Drilling the Severnaya Truba field in Aktobe, Kazakhstan, has been costly and time consuming. In combination with a drilling-fluid-powered percussion hammer (FPPH), a fit-for-application polycrystalline-diamond-compact (PDC) bit with depth-of-cut (DOC) -control features was used to minimize the exposure of the cutting structure and prevent breakage. The mechanical lifting and falling action creates a rapid variation in weight on bit (WOB), allowing the bit’s DOC to fluctuate while overcoming different stresses. These variations, along with the percussion pulse created with each stroke, led to increased rates of penetration (ROPs).
Introduction
Drilling with an air hammer is a technique whereby gases (typically compressed air or nitrogen) are used to operate a pneumatic hammer, to cool the drill bit, and to lift cuttings out of the wellbore.
