XTO Energy Inc. said yesterday it would pay US$1.85-billion in cash and stock to buy more than 350,000 acres of property in the Bakken Shale region of the western United States. The purchase from privately held Headington Oil Co. is expected to close on July 15 and would immediately add 10,000 barrels of oil equivalent production per day to XTO's output. XTO estimates reserves from its portion of the shale formation would total 68 million barrels of oil equivalent, with 60% of that classified as "proved developed" resources. Production from the Bakken Shale, which stretches across Montana and North Dakota and into Saskatchewan, began ramping up earlier this decade. XTO will pay US$1.06 -billion in cash to Headington and 11,742,391 shares of XTO common stock, valued at about US$790-million.