Iranian crude oil cargoes readily available to Chinese buyers have nearly dried up following the reinstated U.S. blockade on Iran’s oil exports, suggesting that independent Chinese refiners, the biggest buyers of Iranian crude, may have to turn to alternative supply as soon as next month.Total Iranian crude volume outside the Persian Gulf and Gulf of Oman is currently about 83 million barrels, down from over 100 million barrels before the U.S. reinstated the blockade in the middle of July, when the U.S.-Iran talks to make a deal collapsed, according to data from Kpler. Around half of these 83 million barrels, or about 40 million barrels, are in floating storage around Singapore’s Eastern Outer Port Limits (EOPL) anchorage, Muyu Xu, senior crude analyst at Kpler, said on Friday.But it is likely that only two cargoes, equal to a total of 4 million barrels, have remained unsold out of the 40 million barrels offshore Singapore, market participants told Kpler.“This suggests buyers could face virtually no new Iranian supplies available for late-September delivery onwards, given that no laden Iranian tankers have so far managed to break through the US blockade,” Xu noted.The rapidly thinning available Iranian supply out of the blockade has driven the price of Iranian Light crude to a premium of $3.50 over ICE Brent this week, sharply higher compared to a discount of $3.50 a week earlier, Kpler’s Xu said.The U.S. blockade has been effective in stifling Iranian exports from Kharg Island, the key export terminal handling 90% of shipments, analysts and vessel-tracking data services say.Iranian supply to China faces further squeezes as U.S. President Donald Trump this week announced the “most crushing economic operation ever taken against any country”, referring to Iran, and warned any country extending a “lifeline” to Iran could face “TREMENDOUS Economic Consequences.”The U.S. President did not explicitly name any country, but in the oil market, Iran’s key customer is none other than China, which has been buying more than 90% of all sanctioned Iranian oil in recent years.Earlier this month, analysts expected that China’s independent refiners are likely to return to buying higher volumes of Iran’s crude oil in August as stockpiles in Shandong, home to the independent Chinese refiners, have dropped to the lowest level this year after the biggest estimated monthly draw in a decade.With the U.S. blockade effectively crippling Iranian supply, “Chinese teapots will need to step up purchases of alternative feedstocks, such as Russian Urals crude or fuel oil, as ESPO supplies were sold out weeks ago, or risk cutting throughput in October when their inventories run thin,” Kpler’s Xu said.By Tsvetana Paraskova for Oilprice.comMore Top Reads From Oilprice.comChina’s Oil Imports Set to Rebound as Refiners Hunt for New SupplyIraq-Syria Oil Pipeline to Bypass Hormuz Is 4 Years and $15 Billion AwayChina's Renewables Boom Faces Record Clean Power Curtailments