King/Horn Mt. (MC084) - Anadarko

Project Location and Discovery

The Horn Mountain Field is located in the Gulf of Mexico, approximately 160 kilometers southeast of New Orleans. It is situated in Mississippi Canyon blocks 126 and 127, at a water depth of 5,400 feet.

The field was initially developed and operated by BP (66.7%) in partnership with Occidental Petroleum (33.3%) starting in 2002.
The ownership changed hands several times: Plains Exploration & Production acquired the field, which was then acquired by Freeport-McMoRan. Freeport-McMoRan sold its stake to Anadarko in 2016.
In August 2019, Occidental Petroleum acquired Anadarko, becoming the sole operator of the field with 100% working interest.

The field is characterized by a structurally complex reservoir setting.
Exploration drilling began in July 1999, and the discovery was announced in August 1999 when the semi-submersible drilling rig Ocean Victory encountered nearly 300 feet of pay from four Miocene intervals. A side-track revealed a column of around 550 feet.

Delineation drilling started immediately after the discovery, significantly reducing the total development time.
Eight production wells and two injection wells were drilled in 2001 using the Ocean Victory rig. The wells averaged 16 days per every 10,000 feet drilled, and the project went from discovery to production in just under 40 months.
The initial production rates were approximately 15,000 barrels of oil per day (bpd) and 12 million cubic feet of gas per day (MMcf). Production peaked at over 65,000 bpd and 68 MMcf in 2003. By 2018, oil production had declined to about 12,500 bpd.

Under Anadarko's operation, several development wells were drilled:
- The first development well in 2017 encountered over 70 feet of net oil pay and was brought online in the second quarter of 2017.
- The second development well in 2017 encountered 120 feet of high-quality oil pay and was brought online in the third quarter of 2017.
- The third development well in the fourth quarter of 2017 encountered 42 feet of high-quality oil pay and came online in the second quarter of 2018, producing approximately 8,000 bpd from a single zone.

The production facility is a spar platform designed to support 14 dry trees. The wells connect to the spar via a dual barrier riser system, consisting of a 9 5/8 internal riser set into a 12¾ outer riser, designed by ABB Vetco Gray.
The spar hull was constructed in Finland and installed in the Gulf of Mexico in June 2002. The topsides production facility and quarters packages were integrated with the spar hull in June 2002.
Pipeline infrastructure was provided by Intec Engineering, and the lines were laid by Allseas’ vessel Solitaire.

GATE Energy provided full commissioning services for the addition of gas lift to the Horn Mountain facility, enhancing the production capabilities of the field.

The project is expected to result in the ultimate recovery of an estimated 150 million barrels of oil and gas equivalent.