London (Platts)--11Nov2013/946 am EST/1446 GMT

France's national geological and environment agencies have published a joint study outlining several significant risks of coalbed gas exploration without using hydraulic fracturing, and called for access to exploration sites to examine specific dangers.

Geological agency BRGM and industrial environment agency INERIS studied findings from coalbed methane projects around the world, and in a summary published Friday, the groups said several environmental risks remain in bringing the gas to the surface.

France has a national ban on hydraulic fracturing -- implemented in 2011 in response to rising opposition to shale gas exploration -- which also applies to coalbed methane drilling.

However, coalbed deposits tapped in the exploration process are often sufficiently cracked to not require the chemical pumping process of hydraulic fracturing, and often not as deep underground as shale gas resources.

However, the process typically still requires a large land area to conduct horizontal drilling and in their report, BRGM and INERIS said there remain important risks from leakage when transporting gas to the surface under high pressure.

Explorers need to ensure the sealing of exploration wells to prevent pockets of gas forming in natural caves and health problems from gas in the water supply could occur "under certain environmental conditions," the agencies said.

Two permit decisions by the French government last month showed that the only current route for coalbed methane explorers is to move away from hydraulic fracturing.

The energy ministry said it had rejected "definitively" a permit request for coalbed methane exploration made by Singapore-registered Hexagon Gaz, saying the impact study supplied by the firm was "insufficient to properly evaluate the intended practices." The site in question lies next to two areas in which explorers had intended to use hydraulic fracturing.

However, the ban on hydraulic fracturing has not deterred other coalbed explorers and last month the government extended the Blue Lorraine Sud exploration permit held by coal bed gas specialist European Gas Ltd, where the firm has successfully flowed gas without using hydraulic fracturing.

In their report, BRGM and INERIS highlighted that there remains a lack of data concerning the impact of commercial drilling of coalbed methane, and said that the French government's planned revision of the Mining Code should include more specifics on coal bed techniques.

The agencies also said that France's coalbed gas resources are, in general, difficult to access and raised the question of whether exploration projects would be profitable given "limited quantities" of recoverable methane.

--Robin Sayles, newsdesk@platts.com --Edited by Alisdair Bowles, alisdair.bowles@platts.com

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