It took years to lift a ban on most U.S. oil exports. It took a week for the first shipment to be announced. Enterprise Products Partners LP will load 600,000 barrels of domestic crude onto a tanker in the Houston Ship Channel during the first week of January. It sold the cargo to merchant trading giant Vitol Group, which will probably send it to Europe, according to two people familiar with the transaction. It’s the company’s first shipment since Obama signed a spending bill last week that repealed broad limits against exports of unrefined crude oil that had been in place since 1975. “We are excited to announce our first contract to export U.S. crude oil, which to our knowledge may be the first export cargo of U.S. crude oil from the Gulf Coast in almost 40 years,” Jim Teague, Enterprise’s chief operating officer, said in a written statement. […]