While many of us were putting Christmas trees up in our homes in December, BG Group was working with Petrobras to install the first Wet Christmas Tree (WCT) by using a vessel and cables, as opposed to rig, in the JV pre-salt Santos area, offshore Brazil.

A WCT is a device installed at the wellhead comprising a series of remotely operated valves to safely control the flow of fluids (oil, water and gas) from the reservoirs to the surface.

The WCT was installed in the well 7-SPH-2-SPS, in the Sapinhoá field, Santos Basin, at water depth of 2,130 metres.

"BG Group has strongly supported the development and implementation of this new technology in Santos field deepwater", said Shaun Hancock, VP Well Engineering in Brazil, "by providing technical studies and supporting the contracting of a second vessel, which is expected to start operations in mid-2016."

Substantial time savings

Andre Pinheiro, Principal Completion Engineer at BG Brasil. "It took less than two and a half days to install the first Wet Christmas Tree; including navigation time, the total time per well is around four and a half days, compared to 15 days using a Drillship Rig. This generates an approximate saving of $8 million per well using this new technique," he added.

The installation of the WCT and Production Base (BAP) on wire from the same vessel started in Brazil back in 2009 at the Petobras-owned field in the Espirito Santo Basin, said Shaun. "Due to deeper water challenges in our pre-salt fields, it has taken a few years to develop this technology for Santos environment."

"By the end of 2016, Petrobras expects most of Santos basin subsea Christmas trees and production adapter bases to be installed by cable," confirmed Shaun.