The consortium of oil majors developing the giant Kashagan oil field in Kazakhstan has begun test pumping, it said on Sept. 29, as the $50 billion project prepares for commercial production.

The field off Kazakhstan's Caspian coast first started production in 2013, but output was suspended shortly after launch because of technical problems with the gas pipelines.

"NCOC confirms that as part of the complex process of commissioning and testing now underway, hydrocarbons are being introduced to certain parts of the facilities including the newly replaced pipelines to shore," the North Caspian Operating Co.said in a statement.

The NCOC consortium comprises China National Petroleum Corp., ExxonMobil Corp. (NYSE: XOM), Eni, Royal Dutch Shell Plc (NYSE: RDS.A), Total, Inpex and KazMunaiGas.

"Further information may be available once we reach initial stable production levels," its statement added.

The Kazakh Energy Ministry had mistakenly announced earlier in the day that production had started. It withdrew the statement and said that initial output would begin in late September or early October.

Kashagan is initially expected to produce 75,000 barrels per day (Mbbl/d) in October, rising to between 150 Mbbl/d and 180 Mbbl/d in November and December of 2016.