By Arathy Somasekhar HOUSTON (Reuters) -Oil rose $2 a barrel on Monday on the prospect of even tighter supplies loomed over the market as the Group of Seven nations promised to tighten the squeeze on Russian President Vladimir Putin’s war chest while actually lowering energy prices. Brent crude futures settled $1.97, or 1.7% higher, at $115.09 a barrel, while U.S. West Texas Intermediate crude closed up $1.95, or 1.8%, at $109.57 a barrel. The group of wealthy nations vowed to stand with Ukraine “for as long as it takes”, proposing to cap the price of Russian oil as part of new sanctions to hi…