The de facto leader of the Organization of the Petroleum Exporting Countries (OPEC) this month deepened its production cuts to 1 million barrels per day in response to benchmark prices that fell to below $72 a barrel this summer.
"The kingdom's curbs have had an outsized impact on the supply of medium-and heavy-sour barrels," Mark Rossano, a partner at energy data provider Primary Vision Network, said.
Futures contract structure of the global benchmark Brent and U.S. benchmark West Texas Intermediate also indicated the market is tightening.
The front month Brent contract traded $2.64 a barrel higher than the six month February 2024 contract , while WTI front month contract was $2.15 higher than the six month contract on Wednesday. At the end of June, both front month contracts were at a discount to the six month contract.
The sour crude increases - seen among North Sea, U.S. and Canadian sour crude grades - have jumped as oil refiners in China, Europe and the U.S. bid up dwindling supplies from sanctions on Russia and Saudi Arabia's cutbacks, according to traders and brokers.
Also pushing up sour crudes are U.S. government purchases to restock its emergency reserves, production outages from Canadian wildfires, and worries about potential for Atlantic hurricane season to cut production of U.S. sour crude.
Most of Saudi Arabia's crude oils, such as Arab Light, Medium and Heavy, are sour grades, a type that requires more complex refining and typically trades at a discount to sweet crude, which has lower sulfur content.
But sour prices are no longer cheap. Norway's medium sour Johan Sverdrup crude climbed on Friday to a record $3.50 per barrel premium to dated Brent, according to traders, compared with a more than $6 discount in December.
U.S. Mars sour crude prices on Thursday of last week also traded at a $2 per barrel premium to U.S. crude futures at Cushing hub, its highest in three years. It traded at a premium to light, sweet WTI Midland at East Houston terminal, something rarely seen before.
Mars also traded at a $3.70 premium to Middle East crude benchmark Dubai, significantly higher than spot Middle Eastern crude.
Western Canadian Select heavy crude, another widely discounted sour grade, traded at the U.S. Gulf Coast on Monday at a $2.30 per barrel discount, compared with a more than $8 per barrel discount as recently as March, according to brokerage CalRock.
Saudi Arabia's price hike to Asia, the second month in a row, has pushed some Chinese refiners to seek cheaper sour crude alternatives from the spot market, traders and brokers said. This has lifted prices for other sour crudes.
U.S. Gulf Coast refiners, which are mostly configured to run sour crude, likely will purchase more Latin American barrels, said Rohit Rathod, an analyst at energy data provider Vortexa.
"OPEC+ players are pulling back supplies and we are already in a tight market at least for sour crudes."
Reporting by Arathy Somasekhar in Houston; additional reporting by Stephanie Kelly in New York and Muyu Xu in Singapore Editing by Matthew Lewis and Diane Craft
