This document describes HDD assist methods using pipe rammers to help with problematic horizontal directional drills. It outlines four main methods - washover casings, pullback assist, pipe extraction, and drill stem recovery. For each method it provides details on the process and equipment used as well as examples of jobs where each method helped complete challenging HDD projects.

1. HDD ASSIST METHODS
PIPE RAMMING

2. HDD RAM ASSIST
• When problems arise while
horizontal directional drilling
HDD ASSIST
(HDD) costs begin to add up with
each tick of the clock.
PIPE RAMMING
• Quick reaction time and expert
technical support are critical to
salvaging a bore gone bad.
• The percussive power of pipe
rammers can help free stuck
product pipes, drill stems, and
help remove product pipes on
failed bores.

3. FOUR METHODS
•Washover casings
HDD ASSIST
•Pull back assist
PIPE RAMMING
•Pipe extraction
•Drill stem recovery

4. WASHOVER CASING METHOD
HDD ASSIST
PIPE RAMMING
• Used as a pilot for large HDD projects • Makes a guide down hole for mud motors
• Casings are rammed through difficult soil • Casing provides a path for drill fluid
conditions to rock or solid soil recycling and reduces the loss of fluids
in surface soils

5. ON THE JOB: WASHOVER CASINGS
• Hong Kong, China
–Wash over casing
HDD ASSIST
• Pipe sizes
PIPE RAMMING
–2 – 54” casings
• Equipment
–24” Rammer
• Ram distance
–2 @ 66’

6. PULL BACK ASSIST METHOD
HDD ASSIST
PIPE RAMMING
• Assist HDD when pullback is not possible • Percussive power frees immobilized
and machine still has rotation capabilities product pipes.
• Rammer attached to product pipe

7. PULLBACK ASSIST
HDD ASSIST CONNECTION METHOD STEEL
PIPE RAMMING
Rammer is locked into steel casing via collets. Steel casing is installed using
pullback force of HDD and percussive force of the rammer.

8. PULLBACK ASSSIST
CONNECTION METHOD HDPE
(OPTION 1)
HDD ASSIST
PIPE RAMMING
Rammer is locked into steel casing via collets. The steel casing is connected to
the HDPE product pipe via steel to HDPE flange compression kit. HDD pull force
is used in conjunction with the rammer to install the pipe.

9. PULLBACK ASSIST
CONNECTION METHOD HDPE
(OPTION 2)
HDD ASSIST
PIPE RAMMING
Rammer is locked into steel casing via collets. Steel casing is welded to
steel ring that is flush with HDPE face, and welded to steel sleeve. Steel
sleeve is bolted to HDPE product pipe. HDD pull force is used in conjunction
with the rammer to install the pipe.

10. ON THE JOB: PULLBACK ASSIST
• Normangee, TX
–Pullback Assist (pipe stuck for 4
HDD ASSIST
days before start of assist)
• Reason for pullback failure –
PIPE RAMMING
excessive flooding in area
caused collapsed entry pit and
hole.
• HDD Rig
–500,000 lb pullback
• Pipe
–2,800’ of 36” casing
• Equipment
–24” Rammer

11. ON THE JOB: PULLBACK ASSIST
• Stewart, FL
–HDPE Pullback Assist, pipe sat
HDD ASSIST
for more than two weeks before
assist could be started due to
PIPE RAMMING
excessive hurricane season.
• HDD Rig
–1.2 M lb custom drill rig
• Pipe size
–4,500’ of 24” HDPE pipe 80’
deep
• Equipment
–24” Rammer

12. PIPE EXTRACTION METHOD
HDD ASSIST
PIPE RAMMING
• Remove stuck product pipe and bore • Percussive action along with static
again tension pulls product pipe, removing it
• Rammer is attached to product pipe by from the bore
fabricating an adaptor

13. PIPE EXTRACTION
HDD ASSIST CONNECTION METHOD FOR STEEL CASING
PIPE RAMMING
Rammer is locked into steel casing that is welded onto the product casing.
Static pull force is used in conjunction with the rammer to extract the product
casing.

14. PIPE EXTRACTION
HDD ASSIST CONNECTION METHOD FOR HDPE
PIPE RAMMING
Rammer is locked into steel casing that is welded onto the steel
sleeve. Steel sleeve is bolted to HDPE product pipe. Static pull force
is used in conjunction with the rammer to extract the product casing.

15. ON THE JOB: PIPE EXTRACTION
• Orlando, FL
–HDPE Pipe Extraction
HDD ASSIST
• Pipe size
PIPE RAMMING
–850’ extraction of 30” HDPE pipe
• Equipment
–16” Rammer

16. DRILL STEM RECOVERY METHOD
HDD ASSIST
PIPE RAMMING
• Recover expensive stuck drill rod • Kinetic energy is used to assist in
• Rammer is attached the to drill rod by pulling or pushing rod out of the ground
fabricating an adaptor with the assist of static tension

17. ON THE JOB: DRILL STEM RECOVERY
HDD ASSIST
PIPE RAMMING

18. RECOMMENDED HAMMERS
Calculated
Rammer Impact Rate Pipe Diameter
HDD Class Impact Force
Size BPM Range
at 1 ft/min*
HDD ASSIST
7” 24,000 lbs 295 184,000 lbs 8” – 16”
PIPE RAMMING
24,000; 33,000;
8” 223 252,000 lbs 8” – 24”
50,000 lbs
33,000; 50,000;
12” 271 744,000 lbs 12” – 36”
80,000 lbs
16” 80,000 lbs 231 1,094,000 lbs 12” – 48”
80,000;
20” 190 1,740,000 lbs 20” – 54”
150,000 lbs
150,000 lbs
24” 177 2,020,000 lbs 24” – 72”
and larger
*The numbers shown here are based on calculation and are for comparative purposes only between various models of HammerHead
Rammers. The numbers are not intended for engineering applications.

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