Deep-water oil and gas field development
Mississippi Canyon Block 816, Gulf of Mexico, US
LLOG Exploration Offshore
Taggart is a deep-water oil and natural gas field located at a water depth of 5,650ft in the Mississippi Canyon Block 816 of the outer continental shelf (OCS) in the Gulf of Mexico, US.
LLOG Exploration Offshore is the owner and operator of the project. The company approved the project for development and entered a tieback agreement with Williams for the recovery and processing of reserves from Taggart, in June 2020.
Expected to come on stream in early 2022, the Taggart field is estimated to produce 27 million barrels of oil equivalent over a period of eight years.
Echo Offshore conducted an archaeological analysis based on the Bureau of Ocean Energy Management (BOEM) Gulf of Mexico OCS Region to support the exploration plans of LLOG.
Taggart location and discovery
Taggart discovery lies in the license area of OCS G-33178, located 88.51km away from the nearest coast in Plaquemines Parish, Louisiana in the US.
Taggart was discovered by the drilling of the Mississippi Canyon 816 #1 exploratory well in the Pliocene and Upper Miocene sands to a depth of 11,562ft in August 2013. It encountered a net pay of 97ft of oil and gas condensate in two Miocene sands formations.
Details of Taggart appraisal
Taggart discovery was appraised by the drilling of two subsequent appraisal wells. The first appraisal well was drilled in 2015 to encounter a net pay of 147ft, followed by the second appraisal well in 2019, which hit 84ft of net pay.
The supplemental exploration plan involves the drilling of four wells, Well A, Well B, Well C, and Well D. A dynamic positioning semi-submersible drilling rig or drillship is being utilised by LLOG for the drilling operations. The drilling unit includes well control, pollution prevention, and blowout prevention equipment for safety.
The drilling activities of the first three wells were completed by April 2020, while the fourth well drilling will be completed by May 2021.
Taggart oil field development details
Taggart discovery will be developed by tying it back to the Williams’ Devils Tower Spar, located 140mi south-east of New Orleans in the Mississippi Canyon 773 area.
Under the tieback deal, Williams will provide offshore crude oil and gas gathering and production handling services via its Mountaineer and Canyon Chief pipeline systems as well as onshore gas treatment and processing services. The natural gas will be transported to the Mobile Bay Processing Plant owned by Williams, while the liquids of the natural gas will be piped to a fractionation facility at the Baton Rouge in Louisiana. Williams holds a 33% interest in the facility which has the capacity of 60,000 barrels per day. The hydrocarbons are then sent for marketing.
Details of Devils Tower
Devils Tower is one of the world’s deepest dry tree truss spar-based platform located at a water depth of 5,610ft in the Gulf of Mexico.
The facility comprises topsides, hull, mooring system, as well as production facilities. It includes eight wells with eight dry trees and two export pipelines.
The hull measures 586ft in length, and 94ft in diameter. The topside weighs 9,300t with maximum payload, including drilling rig. A nine-line permanent, taut catenary system moors the spar platform. Suction pile anchors at the seabed secure the mooring systems, while the buoyant air cans provide the top tension for the risers.
The platform has the capacity of 60,000 barrels of oil per day and 210 million cubic feet of gas per day. First oil from the facility was achieved in May 2004.