ABUJA, Nigeria -- A float-over installation done on the Chevron-operated Escravos Gas Project 3A offshore Nigeria is being viewed as a trend for future installations in the area. "I believe we will see more projects like this," said Duane Simmons, Chevron Nigeria Ltd. Simmons spoke to an audience at Offshore West Africa on Jan. 29.
"The float-over method was used on this project because of cost and technical reasons," Simmons said. "And this type of installation method is becoming increasingly attractive as heavy-lift vessels are scarce and it's proven effective in shallow water." According to Simmons, 40 float-over installations have been done worldwide; four in Nigeria.
Float-over installation for Escravos was selected during the project appraisal phase, Simmons said. The topside installation was carried out within a 12-hour window. The float-over system fitted with eight jacks raised the 2,000-metric ton (2,205-ton) topside 2.2 m (7.2 ft). The jacks subsequently retracted and the topside was positioned on the jacket fixed in 8.7 m (28.5 ft) of water. The project was completed in 2Q 2007.
While the float-over installation was effective and cost-efficient, the most important component of Escravos is that it will eliminate gas flaring and monetize the associate gas in OML 90, according to Simmons. Phase 3A has capacity to compress and dehydrate 70 MMcf/d of natural gas.