Goldman Sachs has raised its oil price forecast to $100 a barrel from $93 a barrel, but says that most of the price rally has already run its course.

The bank has lifted the Brent crude 12-month-ahead price forecast, as "a significantly lower OPEC supply and higher demand more than offset significantly higher U.S. supply," it said in a note.

Saudi Arabia will start unwinding its 1 million barrel a day supply cut in the second quarter of next year, but other OPEC+ cuts will likely remain in place all year, according to Goldman.

Still, Brent is unlikely to exceed $105 a barrel as supply elsewhere picks up and demand takes a hit from high oil prices, the bank says.