Oil prices rose on Monday on news that OPEC only added a modest amount of additional supply to the market in September, contrary to previous expectations. Saudi Arabia had promised that it would ramp up oil production in September and again in October, despite the non-decision from OPEC+ on an official increase in output. However, a report from Reuters suggests that while Riyadh followed through on this pledge last month, it only added a relatively modest 50,000 barrels per day compared to August levels. In fact, all of OPEC produced 32.85 million…