Work in Perdido Development Completed

The Perdido Development, located approximately 200 miles south of Freeport, Texas, is operated by Shell on behalf of partners Chevron and BP.

A regional Direct Vertical Access (DVA) host spar in Alaminos Canyon 857 will be the central processing center for various subsea tiebacks.  Perdido comprises three main development fields:  Great White, Silvertip, and Tobago.  The regional DVA spar will be the deepest drilling and production facility in the world and the first of its kind in the ultra deepwater of the Gulf of Mexico.

The Marine Construction Survey Division of Fugro Chance installed, calibrated, and operated a Wideband Medium Frequency (MF) acoustic positioning system providing high-accuracy subsea positioning and depth control for a 23-well batch installation and a five-well separation and boosting system (SBS) at the Perdido host DVA site.

The rapid update rate from the Wideband MF digiquartz Compatts provided for real-time depth monitoring during the well casing jetting operations.  This helped mitigate the well batch installation with both positional and height datum tolerances being met.

To optimize keel joint length, riser design, construction and drilling rig riser configuration time, the tops of all casings were required to be installed to the same datum with a tolerance of +/- one foot.  The initial casing was installed using depths corrected to the site-specific datum and the remaining casings were installed using relative depth measurements with the first casing as the benchmark.

Following installation, a high accuracy, precise digiquartz depth loop over all 23 wells was attained.  Results show that the depth for all wells ranged within a window of only one foot.