How carbon capture and storage can contribute to the prevention of future global warming. The importance of reusing oil and gas wells in the context of CCS

„Human activities are estimated to have caused approximately 1.0°C of global warming above pre-industrial levels, with a likely range of 0.8°C to 1.2°C. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.” These statements are quoted from a report written and published in 2018 by the Intergovernmental Panel on Climate Change (IPCC) shows.

IPCC is an intergovernmental body of the United Nations that is dedicated to providing the world with objective, scientific information relevant to understanding the scientific basis of the risk of human-induced climate change, its natural, political, and economic impacts, and possible response options.

For those concerned about the future of their children, these two statements can only be deeply worrying. We are all affected by the global warming. If not directly, at least through the media reports, we have all witnessed extreme weather phenomena in the recent years – more frequent and more intense storms and hurricanes, devastating droughts and floods. 

Something needs to be changed. Scientists are primarily the ones able to propose technological solutions to limit global warming to a value that does not exceed 1.5 degrees Celsius, a threshold that the IPCC considers critical.Now more than ever it is imperative to drasticallyreduce emissions of greenhouse gases which cause global warming such as carbon dioxide, followed by the gradual creation of an energy future in which these harmful emissions to disappear once and for all. 

This is only achievable by widely applying a portfolio of solutions that includes  energy efficiency improvements, increasing renewable energy capacity, increasing the efficiency of energy production, changing the type of fuel (both domestically and industrially), increasing the share of nuclear energy in overall energy production and, last but not least, the widespread application of carbon capture and storage (CCS) technology.

What does carbon capture and storage actually consist of?

This technology involves capturing carbon dioxide from an industrial source of emissions, transporting it, injecting it and storing it in suitable, deep, underground  geological environment. Only last year The International Energy Agency estimated that a drastic reduction in greenhouse gas emissions requires the capture of at least 2.3 giga tonnes of carbon dioxide (CO₂) per year by 2060 and the annual operational development of at least 30 new storage deposits.

Carbon dioxide capture and storage projects already exist in the United States, Brazil, China, Australia, the United Arab Emirates and Norway. The country that most successfully applies this new technology is the USA, where CO₂ storage projects benefit from financial incentive policies, which provide significant tax deductions. In Europe, Norway is the only country where two such large-scale projects are operational, both in the North Sea – Snøhvit and Sleipner -, through which more than 20 megatons of carbon dioxide have already been stored. In 2019 the Global Carbon Capture and Storage Institute (GCCSI) estimated that, once operational, 10 other large-scale projects at various stages of development from different European countries will capture 20.8 megatons per year. 

Carbon capture and storage in Romania

At the moment, there are no operational CCS projects in Romania. The only project proposed was GETICA CCS (2010 – 2012), carried out under the coordination of the Institute of Studies and Power Engineering in Bucharest. Apart the coordinator, within this project, GeoEcoMar collaborated with two private companies – ALSTOM Carbon Capture (Germany) and SCHLUMBERGER Carbon Services (France). GETICA CCS, located in Oltenia region, stalled due to insufficient funding and the withdrawal of governmental support. It was a full chain demonstration project designed to capture the CO2 from the Turceni power plant, onshore pipeline transport and injection and storage in a deep saline aquifer. 

The Feasibility Study for GETICA CCS was completed with GeoEcoMar coordinating the storage section. It involved the selection of two storage sites from Oltenia region, the elaboration of the structural model for each of the two selected sites, as well as the preliminary analysis of the CO2 dynamics within the storage complex. GeoEcoMar also conducted an integrity study on a number of abandoned hydrocarbon wells (completely out of production and exploration). Before stalling, the project’s partners designed the advanced exploration phase for one site, considered to be the most suitable for storage. GETICA CCS was funded by the Global CCS Institute (Australia) and the Ministry of Economy (Romania).

The CCS technology is however recognized as necessary and beneficial in the national climate change strategies as it allows the continued use of fossil fuels for energy production. It also enables a transition towards meeting national energy needs fully and safely by renewable or other energy sources. Carbon capture and storage can also make a significant contribution to reducing emissions from industries such as steel and cement or the chemical industry which are otherwise difficult to decarbonize. 

The storage of carbon dioxide is legally regulated by the Romanian National Agency for Mineral Resources (NAMR). The European Directive on the Geological Storage of CO₂ (Directive 31/2009 / EC) was adapted and subsequently adopted by the Romanian authorities in 2011. In the following years, NAMR developed the specific procedures for granting permits for CO₂ exploration and storage.

Why is the reuse of the existing wells necessary?

More than 150 years of oil and natural gas exploitation produced numerous wells that have now temporarily or completely ceased production. From the perspective of geological storage of carbon dioxide, these wells represent both an opportunity and a challenge. The opportunity lies in the possibility of reusing them. In this case, the financial investments required could be reduced from the outset, thus eliminating one of the impediments that most often make these geological projects difficult to start. The challenge is related to the potential risk that these wells could pose to long-term storage, given the fact that they could potentially become migration pathways for injected CO₂. This can be prevented by performing integrity studies for each well.

This is the context in which the REX-CO₂ Project appeared (The full name of the project is Re-using EXisting Wells for CO2 Storage Operations). It seeks to answer an important scientific research question – what are the appropriate evaluation criteria for which a hydrocarbon well can be reused for CO₂ storage in a reliable and economically feasible way?

The project’s goal is to develop the methodologies and tools needed to assess the reuse potential of existing oil and gas wells for CO₂ operations. The assessment will take into account the technical, environmental, economic and social characteristics of the re-use operation. The methodology and application tools will be tested on pre-selected wells and oil and gas fields from the partner countries. Project information and results will be publicly available on the project website and will help stakeholders (researchers, industry experts, regulators) make informed decisions about the potential reuse of wells. 

The consortium, coordinated by TNO (the Netherlands Organisation for Applied Scientific Research), consists of research institutes and industrial partners from the Netherlands, Romania, the United Kingdom, the United States, France and Norway. The project has regulatory authorities as associated partners in the United Kingdom and Romania. 

The REX-CO₂ project (2019 – 2022) receives international funding through the second phase of ACT (Accelerating CCS Technologies) Programme under the Project No. 299681. ACT is an initiative of 16 scientific research funding agencies in Europe and the USA that aims to stimulate the development of carbon capture and storage technology. In its first phase, the programme was partially financially supported by the European Commission. In the following phases, the national scientific research funding agencies will solely fund the Programme. The Romanian funding agency for scientific research is UEFISCDI.

GeoEcoMar in the International Project REX-CO₂

GeoEcoMar coordinates the “Legal, environmental and social aspects” work package (work package 6). This work package primarily assumes that each of the six participating countries will review its own legal provisions on the reuse of oil and gas wells for carbon storage. The analyses will seek to identify the possible legal gaps that the regulators need to address in order to enable well reuse. The partners will also make recommendations for the future operators that will ease the process of obtaining permits for well reuse. Another important activity of the work package refers to the implementation of public surveys on the appropriateness of reusing wells in each partner country. These surveys are aimed at several types of target groups (professors, students, scientific researchers, oil and gas industry operators, non-profit environmental organizations, etc.) and will be organized by country coordinator by the end of 2020. 

The Romanian researchers from GeoEcoMar will coordinate a case study of the potential reuse of some wells in Bihor County (Romania). The software elaborated under the coordination of Los Alamos National Laboratory in the USA and TNO will be used and possibly improved after the testing on pre-selected wells. The case study was selected in close cooperation with NAMR, which is an associated partner in the project. Other case studies within the project will also test the software.

GeoEcoMar’s involvement in REX-CO2 Project took into account the experience of the Romanian scientists in GETICA CCS Project (2010 – 2012). That project also included a study of the wells intercepting the proposed storage complex, which meant both their identification and field assessment. The study focused primarily on the risk that the old wells (out of production and exploration) may pose to the safety of CO2 storage.

More information on REX-CO2 Project can be found on the website https://rex-co2.eu. 

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Dr. Alexandra Dudu, Ruxandra Zamfir – GeoEcoMar