temperature and pressure in the svartsengi ... - Orkustofnun

3ABSTRACTThiS report ls a study of the distribution of an d changesin temperature and pressure in the high temperaturegeothermal field of Svartsengi. Use ls made of t h e variousmeasurements of the 12 individual wells at differentperiods and the cross-sections made from thes e measurementa. Consideration is given to the effect of drilling,redrl111ng and reinjection on the t emperature profiles ofthe wells and the cross - sect 10ns and appropriate selectionsare made of reliable and repr esentative profiles ofthe many measurements. Bol11ng conditions of th e reservoirand evolution with time is studied. Some possibilitiesthat can cause the reservoir to be coo11ng down arepresented and discussed. They are boiling effect s, lateralcold inflow, episoidal cold inflow and decr e ased lateralinflow of hot fl u ids.This study shows that there is a sUbstantial cooling andpressure drawdown due to exploitation deep in thereservoir. It is found that temperature of the fluid isfairly stable during exploitation. However, in the timebetween 1982 and 1983 significant t emperature changes areobserved In the reservoir. Th e reason for the cooli ng ofthe reservoir is found to be most li kely a recharge of coldinflow.