Using Sonic MWD to Predict CPT Values-PPT Presentation

PPT Presentation

Pdf Summary

The presentation explores using Sonic Measurement While Drilling (MWD) data to estimate Cone Penetration Test (CPT) values, particularly where CPT rigs cannot operate. Sonic drilling uses counter-rotating masses to generate vertical vibration, helping reduce resistance along the drill string and improve drilling efficiency.<br /><br />Sonic MWD records variables such as frequency, pressure, harmonics, vibration, resonance, and drilling parameters. These measurements may reveal soil and rock properties, including through accelerometer signals: distortion and noise differ with the mechanical characteristics of the material.<br /><br />A random forest classification model identified soil classes with 92% accuracy. The presentation also describes random forest regression models for predicting CPT tip resistance, sleeve friction, and pore water pressure. Reported R² values were 0.96, 0.86, and 0.93, respectively. Sonic frequency was the most influential predictor, followed by flushing pressure and sonic pressure.<br /><br />The main challenge is that CPT measurements are highly standardized, while Sonic MWD data are multivariate and can vary with geology, drilling methods, equipment, and tooling. Future work will expand the data across more geological settings and drilling configurations, while developing the modelling approach incrementally. The presenters also note that their views are their own and that DFI does not guarantee the information’s accuracy or endorse its recommendations.

Keywords

Sonic MWD

Cone Penetration Test

CPT estimation

random forest

soil classification

tip resistance

sleeve friction

pore water pressure

drilling parameters

geotechnical data