Lost Circulation Experience in Geothermal Wells

Lost circulation during drilling and cementing in geothermal wells is a problem common to most geothermal areas. Material and rig time costs due to lost circulation often represent one fourth or more of the total well cost. Assessment of the general drilling and completion practices commonly used for handling lost circulation have been surveyed and evaluated under a study sponsored by Sandia National Laboratories. Results of this study, including interviews with geothermal production companies and with drilling fluid service companies, are reported in the paper. Conclusions and recommendations are presented for control of lost circulation during geothermal operations. Recent improvements in lost circulation materials and techniques and potential equipment solutions to the lost circulation problem are discussed. Research needs are also identified