In the field of oil and gas drilling, choosing the most suitable PDC composite sheet (PDC rock cutter) is definitely the core factor to balance the two key indicators of penetration rate (ROP) and durability. For drilling engineers who often have to deal with abrasive hard rock or those troublesome interlayer formations, the so-called “best” cutting teeth are actually very clearly defined: they must have high impact toughness (to prevent catastrophic tooth chipping) and excellent thermal stability (to resist hot cracking).

In this link, the first task is to find a source factory that strictly follows API standards and has consistent and stable quality. This is not only to ensure performance, but also to actually control project costs by reducing non-productive time (NPT).

In this guide, I will disassemble how to optimize your drilling performance from the two dimensions of technical specifications and manufacturing standards.

The Technical Core

Role of cobalt leaching process (deep cobalt removal technology)

In the process of oil and gas drilling, the high temperature generated by friction will cause the residual cobalt catalyst in the diamond polycrystalline layer to expand. This expansion creates internal stresses that lead to microcracks, which we call “thermal degradation” in the industry “.

Solution: We use advanced deep decobalation technology (Deep Leaching Technology). To put it bluntly, it is to remove the cobalt catalyst from the working surface of the diamond layer. This can significantly improve thermal stability.
Result: The cutting teeth retain a sharp cutting edge even at temperatures above 700°C. In my experience, this is essential to maintain an ideal ROP in deep, hot wells.

Interface engineering: prevent delamination

The bonding surface between the polycrystalline diamond layer and the tungsten carbide substrate is often a “soft rib” under high impact conditions “.

Non-Planar Interface (NPI): I personally strongly oppose the use of simple planar interfaces in complex conditions. Instead, we design complex, stress-releasing geometries in the bonding layer. This can disperse the impact energy more effectively. This design significantly reduces the risk of delamination (flaking) when drilling unstable formations such as conglomerate or crushed limestone.

Formation-Specific Selection

Take a general-purpose cutter to drill a specific formation, either ROP can’t go up, or you have to pull out ahead of time. According to the current drilling data on hand, I suggest that you clarify the requirements according to the following categories:

For soft to medium hard formations (shale, sandstone, mudstone)

• Primary goal: aggressive shear, pull ROP full.
• Recommended tooth type: Standard flat teeth with emphasis on wear resistance (Standard Flat Cutters).
• Chamfer design: In this case, I tend to choose a smaller chamfer angle. In this way, at lower weight on bit (WOB), the teeth can also eat deeper into the formation.

For hard and abrasive formations (granite, quartzite, hard limestone)

• Primary goal: survival and impact durability.
• Recommended tooth type: Axe-shaped teeth (Axe/Ridge) or tapered teeth. These unique geometric structures can concentrate the crushing force and are much more efficient than simple shear breaking.
• Chamfer design: double chamfer or large angle chamfer here is necessary, mainly to protect the cutting edge from cracking when it hits the hard interlayer.

Identifying and Solving PDC Wear Issues

Looking at the wear of the cutting teeth, we can basically infer the working conditions of the underground:

• Smooth Wear (Flat Spot): This is normal. But if you grind too fast, you have to change to a higher diamond density or a finer grain size of the matrix.
• Crack/Chipping: This is a typical “brittle failure”. The teeth are too hard, or the impact toughness is not enough. You need to change to a more “leather” (better toughness) brand, or optimize the interface design.
• Heat crack (snakeskin/Heat Checking): The teeth are overheated. To see this, you must go to the teeth with deep cobalt removal, or go back to check whether there is a problem with the hydraulic cooling design of the drill bit.

Purchasing PDC Rock Cutter

Finally, when checking quality control (QC), these three test data are indispensable:

• VTL (vertical lathe) test: simulate severe wear to ensure that the life standard.
• Drop Tower: Measure the total impact energy absorption, which is a hard indicator to ensure toughness.
• C- Scan ultrasonic flaw detection: must ensure that the diamond-cemented carbide interface zero internal defects, zero risk of delamination.

About the Author Michael Ross 
I am Michael Ross ,the Senior PDC Material & Application Engineer . With over 11 years of experience in superhard materials and drilling dynamics, I specialize in failure analysis and cutter optimization for complex oil & gas formations. Holding a Master’s degree in Material Science, I focus on bridging the gap between manufacturing metallurgy and downhole application, dedicated to helping drilling teams eliminate premature bit failure and maximize ROP.