Chevron Corp.'s (NYSE: CVX) Venezuela oil fields continue to operate normally, a senior executive at the U.S. company said March 26, even as concerns mount about the OPEC member's production due to a host of challenges.

Chevron operates in Venezuela, home to the world's largest oil reserves, as part of its 30% stake in the Petropiar joint venture with PDVSA, the Venezuelan state-controlled oil company.

Even as ExxonMobil Corp. (NYSE: XOM) and other companies in recent years have left the country, Chevron has stayed and has consistently said its operations there are fine.

"The upstream operations are still functioning and our focus is on safe operations and protecting people," Jay Johnson, Chevron's head of upstream operations, told Reuters on the sidelines of the Scotia Howard Weil energy conference in New Orleans.

Johnson declined to comment when asked if Chevron has been asked by PDVSA—or expects to be asked—to divert crude from export to PDVSA refineries.

Reuters reported last fall that PDVSA asked the Petropiar joint venture with Chevron to turn over as much as 45% of the oil it planned to export in November with no immediate reimbursement.

Venezuela's overall oil production fell to a 28-year low last year amidst insufficient investments, payment delays to suppliers, U.S. sanctions and a talent brain drain.

Separately, Johnson said the recent U.S. tax overhaul has not had a "major impact" on the company, the world's third-largest publicly traded oil producer, as it already uses much of its cash generated overseas on foreign operations.

"On balance, though, a lower tax rate is better for us and does make the U.S. more competitive," said Johnson.

When asked his views on renewable energy, Johnson said he supports all forms of energy, including solar and wind. He added he has a solar array built onto the roof of his California home.

"It only takes a day or two without power for people to realize how important energy is to our lives," said Johnson, who joined Chevron 37 years ago and has been in his current role since 2015.