The first-ever cargo of Guyana's crude for export is scheduled to begin loading this weekend so the oil can be processed at Exxon Mobil's refining system, the company told Reuters on Friday.

Exxon has so far made 15 discoveries of oil reserves in Guyana, turning a risky exploration venture into one of the world's most promising oil mega-projects. The company is entitled to the first two crude cargoes to be exported from the Liza field, which it shares with U.S.-based Hess Corp and China's CNOOC.

The Exxon-led consortium has discovered more than 6 billion barrels of recoverable oil and gas resources off Guyana's coast, which could eventually produce 750,000 barrels per day.

Those finds are turning Guyana, an impoverished nation with no history of crude output that borders longtime producers Venezuela and Brazil, into a hot property for oil investment.

The tanker Yannis P, flagged by the Marshall Islands, arrived on Friday in Guyanese waters. It plans to transport up to 1 million barrels of Guyana's Liza crude, which would arrive into the United Kingdom in late January, according to Refinitiv Eikon's vessel tracking data.

The shipments following the two Exxon cargoes are to be taken in February by Hess and Guyana's government. The government already awarded its first three cargoes of Liza crude to Royal Dutch Shell through an open-market tender.

Guyana's first crude production started in December, ahead of schedule.

(Reporting by Neil Marks and Jennifer Hiller; Writing by Marianna Parraga Editing by Leslie Adler)