Thunder Horse oil field, located approximately 240km off the south-eastern coast of New Orleans, US, is one of the biggest producing fields in the deepwater Gulf of Mexico.

The offshore field is operated by BP, which holds 75% equity interest, and the remaining 25% is owned by ExxonMobil.

Brought on stream in June 2008, the Thunder Horse project comprised the simultaneous development of two adjacent fields, namely Thunder Horse North and Thunder Horse South.

Thunder Horse is considered to be the world’s first major high-pressure, high-temperature subsea project.

The Thunder Horse South Expansion project completed in December 2016 and the Thunder Horse Northwest Expansion project completed in October 2018 further boosted the field’s production capacity by 50,000 barrels of oil equivalent per day (boe/d) and 30,000boe/d, respectively.

The Thunder Horse field has the capacity to produce 250,000 barrels of oil along with 200 million cubic feet (mcf) of gas a day.

Thunder Horse oil field discovery and development history

Situated in deepwater Gulf of Mexico at a water depth of 6,000ft in Mississippi Canyon Block 776, 777 and 778 in the Boarshead Basin, the Thunder Horse oil field was discovered in July 1999.

It is one of the biggest deepwater oil field discoveries in the Gulf of Mexico. Lying 6,000m beneath the seabed, the reservoir for the offshore oil field comprises Upper Miocene turbidite sandstones.

Production from the offshore field was delayed until 2008, as the project development was affected due to the Dennis Hurricane in 2005.

Thunder Horse production infrastructure details

The Thunder Horse oil field was developed with 25 wet-tree subsea wells tied back to a semi-submersible production and drilling quarter (PDQ) facility.

Moored at a water depth of 6,050ft, the PDQ facility consists of three production/utility modules for production, compression and power generation. The lift weight of the topside modules is 21,000t. The topside modules were fabricated by J Ray McDermott in Morgan City, Louisiana.

The semi-submersible facility is designed to process 250,000 barrels of oil and 200 million metric cubic feet (Mmcf) of gas a day.

The hull of the facility weighs 60,000t, and consists of two 22mx26mx36m columns and two 22mx23mx36m columns connected by 11.5m pontoons. The 15,000m³ hull was built by Daewoo Shipbuilding at its Okpo yard in South Korea.

The Thunder Horse PDQ has also the capacity to treat approximately 140,000 barrels of produced water a day and inject up to  300,000 barrels of water a day for reservoir support.

The PDQ also houses 90MW power generation facility and living quarters for 298 persons.

Thunder Horse South expansion details

The Thunder Horse South expansion project, which was completed in December 2016, involved the installation of a new subsea production system and the drilling and tying-back of four new oil production wells to the existing Thunder Horse platform through two new 11,000ft production flowlines.

The new subsea production system is located approximately 3.2km south to the Thunder Horse platform.

Thunder Horse Northwest expansion details

Brought into production in October 2018, the Thunder Horse Northwest expansion project increased the production capacity of the field by 30,000boe/d.

The expansion project involved tying two new production wells into existing flowlines approximately 3.2km north of the Thunder Horse platform and the installation of a new two-slot subsea manifold.

Oil and gas supply from the Thunder Horse field

The oil from the Thunder Horse field is supplied to Louisiana’s oil markets via Proteus and Endymion pipelines of the Mardi Gras Transportation System operated by BP, whereas the processed gas is transported by Okeanos and Destin pipeline systems.

The 112km-long Proteus pipeline supplies oil from the Thunder Horse platform to the booster station located at South Pass Block 89, Louisiana coast.

The Endymion pipeline further supplies the oil to the Louisiana Offshore Oil Port (LOOP) storage and offloading facilities.

The LOOP facility has a dedicated storage and offloading capacity for 1.8 million barrels of Thunder Horse oil. It supplies oil to the refineries in Texas, Louisiana, and other Midwest countries via Norco, Equilon, Locap and CAM pipeline system.

Contractors involved

FMC Technologies (now Technip) and Heerema Marine Contractors were the main subsea contractors for the Thunder Horse oil field development project.

GVA, a wholly-owned subsidiary of KBR, provided the front-end engineering and design (FEED) for the Thunder Horse semi-submersible processing and drilling facility.

The topside of the PDQ was constructed by J Ray McDermott, whereas Daewoo Shipbuilding and Marine Engineering constructed the hull of the PDQ.

Technip was contracted in May 2015 for the design, engineering, fabrication, installation, and pre-commissioning of the new production pipeline systems associated with the Thunder Horse South expansion project.