Stratigraphic Accumulation of Oil in Salt Creek Field, Natrona County, Wyoming: ABSTRACT

Abstract

Salt Creek field has produced about 420,000,000 barrels of oil. Most of this production is from the second Frontier sandstone, which is one of many sandstone bodies that are interbedded with marine shale in the lower part (between the top of the Mowry and the base of the Niobrara Shales, hereafter referred to as interval A) of the Upper Cretaceous, Rocky Mountain area, United States and Canada. Interval A is thick (over 1,000 ft.) in central, northeastern, and west-central Wyoming and southeastern Montana. Another area where interval A is thick is in northwestern Montana and western Alberta. In some areas, interval A is entirely marine shale; in other areas the interval contains abundant sandstone bodies. The sand was transported by a series of river systems that formed d ltaic complexes at several places at the margins of the early Upper Cretaceous sea. These deltaic deposits are represented by the D sandstone of the Denver basin, the Ferrin Sandstone of Utah, the Cardium and Badhart Sandstones of Canada, and the Frontier Sandstone of Wyoming. The second Frontier sandstone that produces at Salt Creek field is an offshore bar associated with the eastern terminus of one stage of the Frontier delta. The sandstone body is several miles wide, over 60 mi. long, and up to 100 ft. thick. Salt Creek anticline (formed at the end of the Cretaceous) is located in an area of excellent sandstone conditions and caused structural accumulation of primarily stratigraphic oil. There are other sandstone bodies related to the Frontier delta containing stratigraphic oil that are not draped over an obvious anticline. The Wind River and Bighorn basins and parts of the Green River and Powder River basins probably contain more Salt Creek-type fields. End_of_Article - Last_Page 1574------------