Can The Hydrocarbons Industry Be A Strong Driver To The Grow Of The Geothermal Energy Sector? “An Evaluation Of The Geothermal Potential In The Italian Country”

Abstract

Global changes urge a radical transformation and improvement of the energy producing systems to meet the decarbonisation targets of the European economy by 2050 and a reduction of greenhouse gas emissions. In this context, a key point for the geothermal sector is the need to reduce uncertainties on profitability and to design sustainable solution for large-scale development out of the conventional assets. The large knowledge accumulated in the oil&gas industry should be highly profitable to the understanding of the possible ways of growth in the relatively young geothermal industry. Since ’90, American and Chinese oil companies have studied the possibility of co-producing geothermal energy from oil and gas wells. Those projects were the first trials in making cross-over knowledge between the two energy sectors. Today a key issue in the oil industry is the management of produced waters. In fact, the oil and gas production in its mature stage is often associated to a large amount of brines or formation waters which must be treated continuously. Since these formation waters could not be released to the environment they are reinjected in the subsurface. The analogies with the doublet geothermal plant are clear. A possible way to accelerate the implementation of complementary geothermal- hydrocarbon production opportunities is to proceed to an evaluation of the available thermal potential ready to use. The selection of the final utilization and the potential of geothermal production depends on the temperature, pressure and flow rate of water, which are function of local geothermal gradient, well depth, and poro-perm properties of the reservoir rocks. Therefore, well information available in the databases of the oil&gas industries can give a real idea of the potential successful projects. The oil and gas fields in the Italian territory are distributed in thrust belt, foredeep basin, and foreland geological settings. Hydrocarbon occurrences are related to at least five major petroleum systems which are associated to both carbonate and siliciclastic reservoir rocks ranging in age from Triassic to Paleogene and from Oligocene to Pleistocene, respectively. At the end of 2017, the total number of productive wells on the Italian territory was 1594, 881 wells are onshore and 771 are offshore. The possibility of a synergic integration of geothermal energy in these oil&gas fields represents a chance for Italy to increase the share of renewable energy production and to reduce the waste heat. Furthermore, the conversion of hydrocarbons fields into geothermal ones may be an opportunity to create a positive social response in the area where the oil and gas wells are located. The use of existing wells is a benefit for the oil companies, which avoid the cost of mining closure of the wells and for the geothermal companies, which avoid the cost of drilling new wells. A major obstacle is constituted by the administrative procedures to achieve a transfer from a hydrocarbon license to a geothermal one.

AAPG Datapages/Search and Discovery Article #90346 ©2019 AAPG European Region, 3rd Hydrocarbon Geothermal Cross Over Technology Workshop, Geneva, Switzerland, April 9-10, 2019