* U.S. crude stocks fell sharply last week
* Venezuela risk adds bullish tone
* Nigeria agrees to join push to rein in output
* Oil prices have been pressured by global oversupply (Updates throughout, changes dateline previous SINGAPORE)
LONDON, July 26 (Reuters) - Oil prices firmed on Wednesday, holding near eight-week highs, as a fall in U.S. inventories bolstered expectations that the long-oversupplied market was moving toward balance.
Brent crude futures rose 30 cents to $50.50 a barrel by 0959 GMT, after rallying more than 3 percent on Tuesday.
U.S. West Texas Intermediate futures climbed 40 cents to $48.29 a barrel.
U.S. crude stockpiles fell sharply last week as refineries boosted output, while gasoline inventories increased and distillate stocks decreased, data from industry group the American Petroleum Institute showed on Tuesday.
Crude inventories fell 10.2 million barrels in the week ending July 21 to 487 million, more than the expected decrease of 2.6 million barrels. Data from the U.S. Energy Information Administration on Wednesday could provide more support, with forecasts of a drop for a fourth week in a row.
Tuesday's stock draw added to hopes the long-awaited oil market rebalancing was underway. Saudi Arabia said on Monday it would limit oil exports to 6.6 million barrels per day (bpd) in August, down nearly 1 million bpd from a year earlier.
"The market has been tightening and the refinery margins are strong," said PetroMatrix managing director Olivier Jakob, saying the U.S. stock draw offered a boost to prices. "You add geopolitical risk premium for Venezuela, and you've got a strong market."
Venezuela, an OPEC member producing about 2 million bpd of oil, faces deepening economic woes and protests.
President Nicolas Maduro's adversaries plan strikes to push him to abandon a weekend election. The United States is considering financial sanctions to halt dollar payments for the country's oil.
Nigerian output slipped this week as leaks forced Shell to shut a pipeline exporting some 180,000 bpd of oil. Nigeria, which has been exempted from OPEC-led production curbs, also agreed to cap or cut output when it stabilized at 1.8 million bpd.
But analysts said the current oil price rally could encourage more production, particularly from the United States.
"Relieved bulls should be careful what they wish for. Any price rebound will only embolden U.S. shale producers at a time when rumors have started to emerge that the U.S. shale boom is slowing," PVM oil analyst Stephen Brennock said in a note.
Anadarko Petroleum Corp said on Monday it would cut its 2017 capital budget by $300 million because of depressed oil prices, the first major U.S. oil producer to do so, after posting a larger-than-expected quarterly loss. (Additional reporting by Fergus Jensen in Singapore; Editing by Edmund Blair)