The Caister Murdoch System (CMS) was a major

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon ...

collection, processing and transportation system in the UK sector of the southern

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

. It comprised 11 platforms, 8 subsea

wellhead A wellhead is the component at the surface of an oil or gas well that provides the structural and pressure-containing interface for the drilling and production equipment. The primary purpose of a wellhead is to provide the suspension point and ...

completions and interconnecting pipelines centered about 155 km east of Flamborough Head Yorkshire. It operated from 1993 to 2018.

Background

The Caister Murdoch System (CMS) was originally conceived by

Conoco Conoco Inc. ( ) was an American oil and gas company that operated from 1875 until 2002, when it merged with Phillips Petroleum to form ConocoPhillips. Founded by Isaac Elder Blake in 1875 as the "Continental Oil and Transportation Company". Curre ...

(U.K.) Ltd. and Total Oil Marine plc to develop the Murdock and Caister gas fields. Caister had been discovered by Total in Block 44/23 in January 1968 in

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

Bunter Sands. However, its remote location near the UK /

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

median line meant there was no infrastructure to support the export of gas. The Caister Carboniferous gas field was discovered by Total in Block 44/23 in February 1985 and the Murdoch Carboniferous field by Conoco in Block 44/22 in August 1985. The discovery by

Shell Oil Shell plc is a British multinational oil and gas company headquartered in London, England. Shell is a public limited company with a primary listing on the London Stock Exchange (LSE) and secondary listings on Euronext Amsterdam and the New ...

of the Schooner Carboniferous gas field in Block 44/26 in December 1986 made the development of CMS viable. The hub of the CMS was the Murdoch installation which initially comprised just the Murdoch MD platform. The Caister platform, installed in 1993, was an unmanned satellite. Production from MD began in October 1993 and was through the 188 km 26” pipeline to the

Theddlethorpe gas terminal Theddlethorpe Gas Terminal (TGT) is a former gas terminal on the Lincolnshire coast on ''Mablethorpe Road'' at Theddlethorpe St Helen close to Mablethorpe in East Lindsey in England. It is just off the A1031 and next door to a holiday camp and Ma ...

(TGT) in Lincolnshire. Conoco's Boulton field (1997) and Shell's Schooner and Ketch platforms were tied into the Murdoch system in 1996 and 1999 respectively. As wellhead pressures declined a compression platform Murdoch MC and an accommodation platform Murdoch MA were bridge linked to Murdoch MD. Other fields were tied in from 2000 to 2012.

List

The locations, properties and late-life (2017) operatorship of gas fields tied into CMS were as follows.

Names

The names of gas fields in the area are derived from several themes. * 18th and 19th century scientists, engineers and inventors:

Matthew Boulton Matthew Boulton (; 3 September 172817 August 1809) was an English manufacturer and business partner of Scottish engineer James Watt. In the final quarter of the 18th century, the partnership installed hundreds of Boulton & Watt steam engin ...

;

Henry Cavendish Henry Cavendish ( ; 10 October 1731 – 24 February 1810) was an English natural philosopher and scientist who was an important experimental and theoretical chemist and physicist. He is noted for his discovery of hydrogen, which he termed "infl ...

;

Thomas Hawksley Thomas Hawksley ( – ) was an English civil engineer of the 19th century, particularly associated with early water supply and coal gas engineering projects. Hawksley was, with John Frederick Bateman, the leading British water engineer of the ...

; Hunter;

Lord Kelvin William Thomson, 1st Baron Kelvin, (26 June 182417 December 1907) was a British mathematician, mathematical physicist and engineer born in Belfast. Professor of Natural Philosophy at the University of Glasgow for 53 years, he did important ...

; John McAdam; Munro;

William Murdoch William Murdoch (sometimes spelled Murdock) (21 August 1754 – 15 November 1839) was a Scottish engineer and inventor. Murdoch was employed by the firm of Boulton & Watt and worked for them in Cornwall, as a steam engine erector for ten yea ...

; James Watt. * Sailing vessels:

Ketch A ketch is a two- masted sailboat whose mainmast is taller than the mizzen mast (or aft-mast), and whose mizzen mast is stepped forward of the rudder post. The mizzen mast stepped forward of the rudder post is what distinguishes the ketch fro ...

;

Schooner A schooner () is a type of sailing vessel defined by its rig: fore-and-aft rigged on all of two or more masts and, in the case of a two-masted schooner, the foremast generally being shorter than the mainmast. A common variant, the topsail schoo ...

. * A Norfolk castle: Caister. *Personal names: Katy, Rita. *Gemstone:

Topaz Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al Si O( F, OH). It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can ma ...

(cf. Amethyst gas field).

Developments

The gas fields were developed through an array of platforms and subsea facilities. These were as shown in the following table, together with data on the peak rate and cumulative production of gas in million cubic metres (mcm). In addition to the gas pipelines there was also a methanol distribution system. Methanol/corrosion inhibitor was pumped from TGT through a 4-inch pipeline to Murdoch MD. From here it was distributed to the platforms and wellheads through 3-inch and 2-inch pipelines. New pipeline reception facilities and process plant was installed at TGT as part of the CMS development.

Production

The production profile, in mcm/y, of the Murdoch field was as shown.

Gas compression

Wellhead gas from the individual fields was routed to either the Suction, the Interstage or the Discharge Manifold on Murdoch MC depending on its pressure.Murdoch Compression Flow scheme (undated) Gas from the Suction Manifold was routed to the Suction

Slug Catcher Slug Catcher is the name of a unit in the gas refinery or petroleum industry in which slugs at the outlet of pipelines are collected or caught. A slug is a large quantity of gas or liquid that exists in the pipeline. Slugs Pipelines that tran ...

where liquids were removed. Gas flowed successively to the LP Suction Scrubber, the First Stage Gas

Compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Compressors are similar to pumps: both increase the pressure on a fluid and both can trans ...

and the Intercooler. Here it was comingled with gas from the Interstage Manifold which had flowed through the Interstage Slug Catcher. The combined flow was routed to the Interstage Scrubber, the Second Stage Gas Compressor and the Export Gas Cooler. Gas was returned to the MD platform and to the Theddlethorpe trunk line. Recovered liquids were injected into the trunk line. To increase the compression capacity a compressor module was added to the Murdoch MC platform in 2003.

Telecommunications

Murdoch MD was connected to the Tampnet (formerly NorSea Com-1) submarine telecommunications cable system. It has landing points at Lowestoft, Suffolk, UK and Kårstø, Rogaland, Norway. It is connected to: 1. Draupner platform, operated by Gassco 2. Ula oil field, operated by BP 3. Ekofisk, operated by ConocoPhillips 4. Valhall oil field, operated by BP 5. Murdoch gas field, operated by ConocoPhillips (now disconnected)

Decommissioning

Some CMS fields were shut-in in the 2010s when they became uneconomic to operate. Production from the CMS ceased with the shutdown of the Theddlethorpe gas terminal in August 2018. The platforms and subsea wellhead structures are being removed.

References

{{reflist North Sea energy

Natural gas fields in the United Kingdom