Drilling Systems Modeling & Automation, Part 4: Using Simulation to Optimize System Performance

Simulation studies performed on a digital twin aid in exploring the limits of equipment and allow for control strategies to be optimized for common scenarios or prevent hazardous conditions. In this case, we want to ensure safe operation by preventing the ‘crown out’ and ‘floor out’ of the travelling block on the drilling rig.

Safe operation with maximum speed is ensured by maintaining process parameters within operational constraints, expressed by the design space. This design space can be obtained through multiple parallel simulations. Specifically, the model is simulated by varying the values of top drive speed and load. Once the corresponding distances of the travelling block from the top or bottom are obtained, we investigate the design space through visualizations. By doing this, we learn about the infeasible operational areas i.e. the parameter values that are impractical because they lie outside the torque-speed curve of the drive.

We then incorporate these values into the control logic through a look-up table to enforce operator limits. The result is a much safer (and optimized) operation of the travelling block on a drilling rig. This optimized lookup table allows operators to control the drawworks at the maximum possible speed given top-drive load and drum-spool position. This allows maximum speed given safety requirements.

This entire workflow is demonstrated using MATLAB and Simulink which provide several in-built functions and interactive tools to easily check for diagnostics and explore the design space using parallel computing.

Additional Resources:

- MATLAB for the Oil and Gas Industry: https://bit.ly/2FZqYXh - Simulator codes on File Exchange: https://bit.ly/31uCQZO - Simulator codes on GitHub: https://github.com/jonlesage/Drawwork...