France
The PLM-2 exploration well on the Attila licence in France was drilled in the third quarter 2007. In July 2008, well completion and production tests were conducted on the well but only a minor gas flow occurred.
In the first quarter 2006, Tethys Oil and the operator Galli Coz S.A. were awarded the Attila licence by the French government. The licence is located about 250 kilometres east of Paris in the oil and gas producing Paris basin. Attila covers 1,986 square kilometres. Tethys has a 40 per cent interest in the licence with the operator Galli Coz S.A. having 60 per cent. The licence is valid for a period of five years.
The exploration well Pierre Maubeuge 2 was drilled during autumn 2007. The result was sufficiently promising, and a decision to carry out a production test was taken. This test was conducted in the summer 2008 without any production flows.
Geology
In general, the Paris basin is an oil basin because the depth of burial of the source rock is enough to generate oil but not deep enough, i.e. hot enough, to make natural gas. However to the east, starting under the Trois-Fontaines field and extending into Germany, there are gas generating source rocks present in the subsurface. Tethys’ objective in France is to find natural gas accumulations similar to the adjacent gas field Trois-Fontaines. A small natural gas discovery called Montplonne was made within the licence by Esso. The discovery was however non-commercial at the time due to lack of infrastructure. Since then a 36 inch natural gas pipeline has been constructed across the middle of the licence area.
The gas source rocks on the licence are of Carboniferous age, and they are excellent natural gas-generating source rocks. For example, all of the gas produced in the southern North Sea, United Kingdom and Netherlands, were derived from these coals.
The presence of a gas field in this region of France is encouraging because it shows that there is in existence a working system to generate and trap natural gas.
Tethys’ belief is that there has not been sufficient exploration to find more fields. Within the near 2,000 square kilometres Attila licence area, only 12 wells have been drilled deep enough to penetrate the Triassic-aged reservoirs that contain gas in Trois-Fontaines. This drilling density, 1 well per 166 square kilometres, could be compared with the average drilling density for Europe with one exploration well for every 116 square kilometres and in the USA with one per 28 square kilometres.
Work programme
In order to identify fault trends, a comprehensive work programme was carried out in 2006. The programme included acquisition and analyzing of satellite and radar data and reprocessing of about 180 kilometres of existing seismic data. Geochemical surface samples were also collected and analyzed. The result confirmed the prospectivity of the area, and a decision to carry on with the exploration drilling of the Pierre Maubeuge 2 well (PLM-2) was taken The main work in France during the last part of 2006 was geared at securing permits for suitable well locations and detailed discussions and negotiations with local communities involved. The operator conducted several meetings and evaluated a number of possible surface locations from the perspective of suitability and accessibility. On April 24, 2007, drilling permission was received from the French local administration.
By August, all necessary permits had been obtained and preparations at the drill site had started. In mid August, the partner group entered into a drilling contract with French contractor COFOR for the drilling of the Pierre Maubeuge 2 (PLM-2) exploration well. At the end of August, the drilling pad was cemented in place.
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The mobilization of the MR-7000 drilling rig commenced on September 18, and near the end of the month PLM-2 was spudded. After less than three weeks of drilling operations, the well was finalized at a total depth of 1,310 metres. During drilling gas shows were recorded in the Triassic formation below a salt layer. The well was subsequently logged and an 80 metre zone of gross pay was identified. Over this mainly limestone section, a total of 10.5 metres net natural gas pay was calculated. This result was sufficiently promising, and a decision to carry out a production test was taken.
In July 2008, well completion and production tests were conducted on the well but only a minor gas flow occurred. An evaluation of the well results was conducted and it was decided to re-test the well during the autumn of 2008. Higher gas flows were recorded during this test; however the results proved the PLM-2 well to be non commercial in its current state. Although disappointing, this result supports the overall prospectivity of the Attila licence.
| License | Tethys Oil’s share | Total area | Partner |
| Attila | 40 % | 1,986 km 2 | Galli Coz S.A. |
| Total areal | 1,986 km 2 |
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