Surface drilling parameters provide clues as to what the drilling condition is downhole, but they cannot tell the whole story. Drilling dynamics allows us to see the downhole effects of surface parameter changes. This allows for optimization of the drilling process, maximizing rate of penetration (ROP), and enabling mitigation of conditions that end runs prematurely. Drilling dynamics consists of downhole weight-on-bit, downhole torque-on-bit, bend on bit and RPM.
Benefits
Stick Slip Index is derived from downhole RPM, providing surface warning about destructive torsional vibrations
Bending moment allows for identification of backwards whirl – the most destructive of the shock & vibration modes
A direct measurement of downhole weight on bit allows for surface weight to be optimized, preventing over-stacking of surface weight that can break free and damage the mud motor and bit
Bending moment allows for calculation of effective dogleg severity to identify problematic casing areas and stressed drill collar connections
Downhole torque helps identify formation changes and diagnose bit and ROP problems
Assess the motors ability to transfer power to the formations through monitoring of downhole torque variance