Steel jacket moving to Mariner field off UK

A core unit in the development of Mariner heavy oil field is moving to location on the East Shetland Platform of the UK North Sea about 150 km east of the Shetland Islands (OGJ Online, Jan. 14, 2015).

The 22,400-tonne steel jacket for the Mariner A production, drilling, and quarters platform left the Dragados yard in Cadiz, Spain, on Aug. 10, reports Statoil, the operator.

The 1,835-nautical-mile trip to the field, on Block 9/11a, is expected to take 2 weeks. Installation of the topsides, being built by Daewoo Shipbuilding & Marine Engineering Co. Ltd., is due next year. Water depth is about 105 m.

Statoil expects production to begin in 2017 from two reservoirs, which together hold reserves of 250 million bbl. The field will produce into a ship-shaped floating storage and offloading unit at a plateau rate of 55,000 b/d.

The Paleocene Maureen formation, at 1,492 m, holds 14.2° gravity oil with viscosity of 67 cp at reservoir conditions. Oil in the Paleocene Heimdal reservoir, at 1,227 m, is 12.1° gravity and 508 cp.

Drilling to 130 subsurface targets for production or injection will occur from the platform under a contract to Odfjell Drilling and from a Noble Corp. jack up rig under construction. It will involve multibranch technology, sidetracks, and reuse of slots.

Statoil holds a 65.11% interest in the project. JX Nippon Exploration & Production (UK) Ltd. holds 28.79%, and Dyas Mariner Ltd. holds 6%.