Carlile Shale

Subsidence modeling was used to evaluate the thermal maturity profile of the source beds. The subsidence model developed for this area is presented by Pittman (1988). A 107-m core in the Niobrara Formation and Carlile Shale provided consistent vitrinite reflectance data to calibrate the subsidence curves. An Ro of 1.41% corresponds to the base of the Niobrara Formation. This value was used as a control on the development of the subsidence profile that is, a match of 1.41% was obtained for the base of the Niobrara. 

Oil in the small Lyons Sandstone reservoirs along the northwest margin of the Denver Basin has distinctly different characteristics than oil in the Cretaceous reservoirs. The source for the Lyons oil is unknown. The source for the oil in the Lower and Upper Cretaceous reservoirs has been established as Cretaceous shales and limestones (Clayton and Swetland 1980) by oil-to-rock correlation techniques. The Carlile Shale, Greenhorn Limestone,... 

Source rock analyses were made for the Niobrara Formation and the Carlile Shale because of the paucity of data available in public domain literature. The Niobrara in the Wattenberg area is a black shaley limestone and is the richest source rock in the basin. Source rock data used in calculations presented later in this chapter are shown in Table 1. Only analyses made on core samples were used except for the Pierre Shale where a lack of cores necessitated the use of data derived from outcrops and drill cuttings. 

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See also in sourсe #XX -- [ , , ]

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