EXCLUSIVE-Kazakhstan's oil output falls after Ukraine drone attack on major terminal

MOSCOW, Dec 29 (Reuters) - Oil output in Kazakhstan declined by around 6% in December, led by a fall at the vast Chevron-led CVX.N Tengiz oilfield after a Ukrainian drone attack damaged Russia's Black Sea exporting terminal, an industry source said on Monday.

Ukraine has intensified attacks on Russian energy infrastructure in recent months as it seeks to cut Moscow's revenues and its military strength.

Its November 29 drone attack at the Yuzhnaya Ozereevka oil terminal of the Caspian Pipeline Consortium, which handles around 80% of Kazakhstan's oil exports, has disrupted oil sales from Kazakhstan as well as from Russia and drew a rebuke from Kazakhstan's government.

The source, who spoke on condition of anonymity due to the sensitivity of the situation, said that oil and gas condensate output from Kazakhstan, the world's 12th largest oil producer, has declined by 6% in December 1-28 from an average November level to 1.93 million barrels per day.

Production at the Tengiz oilfield in northwestern Kazakhstan on the northeastern shore of the Caspian Sea has decreased by 10% to 719,800 bpd in December 1-28, the source said.

TENGIZ FIELD INVESTED TO INCREASE OUTPUT

Chevron, whose participation in the field's development was approved by Soviet leader Mikhail Gorbachev in 1990, embarked on a $48 billion expansion of Tengiz last January.

It was meant to raise production there to around 1 million barrels of oil equivalent per day, or just under 1% of global oil output, but the export constraints have set back efforts to reach that goal.

Kazakhstan's energy ministry and Tengizchevroil, the operator of Tengiz, the country's largest oilfield, did not immediately reply to a request for comment.

KAZAKHSTAN'S OIL EXPORTS DOWN

The November drone attack has meant Kazakhstan's exports of its flagship CPC Blend will be their lowest in 14 months in December.

The CPC Terminal is the loading point for oil from Kazakhstan's fields operated by U.S. and European oil majors Chevron CVX.N, Exxon Mobil XOM.N, Eni ENI.MI and Shell SHEL.L.

The source said oil exports from Kazakhstan alone via the terminal fell by 19% so far in December from November's average to 1.082 million bpd. CPC also exports a relatively small amount of Russian oil.

Kazakhstan has had to divert part of its oil exports elsewhere, including to the Baku-Tbilisi-Ceyhan pipeline.

The source also said that oil supplies via the Atyrau-Samara pipeline to Russia, which forms part of the route for the Kazakhstan's exports to Germany, have increased in December from November by almost a quarter to 255,500 barrels per day.

Since November 29, the CPC terminal has operated with a single mooring point - SPM-1 - after SPM-2 was taken offline following the drone attack.

SPM-3 was already out of operation, since mid-November, for maintenance, which has been held up by bad weather. Usually, two of the pieces of equipment are engaged in operations, while the third is used as a backup.

(Reporting by Reuters; editing by Guy Faulconbridge and Barbara Lewis)