Oil prices extend gains on Friday, as oil rigs operated by U.S. energy firms declined sharply this week and strong job growth in the United States in January lifted investors' expectations on the demand side.

The number of oil rigs in the United States decreased by 15 to 847 in the week to Feb. 1, marking the lowest level since May 2018, Houston-based energy services company Baker Hughes reported on Friday.

As a key index to gauge future output, the U.S. rig count fall offered a relief for the market clouded by fears of oversupply since late 2018.

On the economic front, the U.S. labor market continued to embrace rising employment and wage increase in January, which underpinned the strength of U.S. economy dragged by the 35-day-long government shutdown.

Nonfarm payrolls surged a seasonally adjusted 304,000 in January, the biggest growth since last February. Wages increased at least 3 percent year over year, climbing up for the sixth consecutive month, the U.S. Labor Department said on Friday.

Job growth mainly appeared in employment at construction sites, retailers and business services as well as at restaurants, hotels and amusement parks.

However, the unemployment rate also rose to 4 percent, a slight uptick from the previous month's 3.9 percent yet a new high over the last seven months.

The Labor Department blamed January's jobless rate growth to the government shutdown since late December 2018, as it caused thousands of federal workers to be counted as on temporary layoff.

The West Texas Intermediate for March delivery rose 1.47 U.S. dollars to settle at 55.26 dollars a barrel on the New York Mercantile Exchange, while Brent crude for February March rose 0.89 dollar to close at 62.79 dollars a barrel on the London ICE Futures Exchange.