Warren Buffett has invested heavily in oil-related stocks in 2013. (Nati Harnik/Associated Press)

In yet another oil-related foray, Warren Buffett’s Berkshire Hathaway has paid $1.4 billion US for a business that makes chemicals to improve the flow of fluids through pipelines.

Berkshire closes the deal on Phillips Specialty Products, a unit of chemical firm Phillips 66,  in the first half of 2014.

"I have long been impressed by the strength of the Phillips 66 business portfolio," Buffett said in a statement. "The flow improver business is a high-quality business with consistently strong financial performance, and it will fit well within Berkshire Hathaway."

Berkshire plans to pay for the deal with Phillips 66 shares from its investment portfolio, with valuation at the time the deal closes. Phillips 66 said it sold because of the attractive offer.

Other oil deals

It also will be expanding its stake in ExxonMobil, the world's biggest oil company, by $3.5 billion. 

Buffett put money into the Alberta oilsands earlier this year, investing $500 million in a stake in Calgary’s Suncor Energy Inc.

He has expressed a lot of faith in energy stocks, paying $5.6 billion to buy utility NV Energy within the past year and investing in exploration company National Oilwell Varco,

He also has publicly endorsed the Keystone XL pipeline, which would carry oil from Alberta to refineries in the southern U.S.

Phillips Special Products develops and manufactures polymers  that maximize the flow potential of pipelines carrying crude oil, refined products or waste water.

 The unit will be folded into Lubrizol, which was a Berkshire acquisition in 2011 and Lubrizol CEO James Hambrick will oversee the integration.