Dando has recently supplied two Watertec 9000 rigs to the Indonesian Department of Public Works and Housing for rural water supply and irrigation around the country.
Featuring the RH11 rotary head which can produce up to 1250Nm of torque or 750rpm, the rigs have the power to turn large diameter drill bits with confidence in a variety of geologies from the relatively small platform of a 4×4 truck. The head has a 3.6m stroke which allows the use of 3m drill rods while keeping the overall length of the rig down when the on the move. With 10,000kgf of pullback the Watertec 9000 is capable of considerably greater depths with 4 1/2” drill rod than the 300m required by the Public Works Department.
The Department of Public Works manages ground water all over the archipelago’s 18,000 islands. The two rigs supplied this year are destined for the Solo Bengawan river area in central Java and the island of Lombok. Though geologically different, both areas typically require wells drilled to between 200-300 metres with a final drilled borehole diameter of 12 inches. Both units employ a reaming method for their boreholes, drilling a pilot hole to depth at 8” to check the viability of the well, and then opening the hole up to 12”. A 17” diameter bit is then sometimes used from the surface to partway down the borehole in order to house larger pumping equipment that is available locally. The reaming method reduces the overall cost of drilling in the event that a suitable aquifer is not encountered. This is particularly problematic in parts of both Java and Lombok island where water assets are not always well mapped.
The local drillers are not familiar with air drilling techniques and, given the locations in which the rigs are being used, prefer a smaller truck mounted unit which is possible without the additional space required for a compressor. This allows the drill team to navigate the narrow lanes and tracks often present on the islands to reach the drill site.
The Indonesian Public Works Department conducted a thorough tender process before deciding on the Dando rigs. Bapak Iwan Januar, a consultant on the tender, explains the choice: “Drilling in Indonesia we face a number of difficulties. Access to the site, the geology, availability of resources and services, and the skill and experience of the drillers are often unpredictable.
“We required a powerful rig for mud drilling on a smaller footprint than other manufacturers could supply. Dando were willing to build the exact rig we required and spent many months discussing the specification until we had the perfect solution. We are delighted with the results.”
Dando has previously supplied 18 trailer mounted Watertec 9000s to the Indonesian army for supplying water to its army bases across the country and, with a history of over 40 years supplying equipment to the region, is quickly becoming recognised as the manufacturer of choice.