Conductor pipe (also called drive pipe, structural pipe, or conductor casing) is the first and largest-diameter casing string installed in a well. It is set before the rig moves on location (or immediately after spudding for offshore wells) and serves as the structural foundation for the entire wellhead and subsequent casing strings.
Conductor pipe is not an afterthought. It carries the weight of all subsequent casing strings, the wellhead, the BOP stack during drilling, and the Christmas tree during production. A failed conductor means a failed well.
Conductor Pipe Functions
Function
Description
Structural Support
Transfers the weight of the wellhead, BOP, and all hung casing strings to the formation or seabed
Hole Stability
Prevents unconsolidated surface formations (gravel, sand, clay) from collapsing into the wellbore during top-hole drilling
Fluid Returns
Provides a conduit for drilling fluid returns to the surface during drilling of the next hole section
Lost Circulation Prevention
Isolates shallow, highly permeable or fractured zones that would otherwise take drilling fluid
Shallow Gas Isolation
Provides a barrier against shallow gas hazards encountered near the surface
Wellhead Foundation
Provides the landing shoulder and connection for the surface casing head housing
Conductor Pipe Types
Onshore Conductors
Installation Method
Description
Typical Size
Depth
Driven / Hammered Conductor
Piled into the ground with a diesel or hydraulic hammer. No hole pre-drilled
16″ to 30″ OD
30 – 100 ft (10 – 30m)
Drilled & Cemented Conductor
A hole is drilled, the conductor is run, and cement is pumped around the annulus
20″ to 36″ OD
50 – 300 ft (15 – 90m)
Augered Conductor
A large-diameter auger bores the hole. Conductor is placed and backfilled
24″ to 48″ OD
20 – 80 ft (6 – 25m)
Offshore Conductors
Installation Method
Description
Typical Size
Depth
Jetted Conductor
Water is pumped through the conductor while it is lowered. Sediment is fluidized and displaced, allowing the conductor to sink under its own weight
26″ to 36″ OD
100 – 400 ft (30 – 120m) below mudline
Drilled & Cemented
Hole is drilled from a jack-up rig or drillship. Conductor run and cemented
30″ to 42″ OD
Varies. Can be hundreds of feet
Piled Conductor
Driven with hydraulic hammer from a barge or rig
24″ to 48″ OD
Varies by soil conditions
Suction Installed
Conductor base is sealed, water is pumped out creating suction that pulls it into the seabed
30″ to 60″ OD
Used in soft seabed conditions
Conductor Pipe Specifications
Parameter
Typical Range
Outside Diameter
16″ to 48″ (406 mm to 1,219 mm). Larger possible for special applications
Wall Thickness
0.375″ to 1.000″ (9.5 mm to 25.4 mm). Thicker wall for driven conductors due to hammer stresses
Length
40 ft joints typical. Shorter for driven (20 ft) due to mast clearance
