World’s first subsea DAS system installed in Gulf of Mexico

Silixa has completed the installation, validation, and operation of what is said to be the world’s first subsea Distributed Acoustic Sensing (DAS) system.

Silixa concluded the installation, validation, and borehole seismic acquisition from a permanently installed fiber-optic DAS system Carina Subsea 4D on BP’s Atlantis Phase 3 subsea field development in the Gulf of Mexico.

The development includes a new subsea production system with eight new wells tied into the current Atlantis platform, 150 miles south of New Orleans.

The Carina Subsea system has been installed in two wells, and installation is continuing over the rest of the field.

According to Silixa, a zero offset DAS VSP was acquired to validate coupling and signal-to-noise characteristics and showed excellent data quality. Subsequent production noise recordings showed little impact even though there was significant production occurring.

“Until now, subsea fields had to rely on sparse data acquisition due to the risk and cost of acquisition,” said Garth Naldrett, Silixa’s chief product officer. “Bringing our engineered distributed fibre optic sensing technology to subsea wells and allowing the same data acquisition we have already enabled on land and platform wells will have a tremendous impact on the industry.”

The system is the world’s first permanent in-well seismic acquisition system for subsea wells, the UK company said.

It can operate independently or provide complementary data to ocean bottom node surveys and is said to be especially effective for reservoirs that are traditionally difficult to image using surface seismic such as pre-salt reservoirs or those beneath gas clouds.