Stratigraphy and petroleum geology of Dockum Group (Triassic), northeastern New Mexico
— Ronald F. Broadhead

The Dockum Group (Triassic) of northeastern New Mexico contains two stratigraphic units of interest as petroleum reservoirs: the Santa Rosa Sandstone and the Cuervo Sandstone Member of the Chinle Formation (Figs. 1, 2). Two accumulations of heavy oil are known to exist in the Santa Rosa Sandstone in northeastern New Mexico: the Santa Rosa tar sands and the Newkirk oil pool (Fig. 3).

The Santa Rosa tar sands (Fig. 3) are a surface exposure of oilimpregnated sandstone that occurs at Santa Rosa Lake in T10N, R21E, Guadalupe County. The Santa Rosa tar sands were mined between 1930 and 1939 by the New Mexico Construction Company. The oil-impregnated sandstone was used for road-surfacing material in New Mexico, Colorado, Oklahoma and Texas. Total production was 153,000 tons (Gorman and Robeck, 1946). The tar sands have been inactive since 1939 because of unfavorable economics. The Santa Rosa tar sands contain an estimated 90.9 million bbl of oil in place; oil gravity is 11.9°API at a temperature of 60°F (Budding, 1980). The geology and petroleum geochemistry of the Santa Rosa tar sands have been discussed by Budding (1979, 1980).

The Newkirk oil pool (Fig. 3) is located in T1 1N, R25-26E, Guadalupe County. Heavy oil occurs in the Santa Rosa Sandstone at depths of 400-800 ft (120-240 m). Oil gravity is 15-17 °AP1 (Martin, 1983). The Newkirk oil pool has never produced commercial amounts of petroleum, but two pilot steamflood projects are currently attempting to recover the heavy oil and produce it commercially. An estimated 39 million bbl of oil are in place at the Newkirk pool (Scott and Joy, 1983). The petroleum geology and sedimentology of the Santa Rosa Sandstone in the Newkirk pool have been comprehensively studied by McKallip (1984).

This article is abstracted from parts of a larger, more comprehensive report (Broadhead, 1984).