Magnetic Prospection of a Tumulus in the Ancient Histria Necropolis

Abstract. Near surface geophysical investigations are employed in archaeology in order to estimate the location, depth, shape and physical properties of buried ancient structures. The geophysical study initiated in 2008 on tumuli located in the Histria necropolis was based on magnetics, the measurements being carried out with a proton precession magnetometer / gradientmeter. The networks where measurements of total magnetic field and magnetic vertical gradient were performed covered each tumulus and small adjacent areas. The magnetic measurement points situated at 2 m interval represented detailed rectangular networks. The necropolis is situated at ca 2 km north-west of Histria ancient Greek city and includes a great number of tumuli of various dimensions and trends. Previous archaeological studies evidenced different rituals of burial for the ca 1300 years of continuous inhabitation during Greek colonization and Roman / Byzantine empires. The magnetic data obtained for the tumulus analyzed in this paper, located toward the north-western limit of the Histria necropolis, suggest quite complex archaeological features, similar to those observed in the excavations. Generally, metallic artifacts, a clay layer affected by fire or active magnetic rocks employed in the buried infrastructures may represent sources of high magnetic anomalies. The magnetic total field and vertical gradient anomalies are interpreted as being here mainly due to burnt materials and buried greenshist structure (high anomalies), or to an outer stone belt made of limestone boulders (low anomalies)

Implementation of the EU CCS Directive in Europe: results and development in 2013

Directive 2009/31/EC of the European Parliament on the geological storage of carbon dioxide, entered into force on June 25th 2009. By the end 2013 the CCS Directive has been fully transposed into national law to the satisfaction of the EC in 20 out of 28 EU Member States, while six EU countries (Austria, Cyprus, Hungary, Ireland, Sweden and Slovenia) had to complete transposing measures. In July 2014 the European Commission closed infringement procedures against Cyprus, Hungary and Ireland, which have notified the EC that they have taken measures to incorporate the CCS Directive into national law. Among other three countries Sweden has updated its legislation and published a new law in their country in March 2014, permitting CO2 storage offshore. The evaluation of the national laws in Poland, which were accepted at national level in November 2013, and Croatia, which entered the EU on 7 July 2013 and simultaneously transposed the CCS directive, is still ongoing in 2014. The first storage permit under the Directive (for the ROAD Project in the offshore Netherlands) has been approved by the EC. While CO2 storage is permitted in a number of European countries, temporary restrictions were applied in Czech Republic, Denmark and Poland. CO2 storage is prohibited except for research and development in Estonia, Finland, Luxembourg, two regions in Belgium and Slovenia due to their geological conditions, but also forbidden in Austraia, Ireland and Latvia. The size of exploration areas for CO2 storage sites is limited in Bulgaria and Hungary. In Germany, only limited CO2 storage will be permitted until 2018 (up to 4 Mt CO2 annually)

Development of a Screening Framework for Re-Use of Existing Wells for CCUS Projects Considering Regulatory, Experimental and Technical Aspects

Oil and gas fields that have reached their end of economic life provide a potential option for geologic CO2 storage in support of the energy transition and efforts to reduce CO2 emissions. Re-use of these existing wells can potentially result in significant cost savings compared to drilling new wells, but also presents a challenge for CCUS (Carbon Capture, Utilisation and Storage) development. Prior to conversion, evaluation of the feasibility of re-using existing oil and gas wells will be required, including consideration of operational and safety requirements. Currently, there are no standard approaches or public tools available to aid in the technical evaluation and to support decision making on well re-use potential for CO2 storage. The REX-CO2 (Re-using EXisting wells for CO2 storage operations) project, funded by the ACT (Accelerating CCUS Technologies) program has developed a first-of-its-kind assessment framework and evaluation tool based on state-of-the-art practices, standards, guidelines and international reference projects. The tool is designed to utilize available data on well construction, subsurface geology, well operational and integrity history to screen the re-usability of wells for CO2 storage operations. The tool provides a thorough qualitative evaluation of the current re-usability potential of existing wells and highlights the most important issues requiring further detailed analysis. The results can be used to design and select mitigation options, ultimately identifying the most promising candidate wells. The tool has been applied to multiple international case studies with tens of wells, both onshore and offshore, covering a wide range of well designs and subsurface settings. The overall goal was to test and demonstrate the evaluation process, identify remediation activities and providing a high-level cost benefit analysis. The tool has recently been applied successfully in the Middle East region for one of the national oil companies, showcasing the assessment framework and identifying potential remediation activities to safely convert a selection of wells into CO2 injectors. The tool development is supplemented by experimental research focused on well cement integrity due to its role as a well barrier element. The emphasis is on mechanical and chemical degradations and damage processes on well barrier elements, including investigation of novel self-healing and active remediation measures. In addition, state-of-the-art research on the conditions of well materials expected in CO2 injection wells have been described, providing recommendations for material selection in a CO2 CCUS storage setting. Lastly, the project evaluated the regulatory and environmental frameworks, permit requirements and social perspectives related to re-using existing oil and gas wells for CO2 storage. All aspects (technical & non-technical) have been integrated in a final set of recommendations to provide insights into the factors that need to be addressed when considering existing wells for re-use in CO2 storage operations

Assessing the reusability of legacy wells for CCS projects: a screening framework, its application and the impact

Existing oil and gas wells have the potential to be re-used for geologic CO2 storage to reach climate goals in the reduction of CO2 emissions while potentially reducing costs associated with well construction for CCS. Currently there are no standard approaches or public tools available to aid in the evaluation of well re-use potential for CO2 storage. The REX-CO2 (Re-using Existing wells for CO2 storage operations) project, funded by the ACT (Accelerating CCS Technologies) program, has the overall objective to provide decision makers with mechanisms and information to evaluate the re-use potential of existing oil and gas wells. The project has developed an assessment framework translated into a standalone well integrity screening tool based on state-of-the-art practices, standards, guidelines and international reference projects. The framework was supported by technical and regulatory requirements, and experimental well integrity research. The tool is designed to utilize available data on well construction, subsurface geology and well operational history to screen the reusability of the existing wells for CO2 storage operations. Each well is screened against five categories: risk of out of zone injection, well integrity primary barrier envelope, well integrity secondary barrier envelope, structural integrity, and material compatibility. For each of these pillars, decision trees have been developed that guide the user through the assessment process. The tool provides a thorough qualitative evaluation of the current reusability potential of the wells using a color-coding system and highlights the most important integrity issues, which can be used to design and select mitigation options. The tool has been applied to ten international case studies with dozens of wells, covering a wide range of well designs and subsurface settings, with the overall goal to test and demonstrate the evaluation process. The tool allows a fast, consistent and complete screening of a large portfolio of wells, aiding the identification of promising candidates for potential re-use in a CO2 storage project. Ultimately, learnings from the framework development and case studies were used to develop recommendations for re-using existing wells for CO2 storage

A screening tool for assessing feasibility of re-using existing oil and gas wells for CCUS operations

An increasing number of oil and gas fields around the world are coming to the end of their production lifetime and have been earmarked as potential targets for deploying large-scale carbon capture, utilization and storage (CCUS) operations. Existing oil and gas fields offer several advantages such as availability of existing infrastructure including wells as well as significant prior knowledge about the field through characterization and operational data. Existing wells at these fields could potentially be used as CO2 injection wells, monitoring wells or production wells for pressure management. Re-using existing oil and gas infrastructure may be particularly crucial for offshore environments where new well development costs could otherwise be prohibitive. Prior to converting the existing oil and gas wells, feasibility of their use as part of a CO2 storage operation will have to be evaluated while taking into consideration operational and safety requirements. Currently there are no standard approaches available for assessing the potential of converting existing wells for re-use in CCUS operations, and no public tools are available to aid the assessment process. As part of the REX-CO2 (Re-using EXisting wells for CO2 storage operations) project funded by the ACT (Accelerating CCS Technologies) program, we have developed a workflow and a well screening tool that will aid in evaluating the feasibility of repurposing existing wells as CO2 storage site wells. The workflow was informed by applicable standards such as ISO 27914, regulatory requirements such as the US-EPA’s Class VI regulation and publicly available information from projects that have performed detailed assessments of using existing oil and gas wells for CO2 storage, including the Peterhead, Kingsnorth and PORTHOS projects. Our assessment approach and the tool are designed to simultaneously save CO2 storage projects resources and time by identifying existing infrastructure that is safe to re-use, while determining which wells must be remediated to ensure safe, long-term storage. The functionality of the tool will be evaluated and validated on six case study sites, one in each of the REX-CO2 project’s partner countries (France, the Netherlands, Norway, Romania, the UK, and the USA)

Public awareness and perceptions of carbon dioxide capture and storage (CCS) : insights from surveys administered to representative samples in six European countries

The representative survey studies provide a comprehensive database on the public awareness and perception of CCS in six selected European countries. Our results provide insights into the public understanding and knowledge of energy related issues and CCS topics. The embedded experimental research provides insights into how information affects CCS perceptions. The results discuss implications for CCS communication methods

CCS Directive Transposition into National Laws in Europe: Progress and Problems by the End of 2011

AbstractThe EU CCS Directive transposition process and related issues in 26 European countries, comprising 24 EU member states, Norway and Croatia were studied in the EU FP7 project: “CGS Europe” in 2011–2012. By the end of 2011 the transposition of the Directive into national law had been approved by the European Commission (EC) in Spain only, but had been approved at national/jurisdictional level in 12 other countries (Austria, Denmark, Estonia, France, Greece, Ireland, Italy, Latvia, Lithuania, the Netherlands, Slovakia and Sweden) and two regions of Belgium. By January 2012, the European Commission had assessed and approved national submissions of CCS legal acts transposing the Directive in Denmark, France, Italy, Lithuania, Malta, the Netherlands and Slovenia. Implementation in the UK was completed in February 2012 and by end March 2012, implementation at national level was also complete in Bulgaria, Czech Republic, Portugal and Romania.Belgium, Croatia, Finland, Germany, Hungary, Norway and Poland had not finished the transposition of the CCS Directive by end March 2012. The process had been complicated by ongoing political debates in Norway, public opposition in Germany and ministerial elections in Poland. More than 20 operating, developing and planned CCS pilot and demonstration projects have been identified in nine European countries. Storage capacity was estimated by CGS Europe project partners as “sufficient at national level” in 17 countries

Regulatory and social aspects related to well re-use in CO2 storage operations

Reusing hydrocarbon fields and wells for CO2 storage could mean substantial savings and a potential acceleration in the deployment of CCS (Carbon Capture and Storage) technology. In addition to the technical suitability of the wells to be re-used for CO2 injection, the existence of a coherent regulatory framework to enable well re-use and stakeholder and public acceptance are essential for the implementation of real projects. Within the REX-CO2 project, the legal, environmental and social aspects related to well re-use in CO2 storage operations have also been investigated. Following an extensive data collection of all relevant regulations, we have made a first assessment of the regulatory frameworks for well re-use in the respective project partner countries (Netherlands, Norway, US, UK, France and Romania). Our assessment indicated that in the six participating countries, with the exception of the US, very little has been regulated specifically for the re-use of existing well infrastructure for CO2 storage operations, even though specific regulations for storage exists. In the US, the Underground Injection Control (UIC) program’s Class VI well regulations identify requirements for converting an existing oil and gas well into a well suitable for use at a CO2 storage site. Based on the initial assessment of regulatory frameworks, we have also made a comparative analysis which highlighted some points of special interest to be evaluated to enable reuse in the current legislation. These refer to transition from hydrocarbon production to CO2 storage (procedure for postponing decommissioning wells, simultaneous hydrocarbon production and CO2 storage, arrangements during mothballing/hibernation), hibernation/temporary abandonment of wells for further re-use (rules for mothballing and hibernation of wells, ownership of wells and costs), specific permitting for well re-use (rules for permitting, monitoring and testing) and policies for well re-use (promoting of well re-use and incentivization). The identified points of interest and periodic consultations with regulators and industry have been used to formulate several recommendations for potential improvement of current legislation to enable well re-use in CO2 storage operations. The first key recommendation is that regulators and governments should assume the role of actively minimizing and mitigating the risk of a gap occurring between hydrocarbon and CO2 storage operations and thus maximizing the potential re-use of oil and gas infrastructure for CCS. Another recommendation is that governmental bodies should supervise and stimulate the inventories of promising options for CO2 storage (e.g. national storage atlases) in order to avoid decommissioning of key assets in these areas. Furthermore, governments should support more open access to data required to identify potentially suitable sites and conduct re-use assessments. Apart from the regulatory framework analysis, we have also made an initial, first-of the kind assessment of the stakeholder and public perception and acceptance relating to re-use of wells for CO2 storage in the partner countries. This assessment was made through a survey reaching 333 respondents; predominantly stakeholders with some knowledge of CCS and targeted groups established at national level by the REX-CO2 project team. The general perception and attitudes of the survey participants towards CCS and re-use of wells for CO2 geological storage were positive. The overall survey trends were also visible at the national level with some minor deviations highlighted in the comments received. The main concerns raised by the respondents relate to the capacity of depleted hydrocarbon reservoirs to permanently store CO2 (France), the risk of leakage (the Netherlands) and the inadequacy of old wells in CO2 injection operations (Romania). The results of the survey and the past experiences from CCS projects were used to provide some guidance on the communication strategies to be implemented for future projects involving re-use in CO2 geological storage