Application of an innovative ridge-ladder-shaped polycrystalline diamond compact cutter to reduce vibration and improve drilling speed.

Abstract

Polycrystalline diamond compact bits have been widely used in the Oil and Gas drilling industry, despite the fact that they may introduce undesired vibration into the drilling process, for example, stick-slip and bit bounce, which accelerate the failure rate and lead to higher drilling costs. First, we develop an innovative ridge-ladder-shaped polycrystalline diamond compact cutter, which has ridge-shaped cutting faces and multiple cutting edges with stepped distribution, in the hope of reducing vibration and improving drilling speed. Then, the scrape tests of ridge-ladder-shaped and general polycrystalline diamond compact cutters are carried out in a laboratory, indicating that the cutting, lateral, and longitudinal forces on ridge-ladder-shaped polycrystalline diamond compact cutters are smaller and with minor fluctuations. Due to different rock-breaking mechanisms, ridge-ladder-shaped polycrystalline diamond compact cutters have higher cutting efficiency compared to general polycrystalline diamond compact cutters, which is also verified experimentally. Finally, the drilling characteristics of a new polycrystalline diamond compact bit fitted with some ridge-ladder-shaped polycrystalline diamond compact cutters are compared to those of a general polycrystalline diamond compact bit by means of finite element simulation. The results show that introducing ridge-ladder-shaped polycrystalline diamond compact cutters can not only reduce the stick-slip vibration, bit bounce, and backward rotation of drill bits effectively, but also improve their rate of penetration.