AUTODRILLER SYSTEM

摘要

An autodriller provides an automatic self calibration system to predict both axial and rotational friction coefficients from the surface measurements such as hookload and surface torque while a drill bit is off bottom. The friction coefficients are used to calculate the friction forces between drillstring and the wellbore while the bit is on bottom during drilling operation to estimate downhole weight on the bit and bit torque, and use the estimates to alter the drilling process.

主权项

1. A method of drilling a formation, the method comprising:
drilling the formation with a drilling system that includes a drillstring and a bit; estimating a friction force on the drillstring; estimating a downhole weight on bit using a surface measurement and the estimated friction force; and taking an action to change drilling of the formation based on estimated downhole weight on bit.