Brent crude was down 33 cents, or 0.8%, at $42.82 a barrel by 0645 GMT, while US crude was down 38 cents, or 0.9%, to $40.73 a barrel.
Brent crude for November delivery dropped 40 cents, or 1%, to $40.63 per barrel by 06:35 GMT. West Texas Intermediate fell 32 cents, or 0.8%, to $38.97.
Brent crude futures rose 59 cents, or 1.4%, to $43.81 a barrel by 1216 GMT. U.S. West Texas Intermediate crude futures gained 47 cents, or 1.2%, to $41.51 a barrel.
Brent crude was down 1 cent at $43.30 a barrel by 0807 GMT, while US West Texas Intermediate (WTI) crude up 1 cent at $41.08.
Brent crude futures climbed 2 cents, or 0.1%, to $43.43 a barrel at 0423 GMT while U.S. West Texas Intermediate (WTI) crude futures fell 7 cents, or 0.2%, to $41.53 a barrel. Both benchmarks rose as much as 0.5% earlier in the session.
Brent crude fell 35 cents, or 0.8%, to $43.97 a barrel by 0541 GMT, and U.S. West Texas Intermediate (WTI) crude dropped 39 cents, or 0.9%, to $41.53.
Brent crude fell 35 cents, or 0.8%, to $43.44 a barrel while West Texas Intermediate (WTI) crude was down 49 cents, or 1.2%, to $40.47 per barrel.
Saudi Arabia’s energy ministry has directed oil producer Saudi Aramco to raise its output capacity to 13 million from 12 million barrels per day (bpd), CEO Amin Nasser said
Brent slumped to $22.5 a barrel leaving it down 65% for the year and hammering petro currencies such as Russia's rouble, Mexico's peso and the Indonesian rupiah by as much as 2%.
Brent crude was down 26 cents or 0.6% at $45.17 a barrel by 0647 GMT, after a gain of around 2% in the previous session. West Texas Intermediate oil also lost 0.6%, a 25 cent decline to $42.42 a barrel which followed a climb of 2.6% on Wednesday.