An oil spill off the coast of China at a field operated by ConocoPhillips has sparked concerns about discrimination against foreign companies and underscored how Chinese regulators are getting stricter on pollution. China, the world’s biggest consumer of energy, has ambitious plans to develop offshore oil and gas, particularly in the challenging but gas-rich terrain of the South China Sea. But China’s first publicly disclosed spill from an offshore oil rig, in Bohai off the northern coast, has been met with a harsh response from regulators that many believe signals a new era of tightening regulations for offshore drilling in China. For the past two decades foreign groups have played a crucial role in developing offshore resources alongside Cnooc, China’s offshore producer, as the Chinese company gradually acquired the technology to conduct offshore drilling itself. Apart from Conoco, Anadarko, BP and Husky Energy have all been involved in offshore oil and gas exploration in China. However, the oil spill this summer at the Penglai 19-3 block, co-owned by Conoco and Cnooc and operated by Conoco, has highlighted the risks that foreign companies face when they are operating in sectors – such as offshore drilling – that become a focus for environmental crackdown. Conoco estimates that 700 barrels of oil and 2,500 barrels of drilling mud were released into the ocean during a series of incidents that began on June 4. Chinese media reports that new leaks continue to be found seeping from the ocean floor, but ConocoPhillips says that less than one barrel of oil has been leaked into the ocean since June 19 and most leaks have been contained. In the months since the leak occurred, Chinese regulators – who waited several weeks to disclose the spill to the public – have gradually escalated their criticisms of Conoco, accusing the company of “negligence” and saying they are preparing a lawsuit over the environmental degradation caused by the spill. Most recently, regulators last week ordered a shutdown of all seven drilling platforms at the Penglai 19-3 block. Analysts say the order was unusually harsh because only two of the seven platforms had reported leaks, and those two had been shut down since July. Production will not be restarted until a new development plan for the block is submitted by Conoco and approved. “ConocoPhillips believes we have been and will continue to be a prudent operator of the Peng Lai field,’’ the company said on Sunday. China’s maritime regulators have “thrown the book at ConocoPhillips,” says Laban Yu, energy analyst at Jefferies, the investment bank. “They are going to make an example out of them,” he adds. “They are saying foreign companies have problems just like our own.” The field – which is one of the largest in China, accounting for about 4 per cent of CNOOC’s production and 3 per cent of Conoco’s production – could remain idle for as long as six months, analysts say, though regulators haven’t specified any time frame. China is the world’s fifth-largest producer of crude oil. “There are tiny spills like this that go on all the time and never get reported,” says one analyst who asked not to be named because of the sensitivity of the subject. Last year one large spill in Dalian at a refinery co-owned by CNPC released hundred of thousands of barrels of oil into the ocean, but went largely unpunished with no companies reported being fined or sued over the incident. However, others point out that the response from maritime authorities fits into a pattern of increasing environmental concerns and tighter regulation. “All developing countries go through a process of paying more and more attention to the environment,” says Lin Boqiang, professor of energy economics at Xiamen University. Mr Lin rejects any comparison between the Bohai spill and the Dalian spill last year. “The laws and regulations for environmental protection are constantly getting stronger, so you can’t compare a spill that happens today to something that happened a year ago.” Cnooc share prices in Hong Kong are down 12 per cent this week from their Friday close. A spokesman for Conoco said the company had complied with the regulator’s orders and that an expert review of the plan to reduce reservoir pressure was set to begin on Tuesday. Operations have stopped at all 180 producing wells on the Penglai 19-3 block, according to the company’s website.