The conventional geothermal resources are concerned with hydrothermal systems. Our view is focused on co-production and well heat exchanger, classified as non-conventional systems.
Mature oil fields are characterized by a large amount of co-produced water. Oil dewatering and water injection operations tend to increase operational expenditure (OPEX). Therefore, oil companies are seeking to improve production processes. 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 the possible reuse of an oil field as the geothermal one are our specific goals.
One of the more complex technical issues in the geothermal plants is the re-injection of the fluids. These operations entail high economic costs since they require the drilling and maintenance of additional wells, the treatment and the pumping of the fluids. A possible alternative is the use of an indirect system to extract heat, the WellBore Heat eXchanger (WBHX). This kind of well completion allows to extract heat using an heat carrier fluid circulating in a closed loop. Thus, no geothermal fluids production take place and the environmental impact as well as the required energy for re-injection are strongly reduced. Corrosion and scaling problems are also avoided. Disadvantages could be envisaged in the reduction of the heat recovery efficiency.
In the current development of renewable sources is relevant to assess the potential of an air-conditioned public building with a geothermal heat pump system.