Jackdaw gas field is a large offshore natural gas field which lies in Blocks 30/02a, 30/02d and 30/03a in the central North Sea,[1] 150 miles east of Aberdeen.[2] It is wholly owned by BG International Limited, which has been a part of the Shell Group companies since 2016.[3]
| Jackdaw | |
|---|---|
| Country | United Kingdom |
| Region | Central North Sea |
| Location/blocks | 30/02a, 30/02d, 30/03a |
| Offshore/onshore | Offshore |
| Coordinates | 56°54’3.73"N 2°22'50.73"E |
| Operator | Shell UK |
| Owner | BG International Limited |
| Field history | |
| Discovery | 2005 |
| Production | |
| Current production of gas | 200×106 cu ft/d (5.7×106 m3/d) |
| Estimated gas in place | 200 million barrels oil equivalent |
| Producing formations | Upper Jurassic |
The Jackdaw field is being developed as a 'not permanently attended' platform in a water depth of 78 m, 30 km south east of the Shearwater installation to which fluids from Jackdaw are exported.
The Jackdaw reservoir
editThe reservoir is in the Upper Jurassic Heather Formation and is compartmentalised into two separate reservoir units. The properties of the reservoir and the fluids are as follows.[4]
| Property | Value |
|---|---|
| Fluid type | Gas / gas condensate |
| Initial reservoir pressure (psi at datum 5,174 m TVDss) | 17,158 |
| Initial reservoir temperature (°C) | 191 |
| Formation volume factor (cf/scf) | 0.002528 – 0.002759 |
| Dew point (psi) | 6,351 – 6,450 |
| Gas viscosity (cP) | 0.051 – 0.0648 |
| Gas density (g/cm3) | 0.351 – 0.4293 |
| Gas condensate API gravity (°) | 34.9 – 49 |
| Wax (% wt at -36 °C) | 17 |
| Wax appearance temperature (°C) | 46 |
| Asphaltene content (wt %) | 0 |
| Carbon dioxide (CO2) (mol %) | 4.2 |
| Hydrogen sulphide (H2S)(ppmv) | 30 |
| Mercury (Hg)(ng/m3 (gas)) | 350 |
| Mercury (Hg) (µg/kg (condensate)) | 15 |
The Jackdaw field is classified as an Ultra high pressure high temperature (uHPHT) field. Such fields are defined as having a reservoir pressure greater than 12,500 psi, and a temperature exceeding 166 °C.[4]
Fluid production
editThe Jackdaw wellhead platform (WHP) is a four leg installation located at: 56°54’3.73"N and 2°22'50.73"E.[4] The installation supports four wellheads. No hydrocarbon processing takes place on Jackdaw, the well fluids are sent to Shearwater for processing. The topsides pipework is rated for the full shut-in pressure of the wells. Transfer of fluids from Jackdaw to Shearwater is through a 31km long pipeline 12-inch internal diameter, 18-inch outside diameter pipe-in-pipe. A pipeline overpressure protection system (OPPS) protects the pipeline from the wellhead pressure.[4]
References
edit- ^ "Shell gives final greenlight to Jackdaw gas project in North Sea". Reuters. 26 July 2022. Retrieved 8 September 2022.
- ^ Kevin Keane (26 July 2022). "Greenpeace lodges legal bid to halt Jackdaw gas field in North Sea". BBC. BBC. Retrieved 8 September 2022.
- ^ "Shell invests in the Jackdaw gas field in the UK North Sea". Jul 25, 2022. Retrieved 8 September 2022.
- ^ a b c d "Jackdaw Field Development Environmental Statement" (PDF). Retrieved 1 October 2024.