{{Short description|Natural gas field in North Yorkshire, England}} {{Use dmy dates|date=September 2025}} {{Use British English|date=September 2025}} The '''Lockton natural gas field''', also known as the '''Ebberston Moor natural gas field''', is a natural gas field under the North York Moors National Park in the United Kingdom.
== Discovery and opening == The field was discovered by the Home Oil Company of Canada in 1966.<ref>{{cite web |url=http://www.ryedalegas.co.uk/history |title=Friends of Ryedale Gas Exploration |access-date=3 September 2016 |archive-date=16 September 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160916170618/http://www.ryedalegas.co.uk/history}}</ref> It is located at a depth of {{convert|5,700|ft|m|abbr=on}} in Middle Magnesian Limestone.<ref name=":1">{{cite book|title=Britain's Onshore Oil Industry|last=Huxley|first=J.|publisher=Springer|year=1983|pages=66–68}}</ref> The gas is about 94% methane, 3% inert gas with traces of hydrogen sulphide.<ref name=":2">{{cite web|url=https://books.google.com/books?id=qLDJukH3hPgC&dq=lockton+gas+field&pg=PA615|title=New Scientist |page=615|date=18 March 1971|access-date=3 September 2016}}</ref> Recoverable reserves were initially estimated to be 250 billion cubic feet (7 billion m<sup>3</sup>).<ref name=":3">{{cite book|title=Natural Gas|last=Tiratsoo|first=E. N.|publisher=Scientific Press Ltd|year=1972|location=Beaconsfield|pages=206, 377}}</ref> In an agreement between the Gas Council and Home Oil/Gas Council Exploration provision was to have been made to use the Lockton gas field for the seasonal storage of natural gas.<ref>{{cite book|title=Natural Gas|last=Tiratsoo|first=E. N.|publisher=Scientific Press Ltd|year=1972|location=Beaconsfield|page=176}}</ref>
To minimise development within the national park area only the gas wells, a field gathering station and underground pipelines were located in the Park. Gas from the gathering station was piped at 1,075 psi (74 bar) via an {{convert|18|in|mm|adj=on}} diameter underground pipeline {{convert|9|mi|km|spell=in}} to a treatment plant in Outgang Lane on the outskirts of Pickering.<ref name=":0">{{cite book|title=North Sea Heritage|last=Wilson|first=D. Scott|publisher=British Gas|year=1974|location=London|pages=31–33}}</ref> Construction of the plant at Pickering started in May 1969 and was operational by August 1971. The total cost of the facilities was £4–£8 million.<ref name=":1" /><ref name=":2" /> It employed about 24 people.<ref name=":1" />
== Operation == Hot water from the treatment plant was circulated in small-bore pipes alongside the pipeline to reduce heat losses and potential hydrate formation, an ice-like substance that can cause blockages. At the Pickering treatment plant raw gas was routed through a slug catcher and inlet separator to remove liquid hydrocarbons and water. Gas flowed to two parallel vetrocoke absorbers where it was washed with a counter-current aqueous solution of soda ash and arsenic compounds to convert the hydrogen sulphide to elemental sulphur. Gas then flowed to a hydrocarbon recovery unit where it was chilled to remove further liquid hydrocarbons, the dry sulphur-free gas passed through a British Gas metering station to Feeder No. 6 of the National Transmission System which passes through Pickering. The sulphur-rich solution from the absorbers was routed to oxidiser regenerators where air was bubbled through the solution to remove the sulphur in the form of a froth. The froth was dried in a rotary vacuum filter and heated in an autoclave to allow removal of impurities prior to being stored in tanks at about 130 °C from where it was removed by heated road tanker. The regenerated absorber solution from the oxidisers, together with recovered solution from the vacuum filters, was returned for reuse in the vetrocoke absorbers. Hydrocarbon liquids were routed to condensate stabilizers and then to storage tanks for removal by road tanker.<ref name=":0" />
== Production, closure and redevelopment == The original agreement between Home Oil and British Gas was a 15-year contract valued at £27 million for the delivery of {{convert|75|e6ft3|e6m3|abbr=off|lk=on}} per day of gas at standard conditions with a maximum flow of {{convert|100|e6ft3|e6m3|abbr=unit}} per day.<ref name=":2" /><ref name=":3" /> By 1974 aquifer water ingress into the gas reservoir had significantly reduced gas production to about {{convert|1|e6ft3|e3m3|abbr=unit}} per day.<ref>{{cite web |url=https://www.geolsoc.org.uk/~/media/shared/documents/specialist%20and%20regional%20groups/petroleum/Oil%20History%20Abstract%20Book.pdf?la=en |title=European Oil and Gas Industry History Conference, 3–4 March 2016, pp. 24–5 |access-date=3 September 2016 |archive-date=15 September 2016 |archive-url=https://web.archive.org/web/20160915022849/https://www.geolsoc.org.uk/~/media/shared/documents/specialist%20and%20regional%20groups/petroleum/Oil%20History%20Abstract%20Book.pdf?la=en |url-status=dead}}</ref> The production and gas treatment facility was permanently shut down in October 1974.<ref name=":1" /> Over three years it had produced {{convert|11.3|e9ft3|e6m3|abbr=unit}} at standard conditions, only 4.5% of the estimated recoverable reserves.
The Lockton gas field is now known as Ebberston Moor. It is licensed to Third Energy.<ref name=":4">{{cite web|url=https://www.third-energy.com/assets-operations|title=Third Energy Ebberston Moor development|access-date=3 September 2016|archive-date=7 April 2019|archive-url=https://web.archive.org/web/20190407174804/https://www.third-energy.com/assets-operations|url-status=dead}}</ref> In 2014 Third Energy announced a joint venture with Moorland Energy Limited (MEL) to develop the Ebberston Moor South development. Gas from the existing Ebberston Moor South well will be transported via a new 14-km pipeline to the Knapton Generating Station.<ref name=":4" />
== References == {{reflist|30em}}
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Category:Natural gas fields in the United Kingdom Category:North Yorkshire