Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia SASEG Annual Convention Geneva June 2019 History of the Exploration and Exploitation of the Tertiary Bituminous Sandstones in the Dardagny Area west of Geneva compiled by Bernhard Gunzenhauser 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 1 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia Tectonic Map of Western Switzerland Jura Molasse Prealpes Area of bituminous Basin Molasse sandstones west of Geneva Geneva Subalpine Chains 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 2 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia Location Map of Seismic & Schematic Cross Sections Geneva Basin Molasse Jura Basin Prealpes Dardagny area Location of seismic and geological sections Subalpine Ref.: Chains 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 3 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia Area of Bituminous Lower Freshwater Interpreted Seismic and Schematic Cross Sections Molasse Sandstones Vuache Geneva Basin Humilly-2 Salève Salève-2 Bornes W E NW SE Ref.: Area of Bituminous Lower Freshwater Molasse Sandstones Ref.: IAS 2014 Field Trip B1 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 4 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia Stratigraphic Section LFM Molasse Ref.: https://data.geo.admin.ch/ch.swisstopo.geologie-geologischer_atlas/legenden/12.png The Lower Freshwater Molasse (LFM) consists of fluviatile sandstones and marls deposited in a low sinuosity river and flood plain environment. LFM Molasse LFM Chattian 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 5 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia Play Types in the Geneva Basin Gas play sourced from Permo-Carboniferous coals present in half grabens. This is the conventional play that has been pursued since many years on the Swiss Plateau with only minor success. Recently, a well drilled at the eastern end of Lake Geneva (well Noville-1) encountered gas in tight Permian sandstones. Oil play sourced from the organic-rich Posidonia shales in the Toarcian. This source rock located at depths of 2’500- 3’000 m is mature for oil in the Geneva Basin and has produced the 14°API oil recovered in the wells Gex and the bitumen impregnated Molasse sandstones in Canton Geneva and karstified Urgonian limestones cored during the construction at the CERN of the LEP (Large Electron Positron Collider) tunnel north of Geneva City. Unfortunately, the migrating oil has not found any trap/seal and reached very close to surface where it has been biodegraded. Posidonia shales are only 14m thick in Humilly-2 and thin towards the northeast in Canton Vaud. The main problem in the Greater Geneva area to allow hydrocarbon accumulation is the a) lack of large structures (although the seismic grid presently available is fairly large), b) effective seals and c) good reservoir quality formations. Potential reservoirs are the Permian sandstones, the Muschelkalk and the bioclastic and oolitic limestones of the Dogger. Reefal carbonates in the Kimmeridgian might be of reservoir quality, but most likely lack a seal. The karstified top surface of the Lower Cretaceous and its siliclastic "Sidérolithique” infill might also be of interest (see bitumen impregnations in the CERN's LEP tunnel above). In this case sealing would depend on the presence of shales in the Molasse. The presence of heavy oil and bitumen generated from the Posidonia shales in the Molasse sandstones and in the Gex wells, respectively and the Molasse at outcrop demonstrates that in this area the migrating oil has not encountered a sealing/trapping system in the whole Mesozoic sequence or that the latter is fractured by transpressional faults. Source: GEOLOGY OF WESTERN SWITZERLAND AND NEARBY FRANCE IN A GEO- ENERGY PERSPECTIVE by Andrea Moscariello and Carole Nawratil De Bono, 2015 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 6 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia History of the Geneva Bituminous Sandstones 18th Century 1769 Jean-Philippe Horneca (dit Horngacher) of Dardagny was trying to establish a company to look for bitumen which was thought to be an indication of coal. 1770 H.B. de Saussure in his book “Voyages dans les Alpes” described the bituminous sandstones in the Geneva area, particularly in the “Nant de Roulavaz”. De Saussure gave a speech at an academic gathering in which he encouraged the public to pay for excavating quarries at Dardagny, believing that there was reason to find thick layers of coal. Based on de Saussure's pledge - a sum of four hundred Louis was collected from twenty-five individuals, but it was impossible to agree with the landowners on the distribution of possible profits and hence no activities resulted thereafter. 1794 The register of the Society of the Arts of December 26, indicates that new research was carried out in Nant-Punais to discover a coal mine, but without results. References: this and following pages: de Girard R. Les Gites d‘Hydrocarbures de la Suisse Occidentale 1913 and Lagotala H. Les gîtes bitumineux de Dardagny (Genève). Le Globe. Revue genevoise de géographie, tome 71, 1935 and Andrea Moscariello and Carole Nawratil De Bono, 2015 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 7 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia History of the Geneva Bituminous Sandstones 19th Century (1) 1824 On October 24 a public limited company with the title «Société pour la recherche et l'exploitation de diverses substances minérales et spécialement de la houille ("Society for Research and Exploitation of Mineral Substances and especially Coal") was formed in Geneva. No activities were reported. 1825 On 29 December, M. Tessier from Geneva and owner of coal mines in France started with a first “puits” (shaft/well) and a gallery at the “culmination point of Dardagny” (Bois de Roulavaz or Roulave). Apparently the well only found bituminous molasse sandstones and was abandoned at 16 m depth due to strong gas eruptions. The exact location of this first shaft is not known. 1826 On 16 November an article in the “Journal de Genève” announced a discovery of “a lot of oil” in the vicinity of Dardagny. Further it says: “This oil obtained flows naturally, is black, of excellent quality, and floats on the water coming out with the oil”.. The article most likely refers to the second “puits” (shaft/well) by Tessier which was probably started in March 1826 and excavated to a depth of 12 m (40 ft). This “puits Tessier” is most likely the “mine de goudron” on the left bank of Nant Punais as described in various articles and depicted in maps of that time. Apparently, excellent quality of bitumen was found. The well was deepend to 50 ft without finding coal. In order to exploit petroleum oil, it was decided to excavate a gallery starting from the shaft at a depth of 40 ft and going upward with an inclination of 45 degrees to reach the surface at some distance of the shaft. The operators assumed to collect 30 litres of bitumen a day. According to Pareto, the well reached a depth of 30 m and was stopped in 1827. 22 June 2019 B. Gunzenhauser - Dardagny Bituminous Sandstones 8 Swiss Association of Energy Geoscientists Association suisse des géoscientifiques de l’énergie Schweiz. Vereinigung von Energie-Geowissenschaftern Associazione svizzera geoscienziati dell’ energia History of the Geneva Bituminous Sandstones 19th Century (2) 1836-1839 Bitumen was more and more used as pavement and from 1836 until 1839 a company headed by M. de Grenus installed boilers at the Nant Punais to extract the bitumen which was transported to Geneva, where the company Sandino and Girel used the “goudron” or “mastic” to cover the market of the Corraterie (1838), for the paving of a brewery of Plainpalais, a terrace in Pregny, and in 1839 these products were used for special works at the Fort de l'Ecluse. 1838 The parliament of Geneva dealt with a mining legislation, which was applied for the first time in 1839. 1839 Extraction at the Puits Tessier (mine de goudron) stopped, probably for not having enough supply. 1850 A well (puits) was sunk on the right bank of the Allondon river near the railway bridge at La Plaine with the aim to find coal. After crossing 36 m of bituminous sandstones, the well had to be stopped because of gas emanations to an extent that a ventilator had to be installed. 1856-1894