N. Thunder Horse (MC776) - BP

Location

The North Thunder Horse field is located in the Mississippi Canyon area of the Gulf of Mexico, approximately 5 miles northwest of the main Thunder Horse field. Specifically, it is situated in block MC 776, about 150 miles southeast of New Orleans, Louisiana.

Discovery and Development

The North Thunder Horse field was discovered in February 2001, with a well drilled to a depth of 26,000 feet (7,900 meters) in 5,640 feet of water. This discovery was part of the broader Thunder Horse project, which also includes the main Thunder Horse field (MC 778) and the Thunder Horse South field (MC 822).

Geology and Reservoir Characteristics

The North Thunder Horse field is characterized by its deepwater and high-pressure, high-temperature (HP/HT) reservoir conditions. The field is part of a complex geological structure, with the reservoirs located below a salt canopy and against a salt wall. This complexity posed significant technological challenges during the development phase.

Production

The North Thunder Horse field is produced through the same semi-submersible platform as the main Thunder Horse field. The production from this field has been integrated into the overall Thunder Horse production system.

• Peak Production: The average production per well in the North Thunder Horse field peaked at about 32,000 barrels per day (b/d), which is lower than the main Thunder Horse field's peak of over 40,000 b/d per well.
• Total Production: The collective oil production from both the main and North Thunder Horse fields displayed a bumpy plateau, with a peak above 7 million barrels per month (about 240,000 b/d). However, production declined significantly in 2011 due to natural decline and the lack of new wells following the drilling moratorium after the Macondo oil spill.

Wells and Infrastructure

• Number of Wells: As of May 2011, there were 15 producing wells across both the main and North Thunder Horse fields, although the designed development plan included 25 wet-tree subsea wells tied to the floating platform.
• Subsea Systems: The production from the North Thunder Horse field is connected to the main platform via subsea systems. The Northwest Expansion, which includes the North Thunder Horse field, involved the construction of a two-slot subsea manifold and the drilling of two production wells.

Production History and Challenges

• Initial Production: The North Thunder Horse field began producing as part of the broader Thunder Horse project, with first oil achieved in June 2008 for the main field.
• Decline and Moratorium: Production declined after 2009, partly due to the natural decline of existing wells and the impact of the drilling moratorium following the Macondo oil spill in 2010. This moratorium delayed the drilling of new wells necessary to maintain and increase production levels.

Current Status and Future Plans

While specific recent production figures for the North Thunder Horse field alone are not detailed, the overall Thunder Horse project continues to see expansions and new developments. The Thunder Horse South Expansion Phase 2, which includes additional wells and infrastructure, aims to increase the field's overall production capacity. BP plans to continue growing its Gulf of Mexico production, targeting around 400,000 barrels of oil equivalent per day by the mid-2020s.

In summary, the North Thunder Horse field is an integral part of the larger Thunder Horse project, characterized by its deepwater HP/HT reservoirs, complex geology, and significant production contributions to the overall project output.