CO2 geological storage by ECBM techniques in the Sulcis area (SW Sardinia Region, Italy).

Abstract

An ECBM (Enhanced Coal Bed Methane as evolution of CBM techniques) pre-feasibility study started for the Sulcis Coal Province in December 2004 on the basis of the experience gathered: 1) by INGV, from ongoing and past projects dealing with CO2 geological storage, i.e., Weyburn test-field (Canada) by EOR techniques and from the studies of “CO2 analogues” in Italy; 2) by the coal industry of the Sulcis Province (Sotacarbo S.p.A. & Carbosulcis S.p.A.); 3) by ETH – Zurich, specifically on the coal adsorption properties, and 4) by IES S.r.l. reservoir engineering and gas storage industrial activity. This paper discusses the state of art of the project in the frame of the worldwide ECBM projects as a whole, on the basis of the yet acquired information and available experimental data. Environmental impact considerations are highlighted on the basis of the available Italian legal tools, giving hints for future EU, Italian and new regional legislation and strategies. A new concept of CO2 as “no waste” product in the coal/hydrocarbons provinces for ECBM/EOR exploitation is depicted, defining CO2 a “ natural climatealterant factor”. Geochemical, structural-geology, stratigraphic and reservoir engineering considerations are discussed. The first newly gathered experimental data, including CO2/CH4 coal adsorption capacity data are showed, even if they are preliminary. Starting from the geological and logistical available data, a MapInfo GIS structure was built up, to be jointed later to other EC “CO2 storage” data-GIS as the GETSCO EC project structure. The most important objective of this Phase I is the selection of the best for a ECBM test-pilot site, which will be followed (Phase II) by scaled up site and possibly by a future network (Phase III); these phases are foreseen to be accompanied by the selection of the progressively addedCO2 industrial sources (inserted in the Map-info GIS) to be used within the project economic spreadsheet model. CO2 geological storage in Sardinia is evaluated as a whole, considering the seismotectonic framework and the CO2 industrial sources available or foreseen in the next years.