* Crude falls for second straight week
* U.S. rig count highest since March 2015 -Baker Hughes
* China refinery throughput hits record high in Sept
* WTI in contango as Cushing stockpiles expected to rise (Updates with CFTC data)
By Stephanie Kelly
NEW YORK, Oct 19 (Reuters) - Oil prices rose on Friday on signs of surging demand in China, the world's No. 2 oil consumer, although prices were headed for a second weekly decline on swelling U.S. inventories and concern that trade wars were curbing economic activity.
Brent crude futures rose 49 cents to settle at $79.78 a barrel. West Texas Intermediate (WTI) crude futures rose 47 cents to settle at $69.12 a barrel.
For the week, Brent fell 0.9 percent, while U.S. crude lost 3.1 percent. Both contracts have fallen around $7 a barrel below four-year highs reached in early October.
WTI's discount to Brent WTCLc1-LCOc1 widened to its most since June 8, hitting $11.00 a barrel.
Refinery throughput in China, the world's largest oil importer, rose in September to a record 12.49 million barrels per day (bpd), government data showed.
The data fed hopes about oil demand in China, even though economic growth slowed in the third quarter to its weakest since the global financial crisis.
An OPEC and non-OPEC monitoring committee found that oil producers' compliance with a supply-reduction agreement fell to 111 percent in September from 129 percent in August, three sources familiar with the matter said. The Organization of the Petroleum Exporting Countries has led cuts from major oil producers since 2017 to shore up prices.
"OPEC and non-OPEC production increases have not quite equaled the loss in Iranian supply, giving the market concern about whether or not they will be able to fulfill the shortfall," said Andrew Lipow, president of Lipow Oil Associates.
The market has been focused on U.S. sanctions on Iran, which take effect on Nov. 4 and are designed to cut crude exports from the country.
Pressuring prices this week was U.S. government data showing crude inventories last week climbed 6.5 million barrels, a fourth straight weekly build and almost triple the amount analysts had forecast.
Rising supplies, particularly at Cushing, Oklahoma, the delivery hub for WTI, pushed the market into contango, in which nearby prices trade lower than forward prices. This happened on Thursday for the first time since May 22.
On Friday, front-month U.S. crude futures traded at the biggest discount to the second month in nearly a year. Traders anticipated further inventory builds in Cushing as new pipelines come online.
The U.S. oil drilling rig count, an early indicator of future output, rose by four to 873 this week, the highest since March 2015, General Electric Co's Baker Hughes energy services firm said on Friday. RIG-OL-USA-BHI
Money managers cut net long U.S. crude futures and options positions in New York and London by 37,080 contracts to 259,375 in the week to Oct. 16, the U.S. Commodity Futures Trading Commission (CFTC) said on Friday - the lowest level since Sept. 19, 2017.
Reporting by Stephanie Kelly in New York, Christopher Johnson in London and Roslan Khasawneh in Singapore; Editing by Marguerita Choy, David Gregorio, Nick Zieminski and Will Dunham