Tom-Tom and Tomahawk San Andres Oil Fields, Chaves and Roosevelt Counties, New Mexico

ABSTRACT The Tom-Tom field was discovered by Amoco in 1967 and the nearby Tomahawk field was discovered by Sundance Oil Co. in 1977. As of September 1, 1979, there were 49 wells producing at Tom-Tom and 22 wells at Tomahawk. Cumulative oil production to August 1, 1979, is 913,725 bbl at Tom-Tom and 331,917 bbl at Tomahawk. Geologic studies indicate no separation between the two fields and at the present rate of drilling activity, the fields should link up in early 1980. Both fields are stratigraphic traps in the P-2 zone of the San Andres formation. The P-3 zone is also productive from a small stratigraphic trap in the Tomahawk field. The P-2 zone is approximately 100 ft (30 m) thick, with the main field pay developed in the upper 50 ft (15 m). This interval is a sucrosic, vugular dolomite in which two predolomitization facies can be recognized, an upper oolitic limestone facies and an underlying crinoidal, argillaceous limestone facies. A dolomite bed near the base of the P-2 zone has 4 to 15 ft (1 to 5 m) of porosity over most of the field and is productive in several local areas. Productive porosity in the P-2 zone ranges from 4 to 10% and the thickness of net pay ranges from 10 to 45 ft (3 to 14 m). Good permeability is dependent upon fractures. Several locally successful techniques for fracture detection are used.