The operator of a large pipeline capable of delivering some 450,000 barrels per day (bbl/d) of Permian crude into the U.S. storage hub of Cushing, Okla., will extend an outage due to a pressure issue, the firm told shippers on Oct. 13.

The pipeline is the largest outbound pipeline from the biggest oil shale play in the U.S., the Permian Basin, and news of the extended outage caused a narrowing in the spread between the front-month to second-month crude contracts, as traders anticipated a draw of nearly 2 MMbbl a week from Cushing due to the outage.

Plains All American LP's (NYSE: PAA) Permian pipeline sent a notice to customers on Oct. 13, seen by Reuters, saying it had delayed a planned restart due to an unspecified "pressure deviation." The pipeline was set to restart on Oct. 13 after a 10-day hydrotest.

The discount for front-month U.S. crude futures to the second month tightened by nearly 10 cents after the news, trading to just 33 cents.

Local cash prices, known as West Texas Intermediate at Midland, Texas, plunged to trade at a $1/bbl discount to U.S. crude futures from a 15-cent discount earlier in the day, dealers said.

If work on the pipeline is not completed by Oct. 20, storage on the pipeline, along with storage on the Plains systems and other third party pipelines west of Colorado City, Texas, could become full, according to the notice. Traders added that full storage could lead to another price slump for cash prices.

Plains said that there would be no movement of crude oil from Colorado City to the north of the Basin System, which connects into Cushing. It added that deliveries to Cushing and connecting carriers at Wichita Falls, Texas, from the Wichita Falls station will be suspended on Oct. 14.

A company spokesman could not immediately be reached for comment.