Stratigraphic identification using real-time drilling data

Abstract

Identification of stratigraphic interfaces and lithology is a key aspect in geological and geotechnical investigations. In this study, a monitoring while-drilling system was developed, along with a corresponding data pre-processing method. The method can handle invalid drilling data generated during manual operations. The correlation between various drilling parameters was analyzed, and a database of stratigraphic interfaces and key lithology identification based on the monitoring parameters was established. The average drilling speed was found to be the most suitable parameter for stratigraphic and lithology identification, and when the average drilling speed varied over a wide range, it corresponded to a stratigraphic interface. The average drilling speeds in sandy mudstone and sandstone strata were in the ranges of 0.1–0.2 m/min and 0.2–0.29 m/min, respectively. The results obtained using the present method were consistent with geotechnical survey results. The proposed method can be used for real-time lithology identification and represents a novel approach for intelligent geotechnical surveying.

Keywords

• Monitoring while-drilling
• Drilling parameters
• Geotechnical stratigraphy
• Lithology identification