Deep Geothermal Energy Potential in the Madrid Basin

Abstract

The Madrid Basin geothermal potential was discovered in 1980 thanks to an oil exploration well drilled by Shell-Campsa which showed temperatures of 88ºC and 156ºC degrees at 1700 mts and 3400 mts depth respectively. That low enthalpy geothermal reservoir was further assessed by four exploratory wells. The latest well was drilled in 1990. These wells have identified a dependable geothermal resource, hosted in a Tertiary, clastic, consolidated sandstone reservoir consisting of a thick multilayered sequence (200-800m) with temperatures ranging from 70º to 90ºC and depths of 1500 to 2150 m., overlying a Mesozoic sequence, suitable to be exploited for thermal uses in several district heating grids around Madrid in areas displaying adequate heat loads. A medium-enthalpy reservoir was also identified at the contact between Mesozoic Cretaceous limestones and fractured basement granites at 3400m depth, with measured temperatures of 156ºC, that could be developed and exploited using a combined power and heat production (CPH) scheme within the Madrid suburban areas.