| Abstract |
In current energy outlook and oil price trends any operation in extending the life of oil&gas fields is welcome. Mature oil fields are characterised by a large amount of co-produced water. Oil dewatering and water injection operations tend to increase operational expenditure (OPEX). Often, produced fluids have a high temperature and cooling is adopted. The waste heat recovery from the produced stream could be a quite interesting option. Increase in profitability of small oil and gas producers as well as possible reuse of an oil filed as a geothermal field are possible goal. Considering the large number of oil wells that are abandoned every year around the world that could be potentially exploited to produce energy again, reuse becomes a need. The present study analyses different implementation scenarios of geothermal uses of oil wells in a depleting field. Scenarios assume to implement possible solutions during the oil production field life up to its complete conversion to a fully geothermal field. Three different scenarios considering the possible use of hot stream from the wells have been studied. A first scenario concern the direct use in district heating; a second option of exploitation is in electric power generation through an Organic Rankine Cycle (ORC) plant; finally, a possible cogeneration scheme of electric power and heat have been assumed. The comparison of the different scenarios highlight an optimal configuration of the exploitation of the field, a combination of electrical generation and district heating. The choice to operate in cogeneration, in fact, allows to maximize overall system efficiency, reducing heat loss. The produced heat and electricity will be supplied to the nearby community, through a district heating network, extending the service to a large number of buildings. |