Caliper approximate estimation using ECD

Correcting for ECD: The ECD reading accounts for both the hydrostatic pressure and the frictional losses. By knowing the measured ECD and the parameters affecting frictional losses, the hole size can be estimated using the relationship:

This approach provides a basic estimate for hole size based on the available Annular Pressure While Drilling (APWD) data. However, for higher accuracy, especially in complex well geometries or deviated wells, a more detailed modeling approach or empirical calibration of the relationship between ECD, ESD, and hole diameter may be required.

In summary, estimating hole caliper using APWD services requires a combination of direct measurement tools (e.g., caliper logs, ultrasonic tools) and advanced data analytics that interpret real-time drilling data and integrate multiple sources of information to estimate the hole diameter accurately.