The Heidrun Field - Development Overview

Heidrun, an oil and gas field lying in 345 meters of water off the coast of Norway, has been developed using the world`s first concrete Tension Leg Platform (TLP). The TLP substructure, comprised of the Hull and Module Support Beams (MSB`s) is built of high strength lightweight aggregative concrete. The MSB concept eliminated the need for a module support frame and enabled the modules to be mat3ed with the substructure by ballasting and deballasting, without the use of expensive heavy lift vessels. The TLP topsides consists of five main modules and a drilling rig. The design concept of these large modules as self contained elements enabled them to be pre-commissioned to a large extent at the fabrication yards, prior to load out. Sixteen tubular steel Tethers anchor the platform to four concrete Foundations on the seabed. These Foundations were towed to the field and lowered into position by ballasting, again without the use of heavy lift vessels. Installation of a subsea Well Template enabled the first wells to be pre-drilled and pre-completed before the platform was towed to the field, enabling an early production start after platform installation. Two oil export pipelines and one gas export line were completed onshoremore » then wet towed to the field using the controlled depth tow method. Titanium is used for the platform Drilling Riser, providing the same strength as conventional materials but with considerable weight savings. Produced oil from Heidrun is offloaded directly into shuttle tankers, without intermediate storage, using the innovative Submerged Turret Loading technology.« less