An American Auger DD8 horizontal directional drilling (HDD) rig and a Grundoram Taurus were used on the project. The Grundoram was used to assist in the pipe pulling because the pipe was too big for the DD8 rig and ground conditions were difficult to stabilise.
The rig was set up 40 m back from the point of intersection (PI). The Gulf British Drilling crew had to take into consideration the cables present in the ground. The crew used a mixture of bentonite, soda ash and sweet water to remove the sand from the bore.
The pilot bore was drilled down to the PI at 6 m depth and level angle, the drilled head was then thrust through the ground maintaining a horizontal line until it reached the exit pit. The drill head was then removed and fly-cutter type reamers were attached while drill pipe was added to the rear of the reamer to ensure the crew did not lose the bore.
Once the crew were satisfied with the bore hole, a decision to pull the product pipe was made following inspection by Aramco personnel. A 70 m long trench was dug to allow the product pipe to be pulled straight through. The Grundoram was attached to the rear of the pipe as the rig pressures increased. Good communication between Ram and HDD operators was essential so the ramming was performed at the same speed as the pull. The 60 m product pipe took four hours to install.



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