HOUSTON/CARACAS (Reuters) - As political turmoil in Venezuela mounts, oil firms including Norwegian major Statoil ASA STL.OL and Spain's Repsol SA REP.MC have further reduced their already-dwindling ranks of expatriate employees in the country, sources familiar with the situation said.

The corporate logo of Repsol is seen in their office in Caracas, Venezuela April 25, 2017. REUTERS/Carlos Garcia Rawlins

Statoil, Repsol and Chevron Corp CVX.N are among the foreign oil companies that hold minority stakes in more than 40 joint ventures with state-run Petroleos de Venezuela [PDVSA.UL] (PDVSA), providing cash-strapped Venezuela with crucial crude production and income amid a debilitating economic crisis.

Venezuela, South America’s largest oil exporter, has been pummeled by a brutal economic crisis that has millions skipping meals, unable to afford soaring prices for basic goods and facing long lines for scarce products.

More than a dozen people have been killed during near daily clashes this month between security forces and protesters calling for elections, the release of jailed activists, and autonomy for the opposition-led congress.

At least 10 people have also died during night-time looting. Leftist President Nicolas Maduro has accused the protesters of plotting a coup against him.

There are no reports of the unrest affecting operations in Venezuela’s often isolated oil fields, but some firms have been spooked by frequent barricades blocking streets and National Guard forces firing tear gas in capital Caracas, where foreign oil companies are usually based.

Statoil, which has a joint venture in the country’s Orinoco Belt extra-heavy crude region, has withdrawn its five to six expatriate staff that remained in the country, two sources said. Statoil’s website says it has 30 employees in Venezuela including local staff, although it was not clear how many were native Venezuelans.

Some expatriate staff with family at Repsol, which has a 40 percent stake in the Petroquiriquire joint venture with PDVSA and also participates in the Orinoco, have recently left the country, although others remain, two separate sources said. Repsol has about 10 non-Venezuelan employees.

The sources all spoke within the past few days and requested anonymity because they were not authorized to talk to the media.

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Statoil said it has been following the situation to guarantee the safety of its staff, including local employees and expatriates. Its operations are proceeding as normal, it added.

Repsol did not respond to requests for information. Chevron declined to comment on security and personnel issues. Russia's Rosneft ROSN.MM told Reuters on Tuesday that "the inner political situation in Venezuela does not affect the operation of the joint venture. The works are carried out as scheduled."

HIGH-RISK OPERATION

The turmoil underlines the difficulty oil companies encounter maintaining operations in high-risk countries from Latin America to Africa to the Middle East. Such markets typically compel the firms to pay premium salaries for expats and employ specialized security staff to protect their families.

Chevron last year advised expats living in Venezuela with their families to transfer to other locations, company sources said, part of a gradual winnowing down of expat staff as life grew more difficult there.

Venezuela’s crime epidemic has long plagued foreign staffs. Worsening shortages of goods are also making the country increasingly inhospitable.

Top Chinese oil executives nearly all relocated to neighboring Colombia about a year ago because they were frequently targeted by kidnappers, a source said.

Foreign oil executives who remain in Caracas are typically restricted to living in certain areas, sometimes banned from traveling after dark, and compelled to move around in armored vehicles.

The recent moves by foreign oil companies recall an exit of foreign staff from oil majors in Venezuela amid heightened protests in 2014. Those demonstrations ultimately wilted due to protester fatigue, a tough government response, and because unrest largely failed to spread to poorer areas.

At Chevron, which participates in two oil projects in the Orinoco Belt, expats are staying put for now but the company has been monitoring looting to decide whether to change their status, another source said.

The U.S. embassy in Caracas last week recommended its citizens living in Venezuela avoid areas where demonstrations may erupt spontaneously as protests may result in violence.