Squeeze with Foamed Cement Cuts Nonproductive Time in a Geothermal Well

Abstract

During geothermal-drilling operations in a field in central California, the operating company reduced nonproductive time (NPT) by 78% by squeeze cementing a lost-circulation (LC) zone with cement foamed by adding nitrogen to the slurry. The slurry design chosen was nitrogen-foamed Class G cement with an accelerator. A slurry volume of 3,000 sacks pumped in three foam squeeze stages (approximately 1,000 sacks each) repaired the well and enabled drilling ahead. The process took three days to complete; similar operations in the area where conventional cements and processes were applied typically required two weeks to complete. This paper presents the case history of the last of the three foamed cement squeeze stages performed. Cementing challenges, solutions, wellbore diagrams, and job procedures are discussed.