Judy Map

The Judy and Joanne fields are located in Quadrant 30 of the United Kingdom Continental Shelf, approximately 150 miles south-east of Aberdeen. Hydrocarbons were first discovered in the Joanne field in 1980 and in 1992 extensive geological work determined that development should be pursued. Commercial oil production and gas from Judy/Joanne began in 1997. After being processed on the Judy Platform, gas is transported through the Central Area Transmission System (CATS) pipeline and liquids are transported to Teesside through the Norpipe system.

Key Facts

Block 30/7a, 30/12a, 30/6a, 30/13d, 30/7c Judy
Sector U.K. Central North Sea
Approx Distance to Land 130 nautical miles SE of Aberdeen
Water Depth Judy Platform - 75 metres (246ft)
Joanne Manifold - 79 metres (259ft)
Hydrocarbons Produced Gas & Oil/Liquids
Export Method Product is exported via the Judy Platform as follows:
  • Gas to Teesside via the CATS pipeline
  • Liquids to Teesside via the Norpipe system
Manned/Unmanned Manned
Operated/Non-Operated Operated
% of Chrysaor Equity 67.0%
First Production June 1997
Accommodation on Board 101
Key Commercial Terms There are currently no true third party agreements in place for the transportation and/or processing of product via the Judy Platform. However there are third parties who have tied directly into the J-Block Spurline (see Infrastructure Access Agreeement Summaries)


Entry Specification:

The entry specification for any future third-party production is dependent upon the point at which such production would enter the Judy facilities and the composition of production already being processed at that time. The entry specification will cover areas that affect onward transportation as well as those which impact the Judy platform itself e.g. slugging limitations and contaminants.
Exit  Specification:
Liquids – any liquids processed on the Judy facilities would be transported to Teesside through the J-Block Spur to the Norpipe System. The exit specification from the Judy facilities is the Norpipe entry specification, which is directly negotiable between any prospective user and the Norpipe operator. However, any exit specification must be achievable with the processing facilities available on Judy.
Gas – any gas processed on the Judy facilities would be transported through the CATS Pipeline via the T6 entry point. The exit specification from the Judy facilities is the CATS entry specification which is directly negotiable between any prospective user and the CATS operator. However, any exit specification must be achievable with the processing facilities available on Judy. Following on from transportation through CATS further processing would be required at either the CATS processing facility or TGPP.
Outline details of Primary separation processing facilities:
Primary oil and gas separation is achieved by HP separators. The oil is conditioned by a second stage LP separator to the pipeline entry specification (145 psia true vapour pressure at 100oF) prior to export.
Outline details of gas treatment facilities:
The gas from the separators is compressed and dehydrated by a triethylene glycol system to achieve a maximum water content of 15kg per million cubic metres. The hydrocarbon dewpoint of -2oC at all pressures greater than 92 barg is achieved by NGL removal at the suction scrubbers of the second compression stage. Judy has limited H2S removal facilities.


The basic capacity information is portrayed by colour coded 'traffic lights' that reflect thresholds of availability over the next 5 years

Available Capacities

5% to 25% 
Judy Platform firm processing capacity available Ullage as % of system capacity Comment
2021 2022 2023 2024 2025
Oil export capacity1  
Oil export pipeline capacity1  
Gas compression capacity2 3  
Gas export capacity  
Gas export pipeline capacity  
Gas lift capacity4  
Produced water handling capacity6  
Dehydration capacity5  
H2S removal capacity  
Water injection capacity            


(1) The design capacity of the Judy oil export system is 100,000 bbls/d from two booster and main oil line pumps. However, there is also the ability to tie directly into the J-Block Spur, then onwards to the Norpipe system. The capacity of the J-Block spur line is dependent on the combined throughputs of the J-Block spur and Norpipe trunkline.
(2) There are two compression trains. With both trains operating the system has a total capacity of 320 MMSCFD at 15.5 barg separator pressure.
(3) Compressor optimisation was implemented in Q2 2017, re-wheeling both compression trains to reduce the separator pressures. Post-optimisation, the compressors can deliver 320 MMSCFD at 15.5 barg separator pressure. The nameplate capacity of 450 MMSCFD is maintained at around 26 barg separator pressure.
(4) Gas is available at compressor second stage discharge pressure, typically about 150 barg. A gas lift manifold was installed in 2018 with capacity to inject to six wells. Gas lift is currently only provided to 1 of the Judy wells.
(5) Achieves a maximum water content of 15 kg per million cubic metres.
(6) Produced water is separated at the LP separator, the system has a hydraulic capacity of 12,000 bbl/day. Treatment is by hydro cyclones, compact flotation unit and a de-gasser. There are no re-injection facilities. Additional produced water capacity may be available via the Jasmine hydro cyclones on JURP however these have yet to be commissioned. Please note, modifications required on Judy for new business may be limited due to facilities constraints.

While this information has been prepared in good faith, no warranty or representation (implied or expressed) is made as to its accuracy, completeness or relevance for use by any other party and no liability is accepted by Chrysaor under any circumstances relating to the information and the use thereof.

Last Update: December 2020

.pdf copy available here

Contact Information

Gillian O'Hara

T: 44 (0) 1224 205131