HOUSTON, Aug 3 (Reuters) - Plains All American on Wednesday raised its 2022 profit forecast for the second time this year, and said it expects strong demand on its pipelines carrying U.S. shale oil to the Gulf Coast.

The pipeline operator increased full-year adjusted earnings guidance by $100 million to about $2.38 billion, as it expects higher crude and natural gas liquids volumes.

U.S. crude oil has been in high demand in international markets with West Texas Intermediate crude trading at a discount to globally-traded Brent crude, making purchases attractive to foreign buyers.

U.S. light sweet crude, a bulk of which is produced in the Permian basin of West Texas and New Mexico, also has been snapped up in Europe with buyers looking to replace Russian barrels.

"The marginal demand right now is the international (market)," said Jeremy Goebel, Plain's chief commercial officer. Prices at the Corpus Christi, Texas, export hub are selling at a premium to Houston and other export ports.

"Right now, Corpus (Christi) is the best price with low inventories and high prices," he said.

Plains has two key long-haul pipelines, Cactus and Cactus II, which move oil from the Permian basin to Corpus Christi.

Plain's Chief Executive Officer Willie Chiang also said he expects more volumes to reach its long-haul pipelines as production in the Permian basin ramps up.

Average daily crude oil volumes in the second quarter rose 30% on its Permian basin pipelines, Plains said, with oilfield activity trending about 10% above its initial expectations.

Its shares rose 3.6% in after-hours trading on Wednesday to $11.19.

Larger pipeline rival Magellan Midstream Partners gave a similar view last week, saying Permian volumes on its Longhorn and Bridgetex pipelines to Houston declined as shippers likely moved barrels to the international market.

Plains' adjusted second quarter net income allocated to common unitholders rose 29% to $210 million. (Reporting by Arathy Somasekhar in Houston Editing by Chris Reese)