LONDON—Oil prices hit a fresh three-year high on Friday, climbing above $85 a barrel on forecasts of a supply deficit over the next few months as rocketing gas and coal prices stoke a switch to oil products. Brent crude futures were up 80 cents, or 0.95 percent, to $84.80 a barrel at 0930 GMT. Front-month prices, which earlier touched their highest since October 2018 at $85.10, are set to climb for the sixth straight week, heading for a 3 percent hike this week. U.S. West Texas Intermediate (WTI) crude futures rose 73 cents, or 0.9 percent, to $82.04 a barrel. The contract is heading for a 3.3 percent gain on the week, up for the eighth consecutive week. Strong stock markets on both sides of the Atlantic, often traced by oil prices, also gave a boost. Analysts pointed to a sharp drop in OECD oil stockpiles to their lowest level …