Siri, Nini and Cecilie oil fields

{{Infobox oil field|name=Siri oil field|coordinates=56.482686N 4.911144E|country=Denmark|region=North Sea|blocks=5604/20|offonshore=Offshore|operators=DONG E & P A/S|discovery=1995|start_production=1999|peak_year=2000|peak_of_production=2.188 million cubic metres per year|formations=Paleocene sandstone structural trap}}

The Siri oil field and its satellites, Nini and Cecille, are oil producing fields in the Danish sector of the southern North Sea. Operating since 1999 and 2003 they are the most northerly of Denmark's offshore oil assets located close to the Denmark-Norway median line.

The fields

The Siri field comprises a sandstone reservoir of oil with a low gas content.{{Cite web |last=Danish Energy Agency |date=2013 |title=Oil and gas production in Denmark |url=https://ens.dk/sites/ens.dk/files/OlieGas/oil_and_gas_in_denmark_2013.pdf |access-date=9 November 2023 |publication-place=Copenhagen}} It is in Block 5604/20 in the far north of the Danish sector near the Denmark-Norway median line.{{Cite web |date=2021 |title=Danish oil and gas fields |url=https://ens.dk/sites/ens.dk/files/OlieGas/anlaeg_felter_eft-tilladelser_i_nordsoen_2021_eng.png |access-date=10 November 2023}} The Siri reservoir comprises four areas: Siri Central; Siri North; to the north east Stine segment 2; and Stine segment 1. The field is developed through a single installation (designated SCA) located over the Siri Central formation with subsea wells exploiting Stine1 & 2.{{Cite web |title=Statoil Oil and Gas Field Project |url=https://www.offshore-technology.com/projects/siri/?cf-view |access-date=9 November 2023}}

The Nini field is to the north east of the Siri field and is a sandstone oil reservoir. It has been developed through two platforms (Nini A and Nini B also known as Nini East and Nini West) with well fluids piped to Siri SCA installation for processing.

The Cecilie field is located south west of the Siri field, it too is a sandstone oil reservoir. It has been developed by a wellhead platform with well fluids routed to Siri SCA for processing.

Key parameters of the fields are given in the table.

class="wikitable"

|+Siri, Nini and Cecilie fields properties

|Field

!Siri

!Nini

!Cecille

Reservoir rock

|Sandstone

|Sandstome

|Sandstone

Trap

|Structural trap

|Structural and stratigraphic trap

|Structural and stratigraphic trap

Geological age

|Paleocene

|Eocene/Paleocene              

|Paleocene

Depth

|2060 m

|1700 m

|2200 m

Discovery

|1995

|2000

|2000

Field delineation

|63 km2

|45 km2

|23 km2

Oil reserves

|1.1 million m3

|1.1 million m3

|0.2 million m3

Gas reserves

|0

|0

|0

Owners and operators

The licence for the Siri field was originally owned by Dong Energy (50%), Altinex (20%) and Talisman (30%). The operator licence was taken over by Dong Energy from Statoil in 2002. The Siri, Nini and Cecilie fields are currently owned and operated by DONG E & P A/S.

Production infrastructure

The fields have been exploited by several subsea and topside installations, as shown in the table.

class="wikitable"

|+Siri, Nini and Cecilie installations{{Cite web |last=OSPAR |date=2021 |title=OSPAR Inventory of Offshore Installations - 2021 |url=https://odims.ospar.org/en/submissions/ospar_offshore_installations_2021_02/ |access-date=9 November 2020}}{{Cite web |last=A Barrel Full |title=Siri Oil Field |url=http://abarrelfull.wikidot.com/siri-oil-field |access-date=9 November 2023}}

|Name

!Siri (SCA)

!Stine SCB-1

!Stine SCB-2

!Nini A

(Nini West)

!Nini B

(Nini East)

!Cecilie

Block

|5604/20

|5604/20

|5604/20

|5605/10 & 14

|5605/10 & 14

|5604/19 & 20

Coordinates

|56.482686°N

4.911144°E

|56.505947N

5.040943E

|

|56.640805N

5.321124E

|56.674771N

5.412430E

|56.402115N

4.759621E

Water depth, m

|60

|60

|60

|60

|60

|60

Commissioned

|1999

|2004

|

|2003

|2010

|2003

Type

|Fixed steel

|Subsea

|Subsea

|Fixed steel

|Fixed steel

|Fixed steel

Function

|Wellheads, processing, accommodation (60 beds)

|Wellhead

|Wellhead

|Wellheads

|Wellheads

|Wellheads

Wells, production

|6

|1

|1

| colspan="2" |8

|3 oil, 1 gas

Wells, injection

|2

|1

|0

| colspan="2" |6

|0

Substructure weight, tonnes

|2000

|160

|

|2000

|2000

|2000

Topside weight, tonnes

|8000

|0

|

|700

|700

|700

The Siri, Nini and Cecilie fields are stranded assets remote from export infrastructure such as pipelines. Oil from SCA is routed to a 50,000 m3 storage tank on the seabed. The tank is 50 m x 66 m and  17.5 m high. It is emptied periodically by tanker via a Single Anchor Loading (SAL) buoy mooring system.

= Pipelines =

In addition to the offshore installations there are a number of pipelines connecting and transferring fluids within the fields

class="wikitable"

|+Siri, Nini and Cecilie and connected pipelines

!From

!To

!Fluid

!Length, km

!Diameter, inches

!Note

SCB-1

|SCA

|Well fluids

|9

|8

|

SCB-1

|SBC-2

|Injection water

|adjacent

|

|

SCA

|SCB-1

|Lift gas

|9

|3

|

SCA

|SAL

|Crude oil

|

|16

|

Nini B

|Nini A

|Well fluids

|7

|8

|

Nini A

|SCA

|Well fluids

|32

|14

|

Cecilie

|SCA

|Well fluids

|13

|12

|

SCA

|Nini A

|Injection water

|32

|10

|

Nini A

|Nini B

|Injection water

|7

|10

|

SCA

|Nini A

|Lift gas

|32

|4

|

Nini A

|Nini B

|Lift gas

|7

|4

|

SCA

|Cecilie

|Lift gas

|13

|4

|

SCA

|Cecilie

|Injection water

|13

|10

|

Oil production

The oil produced across the fields is shown in the tables.

class="wikitable"

|+Siri, Nini and Cecilie oil production (1000 m3) 1999-2010{{Cite web |last=Danish Energy Agency |date=2022 |title=Monthly and yearly production |url=https://ens.dk/en/our-services/oil-and-gas-related-data/monthly-and-yearly-production |access-date=9 November 2023 |publication-place=Copenhagen}}

|

|1999

|2000

|2001

|2002

|2003

|2004

|2005

|2006

|2007

|2008

|2009

|2010

Siri

|1,593

|2,118

|1,761

|1,487

|925

|693

|703

|595

|508

|598

|326

|286

Cecilie

|0

|0

|0

|0

|166

|310

|183

|116

|88

|66

|38

|33

Nini

|0

|0

|0

|0

|391

|1,477

|624

|377

|323

|355

|159

|544

class="wikitable"

|+Siri, Nini and Cecilie oil production (1000 m3) 2011-22

|

|2011

|2012

|2013

|2014

|2015

|2016

|2017

|2018

|2019

|2020

|2021

|2022

Siri

|161

|232

|131

|94

|200

|206

|189

|162

|124

|79

|60

|53

Cecilie

|39

|32

|17

|10

|23

|39

|32

|31

|28

|25

|23

|23

Mini

|569

|454

|268

|336

|299

|310

|208

|141

|117

|89

|83

|75

Water and recovered gas are co-injected into the Siri and Nini reservoirs to increase oil recovery. An average of 2.98 million m3 of water per year is injected.

The future

The Project Greensand{{Cite web |title=Project Greensand |url=https://www.projectgreensand.com/en |access-date=11 November 2023}} consortium has identified the Nini West subsea reservoir as a feasible carbon dioxide (CO2) storage facility.{{Cite web |date=2023 |title=Denmark Starting signal for successful CCS |url=https://wintershalldea.com/en/where-we-are/denmark}} The reservoir is suitable for injecting 0.45 million tonnes CO2 per year per well for a 10-year period and that it can safely contain the CO2 in compressed form. If successful the project could be extended to the whole Siri field. Work on the project is ongoing.

See also

References