BP announced it started oil production from the so-called PSVM development, which consists of the Plutao, Saturno, Venus and Marte fields in deep Angolan waters.
Production from three wells in the Plutao section is expected to reach 70,000 barrels of oil per day.
"The PSVM start-up is the reward for many years of hard work and collaboration both in Angola and overseas to deliver this world-class project," Martyn Morris, regional president of BP Angola, said in a statement. "This is a further step in the confirmation of Angola's potential as a global energy player."
Angola is the No. 2 oil producer in the region behind Nigeria. The U.S. Energy Department's Energy Information Administration estimates there are 9.5 billion barrels of proven oil reserves there.
BP said the PSVM complex is expected to produce around 150,000 bpd once all three areas start production next year.
The company describes the project as the biggest development of its kind in the world. Oil production in Angola has increased steadily despite civil war that raged since 2002.
BP has worked there since the 1970s.