Earlier in October, Brent's barrel rose to $ 86 on fears of a slowdown in Iran's exports.
A month later, on Friday, a business day before sanctions against Iran came into effect, it fell just $ 73.
October was not only unfortunate for actions. The oil market corrected the rally accumulated in the year and, mainly, active since mid-August.
Widespread fears of a slowdown in world economic growth have affected forecasts of oil demand. But in the last few sessions, coinciding with the more favorable outlook on trade relations and growth, the price of oil remains unattended.
The correction also accelerated in full countdown to the start of US sanctions against Iran.
The blockade on Iranian crude oil exports came into effect today. The relevance of that date, however, is undermined by the US decision to grant temporary permission to eight importing countries to continue buying Iranian oil until they find alternative supplies.
Countries such as Japan, South Korea and India were the recipients of this temporary permit.
Analysts at Goldman Sachs estimate that Iranian exports will be cut by less than half by the end of the year to 1.15 million barrels a day, compared with 2.5 million recorded in the middle of this year.
The more moderate impact of the envisaged by the entry into force of the embargo on Iran was preceded by a significant increase in supply by major producing countries.
Iran's historic rival Saudi Arabia, amid international pressure on the Khashoggi case, has launched an offer to boost production to 12 million barrels a day.
October numbers already show a notable increase in pumping, despite falling exports from Iran, OPEC's third-largest producer.
With the price spike since 2014, total oil cartel production in October reached 33.31 million barrels per day, 390,000 more than in September and the highest level since 2016.
Russia, also committed to pumping quotas agreed with OPEC, boosted its pumping in October to 11.41 million barrels a day, its 30-year high.
In the ranking of the largest producing countries, along with Russia and Saudi Arabia, are located the United States, with a pumping of more than 11 million barrels per day.