Oil futures booked solid weekly gains, boosted by the Federal Reserve’s large interest-rate cut and a renewed rise in tensions in the Middle East.

The Brent/WTI spread has historically ranged between $4/bbl and $8/bbl, but it can expand or contract based on factors related to U.S. and international supply and demand conditions. For example, the Brent/WTI spread hit nearly $14/bbl in April 2011 when protests sparked market fears of significant oil supply disruptions in the Middle East.

Oil prices eased on Friday, but were on track to register gains for a second straight week following a large cut in U.S. interest rates and declining global stockpiles. Brent futures were down 32 cents,