The Integrated Dynamic Engineering Analysis System (IDEAS) is a proprietary process developed by Smith Bits to certify the performance capabilities of a bit design through a

IDEAS certified directional bits are designed to remain stable and deliver superior performance with different types of rotary steerable systems in a wide range of applications. (Image courtesy of Smith Bits)
dynamic simulation and modeling methodology. It takes into account not just the lithology at the rock/cutter interface, but also the drillstring, drive system, bottomhole assembly (BHA) and the total system’s influence on bit behavior. The process starts with bit performance data, geological information, BHA details and dull bit analysis. Additionally, actual laboratory rock/cutter tests are devised and carried out for the target formations. Laboratory data from the system quantify actual cutter forces and rock removal rates that are then used for the design analysis in lithologies that compare to the particular field application, rather, than estimated rock/cutter behaviors.

Once the actual rock/cutter data is obtained, it is integrated into a full bit design model to determine the characteristics of the bit in actual drilling conditions. This model allows examination of the bit in a confined mode for initial design development and delivers an accurate projection of a bit’s performance (geometry, parameters and lithology variations) in a fully dynamic simulation mode representing a real drilling environment. Outputs from these simulations enable the designer to “match” the projected performance to the desired performance objectives of the bit and to help ensure that the highest degree of dynamic stability is engineered into the bit.

The IDEAS analysis engineer inputs customer-supplied BHA, lithology, hole size and other pertinent information into the simulation model and evaluates the individual bit design’s performance in the specific application under consideration. Typically, several bit designs will be evaluated.

Keep directional wells on target
It was once thought that each type of rotary steerable system or steerable motor BHA required its own individual bit design, and each bit required highly specialized directional features. The IDEAS system has helped to change this perception.

Polycrystalline diamond compact bits can now be certified as both dynamically stable and directionally responsive across a range of demanding directional applications by incorporating all system elements into the analysis. In addition, all types of rotary steerable systems can be accurately modeled individually.

The system has demonstrated that a single bit design can in fact provide exceptional drilling performance when used with a range of directional drilling system types if the bit has been designed to remain dynamically stable. Using the system to analyze conventional designs has revealed that the range of special directional features previously incorporated into a bit served as a crutch that allowed unstable bit designs to drill acceptably in a specific directional application.

However, a slightly different BHA or a different application would reveal its unstable character, requiring a new or modified bit to compensate for the inherent instability of the design under the new conditions.

Bits designed with the system are directionally certified to remain stable and to perform well with different types of steering systems in a wide range of applications. The risk of
poor performance is greatly reduced should it become necessary to change the system configuration, operating parameters or something else. Finally, experience has shown that drilling with a stable bit reduces expensive tool failures, lowers drilling costs and provides a smoother, high quality well bore.

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