Venezuelan oil resumed flowing to the U.S. in January under a Treasury Department license granted to Chevron that allowed it to expand output there and export the oil.
Refiners including Valero and Phillips 66 (PSX.N) have bought cargoes from Chevron, according to U.S. Customs and shipping data.
Chevron's license - and approvals granted to European firms Eni (ENI.MI) and Repsol (REP.MC) - allow only for oil or debt swaps.
Chevron's resumption of Venezuelan crude imports has not led to an increase in the country's overall exports this year, according to PDVSA schedules and Refinitiv Eikon data.
2 U.S. oil company exported some 86,000 barrels per day of Venezuelan oil in February.