@ Sam Stickland,
Clive, do you have a link/further information...
Sorry I can't find a link specificaly to it. It was back in the 1980's somebody discovered that the geology under Paris and environs and wanted to drill test wells to find what was there . In order to passify the locals who were most definatly not keen the Total SA test drills in the Champs-Elysees were "hidden" behind false building fronts. Most of the test drills were dry and later one or two that were not actually had real buildings put over the top as well.
However even though central Paris it's self was not destined back then to be a major production site. It was actualy found that the best area was some fifty or so miles outside of Paris towards the champagne and brie producing area. And at it's peak in 1988 it was producing around 40,000 barrels a day which has dropped back to around 10,000 currently.
What however brought it back to mind was a chat with a French friend a few days ago apparently there was a bit of an uproar prior to the French Presidential ellections in France because a US company had been given experimental permits to start shale oil fracking under Paris , and apparently it's started again. My friend being somewhat younger than me (most people are ;-) was not even aware that for over a quater of a century the Parisian countryside and one or two back streets of Paris have been oil producers...
16 months ago the previous uproar had caused the legislators to put forward laws to ban Fracking.And this caused the companies involved significant problems,
 Back in the late 1970s early 1980s back befor Digital Signal Processing had made it out of the computer research labs the geological sismic "echo sounding" of strata using large quantities of explosives  and geophones did not work to well in busy cities due to urban noise drowning out any signals.
 Apparently for some strange reason people setting off large quantities of dynamite around Paris was considered unpopular with the locals many of whom had lived through WWII.
 Currently Vermilion Energy Inc., Toreador Resources Corp and partner Hess Corp. are targeting oil trapped in Paris Basin shale rock previously thought too hard to extract, and Vermilion has told the industry it has had positive results so far in the Paris Basin. However the techniques developed to do this known by many under the collective term "fracking" uses various explosive hydröooooooooooooooooooooooooooooooooootechniques to blast water and chemicals to pulverize the rock and release hydrocarbons from the shale. This process which has supposadly revolutionized and significantly boosted U.S. natural gas production since 2006, is unpopular with the French populous in the area . So much so that it's caused significant delays and prompted Craig McKenzie (Toreador's CEO) to say, “If the Paris Basin was in West Texas it would already be drilled and would have pretty substantial production”.
 Even in the home of Fracking the US it is very unpopular and has been accused of much damage to the environment and water supplies. For instance the gas-rich Marcellus Shale running from West Virginia down to New York has had 1,785 wells have been drilled in Pennsylvania’s portion since 2008, However New York regulators have under public preasure placed a moratorium on Fracking because of what has been said is the high likely hood of pollution of groundwater in what is a high population density area of the US.