Bit Design for Beginners

Drill bits are like cars. You can look at the fanciest and fastest cars, say a Ferrari. However, if your Ferrari is fitted with inferior components, the performance you achieve will not be what you expected.

Drill bits need to deliver every time to ensure that the power delivered by the drilling system is used to the best effect. They need to be extremely reliable in terms of efficiency and longevity. That is why drill bit design is critical to the overall success of the drilling operation.

They are engineered to penetrate rock formations. These rotating apparatuses typically consist of rolling cones or fixed cutters (predominantly Polycrystalline Diamonds or PDC’s) and employ some of the toughest man-made materials. Such a tool produces a cylindrical hole (wellbore) which is then used to extract hydrocarbons.

Don’t underestimate the importance of the drill bit

While a drill bit appears to be a single component of the drilling system, it is critical to the overall system’s success. The better the drill bit, the longer it can continue to cut through the formations.

Poor drill design can be detrimental to a project. The drill bit needs to be compatible with the lithology you need it to drill and the drilling system it will be used on. You must think about the above when considering the type of drill bit to use. The wrong bit will slow down your drilling system or, worse, it will halt your work. This ultimately leads to increased overall costs, longer drilling times, disappointing rates of penetration (ROP), and severely delayed projects.  `

Of course, there are more ways to drive drilling optimisation which should also be considered. We touch on some in our recent article, ‘5 Ways to Drive Drilling Optimisation Efficiency’. 

Types of drill bits

There are several types of drill bits, such as Polycrystalline Diamond Compact (PDC) bit, tungsten carbide insert bit, steel tooth bit, and impregnated diamond bit.  

Nowadays, the most important type is the PDC bit. PDC bits are incredibly tough and rigid; they are made of polycrystalline diamond (man-made synthetic diamond) with a substrate of carbide at very high temperatures and pressure.

The key principles of bit design

The basic building blocks for fixed cutter drill PDC bit design include:

  • Bit profile
  • Cutting structure
  • Material
  • Cleaning

The design basics have remained consistent for PDC and roller cone bits. Primarily due to space restrictions, it is notoriously difficult to make major alterations to the fundamental design. However, over time, there are some advancements, thanks to the development of new technology, materials and changing industry requirements.

Within Oil and Gas, the design requirements have increased for fixed cutter drill bits to drill an expanded envelope of lithologies. New PDC cutter technology has enabled product advancements to drive drilling efficiency and cost reductions.

Getting started with bit design

Invest in training

At Aurora, we deliver independent training modules to help teams understand the complexities of drill bit design and how they apply to different drilling projects. This enables you to evaluate your project needs and the tools you need to achieve your goals.

Take advice from experts

Engage with engineers who understand the drilling process. Engineers can provide critical insight into what has happened before on drilling projects, what worked and what didn’t. Working with Aurora, you can access this drilling engineering expertise. 

Use new technology to analyse data 

You can use state-of-the-art computer modelling to better understand the performance of different wells. At Aurora, we analyse well data to explore the relationship between multiple wells’ drilling characteristics worldwide based on each well’s geological profile.

Our Aurora Well Optimisation System (AWOS) provides a visualisation layer for well data, allowing us to identify issues at every stage of the project. Therefore, we can predict the drilling system’s performance before operations start. We review the complete drilling process to identify issues and opportunities at the earliest part of the process.

Contact our team of drilling experts at to learn more.