((Corrects figure in 12th paragraph to 31.51 from 30.51))
By Alex Lawler
LONDON (Reuters) - OPEC on Tuesday raised its forecast of oil supplies from non-member countries in 2015, a sign that crude's price collapse is taking longer than expected to hit U.S. shale drillers and other competing sources.
In a monthly report, the Organization of the Petroleum Exporting Countries (OPEC) forecast no extra demand for its crude oil this year despite faster global growth in consumption, because of higher-than-expected production from the United States and other countries outside the group.
Oil is trading below $50 a barrel, close to its 2015 low after an 18 percent drop in July. But OPEC has refused to cut output, seeking to recover market share by slowing higher-cost production in the United States and elsewhere that had been encouraged by OPEC's prior policy of keeping prices near $100.
Earlier this year, OPEC slashed its prediction of non-OPEC supply for 2015, expecting lower prices to prompt a slowdown. But on Tuesday, it raised the forecast by about 90,000 barrels per day (bpd), following a 220,000-bpd increase in last month's report.
"U.S. onshore production from unconventional sources is currently expected to decline marginally in the second half of 2015 through year-end, while U.S. offshore production is expected to grow due to project start-ups," OPEC said.
"Recent developments in the upstream as well as renewed oil price volatility have made forecasting non-OPEC supply more challenging."
U.S. energy companies have been adding drilling rigs in recent weeks despite the price drop, and OPEC in the report raised its forecast of U.S. output in 2015 by 20,000 bpd. In March, OPEC was expecting a fall in production possibly by late 2015 as drilling subsided.
"OPEC is starting to recognise the resilience of U.S. shale," said Jamie Webster, analyst at IHS in Washington and an OPEC expert.
LOWER COSTS
A reduction in the cost of oil projects since the price crash is helping non-OPEC supply to compete in the market.
"The OPEC secretariat is indeed re-evaluating non-OPEC supply's ability to withstand prices," said Samuel Ciszuk, senior adviser on security of supply to the Swedish Energy Agency.
"Project costs have come down a lot and are continuing to fall, according to recent data. This is particularly so with regards to the U.S. light, tight oil - which has provided most of non-OPEC output growth, or in OPEC's view the oversupply."
OPEC also said its members continue to boost supplies. According to secondary sources cited by the report, OPEC produced 31.51 million bpd in July - 1.5 million bpd more than its 30-million-bpd target.
With OPEC forecasting demand for its crude will average 29.23 million bpd in 2015 - steady from last month - the report points to a 2.28-million-bpd supply surplus in the market if the group kept pumping at July's rate.
But Saudi Arabia, the driving force behind's OPEC's refusal to cut output, told OPEC it trimmed production by 200,000 bpd to 10.36 million bpd in July, down from June's record rate.
Some OPEC members such as Algeria are concerned by the drop in prices and want the group to reduce supply. Gulf members, however, have rebuffed calls for an emergency OPEC meeting and show no sign of willingness to consider output cuts.
In the report, OPEC still sees a sizeable slowdown in supply growth from non-OPEC next year and stuck to its view that rising global demand would erode the surplus in the market.
"Crude oil demand in the coming months should continue to improve and, thus, gradually reduce the imbalance in oil
supply-demand fundamentals," it said.
(Editing by Dale Hudson)
