Rehabilitation of geothermal wells with scaling problems

Abstract

This report presents an overview on the problems caused by solid deposition in production wells and describes methods to minimize the problem they cause. The main scale types found in geothermal systems are described along with case histories. Several methods to rehabilitate wells with scaling problems have been adopted in various countries in order to recover the well output. The location of the scaling zones and the mechanical conditions of wells are most influential in selecting the appropriate alternative for rehabilitation. Two case histories are included in this report, where the author witnessed cleaning operations. They are from the Ahuachapán geothermal field in El Salvador and the Krafla geothermal field in Iceland. The main activities carried out in wells of these geothermal fields are presented in order to compare the methodology used. Also, deposition cases from other geothermal fields in the world are presented. The author considers that the study of the methods used to clean the wells mechanically with a drill rig, will be very useful for similar future operations in the geothermal fields of El Salvador.