Deviated wells are normally drilled using a steerable system which is a combination of bent sub, motor and MWD allowing both rotary drilling and sliding without tripping for directional changes.
Bottom Hole Assembly
Generally the BHA shall comprise:
- tri-cone bit / PBC bits
- straight housing motor (low torque)
- bent sub
- non-magnetic drill collar
- drill collars (as required for WOB at inclination)
- drilling jar
Provisional bottomhole assemblies are generally recommended by the Directional Drilling Contractor as . . .