Life Time Watch of Valhall Reservoir Started

The world's first field wide permanent seismic array is now installed at the Valhall Field offshore Norway.More than 120 km of seismic cables are in place one meter below the seabed. The work was completed on August 29th following 9 weeks of work, on schedule and with no safety incidents. All of the 10,000 receiving channels have been tested and are active.

The next stage will be to start data acquisition using the standby vessel Ocean Flower, equipped with seismic air gun. The first of 50,000 pops (air gun shots) were fired at lunchtime Sunday August 31st which proves that the system is fully operational. 15 days of continuous activity are needed to cover the shooting area of 140 square kilometers. The entire data acquisition work is managed from the vessel and the data is immediately transferred to shore via fiber optic cable. Personnel from OyO, the manufacturer of the system, are in place in the onshore operations center to monitor the dataflow. The data-processing contractor PGS has four people working in-house with BP on construction of 3D images.

The next survey will be acquired towards the end of the year, and new images are then constructed and compared with the previous, to detect changes induced by production The first 3D images are expected by Christmas while the 4D images, the difference between the two first 3D snapshots of the reservoir, are expected by April next year.