Ali al-Naimi was an unlikely Saudi oil boss. At Saudi Arabian Oil Co., he was known as a technocrat’s technocrat, a company man hired out of a shepherd’s field at age 12—shy and wonky with no political profile. But during about 20 years as oil minister, Mr. Naimi has become the most influential voice in the world oil market and helped steer the Organization of the Petroleum Exporting Countries through some of its most tumultuous times. The spotlight is back on Mr. Naimi this week as he prepares for what may be his last OPEC meeting on Friday . The 79-year-old has previously said he wants to retire, and people familiar with the matter say a successor is being groomed. OPEC ministers on Friday are expected to cement a policy decision that analysts say will be Mr. Naimi’s lasting legacy: Instead of controlling the price of oil by cutting […]