Equatorial Guinea LNG

In 2007, Bechtel completed a liquefied natural gas project on Equatorial Guinea's Bioko Island off the west coast of Africa.

The project is the one in a string of plants Bechtel has built to help meet surging demand for LNG—a highly compressed liquid form of natural gas that can be shipped economically in ocean tankers to distant markets (see Detail Design). It includes everything needed to compress, cool, and liquefy gas from a nearby field to minus 160 degrees Celsius, along with refrigerated tanks to store it and marine shipping facilities. The project will supply at least 3.4 million tonnes of energy to the market each year. As with Bechtel’s LNG projects in Australia, Egypt, and Trinidad, this one uses the industry-leading processing technology developed by ConocoPhillips.

Bechtel's team on Bioko has faced a unique construction challenge: The work site is elevated 60 meters above the ocean, so cryogenic pipes from the inland plant have to cross dense, sloped rain forest to get to the ocean jetty where the LNG will be loaded onto tankers.

The team members considered cutting through vegetation all the way down the slope and building a pipe-rack structure directly over it, but the moist, unstable soil and steep grade changes would have made construction unpredictable and dangerous. Instead, they decided to build a 350-meter steel suspension bridge connected by one onshore and one marine tower. The bridge carries 76-centimeter-diameter export and vapor return pipelines and utilities, and there is a walkway from the top of the bridge down to the LNG loading platform. To design the bridge—the first of its kind—Bechtel chose a contractor that also worked on Bechtel’s Tacoma Narrows Bridge project in Washington state.