Functions and Components of a Drillstring in Oil Drilling

Classified in Technology

Written at on English with a size of 1.76 KB.

Functions of the Drillstring:

  • Transmits rotation to the drillbit
  • Exerts weight on the bit; the compressive force necessary to break the rock
  • Guides and controls the trajectory of the bit
  • Allows fluid circulation for cooling and cleaning

Components of the Drillstring:

  • Drillpipe
  • Drillcollars
  • Accessories including:
  • Heavy-walled drillpipe (HWDP)
  • Stabilisers
  • Reamers
  • Directional control equipment

The Kelly:

  • Transmits rotation and weight-on-bit to the drillbit
  • Supports the weight of the drillstring
  • Connects the swivel to the uppermost length of drillpipe
  • Transmits drilling fluid from the swivel into the drill string

The Top Drive:

A combined rotary table and Kelly mounted on the rig's swivel, assisting in pipe handling during operations.

Drilling Problems:

  • Pipe Sticking
  • Lost Circulation
  • Hole Deviation
  • Pipe Failures
  • Borehole Instability
  • Mud Contamination
  • Formation Damage
  • Hole Cleaning

Mechanical Sticking Causes:

  • Hole pack off or bridging
  • Settled Cuttings
  • Shale Instability
  • Fractured Rocks
  • Key Seating
  • Undergauge Hole

Total Losses:

  • Maintain proper mud weight
  • Minimize annular friction pressure
  • Maintain adequate hole cleaning
  • Set casing to protect weaker formations
  • Treat mud with lost circulation materials if anticipated

If Losses Occur:

  • Pump lost circulation materials in the mud
  • Seal the zone with cement or other blockers
  • Set casing Dry drill (clear water)

Entradas relacionadas: