U.S. energy firms this week added oil rigs for the first week in 11, data showed on Nov. 13, despite continued weak crude prices.

Drillers added two oil rigs in the week ended Nov. 13, bringing the total oil rig count up to 574, oil services company Baker Hughes Inc. said in its closely followed report.

That is about a third of the 1,578 oil rigs operating in same week a year ago. Over the prior 10 weeks, drillers cut 103 oil rigs.

The additions this week showed that at least some drillers were willing to start drilling again even with U.S. oil prices trading in the $40s a barrel in hopes of higher prices in the future.

U.S. oil futures averaged $43 a barrel so far this week, down from $46 last week.

Crude futures were on track for their biggest weekly loss in more than two months, with the U.S. front-month down over $1 on Friday to less than $41 a barrel, as swelling stocks weighed on the market.

Energy traders noted the rate of weekly oil rig reductions over the past two months, about 10 on average, was much lower than the 19 rigs cut on average over the past year or so since the number of rigs peaked at 1,609 in October 2014, due in part to expectations of slightly higher prices in the future.

U.S. crude futures for next year were trading around $46 a barrel, according to the full year 2016 calendar strip on the New York Mercantile Exchange. That however was down from $49 last week.

Higher prices encourage drillers to add rigs. The most recent time crude prices were much higher than now was in May and June, when U.S. futures averaged $60 a barrel.

In response to those higher prices, drillers added 47 rigs over the summer.

The rig count is one of several indicators traders look at to predict whether production will rise or fall in future months. Other factors include how fast energy firms complete previously drilled but unfinished wells and increases in well efficiency and productivity.

U.S. oil production eased to 9.3 million barrels per day (bpd) in August from 9.4 million bpd in July, according to the latest U.S. Energy Information Administration (EIA) production report.

On a weekly basis, U.S. oil output remained at 9.2 million bpd for a second week in a row after holding at 9.1 million bpd for eight consecutive weeks since the start of September, according to EIA's weekly field production report. That however is still well below the 9.6 million bpd peak seen in April.