By Mohi Narayan and Florence Tan NEW DELHI (Reuters) -Oil prices struggled to push ahead on Monday as economic headwinds pressured the global oil demand outlook and offset geopolitical concerns in the Middle East and an attack on a Russian fuel export terminal over the weekend. Brent crude fell 9 cents, or 0.1%, to $78.47 a barrel by 0353 GMT after settling down 54 cents on Friday. The front-month U.S. West Texas Intermediate crude futures, for February delivery, inched up 11 cents to $73.52 a barrel with the contract set to expire later on Monday. The more active March WTI contract was at $73…