Overcoming Common Challenges in Drill Bit Design

Drilling in any environment presents its own set of challenges, and designing the right drill bit to tackle those challenges is crucial for success. At Aurora, we understand the importance of striking a balance between drill bit efficiency and longevity while considering the specific demands of each application.

In this blog, we delve into some of the common challenges in drill bit design and the steps we take to overcome them.

Key Considerations in Drill Bit Design

PDC Drill Bit Profile

The profile of a PDC (Polycrystalline Diamond Compact) drill bit is pivotal to its performance. Two critical features are the inner cone angle and outer taper length. The inner cone angle provides lateral stability and is an important factor in its efficiency, while the outer taper length significantly impacts the product’s longevity. Balancing these features is essential for optimal performance.

PDC Drill Bit Stability

Achieving stability in a PDC drill bit involves factors like the inner cone angle, as described above, blade count, and gauge length. While a deeper cone angle enhances lateral stability, it may limit directional performance in certain scenarios. Blade count and gauge length also play significant roles, with more blades and longer gauge lengths enhancing stability.

Cutter Count, Size, and Shape

The efficiency and longevity of a PDC bit heavily depend on cutter count, size, and shape. Reducing face cutter count in key areas can enhance efficiency, while cutter density and size adjustments cater to varying formation hardness and abrasiveness. However, maintaining adequate cutting structure in high-work-rate areas is crucial for performance.

Bit Cleanability

Efficient evacuation of cuttings is paramount for sustained performance and longevity. Our approach starts with evaluating the PDC bit’s Normalised Face Volume (NFV), that considers the space available for cuttings evacuation. We then analyse junk slot design, nozzle positioning, and nozzle count to ensure hydraulic efficiency for cleaning and cooling.

Overcoming Challenges with Technology and Expertise

The most important criteria for the drilling team is to deliver a usable well/project on time and on budget. We employ a comprehensive approach combining cutting-edge technology and expertise to tackle these challenges effectively.

We leverage our in-house proprietary software programmes i.e. AWOS, BE3, and C3 to assess the PDC drill bit efficiency and longevity to accurately meet the needs of the application. These tools eliminate the risk of selecting the wrong product, ensuring optimal performance while adhering to planned timelines and budgets.

Recognising that each drilling application is unique, we tailor our solutions to meet specific objectives. By carefully balancing design features and application requirements, we deliver drill bits optimised for performance and longevity.

At Aurora, we prioritise continuous improvement in drill bit design and performance. Through rigorous testing, data analysis, and feedback integration, we refine our products to meet evolving industry demands.

Case Study Example

A recent project in the UK Southern North Sea serves as a powerful example of how we overcome design challenges to drive performance gains. We were tasked with implementing our proprietary BE3 efficiency indexing model midway through an 8-well offshore development campaign.

For the first three wells, conventional drill bit designs were used. However, by applying the BE3 model to analyse potential new fixed cutter designs from vendors, we identified an opportunity for improving the penetration rate by 6-10% on the remaining five wells – all while using less weight on bit than the initial wells.

The client approved a trial of the optimised bit design on the 4th well. Facilitated by the BE3’s insights, this low-risk trial was a resounding success. The average penetration rate across the final five wells increased by 43% compared to the first three wells, requiring 33% less weight on bit.

The efficiencies unlocked by the BE3 model saved significant operating time, allowing for on time delivery of the well whilst using a small jack-up rig.

This case study exemplifies how our comprehensive software suite identifies bit design adjustments to maximise performance for application parameters. Rather than operating with a one-size-fits-all approach, Aurora meticulously analyses each environment to deliver optimal, cost-effective solutions.

Designing drill bits to overcome common challenges requires a meticulous approach that balances various design features with application-specific requirements. By leveraging technology, expertise, and a commitment to continuous improvement, Aurora ensures that each drill bit meets the demands of the toughest drilling environments, delivering optimal performance and longevity.

To discuss your current and upcoming drilling projects, email us at abc@aurorabc.com.