Kola Superdeep Borehole

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{{Infobox mine

| name = Kola Superdeep Borehole SG-3

| image = File:Кольская сверхглубокая скважина crop.jpg

| width =

| caption = Superstructure of the Kola Superdeep Borehole, 2007

| pushpin_map = Russia#Russia Murmansk Oblast

| pushpin_mapsize =

| pushpin_map_alt =

| pushpin_map_caption = Location of the borehole in Murmansk Oblast, Russia

| pushpin_image =

| pushpin_label =

| pushpin_label_position =

| coordinates = {{Coord|69.3965|N|30.6100|E|type:landmark_region:RU|display=inline,title}}

| place = Pechengsky District

| subdivision_type = Province

| state/province = Murmansk Oblast

| country = Russia

| products =

| amount =

| financial year =

| type = Scientific borehole

| greatest depth = {{convert|12262|m|ft}}

| opening year = 1965

| active years = {{hlist|1970–1983|1984|1985–1992|1994}}

| closing year = 1995

| owner =

| official website =

| acquisition year =

| module =

}}

The Kola Superdeep Borehole SG-3 ({{langx|ru|Кольская сверхглубокая скважина СГ-3|translit=Kol'skaya sverkhglubokaya skvazhina SG-3}}) is the deepest human-made hole on Earth (since 1979), which attained maximum true vertical depth of {{convert|12262|m|ft mi}} in 1989.{{cite magazine |title=What's the deepest hole ever dug? |date=19 February 2015 |department=Ask Smithsonian |magazine=Smithsonian |publisher=Smithsonian Institution |place=Washington, DC |url=http://www.smithsonianmag.com/smithsonian-institution/ask-smithsonian-whats-deepest-hole-ever-dug-180954349 |last=Ault |first=Alicia}} It is the result of a scientific drilling effort to penetrate as deeply as possible into the Earth's crust conducted by the Soviet Union in the Pechengsky District of the Kola Peninsula, near the Russian border with Norway.

SG (СГ) is a Russian designation for a set of superdeep ({{langx|ru|сверхглубокая}}) boreholes conceived as part of a Soviet scientific research programme of the 1960s, 1970s and 1980s. Aralsor SG-1 (in the Pre-Caspian Basin of west Kazakhstan) and Biyikzhal SG-2 (in Krasnodar Krai), both less than {{convert|6810|m|ft}} deep, preceded Kola SG-3, which was originally intended to reach {{convert|7000|m|ft}} deep.{{cite journal | title=Initial results of geophysical and geochemical investigations of very deep boreholes | first1=F.A. | last1=Alekseyev | first2=N.K. | last2=Kukharenko | first3=G.I. | last3= Voytov | first4=Yu.A. | last4=Galkin | journal=International Geology Review | year=1972 | volume=14 | issue=3 | pages=275–280 | doi=10.1080/00206817209475693| bibcode=1972IGRv...14..275A }} Drilling at Kola SG-3 began in 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig. A total of five {{convert|9|in|cm|order=flip|adj=mid|-diameter}} boreholes were drilled, two branching from a central shaft and two from one of those branches.

In addition to being the deepest human-made hole on Earth, Kola Superdeep Borehole SG-3 was, for almost three decades, the world's longest borehole in measured depth along its bore, until surpassed in 2008 by a hydrocarbon extraction borehole at the Al Shaheen Oil Field in Qatar.{{cite news |title=Maersk Oil finished Drilling (BD-04A) well at Al-Shaheen field, Qatar |date=23 May 2008 |website=Gulf Oil & Gas Marketplace |url=http://www.gulfoilandgas.com/webpro1/main/mainnews.asp?id=6050 |access-date=15 November 2010}}

Drilling

File:1987 CPA 5892.jpg

Drilling at Kola SG-3 began on 24 May 1970 using the Uralmash-4E, a serial drilling rig used for drilling oil wells. The rig was slightly modified to be able to reach a {{convert|7000|m|ft|adj=on}} depth. In 1974, the new purpose-built Uralmash-15000 drilling rig was installed onsite, named after the new target depth, set at {{convert|15000|m|ft}}.{{cite web |last=Королев |first=Владимир |date=2016-08-06 |title=Подземное неземное |website=nplus1.ru |url=https://nplus1.ru/material/2016/08/06/Kola-Superdeep-Borehole |access-date=2021-08-08}}

On 6 June 1979, the world depth record then held by the Bertha Rogers hole in Washita County, Oklahoma, United States, at {{convert|9583|m|ft}},{{cite news |title=The KTB borehole – Germany's superdeep telescope into the Earth's crust |date=January 1995 |website=Oilfield Review |url=http://www.slb.com/media/services/resources/oilfieldreview/ors95/jan95/01950422.pdf |access-date=8 April 2009 |archive-url=https://web.archive.org/web/20081219150858/http://www.slb.com/media/services/resources/oilfieldreview/ors95/jan95/01950422.pdf |archive-date=19 December 2008}} was broken by Kola SG-3.{{cite journal | title=The 50th Anniversary of the Start of Drilling the Kola Superdeep Well | last1=Lobanov | first1=K.V. | last2=Chicherov | first2=M.V. | last3=Sharov | first3=N.V. | journal=Arktika i Sever [Arctic and North] | year=2021 | issue=44 | pages=267–284 | doi=10.37482/issn2221-2698.2021.44.267| doi-access=free }} In October 1982, Kola SG-3's first hole reached {{convert|11662|m|ft}}.{{cite periodical |last1=Яковлев |first1=Ю.Н. |last2=Скуфьин |first2=П.К. |last3=Чвыков |first3=О.С.Ч. |year=2014 |title=Влияние Природных Факторов на Траекторию и Форму Стволов Кольской Сверхглубокой Скважины (СГ-3) |trans-title=The Influence of Natural Factors on the Trajectory and Shape of the Trunks of the Kola Superdeep Borehole (SG-3) |periodical=Вестник Кольского научного центра РАН [Bulletin of the Kola Science Center of the Russian Academy of Sciences] |volume=2014-03 |pages=8–15 |url=https://www.ksc.ru/docs/vestnik/vestnik-3-2014.pdf |lang=ru}}

The second hole was started in January 1983 from a {{convert|9300|m|ft|adj=on}} depth of the first hole. In 1983, the drill passed {{convert|12000|m|ft}} in the second hole, and drilling was stopped for about a year for numerous scientific and celebratory visits to the site. This idle period may have contributed to a breakdown after drilling resumed; on 27 September 1984, after drilling to {{convert|12066|m|ft}}, a {{convert|5|km|mi|adj=on}} section of the drill string twisted off and was left in the hole. Drilling was restarted in September 1986, {{convert|7000|m|ft}} from the first hole.{{Cite web |last=Osadchy |first=A. |date=2002 |title=Legendary Kola Superdeep |url=http://www.nkj.ru/archive/articles/4172/ |access-date=8 May 2009 |website=Наука и жизнь [Journal of Science and Life] |language=ru |volume=5}}

The third hole reached {{convert|12262|m|ft}} in 1989.{{Cite magazine |date=2023-06-01 |title=Why Is China Drilling a 33,000-Feet Hole in Xinjiang? |url=https://time.com/6284032/china-drill-hole-xinjiang/ |access-date=2023-08-16 |magazine=Time |language=en}} In that year, the hole depth was expected to reach {{convert|13500|m|ft}} by the end of 1990 and {{convert|15000|m|ft}} by 1993.{{cite news |title=Kola Superdeep is in the Guinness Book of World Records |periodical=Zemlya I Vselennaya |year=1989 |number=3 |page=9 |language=ru}}{{cite web |first1=Adam |last1=Cassino |year=2003 |title=Depth of the deepest drilling |website=hypertextbook.com |series=The Physics Factbook |url=http://hypertextbook.com/facts/2003/AdamCassino.shtml}}{{Failed verification|date=August 2021}} In June 1990, a breakdown occurred in the third hole at {{convert|12262|m|ft}} of depth.

The drilling of the fourth hole was started in January 1991 from {{convert|9653|m|ft}} of depth of third hole. The drilling of the fourth hole was stopped in April 1992 at {{convert|11882|m|ft}} of depth.

Drilling of the fifth hole started in April 1994 from {{convert|8278|m|ft}} of depth of the third hole. Drilling was stopped in August 1994 at {{convert|8578|m|ft}} of depth due to lack of funds, and the well itself was mothballed.

Research

The stated areas of study of the Kola Superdeep Borehole were the deep structure of the Baltic Shield, seismic discontinuities and the thermal regime in the Earth's crust, the physical and chemical composition of the deep crust and the transition from upper to lower crust, lithospheric geophysics, and to create and develop technologies for deep geophysical study. Drilling penetrated about a third of the way through the Baltic Shield of the continental crust, estimated to be around {{convert|35|km|mi}} deep, reaching Archean rocks at the bottom.{{Cite book |last=Ramberg |first=Ivar B. |url=https://books.google.com/books?id=rMVNE0F2SckC |title=The making of a land: geology of Norway |publisher=Norsk geologisk forening |year=2008 |isbn=978-82-92394-42-7 |location=Trondheim |page=624 |language=en |access-date=27 January 2010 |name-list-style=amp}} Numerous unexpected geophysical discoveries were made:

During the drilling process, the expected basaltic layers at {{convert|7|km|mi}} down were never found, nor were basaltic layers at any depth.{{Cite web |last=Andrei |first=Mihai |date=2014-06-03 |title=The World's Deepest Hole Lies Beneath this Rusty Metal Cap - The Kola Superdeep Borehole |url=https://www.zmescience.com/other/feature-post/worlds-deepest-hole-lies-beneath-rusty-metal-cap-kola-superdeep-borehole/ |access-date=2022-12-28 |website=ZME Science |language=en-US}} There were instead more granites, deeper than predicted. The prediction of a transition at 7 kilometres was based on seismic waves indicating discontinuity, which could have been caused by a transition between rocks, or a metamorphic transition in the granite itself.
Water pooled {{convert|3|-|6|km|mi}} below the surface,{{Cite journal |date=March 1995 |title=95/01953 Characterization of crystalline rocks in deep boreholes. The Kola, Krivoy Rog and Tyrnauz boreholes |url=http://dx.doi.org/10.1016/0140-6701(95)93618-1 |journal=Fuel and Energy Abstracts |volume=36 |issue=2 |pages=133 |doi=10.1016/0140-6701(95)93618-1 |issn=0140-6701|url-access=subscription }} having percolated up through the granite until it reached a layer of impermeable rock.{{Cite web |title=Where is Earth's Water? {{!}} U.S. Geological Survey |url=https://www.usgs.gov/special-topics/water-science-school/science/where-earths-water |access-date=2022-12-28 |website=www.usgs.gov}}{{Cite web |last=Bellows |first=Alan |date=5 March 2007 |title=The Deepest Hole |url=http://www.damninteresting.com/the-deepest-hole/ |access-date=27 December 2014 |website=Damn Interesting}} This water did not naturally vaporize at any depth in the borehole.
The drilling mud that flowed out of the hole was described as "boiling" with an unexpected level of hydrogen gas.{{Cite book |last1=Bodén |first1=Anders |title=Deep Drilling in Crystalline Bedrock: The deep gas drilling in the Siljan impact structure, Sweden and astroblemes |last2=Eriksson |first2=K. Gösta |date=1988 |publisher=Springer-Verlag |isbn=978-0-387-18995-6 |language=en}}
Microscopic plankton fossils were found {{convert|6|km|mi}} below the surface.

In 1992, an international geophysical experiment obtained a reflection seismic crustal cross-section through the well. The Kola-92 working group consisted of researchers from the universities of Glasgow and Edinburgh in the United Kingdom, the University of Wyoming in the United States, and the University of Bergen in Norway, as well as several Russian earth science research institutions.

{{cite journal

|last1=Smythe |first1=D.K. |last2=Smithson |first2=S.B.

|last3=Humphreys |first3=C. |last4=Gillen |first4=C.

|last5=Kristoffersen |first5=Y. |last6=Karaev |first6=N.A.

|last7=Garipov |first7=V.Z. |last8=Pavlenkova |first8=N.I.

|date=1994

|title=Project images crust, collects seismic data in world's largest borehole

|journal=Eos, Transactions American Geophysical Union

|volume=75 |issue=41 |pages=473–476

|doi=10.1029/94EO01089 |issn=2324-9250

|language=en

|url=http://www.davidsmythe.org/professional/pdf/1994%20smythe%20etal%20kola92%20project%20eos.pdf

}}

The experiment was documented in a video recorded by Professor David Smythe,

{{cite AV media

|title=The Kola superdeep borehole in action : geophysical surveys and wellhead operations 1992

|year=1992

|people=Smythe, D.K. (videographer)

|url=https://www.youtube.com/watch?v=P4mzEGeMNAI |via=YouTube |medium=video

}}

which shows the drilling deck in action during an attempt to recover a tool dropped down the hole.

Status

{{multiple image

|align=right |direction=vertical |width=

|image1=Кольская сверхглубокая скважина (2012).jpg |caption1=The borehole site in 2012

|image2=Сама скважина(заварена), август 2012.JPG |caption2=The borehole (welded shut), August 2012

}}

The drilling ended in 1995 due to a lack of funding.{{Cite web |last=Khokhlova |first=Galina |date=15 October 2008 |title=Гордость пойдет в утиль: Кольская сверхглубокая скважина будет ликвидирована |trans-title=Pride goes to waste: Kola superdeep borehole to be scrapped |url=http://www.rg.ru/2008/10/15/skvazhina.html |access-date=9 July 2010 |website=Российская Газета [Rossiyskaya Gazeta] |language=ru}} The scientific team was transferred to the federal state unitary subsidiary enterprise "Kola Superdeep," downsized, and given the new task of thoroughly studying the exposed section. In 2007, the scientific team was dissolved and the equipment was transferred to a private company and partially liquidated.

In 2008, the company was liquidated due to unprofitability,{{cite news |title=Росимущество ликвидирует самую глубокую скважину в мире |date=2008-04-10 |url=https://lenta.ru/news/2008/04/10/skvazh/ |access-date=2021-08-08 |website=lenta.ru |language=ru}} and the site was abandoned. It is still visited by sightseers, who report that the structure over the borehole has been partially destroyed or removed.{{cite web |title=Kola superdeep borehole, Murmansk, Russia |url=https://www.atlasobscura.com/places/kola-superdeep-borehole?mc_cid=69025636df&mc_eid=34be11d5e3 |access-date=14 August 2020 |website=Atlas Obscura}}

Similar projects

The United States had embarked on a similar project in 1957, dubbed Project Mohole, which was intended to penetrate the shallow crust under the Pacific Ocean off Mexico. After initial drilling, the project was abandoned in 1966 when funding was cut off. This program inspired the Ocean Drilling Program, Integrated Ocean Drilling Program, and the present International Ocean Discovery Program.
The KTB superdeep borehole (German Continental Deep Drilling Programme, 1987–1995) at Windischeschenbach in northern Bavaria was drilled to a depth of {{convert|9101|m|ft}}, reaching temperatures of more than {{convert|260|°C|°F}}. Its ambitious measuring program used high-temperature logging tools that were upgraded specifically for KTB.

{{cite journal

|last1=Emmermann |first1=Rolf

|last2=Lauterjung |first2=Jörn

|year=1997

|title=The German continental deep drilling program KTB: Overview and major results

|journal=Journal of Geophysical Research: Solid Earth

|volume=102 |issue=B8 |pages=18179–18201

|doi=10.1029/96JB03945 |doi-access=free

|bibcode=1997JGR...10218179E |issn=2156-2202

|language=en

|url=http://userpage.fu-berlin.de/geodyn/tutorials/Praktikum/pdf/Emmermann-etal1997_JGR.pdf

|archive-url=https://web.archive.org/web/20121030115502/http://userpage.fu-berlin.de/geodyn/tutorials/Praktikum/pdf/Emmermann-etal1997_JGR.pdf

|archive-date=30 October 2012

}}

In 2023, China embarked on a {{convert|10000|m|ft mi|adj=on}} super-deep borehole in the Tarim Basin in the Xinjiang region for scientific, oil and gas exploration.{{Cite web |title=China begins drilling one of world's deepest holes in hunt for discoveries deep inside the Earth |first=Rachel |last=Cheung |work=the Guardian |date=6 June 2023 |access-date=10 June 2023 |url= https://www.theguardian.com/world/2023/jun/06/china-begins-drilling-one-of-worlds-deepest-holes-in-hunt-for-discoveries-deep-inside-the-earth |quote=China has begun digging its deepest borehole in an effort to study areas of the planet deep beneath the surface. The drilling of the borehole began on Tuesday in a desert in the Tarim basin in China’s north-western region of Xinjiang, according to the Chinese state-run Xinhua news agency. With a planned depth of 11,100 metres, the narrow shaft will penetrate more than 10 continental strata and reach the cretaceous system in the Earth’s crust – a series of stratified rocks dating back 145 million years.}}{{Cite web |title=China's 10,000-meter deep dive into scientific exploration |last=Sharma |first=Sejal |work=interestingengineering.com |date=31 May 2023 |access-date=10 June 2023 |url= https://interestingengineering.com/innovation/chinas-10000-meter-deep-dive-into-scientific-exploration}}{{Cite web |title=China drilling hole over 11,000m deep into the desert |work=Sky News |date=2 June 2023 |access-date=10 June 2023 |url= https://news.sky.com/story/china-drilling-hole-over-11-000m-deep-into-the-desert-12894901}} In March 2024, drilling of the borehole, which is known as Shendi Take 1, reached a depth of 10,000 metres.{{Cite web |last=Andeso |first=Albert |date=11 March 2024 |title=China's Deepest Borehole Exceeds 10km Milestone |url=https://www.constructionkenya.com/11932/china-deepest-borehole/ |access-date=11 March 2024 |publisher=Construction Kenya}}

Records

The {{convert|12262|m|ft|adj=on}} deep Kola Superdeep Borehole has been the world's deepest borehole since 1979.

{{cite web

|title=Kola Superdeep Borehole (KSDB)

|work=ICDP

|url=http://www-icdp.icdp-online.org/front_content.php?idcat=695

|access-date=21 July 2017 |url-status=dead

|archive-url=https://web.archive.org/web/20140507113717/http://www-icdp.icdp-online.org/front_content.php?idcat=695

|archive-date=7 May 2014

}}

It was also the longest borehole in the world from 1979 to 2008. Its record length was surpassed in May 2008 by the curved extended reach drilling bore of well BD-04A in the Al Shaheen Oil Field in Qatar, which attained a total length of {{convert|12289|m|ft}} but depth of just {{convert|1387|m|ft}}.

{{cite press release

|title=Transocean GSF rig 127 drills deepest extended-reach well

|date=21 May 2008

|publisher=Transocean Ltd.

|url=http://www.deepwater.com/fw/main/Transocean-GSF-Rig-127-Drills-Deepest-Extended-Reach-Well-283C4.html |access-date=15 November 2010 |url-status=dead

|archive-url=https://web.archive.org/web/20101112192456/http://www.deepwater.com/fw/main/Transocean-GSF-Rig-127-Drills-Deepest-Extended-Reach-Well-283C4.html

|archive-date=12 November 2010

}}

{{cite news

|title=Maersk Oil finished Drilling (BD-04A) well at Al-Shaheen field, Qatar

|date=23 May 2008

|website=Gulf Oil & Gas Marketplace

|url=http://www.gulfoilandgas.com/webpro1/main/mainnews.asp?id=6050

|access-date=15 November 2010

}}

References

External links

[http://superdeep.pechenga.ru/ Official Kola Superdeep Borehole website] {{in lang|ru}}
[https://www.gi.alaska.edu/alaska-science-forum/worlds-deepest-hole The World's Deepest Hole – Alaska Science Forum – July 1985]
[http://www.damninteresting.com/?p=567 The Deepest Hole] 20 June 2006
[http://nauka.relis.ru/06/0205/06205036.htm Kola Superdeep – Scientific research results and experiences by PhD A. Osadchikh] 1984 {{in lang|ru}}
[http://alexeyzaytsev.ru/2017/10/26/kola-superdeep/ Photo report on a trip to the Kola superdeep well in 2017]. Many photos of the current state. {{in lang|ru}}

Category:1970 establishments in the Soviet Union

Category:Buildings and structures in Murmansk Oblast

Category:Cancelled projects

Category:Deepest boreholes

Category:Earth's crust

Category:Science and technology in Russia

Category:Science and technology in the Soviet Union

Category:Structure of the Earth

Category:Vertical distributions

Category:Extreme points of Earth