Buckskin Deepwater Project, Gulf of Mexico

The Buckskin oilfield is located approximately 190 miles (305.7km) south-east of Houston, Texas, off the shore of the Gulf of Mexico, US.

It lies roughly 44 miles (71km) west of Chevron’s Jack oilfield in water depths of 6,800ft.

LLOG affiliates Buckstone Development Company and LLOG Deepwater Development Company currently own a combined 33.8% stake in the oilfield.

Other co-owners include Repsol E&P USA (22.5%), Beacon Offshore Energy Buckskin (18.7%), Navitas Buckskin US (7.5%), Ridgewood Buckskin (8.75%) and ILX Prospect Buckskin (8.75%).

Ridgewood Buckskin and ILX Prospect Buckskin are managed by the Ridgewood Energy Corporation.

LLOG Exploration Offshore is serving as the operator of the project.

Development activities on the project began in January 2018 and first oil was produced in June 2019. Production was achieved with 60% less investment than the initial development plan of $1.4bn.

Buckskin oil field location and reserves

Buckskin field covers six lease blocks, namely 785, 828, 829, 830, 871 and 872 in the Keathley Canyon.

The blocks are located in the deep waters of the Gulf of Mexico.

The oilfield is estimated to contain approximately five billion barrels of oil reserves, while initial output is estimated to reach 30,000 barrels of oil per day.

Discovery and appraisal on Buckskin

Buckskin was discovered by the Keathley Canyon 872 #1 well, also known as the Buckskin No 1 discovery well, which was drilled in 2009 by Repsol.

The well was drilled to a depth of 29,404ft by the Stena Drillmax drilling rig and encountered approximately 400ft of net hydrocarbons pay in the upper and lower Wilcox formations.

A total of three appraisal wells were later spudded in Keathley Canyon 785 and 829.

The wells encountered an average of 375ft of good quality oil pay in the Upper Wilcox formation.

Additional tests were conducted based on data collected from the discovery well in order to test the commercial viability of the field.

Buckskin deepwater project development details

Phase one of the Buckskin deepwater project will include the drilling of two development wells in Keathley Canyon 829.

The wells will be drilled to a total depth of approximately 29,000ft by the Seadrill West Neptune drilling rig, which was moved to the project location during the final quarter of 2017.

Buckskin’s development wells will be tied-back to the Anadarko-operated Lucius Spar offshore platform located at Keathley Canyon 875 using a six-mile (10km) long subsea tieback.

Equipment to be used for the Buckskin project will be rated to 15,000psi, while the flow lines are planned to be dual eight-inch variants equipped with riser base gas lift.

Future phases of the project are slated to involve the drilling of new wells, which are to be connected to the Lucius platform via additional subsea facilities.

Details of the Lucius spar platform

The Lucius spar platform stands in water depths of 7,100ft and is one of the biggest spar platforms to be constructed by Anadarko.

It has a diameter of 110ft and a length of 605ft, while its hull weight is approximately 23,000t.

The platform can process approximately 80,000 barrels of oil per day (bopd) and 450 million standard cubic feet (Mscfd) of gas a day.

Contractors involved

The pre-front-end engineering and design (FEED) activities for the project were carried out by WorleyParsons and INTECSEA, while the FEED activities were conducted by INTECSEA.

Seadrill was contracted to provide the drill rig for the drilling of the Buckskin development wells.

Stena Drilling was contracted to provide drilling services for the project’s discovery well.

TechnipFMC was contracted to supply subsea equipment for the project, while Tenaris supplied line pipe for the tie back.