# Esmond, Forbes and Gordon gas fields

Esmond, Forbes and Gordon are three adjacent, now depleted, natural gas fields in the southern North Sea, 170 km east of Teesside.

## The fields

Esmond, Forbes and Gordon were the most northerly gas fields in the UK sector of the southern North Sea: Esmond was in Block 43/13a, Forbes in Block 43/8a and Gordon in Blocks 43/15a and 43/20a. The fields were named after Scottish clans.
The gas reservoirs are Lower Triassic Bunter sandstones at a depth of 4,470 to 5,755 feet (1,362 to 1,754 metres). The reservoir properties are:
Esmond, Forbes and Gordon reservoir properties :
| Parameter | Esmond | Forbes | Gordon |
| Discovered | June 1982 | January 1970 | June 1969 |
| Thickness, feet | 342 | 187 | 440 |
| Porocity, % | 23-4 | 15-25 | 14-21 |
| Water saturation, % | 16.8 | 15.9 | 22.1 |
| Gas water contact, feet | 4,470 | 5,744 | 5,450 |
| Temperature, °F | 135 | 146 | 142 |
| Pressure at depth, pounds force per square inch @ feet | 2,280 @ 4,600 | 2,800 @ 5,700 | 2,622 @ 5,300 |
| Volume factor, standard cubic feet/reservoir cubic feet | 158 | 179 | 165 |
| Composition methane, % | 91 | 86 | 82 |
| Composition nitrogen, % | 8 | 12 | 16 |
| Gas in place, billion cubic feet (1985) | 381 | 104 | 185 |
| Recoverable reserves, billion cubic metres (1994) | 9.1 | 1.5 | 3.9 |

## Owner and operator

In 1985 the licensees were Hamilton Oil GB plc (48%), Hamilton Bros Petroleum (UK) Ltd (12%), RTZ Oil and Gas Ltd (25%), Blackfriars Oil Co Ltd (12.5&), and Trans-European Co. Ltd (2.5%). The operator was Hamilton Brothers Oil & Gas Ltd. Hamilton Bros remained the operator until BHP assumed operatorship prior to decommissioning in 1995.

## Development

The three fields were individually uneconomic to develop. However, the development was viable if they were developed together. They were configured as a central processing complex (Esmond) and two unmanned satellites, Forbes and Gordon.
Esmond, Forbes and Gordon platform parameters and features :
| Platform | Esmond CP | Esmond CW | Forbes AW | Gordon BW |
| Type | Steel jacket | Steel jacket | Steel jacket | Steel jacket |
| Coordinates | 54°36’18”N 01°25’36”E | | | |
| Function | Processing and accommodation | Wellheads | Satellite drilling and production | Satellite drilling and production |
| Water depth, metres | 31 | 31 | 23 | 17 |
| Jacket fabrication | McDermott, Ardesier | Lewis Offshore, Stornoway | McDermott, Ardesier | McDermott, Ardesier |
| Jacket weight, tonnes | 1,912 | 1,049 | 991 | 857 |
| Topsides fabrication | McDermott, Ardesier | Lewis Offshore, Stornoway | Wm Press, Wallsend | Wm Press, Wallsend |
| Topsides weight, tonnes | 5,960 | 543 | 2,163 | 2,163 |
| Legs | 8 | 4 | 4 | 4 |
| Piles | 16 | 8 | 6 | 6 |
| Well slots | None | 12 (7 wells planned) | 9 (2 planned) | 9 (2 planned) |
| Production capacity, million standard cubic feet per day | 200 MMSCFD (334 MMSCFD winter peak) | – | | |
| Jacket installation | September 1984 | July 1984 | 1984 | 1984 |
| Topsides installation | April 1985 | | Spring 1985 | Spring 1985 |
| Start up | June 1985 | June 1985 | August-October 1985 | August-October 1985 |
| Accommodation | 51 | Nil | 4–6 (emergency) | 4–6 (emergency) |
| Production to: | Bacton gas terminal by pipeline | CP via bridge | CP by pipeline | CP by pipeline |
| Pipeline, length and diameter | 204 km 24-inch | – | 11.5 km 10-inch | 35 km 12-inch |

## Production

Processing facilities on Esmond comprised gas/condensate/water separation, Tri-ethylene glycol (TEG) dehydration, and provision for 20,000 bhp of gas compression. Condensate was injected into the gas export line.
Peak production from the three fields was:
* Esmond 1.2 billion cubic metres per year (bcmy) (1986)
* Forbes 0.5 bcmy (1986)
* Gordon 0.4 bcmy (1986)
By 1995 Esmond had produced around 8.5 x 10$^9$ standard cubic metres. That was about 93% of the recoverable reserves in the reservoir.

## Later developments

Decommissioning was approved in 1993-5; the Forbes platform was recovered to shore in 1993, the Esmond and Gordon installations were taken to a yard in the Netherlands for dismantling in 1995.
The 24-inch Esmond to Bacton pipeline was known as the Esmond Transmission System (ETS). Following decommissioning of Esmond in 1995 the pipeline was reconfigured and reused to transport gas from Tyne and Trent fed by a 20-inch pipeline. The 37 km northerly part of the ETS was disconnected. The remainder was renamed EAGLES East Anglia Gas And Liquids Evacuation System Pipeline. Tyne production ceased in 2015. The Cygnus gas field has used the pipeline since 2016.
There are proposals to use the Esmond reservoir for carbon dioxide storage.