WEB EXCLUSIVE: Dubai's Waterfront calls in Sandvik rigs
24 February 2009
Tophammer drill rigs from Sandvik being used in a dewatering well project at the Dubai Waterfront construction site are achieving faster penetration rates in sand than conventional methods, according to the company.
Contractors have achieved drilling rates of up to 540 m per shift using Sandvik's Ranger 780 Rock Pilot drill rigs and tools at the project in the Jebel Ali district of Dubai, United Arab Emirates (UAE).
The two contractors are using the equipment to drill 6 m deep holes in compacted sand at 1 m spacing for a dewatering system and are producing up to 90 holes each shift.
The Waterfront, intended to be the world's largest man-made development, will extend Dubai's coastal line by 820 km, which is 12 times the current length, and will cover an area of more than 81 million m².
Design and planning for the first five phases of Dubai Waterfront is now complete, with major infrastructure taking place on the first phase - Madinat Al Arab. This includes construction of the 8 km long Palm Cove canal running parallel with the Emirate's coastline.
The Sandvik rigs are currently being used to prepare dewatering wells to allow construction of 3 to 4 m sewer pipeline trenches in the first residential areas off the Palm Cove canal.
According to Jukka Naapuri, general manager for Sandvik Mining and Construction in the Middle East, the concept, although not particularly new, has not often been utilised in the UAE. But, he added, with the sharp increase in dewatering requirements on major projects, such as the Waterfront, the two contractors recognised the potential.
"Advances in Sandvik's hydraulic control system over recent years have also been a factor in using this technique," he added. "The system is able to sense strata changes when drilling and is able to react to different layers of sand and mud much faster."
Experienced Sandvik rig operator, Rodolfo Bumatay, said the flushing system plays a key role in the sand, activating if the drilling is too fast.
"Similarly it is important to observe the flushing pressure to avoid jamming so drilling must be done in a controlled way," he added.
The Ranger 780 Rock Pilot is fitted with 3.66 m long Sandvik T51 rods and 102 mm Retrac button bits. The bits feature a ballistic button design to provide fast penetration and better flushing, Sandvik said.
The Waterfront city has two main components, the mainland covering a 13 km x 7.5 km area and the Waterfront Islands - a six island archipelago stretching 15 km into the Gulf and covering a combined area of 2300 ha. On completion the city will house 1.5 million people.
