Crude prices fell sharply Thursday, with the USA benchmark tallying a two-day drop of more than 4% following a fourth straight weekly climb in crude inventories that has seen domestic supplies swell by a total of 22 million barrels over that period.
Brent crude was down 31 cents at $79.74 a barrel at 1:24 p.m. EDT (1724 GMT).
Meanwhile, sources previously said that during the sanctions scheme of 2011 by the US, TÜPRAŞ was able to purchase 3 to 4 cargoes of Iranian crude a month and that they would want to be able to stick to that this time as well instead of completely stopping.
Exports have declined already to about 1.5 million barrels per day (bpd), up to 1 million bpd below levels seen earlier this year. In 2017, the South purchased 147 million barrels of Iranian oil. Meanwhile, President Donald Trump and his top diplomat cautioned against putting the entire U.S. -Saudi relationship at risk over dissident writer Jamal Khashoggi.
OPEC officials are concerned that increased US oil production and a seasonal buildup of oil stock could put downward pressure on oil prices, according to an internal document shared among members and reviewed by the Wall Street Journal.
A looming "seasonal scale back in refinery demand...could result in oil stock builds", a portion of the report reads, which was circulated among OPEC officials on Thursday.
Moreover, Managing Director of the National Iranian Oil Company (NIOC) Ali Kardor said on Wednesday that the USA threat to get Iran's oil exports to zero was just a "political bluff".
Oil prices nudged higher on Friday on signs of surging demand in China, the world's second-biggest oil user, though prices are set to fall for a second week amid concerns of the ongoing Sino-US trade war is limiting overall economic activity.
Softbank shares plummet amid concerns over Saudi ties
The Saudi consulate referred Reuters to authorities in Riyadh, who did not respond to questions about the 15 Saudis. Trump visited the kingdom on his first overseas trip as president and has touted arms sales to Saudi Arabia.
He also said that the US response to Saudi Arabia would likely be "very severe" but he would still want to get to the bottom of what exactly happened.
"We are engaged with the U.S. on this matter and we have shared our position with the USA at different levels", Kumar said. Oil prices were left unmoved by data from oil-field services firm Baker Hughes that showed the number of USA drilling rigs rose by four this week.
WTI's discount to Brent widened to its most since June 8, hitting $11.00 a barrel.
There has been indication that India may not totally stop import of crude oil from Iran.
Refiners in Turkey, India and possibly China are reportedly negotiating with US officials over waivers to enable them to continue purchasing at least some Iranian oil after November 4.
United States government officials have previously warned that India could face secondary sanctions if it goes ahead with its decision to purchase S-400 systems from Russian Federation.
Continued weakness in global equities was also a weight on crude this week, analysts said, underlining worries about global growth prospects and dampening demand for assets perceived as risky, including most commodities.
Top exporter Saudi Arabia pumped most of the extra oil, raising output by 524,000 bpd in September compared to May, the document showed.