ALBERT

Description: Seven 222Rn soil gas surveys have been accomplished throughout the N-E area of Stromboli Island. The former survey has been performed in July 2001, in a quiescent period since 1985, throughout a grid of 50 sites. The same grid has been repeated, in January 2003, soon after December, 28, 2002 eruption onset. The other surveys have been carried out in March 2003, in June 2003 after the April, 5, 2003 paroxysm event, and in July 2004 and March 2005 (quiescent periods). Finally, CO2 fluxes and soil gas surveys (Rn, CO2, CH4, H2, O2, N2, He) have been performed in March 2007 after the slightly February 2007 eruption onset. Results have highlighted correlated and synchronous 222Rn soil gas changes throughout the grid, allowing to discriminate the sectors of maximum increased 222Rn emission at surface, with a volcano-tectonical significance, mostly in January and March 2003 surveys. The positive NE-SW anomalies have been found maximum up to 13.000 Bq/m3 in January 2003, while after the Rn values returned to pre-eruptive values. Plotting single point concentration versus monitoring time, it is well evident that, in proximity of a paroxysm event, always the same points undergo to a radon concentration increasing. Data set of the investigated area has been divided in eight zones (on the basis of geographic sectors of the island). In every zone maximum Rn values correspond to the paroxysmal phase of the Stromboli eruptions. In particular, highest radon values are found in the “Lampara – COA” and “Town Hall” zones located along the known N40° lineament. After the eruptive phase, concentrations start to decrease. The NW-SE extension could be linked to the ongoing volcano collapse toward the NW located Sciara del Fuoco slope. Also the SE sector could undergo to collapses, along weakness lines (faults and fractures) whose prolongation in the Mole-S14 zone could release anomalous CO2-fluxes and anomalous soil gas concentrations (up to 10-20 % in CO2) dangerous for human health. The importance of geochemical monitoring together with volcanic time series, is a valid tool for evaluating the volcanic hazard.

Description: Unpublished

Description: Reykjavík - ICELAND

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: open

Description: Italy is one of the most promising prone areas to study the CO2 behavior underground, the caprock integrity to the CO2 leakage, mostly in presence of pervious/geochemically active faults, due to a wide availability of CO2 rich reservoirs at a depth between 1 and 10 km, as highlighted by recent literature. These deep CO2 reservoirs generate at least 200 leakage areas at surface throughout Italy which have been defined “Diffuse Degassing Structures” (DDS) by INGV. These are widely studied by INGV institutionally by a long term convention with the Civil Protection Department (DPC) with the aim to catalog, monitor and assess the Natural Gas Hazard (NGH, namely the probability of an area to become a site of poisonous peri – volcanic gas exhalation from soils). More than 150 researcher of INGV are involved in monitoring areas affected by the CO2 presence underground and at surface, by continuous monitoring on-line networks (around 40 stations throughout Italy, including the Etna area, Aeolian Islands, Umbria region, Piemonte region, etc…) and discretely (9 groups of research were involved in the last years to localize, define and monitor almost all the DDSs in Italy), by sampling and analyzing chemical and isotopic compounds, useful to discriminate the origin, evolution and natural gas hazards of the examined DDS. In this paper, we will discuss some DDS catalogued and studied by a Rome INGV Research Unit (UR 11) which focused its work in Central Italy, throughout different DDS, also in relation to the diverse seismotectonic settings, to discover buried faults as possible gas leakage pathways, mostly if they are “geochemically” activated. In particular we discuss, among the discrete monitoring techniques exploited by INGV, soil gas surveying, which consists in a collection of gas samples from the soil zone not saturated (dry zone) to measure the geogas gaseous species both in fluxes (CO2, CH4, 222Rn) and in concentration (He, H2, H2S, helium, hydrogen, CO2, CH4, 222Rn), that permeate the soil pores. The total CO2 flux budget was calculated as “baseline” degassing rate of these “CO2 analogues”. A good discrete areal monitoring is prerequisite to design sound continuous monitoring network to monitor CO2 related parameters in liquid/gas phases, to review the protocol of the Annex II of the European Directivity on CCS.

Description: Published

Description: 2135-2142

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: N/A or not JCR

Description: reserved

Description: 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.

Description: Unpublished

Description: Cagliari, Italy

Description: open

Description: Pantelleria is an active volcanic complex, at present in quiescent status, hosting a high enthalpy geothermal system. Explorative geothermal wells tapped exploitable water-dominated reservoirs at 600-800 m depth with maximum measured temperatures of 250°C. Five field campaigns for soil gas measurements were made in the period from July 2005 to October 2006. CO2 flux was measured with the accumulation chamber method at 807 sites, CO2 concentration and Rn activity in soil atmosphere were measured at 50 cm depth at 728 and 358 sites, respectively. The first campaign covered the whole island (about 83 km2) with an approximately sample density of 3.5 points per km2 for CO2 (flux and concentration) measurements and of 1.6 points per km2 for Rn measurements. The distribution of the sampling points was as far as possible evenly distributed. Only few limited areas resulted uncovered due to accessibility problems (inhabited areas, airport, steep or rough topography). In the following four surveys nine areas were studied with greater detail with sample densities of up to 100 points per km2. Flux measurements for the whole surveys gave values in the range 〈 0.1 - 4700 gCO2 m-2 day-1 (Fig. 1). Organic contribution could not be distinguished with statistical methods and in the present study was considered negligible above 30 g m-2 day-1. The sites displaying flux values above this threshold, representing about 32% of the total population, are almost all located within the 50 ka old caldera. The highest values correspond to the areas of Favara Grande and of the lake Specchio di Venere (Fig. 1), which have long been recognized as sites of anomalous degassing with the presence of active fumarolic vents with temperatures of about 100 °C in the former and thermal springs with abundant bubbling gases and a mofette in the latter. A new anomalous degassing area with very high output values has been identified on the southern flank of Mt. Grande (MGS in Fig. 1). In this area the vegetation cover strongly contrasts with that of the neighboring areas, consisting of scrubby low growing plants, mosses and bare land. Indeed, high CO2 flux values are always measured as long as such vegetation cover is found, abruptly decreasing when higher growing plants are present. The contrast is particularly evident in springtime and can be used as a good marker to individuate anomalous degassing areas. Further areas were studied in detail being sites of fumarolic manifestations. All of them are also sites of anomalous CO2 fluxes although of limited areal extension. The area of the last subaerial volcanic activity (Mursia) was also studied but the measurements were all far below the anomaly threshold. The total CO2 output of the anomalous degassing areas was estimated through geostatistical methods considering only values above the anomaly threshold. Results evidence that most of the output (87%) of the island is due to 3 of the anomalous degassing areas (Lake, MGS and Favare), the first of which accounts for more than 50%. Summing up the contribution of all anomalous areas we obtained a total output of about 0.3 kg s-1 (26 t day-1) over an area of about 0.58 km2. Concentrations of CO2 ranged from 0.039 (atmospheric value) up to 95 % (Fig. 1). The distribution of the values on a probability plot evidenced two statistically distinct populations with an inflection point at about 0.8 %. The values below the threshold (65 % of the population) can be considered as derived from organic activity while those above of magmatic/geothermal origin. The spatial distribution of the sites with anomalous concentrations closely resembles those of anomalous CO2 fluxes. Radon222 activity in the soil ranged from 〈 0.1 to 〉1000 kBq m-3 (Fig. 1). The distribution of the values on a probability plot evidenced three statistically distinct populations with inflection points at 40 and 400 kBq m-3. The lower population (74% of the entire population) probably corresponds to close to equilibrium values in soils with different contents of parent isotopes of the 238U decay chain and could be considered as background population. The values of the other two populations have to be considered anomalous and their high activity values have to be related either to sustained fluxes of a carrier gas (CO2) or/and to enhanced release from the soil due to fumarolic alteration. These anomalous values generally correspond to elevated CO2 flux values and are found close to active or fossil fumarolic areas. The close relationship with fumarolic alteration is confirmed by the contrasting behavior of two of the areas displaying the highest CO2 flux values, namely Favare and Lake. In the former area the high soil temperatures, testifying for anomalous fluxes of hydrothermal fluids, are reflected in a high percentage of anomalous values of soil 222Rn activity. On the contrary at the lake area, where the highest CO2 fluxes are measured, soil temperatures are much lower and consequently also soil 222Rn activity. The only high soil 222Rn activity values are measured along the southern shores of the lake where seeps of thermal water with about 60 °C are present. At Mursia, where recent basaltic lavas and scorias crop out, soil 222Rn activity is particularly low due to the low content of parent radioactive elements in these rocks. Finally, the present study evidenced a few areas were the gas hazard due to both CO2 and radon is elevated with either acute or chronic health issues for humans. These are the western shores of the lake and the village of Rekale the only inhabited area close to an anomalous degassing area.

Description: Published

Description: Patras, Greece

Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi

Description: open