Tor oil field
The Tor oil field is a crude oil and associated gas producing field in the Norwegian sector of the central North Sea. Production of oil and gas started in 1978 and peak oil and gas was achieved in 1979. The field was shut down in 2015 and, following the completion of new wells, started up again in 2020.
The field
The characteristics of the Tor field reservoir are as follows.{{Cite web |last=Norwegian Petroleum |title=Tor field, Norwegian Petroleum |url=https://www.norskpetroleum.no/en/facts/field/tor/ |access-date=12 July 2024}}{{Cite web |last=Norsk Oljemuseum |title=Oil and Gas fields in Norway Tor field, Norsk Oljemuseum |url=https://www.norskolje.museum.no/wp-content/uploads/2016/02/3467_fdf6d757dda446e2bb14aaf4ee8fd1b5.pdf |access-date=12 July 2024}}{{Cite web |last=OSPAR |title=OSPAR Inventory of Offshore Installations - 2021 |url=https://odims.ospar.org/en/search/?search=inventory |access-date=12 July 2024}}
| class="wikitable"
|+Tor field reservoir |Field name |Tor |
| Reservoir
|Late Cretaceous and early Paleocene |
| Block
|2/4 and 2/5 |
| Reservoir depth, metres
|3,200 |
| Gas Oil Ratio, scf/bbl
|1,500 |
| API gravity
|43° |
| Sulfur
|0.1% |
| Pressure, psia
|7,135 |
| Discovered
|November 1970 |
| Original recoverable reserves
|150-260 million bbls oil, 560-900 billion cf gas |
| Now in reserve (2023)
|4.3 million m3 oe oil, 0.4 million m3 oe Gas, 0.3 million m3 oe NGL |
Owners and operator
Infrastructure
The field has been developed with an offshore platform facility, designated Tor E. {{Cite book |last=Oilfield Publications Limited |title=The North Sea Platform Guide |publisher=Oilfield Publications Limited |year=1985 |location=Ledbury |pages=184-6}}
| class="wikitable"
|+Tor field platform Tor E !Parameter !Value |
| Block
|2/4 |
| Latitude
|56.642072°N |
| Longitude
|3.326958°E |
| Water depth, metres
|70 |
| Type
|Fixed steel |
| Platform design
|Kvaerner Engineering |
| Topsides design
|Worley Engineering |
| Function
|Drilling, production, accommodation |
| Bridge
|To flare tower |
| Substructure, tonnes
|5,275 |
| Topsides, tonnes
|6,448 |
| Legs
|8 |
| Piles
|8 |
| Well slots
|18 |
| Accommodation
|58, in 1982 this was replaced by 96 berth accommodation |
| Installed in field
|June 1975 |
| Design throughput
|101,600 bopd, 89 MMscfd gas |
| Processing
|3-phase (oil/gas/water) separator operating at 500 psig, gas dehydration by glycol |
| Export
|7.5 mile, 14-inch gas pipeline and 12-inch oil pipeline to the Ekofisk R |
Production
Production started in July 1978. The production profile was as follows. Units are million standard cubic metres oil equivalent.
| class="wikitable"
|+Tor field production !Year !Oil MMSm3 oe !NGL MMSm3 oe !Gas MMSm3 oe |
| 1978
|1.207351 |0 |0.340779 |
| 1979
|4.526296 |0.139954 |1.156825 |
| 1980
|3.589572 |0.277508 |1.287604 |
| 1981
|1.883789 |0.229188 |1.177126 |
| 1982
|1.53073 |0.272185 |1.341813 |
| 1983
|0.967933 |0.254676 |1.08709 |
| 1984
|0.86721 |0.217469 |0.935608 |
| 1985
|0.824205 |0.201494 |0.779392 |
| 1986
|0.624547 |0.116754 |0.463587 |
| 1987
|0.477363 |0.088523 |0.343058 |
| 1988
|0.482864 |0.095564 |0.31813 |
| 1989
|0.510003 |0.08923 |0.312373 |
| 1990
|0.472642 |0.068414 |0.241651 |
| 1991
|0.346273 |0.037771 |0.161191 |
| 1992
|0.362346 |0.031401 |0.144108 |
| 1993
|0.345858 |0.022479 |0.094797 |
| 1994
|0.338599 |0.019134 |0.074034 |
| 1995
|0.338633 |0.017823 |0.067366 |
| 1996
|0.359242 |0.01719 |0.062885 |
| 1997
|0.34683 |0.017306 |0.057085 |
| 1998
|0.230711 |0.010977 |0.036404 |
| 1999
|0.221491 |0.010784 |0.037131 |
| 2000
|0.255572 |0.010677 |0.040556 |
| 2001
|0.256831 |0.00988 |0.034708 |
| 2002
|0.213535 |0.00818 |0.024964 |
| 2003
|0.162892 |0.00666 |0.017144 |
| 2004
|0.197161 |0.008346 |0.021414 |
| 2005
|0.180349 |0.007957 |0.019744 |
| 2006
|0.164293 |0.008513 |0.023813 |
| 2007
|0.314827 |0.015891 |0.053809 |
| 2008
|0.307169 |0.012521 |0.032965 |
| 2009
|0.291949 |0.010127 |0.024138 |
| 2010
|0.237053 |0.007082 |0.013999 |
| 2011
|0.219272 |0.004878 |0.008242 |
| 2012
|0.22339 |0.005151 |0.007459 |
| 2013
|0.198807 |0.004522 |0.008314 |
| 2014
|0.196979 |0.004482 |0.008718 |
| 2015
|0.180988 |0.003551 |0.006555 |
| 2016
|0 |0 |0 |
| 2017
|0 |0 |0 |
| 2018
|0 |0 |0 |
| 2019
|0 |0 |0 |
| 2020
|0.017476 |0.000875 |0.001435 |
| 2021
|0.804716 |0.036559 |0.073409 |
| 2022
|0.719511 |0.035468 |0.088719 |
| 2023
|0.583491 |0.035511 |0.117698 |
= Developments =
Oil was initially produced by pressure reduction. From 1992, water flood was introduced.
Export from Tor was initially routed by two pipelines to Ekofisk R. Subsequently, in 1998, fluids were routed to Ekofisk 2/4 J.
In 1989, a gas-lift module was added, this allowed eight wells to use gas lift, compared to only three wells formerly.
In 2019, two subsea templates with eight horizontal production wells were tied back to Ekofisk centre.
The remaining recoverable reserves in 2023 were 4.3 million standard cubic meter oil equivalent oil, 0.4 million m3 oe Gas, 0.3 million m3 oe NGL.