Overview
EN ISO 22476-15:2016 - Measuring while drilling (MWD) defines the technical principles for recording and reporting drilling machine parameters during geotechnical investigation drilling. Adopted by CEN as EN ISO 22476-15:2016, this standard applies to top-driven, fully hydraulically powered drill rigs using destructive drilling methods (and can also be applied to core drilling). It establishes requirements for instrumentation, execution, data logging and reporting of drilling parameters used for geotechnical purposes. The standard excludes parameter recording during soil grouting and the drilling of nails, anchors or piles.
Key topics and technical requirements
- Equipment and sensors: requirements for drilling equipment and MWD systems including sensors for hydraulic pressures, penetration length, flushing-medium flow, rotational speed, hammering energy, reflected vibrations and timekeeping.
- Selection of measured parameters: guidance on which drilling parameters to monitor depending on method and objectives.
- Execution and procedures: recommended positioning and leveling of the rig, preparation of measurements, drilling procedure, frequency of logging and registration of penetration length.
- Calibration and checks: equipment checks, calibration and verification procedures to ensure data quality.
- Calculated parameters: definition and computation of derived values such as penetration rate, (net) down-thrust pressure, flushing pressure and drill-head torque.
- Reporting and presentation: standardized reporting requirements, graphical presentation of drilling parameters (illustrated in Annex B) and interpretation guidance (Annex A).
- Factors influencing results: considerations for tool, rig and operator influences on recorded data and how results are relative to test conditions.
Practical applications and users
- Who uses it: geotechnical engineers, site investigation teams, drilling contractors, instrumentation specialists, geotechnical consultants and laboratory analysts.
- Typical applications:
- Real-time monitoring of drilling performance during site investigations.
- Correlation of drilling parameters with soil/rock sampling and geophysical logs.
- Quality control and diagnostic assessment of drilling operations.
- Input for design and construction of foundations, earthworks, tunnels and underground works.
- Benefits: improves data consistency, enables automated logging and post-processing, aids interpretation of subsurface conditions and enhances traceability and QA/QC of investigation drilling.
Related standards
- Part of the ISO 22476 series on geotechnical field testing; EN ISO 22476-15:2016 is the CEN-endorsed version. For complete field-testing programs, use this part alongside other relevant geotechnical investigation standards (other parts of ISO 22476) and local/national drilling practice standards.
