Polycrystalline diamond compact (PDC) bit technology and the application of PDC bits continues to improve and consequently, the window of application for roller-cone bits is being narrowed. This paper will demonstrate how in this narrowed window of tougher application focus, operators can gain additional performance and economic benefits by employing the latest design methods and materials including a new generation of diamond enhanced inserts.
The primary applications of focus where roller-cone bits are still predominantly used in achieving high buildup rates and for drilling through difficult formations such as highly abrasive sections, high interfacial severity (interbedded), and conglomerates. With increasing demands on roller-cone bit technology to handle damaging side and cyclical loading in directional applications, traditional roller-cone cutting structures exhibit premature rates of wear and damage on the outermost (heel row) tungsten carbide inserts (TCI). The loss of useable heel inserts allows for more direct formation contact, resulting in heat and wear in the seal area leading to premature seal failures. The development of improved designs and use of a new generation of superior quality diamond inserts has resulted in extended cutting structure life and consequently, longer seal life for operators.