Thousands of Romanians across the country protested on Thursday against Chevron’s plans to explore for shale gas, demanding the country’s leftist government withdraw concessions and ban drilling of the US company’s first test wells. Chevron has exploration rights for three blocks of 670,000 acres near the Black Sea, and has also bought the concession close to Barlad, on the eastern border with Moldova, for an undisclosed amount. Hydraulic fracturing or fracking to extract shale gas involves injecting water and chemicals at high pressure into underground rock formations. Experts say that if it is done according to best practice it is environmentally safe, but the technology still evokes public concern. The US Energy Information Administration estimates Romania and neighboring Bulgaria and Hungary could have 538 billion cubic meters of shale gas between them, slightly more than Europe’s annual consumption and enough to cover Romania’s for almost 40 years.