By Shariq Khan NEW YORK (Reuters) -Oil prices rose by about a dollar a barrel on Friday, set for their biggest weekly gains since October, as the U.S. dollar dropped to a seven-month low and more indicators pointed toward growing demand from top oil importer China. Brent crude futures rose by 93 cents, or 1.1%, to $84.96 a barrel by 1:39 p.m. EST (1839 GMT). West Texas Intermediate (WTI) crude futures were set for their seventh-straight session of gains, rising by $1.25, or 1.6%, to $79.64 a barrel. Brent has jumped 8% so far this week and WTI is up 7.7%, recouping most of last week’s losses. …