Kashagan oil flows seen delayed until spring - industry sources

* Production at Kashagan not expected before 2014

* Output halted several times by gas leaks

By Mariya Gordeyeva and Alla Afanasyeva

ALMATY/MOSCOW, Nov 11 (Reuters) - Oil is unlikely to flow from Kazakhstan's Kashagan oilfield until spring as the world's biggest crude discovery in half a century faces challenges including leaky pipes, industry sources said on Monday.

On Sunday, Christophe de Margerie, chief executive of France's Total (NYSE: TOT - news) , said the field would not be able to restart before the end of 2013.

The Central Asian nation of 17 million has pinned its hopes for energy revenues on Kashagan. Repeated delays have infuriated the government, which has threatened to fine the multinational consortium operating the project.

Production at the field, which has a projected life of 50-60 years, started on Sept. 11, but came to a halt two weeks later when a gas leak was found. Another leak was discovered in October after a brief restart.

"Kashagan oil exports will be restarted in March, in a best-case scenario," one industry source said.

The North Caspian Operating Company (NCOC), which operates the field, includes Kazakh state oil firm KazMunaiGas, Italy's Eni (NYSE: E - news) , U.S. Exxon Mobil (TLO: XOM-U.TI - news) , Royal Dutch Shell (LSE: RDSB.L - news) and Total. Each owns 16.81 percent.

Japan's Inpex (Stuttgart: I8U.SG - news) owns 7.56 percent. China National Petroleum Corp (CNPC) acquired an 8.33 percent stake this year.

CHALLENGES

The industry sources said there are indications - including plans to ship crude via the Caspian Pipeline Consortium (CPC (Taiwan OTC: 1597.TWO - news) ) - that oil will not flow from the Caspian Sea deposit before spring.

"They aren't counting on volumes (from the field) in CPC. They promise to include other companies in the schedule," the earlier source said.

A CPC spokesman and Kazakhstan's Oil Ministry declined to comment. NCOC did not return telephone calls.

Kazakhstan, which holds 3 percent of the world's recoverable oil reserves, plans to raise oil output to 83 million tonnes (1.66 million barrels per day) in 2014 from this year's expected 82 million tonnes.

Driven mainly by Kashagan, oil output is forecast to climb to 110 million tonnes in 2018.

The initial target for commercial output under a contract with the consortium developing Kashagan is 75,000 bpd.

Some sources compare oil production in Kashagan to the nearby onshore Tengiz oilfield, which has been developed by a consortium led by Chevron Corp. Production delays are fraught with danger of heavy fines in Kazakhstan.

A fire at Tengiz, which raged for almost a year in 1985-1986, was put out only by an underground explosion.

"There are high risks (for oil production at Kashagan). The launch of Tengiz, which is similar in complexity, was stretched by two years, that's why no one will be in a hurry with Kashagan. Safety is paramount," a source at KazMunaiGas said.

"Let the lawyers deal with any possible fines".