Editing Petroleum (section)

==== Oil window (temperature range) ====
Geologists often refer to the temperature range in which oil forms as an ''"oil window"''.<ref name="Stanford_Edu">{{Cite web |last=Malyshev |first=Dmitry |date=December 13, 2013 |title=Origin of oil |url=http://large.stanford.edu/courses/2013/ph240/malyshev2/ |url-status=live |archive-url=https://web.archive.org/web/20210921125720/http://large.stanford.edu/courses/2013/ph240/malyshev2/ |archive-date=September 21, 2021 |access-date=September 21, 2021 |website=large.stanford.edu |language=English}}</ref><ref>{{Cite book |url=https://books.google.com/books?id=xwLHnC9qMsgC&pg=PA104 |title=Polar Prospects:A minerals treaty for Antarctica |publisher=United States, Office of Technology Assessment |year=1989 |isbn=978-1-4289-2232-7 |page=104 |access-date=May 12, 2020 |archive-url=https://web.archive.org/web/20200729203620/https://books.google.com/books?id=xwLHnC9qMsgC&pg=PA104 |archive-date=July 29, 2020 |url-status=live}}</ref><ref name="Schobert-2013" /> Below the minimum temperature oil remains trapped in the form of kerogen. Above the maximum temperature the oil is converted to natural gas through the process of [[thermal cracking]]. Sometimes, oil formed at extreme depths may migrate and become trapped at a much shallower level. The [[Athabasca oil sands]] are one example of this.<ref name="Schobert-2013" />