The Heidelberg field is located in the Gulf of Mexico, about 225km offshore of Louisiana, US, at a water depth of 1,620m (5,310ft). The deepwater oil field consists of the Green Canyon blocks 859, 860, 903, 904 and 948. The offshore field is currently estimated to contain recoverable resources measuring between 200 and 400 million barrels of oil.
Anadarko is the operator of Heidelberg field with 31.5% working interest in it. Other partners for the field development include Marubeni Oil and Gas (12.75%), Eni (12.5%), Apache Deepwater (12.5%), StatoilHydro (12%), ExxonMobil (9.375%) and Cobalt (9.375%).
The Heidelberg field development project was sanctioned in the second quarter of 2013. The oil field commenced its first production in January 2016, ahead of schedule.
Heidelberg field discovery and appraisal
Heidelberg oil field was discovered in February 2009. The discovery well, which was drilled in Green Canyon Block 859, encountered more than 200ft (61m) of net oil pay in high-quality Miocene sands.
Another well was drilled by the ENSCO 8500 semisubmersible rig towards the end of 2009.
Appraisal drilling on the Heidelberg 2 well started in October 2011 with the Discoverer Americas drillship.
The Heidelberg-2 (GC 903-3) appraisal well was drilled in the Green Canyon Block 903 to a total depth of 31,030ft (9,458m), nearly 1.5 miles (2.4km) south of the Heidelberg discovery well. The Heidelberg-2 well was successfully appraised in February 2012. It encountered approximately 250 net feet (76m) of high-quality oil pay.
The data obtained from Heidelberg appraisal and discovery wells indicated the presence of continuous and pressure-connected reservoirs with high-quality oil.
The oil discovery was further appraised in April 2012 followed by the sidetracking of the appraisal well to assess the down deep extent of the Heidelberg field.
Sidetracked down deep to a total depth of 30,440ft (9,278m), the GC 903-3ST1 well traced oil around 700ft (213m) deeper than the previous oil discovery well.
Initial front-end engineering and design (FEED) works for the project were subsequently carried out in the same year.
Developing the Gulf of Mexico-based oil field
A truss spar is used as the drilling and production platform at Heidelberg. The cylindrical and partially submerged spar platform was chosen for its suitability in deepwater oil and gas operation.
The design strengths of a spar include greater capacity to withstand hydrostatic pressure and support high-pressure risers, while offer stability in deepwater against topside buoyancy, as well as natural forces such as typhoons or hurricanes.
The design capacity of the Heidelberg spar is 80,000 barrels of oil and 2.3 million cubic metres of natural gas a day. The fabrication of the hull and topside for the Heidelberg spar facility was completed in 2015.
The Heidelberg crude output is conveyed to an existing third party via a 20in diameter and 55km-long pipeline built, owned and operated by Enbridge.
Contractors involved with Heidelberg oil field
Technip was contracted for the engineering, construction and transport of the 23,000t Heidelberg truss spar. It is the eighth Spar delivered by Technip to Anadarko.
The project management and engineering was executed at Technip’s operating centre in Houston, Texas. The detailed hull design and fabrication was carried out at its construction yard in Pori, Finland.
First Subsea was subcontracted by Technip in July 2013 to supply the subsea mooring connectors for the Heidelberg truss spar platform.
FMC Technologies was awarded a contract by Anadarko in June 2013 to supply subsea equipments, including five enhanced horizontal subsea trees, tree-mounted controls and two manifolds for the Heidelberg field development.
Subsea 7 received a contract in the same month for the engineering, fabrication and installation of risers, pipelines and flowlines. The offshore work under the contract started at the end of 2014 with the use of Seven Borealis pipelay vessel.