Abstract

In the search for oil and gas, the Petroleum Industry has been forced to explore in remote regions of the world where river navigation is limited and where few or no roads exist. Conoco's 6500 km² Mahato Mandian Contract Area in the central part of Sumatra, Indonesia is such a region. When Conoco first started planning an exploratory drilling program, a high cost helirig operation seemed inevitable. It appeared that the drilling rig would have to be moved and supported by helicopters. At that time there were less than 200 km of existing public roads, mostly on the outer edges of the block, and scattered logging roads in the central and northern areas. The one navigable river was accessible only by small barges (25' × 85' × 7') and shallow draft river tugs to a point about 100 km from some of the drilling prospects. The area has a variety of terrain including steep sided mountain forests, gentle rolling hills, grasslands, heavily forested tropical jungle, lowlands, and swamps.

In this setting an infrastructure was successfully built for supporting a 12-well drilling campaign that included base and staging camps, a communication system, marine and aviation support, material and equipment procurement, and a 400 km road system which allowed the drilling rig, heavy equipment and all supplies to be moved by road from the barge offloading point to the various drill sites. To accomplish this, 145 km of old roads were upgraded to permit heavy oilfield traffic (45 tons), and 255 km of new roads along with 53 bridges (spans ranging from 30' to 270'), and one ferry were constructed. All work was completed within the original cost estimates and at less expense than would have been incurred for a helirig operation.

In addition to building a successful infrastructure, an extensive road network was left in the area for public use.