Jackdaw gas field
| 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 |
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]
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
[edit]The 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
[edit]The Jackdaw wellhead platform (WHP) is a four-leg installation located at 56°54′3.73″N 2°22′50.73″E / 56.9010361°N 2.3807583°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.