Elgin–Franklin fields
| Company type | Joint venture |
|---|---|
| Industry | Oil and gas industry |
| Founded | 1985 (Franklin field discovery) |
| Headquarters | Aberdeen , Scotland, United Kingdom |
Area served | North Sea Central Graben region |
Key people | Total E&P UK Limited (operator) |
| Products | Gas condensate, natural gas, condensate |
| Parent | Consortium including Total E&P UK Ltd., Eni Elgin/Franklin Ltd., Harbour Energy Ltd., Esso E&P UK Ltd., Chevron North Sea Ltd., One-Dyas E&P Ltd., Summit E&P Ltd. |
The Elgin–Franklin fields consist of two neighboring gas condensate reservoirs situated in the Central Graben region of the North Sea, positioned eastward of Aberdeen, Scotland at a depth of . This collaborative venture represents the largest high pressure, high temperature development worldwide, encompassing the globe’s hottest field, West Franklin, alongside the Glenelg field.
On 25 March 2012, a gas leakage incident at the Elgin platform necessitated halting production and evacuating personnel. The leak persisted for more than seven weeks and was sealed on 16 May 2012 following well intervention procedures. Production recommenced nearly twelve months later, on 9 March 2013.
History
The Franklin field was identified in 1985 via well 29/5b-4, drilled by Ultramar, with appraisal drilling continuing through 1991. Bearing the name of British explorer Sir John Franklin, its production began in August 2001.
Discovered in 1991 by well 22/30c-8 drilled by Elf Aquitaine, the Elgin field underwent appraisal drilling until 1994. It was named after the Scottish town of Elgin—which also serves as an anagram of Nigel, honoring a prominent geologist—and commenced production in March 2001.
The Glenelg satellite field was located in 1999 by Total through well 29/4d-4 and named after the Scottish locale of Glenelg, Highland. Developed via a step-out well from Elgin, it began producing hydrocarbons in March 2006.
Total discovered the West Franklin reservoir in 2003, which was developed using deviated wells from the Franklin platform. Initial production started in March 2007, followed by a second well coming online by September 2008. A new wellhead platform was installed in 2014; by 2016, three wells had been drilled, with production from well 29/5b-H1Z commencing in 2015. Additionally, an extra wellhead platform named Elgin B, connected to Elgin A, facilitates infill drilling to boost output.
March 2012 gas leak
A gas leak erupted on 25 March 2012 at the Elgin Wellhead platform during efforts to plug and decommission well 22/30c-G4. No injuries occurred; initially, 219 non-essential workers were evacuated from the PUQ and the nearby Rowan Viking drilling rig, with the remaining 19 personnel evacuated later that same day.
At that moment, the fields were producing approximately of oil equivalent, accounting for roughly 7% of the UK's gas supply. The leak released methane along with between two and twenty-three tonnes of condensate, forming a sheen about long on the sea’s surface. The HM Coastguard imposed a exclusion zone extending for ships and for aircraft. Shell E&P also withdrew non-essential personnel from the adjacent Shearwater platform.
Gas emissions peaked at , then declined following the drilling of a relief well. The platform flare burned until it spontaneously extinguished on 31 March 2012 after consuming all volatile materials. The leak was ultimately sealed on 16 May 2012 through well intervention involving pumping mud and cement into the well.
Investigation determined corrosion within the G4 well casing as the root cause, accompanied by a sudden gas release from an untapped chalk reservoir layer in the Hod formation located above the primary reservoir at roughly depth. This formation had been isolated with steel casing during drilling operations in 1997.
Pressure increases were detected on 25 February 2012 within the C annulus of the well; remedial actions commenced on 4 March. Total attributed gas leakage to failure of the C annulus allowing gas to escape from the conductor pipe.
On 5 April 2012, an inspection team comprising Total personnel and Wild Well Control assessed conditions on the platform. Later that month, a diverter assembly was installed around the G4 wellhead to redirect leaking gas—then estimated at —away from critical infrastructure to facilitate control measures.
In May, two rigs engaged in repair efforts: the West Phoenix semi-submersible executed a "top kill" operation by pumping weighted mud into the wellhead—a technique that successfully stopped the leak—while Sedco 714 drilled a relief well (G4-K1) to perform a "bottom kill."
Surveillance aircraft conducted eleven monitoring flights during early May, estimating flow rates at . Total confirmed that leakage ceased on 16 May and production resumed on 9 March 2013.
December 2016 Helicopter Event
On 28 December 2016, a Sikorsky S-92 helicopter (registration G-WNSR) operated by CHC Helicopter encountered "unexpected control responses" during a standard transfer flight between offshore North Sea oil platforms. The crew executed an emergency touchdown on the West Franklin platform, during which the helicopter rotated on the helideck, resulting in damage to the wheels and rotor blades. The helideck itself also sustained damage. None of the nine passengers or two crew members were injured. Subsequently, the aircraft was moved to Aberdeen, where the Air Accidents Investigation Branch (AAIB) commenced an inquiry.
On 9 January 2017, Sikorsky issued a grounding order for all S-92 helicopters pending inspections of the tail rotor, a procedure requiring roughly 11 man-hours. An AAIB update on 11 January disclosed that the tail rotor pitch change shaft bearing had seized due to extreme overheating and wear. This malfunction impaired the tail rotor servo, leading to a loss of tail rotor control. Importantly, the health and usage monitoring systems had detected the defect one day prior to the flight; however, maintenance staff failed to recognize it.
Ownership
Total E&P UK Limited, a subsidiary of Total S.A. (formerly Elf Aquitaine), operates these fields.
Elgin-Franklin and West Franklin
Ownership stakes in Elgin and Franklin are allocated among partners according to a unitisation agreement, with West Franklin held by the same consortium.
| Company | Equity | Note |
|---|---|---|
| Total E&P UK Ltd. | 46.137% | Operator (previously Elf) |
| Eni Elgin/Franklin Ltd. | 21.867% | |
| Harbour Energy Ltd. | 14.110% | formerly Chrysaor Ltd. |
| Harbour Energy Ltd. | 5.200% | formerly Premier Oil UK Ltd. |
| Esso E&P UK Ltd. | 4.375% | |
| Chevron North Sea Ltd. | 3.900% | formerly Texaco |
| One-Dyas E&P Ltd. | 2.1875% | |
| Summit E&P Ltd. | 2.1875% |
Glenelg
The Glenelg partners include:
| Company | Equity | Note |
|---|---|---|
| Total E&P UK Ltd. | 58.73% | Operator (formerly Elf) |
| Harbour Energy Ltd. | 18.57% | formerly Premier Oil UK Ltd. |
| Harbour Energy Ltd. | 14.70% | formerly Chrysaor Ltd. |
| Eni Elgin/Franklin Ltd. | 8.00% |
Franklin field
The Franklin reservoir is characterized by a tilted fault block within Upper Jurassic Fulmar Sandstone, exhibiting porosities exceeding 20%. It lies approximately 5,500 meters deep, with reservoir pressure near 14,000 psi and temperature close to 190°C. Initial estimates placed recoverable reserves at around 820 billion cubic feet (bcf) of natural gas and 120 million barrels of condensate.
Elgin field
Elgin's reservoir consists of a fault-bounded structure situated atop a collapsed Triassic mud pod, segmented by numerous faults into discrete compartments each with distinct gas-water contacts. It shares the Fulmar sandstone reservoir but also contains a lower-quality Pentland formation that remains undeveloped. Initial recoverable reserves were projected at approximately 890 bcf of gas and 245 million barrels of condensate.
West Franklin
Production at West Franklin also derives from the Fulmar formation reservoir.
Glenelg
The Glenelg reservoir is situated within a tilted fault block and contains hydrocarbons in the Fulmar formation.
Development
Positioned in the Central Graben region of the North Sea to the east of Aberdeen, Scotland, the Elgin-Franklin development operates at a water depth of . It consists of three platforms: two wellhead platforms dedicated to the Elgin and Franklin reservoirs respectively, which are interconnected by a bridge, and a central platform housing processing, utilities, and living quarters (PUQ).
The PUQ platform is a pile-supported jack-up structure that accommodates hydrocarbon processing units, control equipment, and living spaces for 97 staff members. Constructed by BARMAC in Nigg, Scotland, it was installed in July 2000. This facility can handle up to of gas and of condensate.
The Franklin wellhead platform (WHP) includes nine well slots—seven targeting the Franklin Field and two extended reach wells accessing West Franklin. Typically unmanned, it is equipped with a helideck and shelter space for 20 personnel. The Elgin WHP has 12 well slots—11 for Elgin and one extended reach well for Glenelg. Both platforms were installed in 1999 and connected to the PUQ via flowlines; however, they do not have drilling capabilities on-site. Drilling and maintenance operations are performed by jack-up rigs functioning in tender mode.
To address limitations of existing facilities and enable further development, the West Franklin and Elgin B platforms were added in 2014. By 2017, West Franklin supported three wells while Elgin B also accommodated three wells.
Crude oil produced is transported through the Forties pipeline system to BP's Kinneil terminal located in Grangemouth. Meanwhile, gas is conveyed via the SEAL Pipeline to Bacton, Norfolk.
Reservoir characteristics
- High pressure/high temperature (HP/HT) wells
- Well depth:
- Pressure range: 600–1100 bar
- Operating pressure: 860 bar
- Fluid temperature:
- Water depth at seabed:
The West Franklin reservoir holds the distinction as the hottest and highest pressure reservoir worldwide, with temperatures reaching and pressures up to .
See also
External links
- Gas leak event at Elgin platform in the North Sea – Total (2012)
- Elgin/Franklin field brochure – Total E&P UK Plc (2004) [Archived]
- Elgin Franklin field overview – Total ICOP (2012) [Archived]
- Total’s operations in the UK – Elgin / Franklin activities (2012) [Archived]
- Platform gas leak flare burning – BBC News (2012)
- Advanced HP/HT drilling: Total’s experience on Elgin/Franklin – Journal of Petroleum Technology (2011) [Archived]
- Elgin / Franklin platform gas leak in UK North Sea – Disease, climate, ecology and evolution (2012)