Improving Drilling Efficiency Through Carbonates Using Non-Planar Shaped PDC Cutter Geometries

Abstract

Abstract The objective of this paper is to review the lab and field testing of Non-Planar shaped (Polycrystalline Diamond Compact) PDC cutters in challenging applications across diverse Oil & Gas wells, and to demonstrate the tangible benefits in terms of efficiency and cost savings in several fields with high content of carbonates. Non-Planar Shaped PDC Cutters from three different companies were selected and tested in both laboratory and field settings. Lab tests were conducted to validate the cutters' efficiency, and the best match for the application was determined prior to field testing. Drilling efficiency tests were conducted at both single cutter and full-scale drill bit levels, and field test wells were selected to set a solid benchmark and perform further evaluation. The Non-Planar Shaped PDC Cutter demonstrated an average of 20% reduction in vertical force required to achieve a given depth of cut, when compared to a legacy cylindrical cutter, in single cutter laboratory tests. In the majority of the cases, the Non-Planar Shaped PDC Cutter's face shapes created a fluid channel behind the cutting ribbon, which decreased frictional losses and promoted cuttings evacuation. The stress in the weight on bit direction was increased, thereby improving fracture propagation. In field trials, the Non-Planar PDC Cutter demonstrated an ROP improvement of between 15 and 30%, with the highest efficiency gains recorded in carbonates. Cutter durability was assessed by comparing the interval drilled and dull condition, which demonstrated parity compared to conventional round cutters. It can be concluded that the Non-Planar Shaped PDC Cutter Geometries bring tangible drilling efficiency gains that directly translate to reduction in drilling costs. This paper demonstrates the importance of exploring different geometric PDC cutter designs. It shows that using non-planar cutters improves drilling efficiency at the micro – single cutter level that can be effectively translated to the macro – full PDC drill bit efficiency level. Field testing highlights that these new geometries can deliver tangible ROP performance without compromise to drill bit durability or reparability.