is compared to CO2 aquifer storage without producing formation water; and the secondary oil recovery mechanism (water flooding) is compared to CO2 aquifer storage performed simultaneously with extraction of water for pressure maintenance. This analogy supports the finding that the “closed aquifer” approach produces a better estimate of CO2 storage without water extraction, and highlights the need for any CO2 storage estimate to specify whether it is intended to represent CO2 storage capacity with or without water extraction

Reserves and resources for CO2 storage in Europe: the CO2StoP project

The challenge of climate change demands reduction in global CO2 emissions. In order to fight global warming many countries are looking at technological solutions to keep the release of CO2 into the atmosphere under control. One of the most promising techniques is carbon dioxide capture and storage (CCS), also known as CO2 geological storage. CCS can reduce the world’s total CO2 release by about one quarter by 2050 (IEA 2008, 2013; Metz et al. 2005). CCS usually involves a series of steps: (1) separation of the CO2 from the gases produced by large power plants or other point sources, (2) compression of the CO2 into supercritical fluid, (3) transportation to a storage location and (4) injecting it into deep underground geological formations. CO2StoP is an acronym for the CO2 Storage Potential in Europe project. The CO2StoP project which started in January 2012 and ended in October 2014 included data from 27 countries (Fig. 1). The data necessary to assess potential locations of CO2 storage resources are found in a database set up in the project. A data analysis system was developed to analyse the complex data in the database, as well as a geographical information system (GIS) that can display the location of potential geological storage formations, individual units of assessment within the formations and any further subdivisions (daughter units, such as hydrocarbon reservoirs or potential structural traps in saline aquifers). Finally, formulae have been developed to calculate the storage resources. The database is housed at the Joint Research Centre, the European Commission in Petten, the Netherlands.JRC.F.6-Energy Technology Policy Outloo

Three layers of energy law for examining CO2 transport for carbon-capture and storage

This research is a legal analysis concerning four scenarios for cross-border carbon dioxide (CO2) transport that could increase the deployment of carbon-capture and storage (CCS) deployment in Europe. The legal analysis categorizes the law into three levels—international, national and local—and considers the four scenarios in light of these three levels of energy law. Upon reviewing the four scenarios, it is clear that the Rotterdam Nucleus (referred to as the ‘Pilot Case’) is the leading scenario and as a result it is explored in more detail. The potential Pilot Case is based on the development of Rotterdam (in the Netherlands) as a southern North Sea hub. Under this Rotterdam Nucleus scenario, captured CO2 will be transported through the Port of Rotterdam to depleted gas fields offshore the Netherlands. CO2 will also be transported through further links using CCS infrastructure to facilitate the processing of undeveloped gas fields offshore UK. The Pilot case contemplates further expansion opportunities, increasing the capture clusters through additional pipelines, expanding to further gas fields and using the port of Rotterdam for CO2 shipping—hence the analysis of the other scenarios may be invaluable in the future development of CO2 networks in the EU. Finally, and an original contribution of this article is that it employs the three lawyers of energy law theoretical framework to an energy problem that was examined by an interdisciplinary research team. Furthermore, this research was developed further through two key industry stakeholder meetings with CCS experts in the EU

Transferring responsibility of CO2 storage sites to the competent authority following site closure

The requirements for pre-qualifying a site for CO2 storage are well developed. Less attention has been paid to rehearsing and preparing for the transfer of responsibility of the storage site from the operator to a governmental authority following closure of the site at the end of the injection period. This is not surprising because the industry is in its infancy and most effort has been focussed on working towards the early stages of the various projects. A procedure for complying to the regulatory requirements for the transport of responsibility in the CCS Directive has been proposed, which consists of a chart with Site Closure Milestones and a traffic light system for treating irregularities in observed behaviour of the storage site, and accompanying criteria. The procedure was successfully tested on the K12-B CO2 injection pilot. Conclusions have been drawn on the basis of several dry runs for reporting the requirements for transfer of responsibility including feedback from operators and regulators

Geocapacity: economic feasibility of CCS in networked systems

Decision Support System (DSS) has been developed to evaluate the technical and economical feasibility of CO2 storage in the subsurface. The DSS performs a detailed, stochastic analysis of the technical and economical aspects of a CCS project, which consists of any number of CO2 sources and sinks plus the connecting pipeline network. The DSS uses the database of CO2 emission points and storage locations in Europe that has been compiled in the EU Geocapacity project. The system is a combination of an internet application, which visualises the database and allows the user to select sources and sinks and create a pipeline network, and an application to be run on a local computer, which performs a stochastic analysis of the costs of a CO2 capture, transport and storage system. The DSS provides not only an estimate of the total CCS cost, but also an analysis of the elements in the CCS chain (capture, compression, transport and storage), enabling a feasibility analysis on several levels. © 2009 Elsevier Ltd. All rights reserved

CO2 injection in low pressure depleted reservoirs

Re-using depleted fields (and platforms and wells) offers advantages over developing storage projects in saline formations. However, with reservoir pressures after production sometimes below 20 bar, there can be a large pressure difference between the reservoir and the transport pipeline at the surface, which will be typically at pressures in the range of 80 - 120 bar. This pressure difference must be carefully managed to ensure that the temperature of the CO2, the surface installations and the well, remain within materials specifications and within proper operating boundaries. Pressure drops of the CO2 result in potentially large decrease in temperature, due to its high Joule-Thomson coefficient; in addition, the temperatures and pressures that occur in a typical CO2 transport and storage system are such that two-phase flow is likely to occur. Pipeline pressure and temperature management can easily be done in a single source- single sink scenario as the pipeline pressure is a free parameter. However, if the pipeline must act as a backbone for multiple wells at different reservoir pressure, pressure and flow management must be balanced carefully. In this paper, the differences between a pipeline as transport and a pipeline as backbone will be discussed in detail

Toolbox of Effects of CO2 Impurities on CO2 Transport and Storage Systems

There is a need to gather new knowledge on the fundamental properties of CO2 mixtures with impurities and their impact on the chain integrity and economics of Carbon Capture & Storage (CCS) chains. One of the main results from the FP7 IMPACTS project is the IMPACTS toolbox, which comprises new experimental data, thermodynamic reference models for CO2 mixtures relevant for CCS and the framework for CCS risk assessment taking Health Safety & Environment aspects, the impact of the quality of the CO2 and CCS chain integrity into account, and finally the recommendations report.publishedVersio

Mitigating CO 2 Leakage by Immobilizing CO 2 into Solid Reaction Products

International audienceIn the unlikely case of CO2 leakage from a storage reservoir, it is desirable to close the leak efficiently and permanently. This could be done by injecting a reactive solution into the leak path, thereby immobilizing migrating CO2 by consuming the gas and forming solid reactants. With regard to permanent closure, it is important to consider materials that are stable in the long-term, ensuring permanent CO2 containment. Numerical modelling was applied to assess the feasibility of injecting calcium-rich water as a CO2-reactive solution to form calcite. A scenarios analyses of key parameters showed that the success of leakage remediation can be up to 95% when carefully balancing the injection rate and distance versus the permeability and leakage rate

Algorithm to create a CCS low-cost pipeline network

Within the EU-funded GeoCapacity project an economic analysis computer tool is developed for the evaluation of carbon capture and storage (CCS) systems comprising of a set of multiple sources of CO2 and storage locations. As a part of that tool, an algorithm has been developed to create low-cost pipeline networks to connect sources of CO2 and storage reservoirs. The main features of the algorithm are: •Input parameters are the size and location of CO2 sources and storage reservoirs•The algorithm determines the trajectory, capacity and costs of the connecting pipes•If necessary junctions are created, i.e. connections are created between sources and pipelines and/or storage locations and pipelines•The algorithm has a step wise approach. The pipeline network is built-up by successively adding a pipe in each step, until all sources are connected to storage reservoirs•In each step all possible combinations are examined and the one with the lowest costs is added to the system•The pipe costs have a non linear relation with the flow rate•Cost ranges for pipeline network are presented reflecting uncertainties in data of supply of CO2 from sources as well in storage capacity of sinks. © 2009 Elsevier Ltd. All rights reserved