Jade

Jade Oil and Gas Project Profile

Location and Geology

• The Jade oil and gas field is located in block 30/2c of the UK North Sea, approximately 17.7 kilometers north of the Judy project.

Discovery and Appraisal

• The field was discovered in 1996 and confirmed by an appraisal well in early 1997. Two appraisal wells were drilled, with one completed as a producer and the other for cuttings injection.

Production Characteristics

• The field tested at a combined rate of 91 million cubic feet of gas per day and 9,700 barrels of condensate per day. The production plateau rate is approximately 188 million cubic feet of gas per day and 16,000 barrels per day (bpd).
• The field produces a light paraffinic condensate with a 3.0% CO2 content and 25 parts per million (ppm) of H2S. The wax content ranges from 19.1wt% to 23.8wt%, with a wax cloud point of 50°C and a dead oil pour point of 12°C.

Development and Operations

• The field was developed by a normally unattended installation tied back to the Judy platform. Three additional wells were drilled over the platform using the harsh environment, deepwater jack-up Galaxy II in cantilever mode. The field came onstream in 2002.
• As of 2008, the field was producing from seven wells. The aggregate production from the Jade field, along with Judy and Joanne, was 336 million standard cubic feet per day (Mmsfcd) and 26,900 barrels of oil per day (bopd).

Platform Design and Infrastructure

• The Jade platform features a three-deck structure comprising a weather deck, mezzanine deck, and main deck, measuring 45m x 35m with an 8m vertical separation between decks. The topsides were built by Heerema in Hartlepool and have a lift weight of 2,000t and a gross-operating weight of 4,700t.
• Safety features include a blast wall separating the wellhead from the utility area and another blast/firewall on the accommodation unit. There is also a fire pump and a TEMPSC lifeboat. Power is provided by dedicated packaged diesel generator sets located on the outside of the platform for easy access.
• Platform access is via an aluminum helideck, and operations are assisted by a pedestal crane with a 36t lift capacity. The topsides and piping are fully pressure-rated to accommodate a 160°C flowing wellhead temperature and an 11,000psi wellhead-design shut-in pressure.

Pipeline and Transportation

• The Jade field is linked to the Judy platform via a 16in pressure-containment pipe in a 20in carrier pipe. To avoid pipeline expansion from heat, eight loops are installed with straight sections buried between the sites.
• Gas is transported through the CATS pipeline to the CATS terminal in Teesside, while oil is taken through the Norpipe pipeline to the Phillips Seal Sands terminal.

Ownership and Partners

• ConocoPhillips is the operator of the Jade field, holding a 32.5% interest. The co-venturers include BG (35%), Texaco (19.93%), Agip (7%), and OMV (5.57%).

Design and Engineering

• Amec carried out the detailed design as an extension of the conceptual design. The Jade platform has a design life of 20 years.