KUWAIT, Aug 13 (Reuters) - Kuwait has begun injecting chemicals into complex oil reservoirs to extract heavier grade oil, in the first operation of its kind in the Middle East, state-owned Kuwait Oil Co said on Sunday.

The project in the north of the country "aims to enhance and develop Kuwait's oil reserves" as part of ambitious long-term goals for the sector, a company statement said.

"Chemical injection of surfactants is often used for heavy oil extraction or for low-permeability reservoirs," said Sadad al-Husseini, a former executive vice president at Saudi Aramco.

"It is a costly enhanced oil recovery and extraction process and sometimes used where conventional production enhancement such as fracking and acid stimulation are not sufficient to yield commercial results," said Husseini, now an energy analyst.

China is a global leader in the extraction technique.

Kuwait's oil production comes mainly from a few mature sites, dominated by the Burgan field in the south. The OPEC member plans to develop other fields.

An official said in February it aimed to increase oil output capacity to 4.75 million barrels per day by 2040.

(Reporting by Ahmed Hagagy; Writing by Reem Shamseddine; Editing by Andrew Roche) ((Reem.Shamseddine@thomsonreuters.com; +966503335202; Reuters Messaging: reem.shamseddine.thomsonreuters.com@reuters.net))