Oil strengthened slightly on Feb. 14, supported by an OPEC-led effort to cut output, while rising production elsewhere kept prices within the narrow ranges that have contained them so far this year.

Brent crude was 55 cents higher at $56.14 per barrel (bbl) by 6:20 a.m. CT (12:20 GMT). West Texas Intermediate light crude oil was up 45 cents at $53.38/bbl.

The two benchmarks fell 2% on Feb. 13. They are both now in the middle of $5/bbl trading ranges seen since early December.

"The usually fairly volatile oil price has barely budged for two months, the reason being conflicting dynamics in the market," said Hans van Cleef, senior energy economist at ABN AMRO Bank in Amsterdam.

OPEC and other exporters including Russia have agreed to cut output by almost 1.8 MMbbl/d during the first half of 2017 in a bid to rein in a global fuel supply overhang.

But undermining these efforts has been rising production in the U.S., where increased drilling activity, especially by shale oil producers, has lifted overall output to 8.98 MMbbl/d, up 6.5% since mid-2016 and to its highest level since April last year.

Although OPEC countries are largely sticking to their agreement with compliance around 90%, investors suspect the cuts may not be maintained, preventing them from having a bigger impact on prices.

"OPEC producers want the market to believe they will stick to the agreed production freeze [cut]. But lessons from the past have made the market deeply suspicious," van Cleef said.

Many analysts say oil producers will have to cut production more quickly to drain the global oversupply this year.

"Based on OPEC’s own numbers, the message is loud and clear," said Tamas Varga, analyst at London broker PVM Oil Associates.

"Improve on compliance, cut production further and extend the deal for the second half of the year if you want to avoid yet another year of global oil inventory builds," Varga added.

ABN has reduced its average Brent price forecast for the first half of 2017 from $55/bbl to $50/bbl, "while allowing for a possible temporary dip towards $45/bbl."