Novel Slim-Matrix PDC Construction Boosts Drilling Efficiency: A Field Study

Abstract

One of the perceived drawbacks of matrix polycrystalline diamond compact (PDC) bits compared with steel PDC bits is their restricted open-face volume and smaller blade standoff, which is primarily caused by the matrix PDC bits' brittle nature. Increased blade standoff gives steel PDC bits a more hydraulically efficient body type, which directly affects ROP. In many drilling applications, operators switch to steel PDC to take advantage of their hydraulic efficiency, and recent developments in hardfacing material has expanded the range of applications of such bits. However, there are applications that are still dominated by matrix PDC bits, and a need arose for matrix material that can allow the molding of slim, hydraulically efficient matrix bodies. A new matrix material with enhanced toughness allows for the design of a slim-body matrix construction. This innovative concept has been validated for structural integrity, which was the main perceived risk. The technology was rolled out for 8½-in and 12¼-in hole sections and deployed in a field test campaign in all of Egypt's different rock columns. The effect and value of faster ROP increases with application complexity and depth and is directly proportional to rig spread rate. Hence, realizing the application limits of slim-body matrix technology was the main intent of this study. Success was measured by observing the effect of hydraulic efficiency across different fields in terms of ROP and cost savings. Further, to isolate the effect of slim-body construction, several tests were conducted between standard matrix and slim-body matrix construction using the same cutting structure layout and PDC cutter grade. The slim-body matrix construction demonstrates significant improvement in cost per foot for applications and is directly proportional to UCS. This feature is advantageous in interbedded applications, where formations fluctuate from hard to soft and vice versa along the drilled column. This new feature has since been standardized in matrix bits and is being rolled out across various applications with the intent of tackling more expensive drilling operations to show a greater reduction in cost per foot.