New Rolling Cutter Bit Design Reduces Gage Wear in Geothermal Applications

Abstract

Geothermal wells are drilled in highly abrasive formation, which frequently induces gage wear on conventional rock bits. This condition results in costly reaming operations. To address this problem, rolling cutter bits were designed specifically to resist the premature gage wear common to geothermal applications. This paper describes the evolution of enhanced gage geothermal bits. The development of extremely abrasion resistant carbide grades expressly of this hostile environment will be examined, as will the new design that features more durable shapes in the heel rows and increased quantities in both the heel and gage rows. Field experience will also be summarized.