Following exploration off the coast of Venezuela, ConocoPhillips was awarded rights to a parcel in the western Gulf of Paria in 1996, and discovered oil at Corocoro in early 1999, when a 12,100 feet (3,700 m) deep test drilling in the southwestern Gulf located three discrete oil sources and a separate natural gas reserve.
[1] Under the original plan, wells would have been drilled in late 2004, but shortly after Venezuela approved the project it revoked permission, citing concerns with the business plan and requiring domestic construction of the drilling platform, as well as increasing the taxable rate on income from 1% to 16%.
[3][4] In February 2005, after a PDVSA subsidiary had taken a stake in the joint venture, the project again received approval.
[3][4][5] That year, however, Venezuela expropriated the field from ConocoPhillips control, seizing its stake in Corocoro and transferring it to PDVSA.
[7] In January 2019, the United States imposed sanctions on PDVSA that prevented it from receiving payment from American customers, including Citgo, which had been the primary purchaser of Corocoro oil.