Oil dips on U.S. inventory surge, doubts on OPEC resolve

By Ethan Lou

NEW YORK (Reuters) - Oil prices dipped on Thursday as investors were still reeling from a record weekly surge in U.S. crude inventories and many remained sceptical about whether OPEC will actually implement its planned output cap.

U.S. crude was down 82 cents, or 1.8 percent, at $44.52 per barrel. At one point, oil had fallen more than $1 a barrel and hit a session low of $44.37.

Brent crude was down 65 cents, or 1.4 percent, at $46.21 a barrel by 1:31 p.m. EDT (1831 GMT). It hit a session low of 45.99.

Traders said energy monitoring service Genscape reported a weekly build of 1.2 million barrels at the U.S. delivery base in Cushing, Oklahoma.

That kept a lid on oil prices after Wednesday's drop to a five-week low. U.S. data released Wednesday showed stockpiles of oil in the United States surged a record 14 million barrels last week.

Prices were also pressured as U.S. equities trimmed gains after government data showed U.S. jobless claims rose last week.

Oil ministers from the Organization of the Petroleum Exporting Countries (OPEC) meet on Nov. 30 in Vienna to agree on a production cap to reduce a global glut and combat low prices.

OPEC has not made clear how much each member should cut, and several have been resistant. Market watchers have grown sceptical that a concrete deal can be reached or enforced, putting a lid on any price rally.

"We've got this rally a few weeks ago, recent weeks on the expectation that we'll see some cohesive cut coming through from OPEC, but that's been slowly unwound," said Matt Smith, director of commodity research at energy data provider ClipperData.

News of an attack on a Nigerian pipeline, which sources say cut the country's output by at least 200,000 barrels, lent some support to crude prices. Nigeria, Africa's largest crude producer, has been hamstrung in months by rebel activity on pipelines and other oil facilities.

Oil prices have been falling for four days, and futures have not recovered to levels reached in October after the preliminary agreement by OPEC to cap production.

U.S. crude peaked near $52 a barrel before slipping in the last two weeks, but resistance to cuts from Iran and Iraq have kept a pressure on prices.

"Ministers meeting in Vienna in four weeks were going to face a tough climb up a steep hill," Credit Suisse analysts said in a note.

(Additional reporting by Sabina Zawadzki in LONDON and Mark Tay in SINGAPORE; Editing by David Gregorio)