ONSHORE DISCOVERIES SPUR SEARCH IN BAY OF BISCAY

Even as France's hydrocarbon exploration scene has fallen to a modem low, operators are renewing interest in the offshore arena they had abandoned during the past 15 years,

Offshore interest had waned under the combined effects of successive setbacks and failing oil prices.

Two onshore discoveries around the Arcachon basin on the Bay of Biscay by Esso Rep, Esso France's exploration and production arm, sparked the recent interest. Then the government scrapped all taxes and royalties on offshore production from this year forward, further bolstering interest.

Reprocessing of old data on France's offshore areas with new computer technology and the introduction of 3D seismic technology have thrown new light on areas that were well explored in past decades.

Elf Aquitaine and Esso Rep, the two veteran discoverers of major oil and gas fields in the Aquitaine basin in southwestern France, are spearheading offshore exploration in the Bay of Biscay.

ESSO REP PLANS

Esso Rep has two new permits in the area.

One is Permis de Lege, where Esso Rep made the Les Arbousiers discovery in Purbeckian (Upper Jurassic) sandstone at yearend 1991 (OGJ, Apr. 13, 1992, p. 26). The Les Pins discovery followed in March 1994.

The other permit is Cap-ferret Ocean, where Esso Rep will carry out an $8.8 million 3D seismic campaign this summer, believing that the Purbeckian theme continues offshore.

"We wouldn't be launching offshore seismic if we hadn't a clear idea of what we were looking for," said Esso Rep President Jean Verre. "Les Arbousiers has proved that even an area which has been thorough explored over 30-40 year could yield something new." Indeed, the area i very fractured, and it is easy to miss a prospect.

Les Arbousiers near the town of Arcachon is no producing 10,000 b/d of oil from three wells-water is being injected into a fourth well-and is now linked b pipeline to Cazaux oil field processing and storage facilities.

Les Pins, a little further north, produces 6 b/d from a deviated well. Les Pins field is located under the town of Arcachon. Esso Rep is operator in association with Elf Aquitaine on Permis de Lege.

OFFSHORE ACTIVITY

On Permis Cap-ferret Ocean Esso has a 100% stake.

During 1993-94 the company concentrated on seismic and believes Purbeckian potential continues offshore, at least to the west and south. Compagnie Generale de Geophysique carried out 121 sq km of seismic during Jan. 25-May 12, 1993, and this led to the I Les Pins well.

A further geological indication of Purbeckian themes running offshore is provided by Esso's Lavergne acreage, between Cap ferret Ocean and Permis de Lege. Lavergne field has produced more than 12.7 million bbl of oil between 1961 and yearend 1993 from Purbeckian sandstone. The field was shut down because of marine erosion.

Bassin d'Arcachon is separated from the Atlantic Ocean by a 3-4 km peninsula with Cap-ferret at its south end. Cap-ferret Ocean is a 20 by 20 km tract along the peninsula.

However, Esso Rep's 1994 exploration/production budget of $49.3 million, slightly higher than last year's, is almost exclusively geared to the Aquitaine basin.

"We might drill one or two wells at yearend on Cap-ferret Ocean depending on interpretation of our summer 3D seismic campaign," Verre said.

In any case such holes would have to be drilled from shore with 3-4 km of displacement, most likely from Les Pins, because the area is environmentally sensitive and a busy tourist attraction.

Elf Aquitaine had carried out conventional seismic some 10 years ago in the area and has reworked it with 3D seismic in the south. It has three offshore permits in the Bay of Biscay.

Offshore the Bay of Biscay, facing Cap-ferret, it is operator in association with Agip on the Born Maritime permit. Located opposite Esso's giant Parentis oil field, the prospects are linked to the Parentis Aptian theme.

A hole drilled in the area in the 1960s had shown interesting oil traces, and 3D seismic has afforded a better view of the subsurface.

Elf and Agip acquired 358 sq km of seismic during August October 1993 on the Antares structure, and a hole is scheduled to be drilled in 1995. Elf is operator with 75% interest in the Pointe d'Arcachon permit. It assumed operatorship from Hunt Oil Co. 2 years ago. The other associate, Total, sold to Coparex.

Interests are held by Elf, Coparex, Hunt, and Enterprise France. About 240 sq km of 3D seismic acquisition is scheduled this year.

Elf is operator of the Mimizan Marine permit with 70% interest. Agip has the other interest. They ran 373 sq km of 3D seismic in 1993. The acreage is further offshore, west of Born Maritime.

MEDITERRANEAN SHELF

Besides the Bay of Biscay, Elf Aquitaine is interested in other offshore areas in France.

On the Mediterranean continental shelf it has requested a permit called Languedoc Roussillon Maritime. Some 15 years ago, in association with Esso and BP, Elf drilled a hole in the deep Mediterranean in 1,000 m of water which proved dry.

Eleven holes have been drilled on the continental shelf, the last one by Union Texas in 1985. The area is being worked over with 3D seismic.

WESTERN APPROACHES

In the western approaches to the English Channel off the Channel Islands, where much drilling took place 15 years ago, Elf is interested in acquiring seismic before asking for a permit.

CGG and Spectrum Geophysical Corp. have requested preliminary authorizations to acquire seismic which they would interpret and sell.

Institut Francais du Petrole has reprocessed data acquired more than 10 years ago, and now that confidentiality has expired it has produced a geochemical study of the western approaches that has opened up fresh geological potential.

Also interested in buying the data are three U.K. companies, Hamilton, British Gas, and Chevron's U.K. subsidiary.