Page 48 - Trenchless Technology Piping Installation and Inspection

New Pipeline Installations 21

Nonmagnetic
drill collar Drill bit

Orientation sub

FIGURE 1.14 HDD step 1: Pilot-hole drilling. (Source: Mears.)

Reamer
Drill pipe

Drill pipe
FIGURE 1.15 HDD step 2: Prereaming. (Source: Mears.)

Reamer Pullhead

Pipe
Swivel
FIGURE 1.16 HDD step 3: Product-pipe pullback. (Source: Mears.)