HART, B., S. RALSER, M. HERRIN, S. COOPER, R. BALCH, and K. NIKOLAISSEN, New Mexico Tech, Socorro, NM

ABSTRACT: 3-D Seismic Reveals Contrasting Reservoir Styles at Dakota and Paradox Levels, Ute Dome, New Mexico

Our multidisciplinary team integrated 3-D seismic, wireline logs, Production data and outcrop observations in order to examine controls on gas production from Dakota (Cretaceous) and Paradox (Pennsylvanian) levels at the Ute Dome Field in northwestern New Mexico (Figure 1). Dakota production was established in 1921, whereas the first production from the Paradox level was established in 1948. Lite Dome is a Laramide feature that formed immediately northwest of the Hogback Monocline by uplift of a basement block that underwent at least one structural inversion in the Late Paleozoic. The structural configuration for these two intervals differs: NW-SE trending normal faults at the Dakota level (formed during Laramide uplift; Figure 2) are absent at the Paradox level (Figure 3) where small offset faults trending both NESW (reverse) and NW-SE (normal, not connected to the faults up-section) are present. Paradox structures formed in response to Pennsylvanian tectonic movements. The Dakota level is compartmentalized by depositional features and faults, whereas the Paradox consists of tight carbonates that produce best from fault-related fractures.

Our results indicate: a) that different structural styles at different stratigraphic levels within a single field can have a profound effect on how that field should be developed, b) that productive fracture swarms ("sweet spots") associated with faults can be mapped using high quality conventional 3-D seismic data, and c) that multidisciplinary integration can be effectively employed to evaluate infill drilling prospects in an old (> 75 years) gas field.

AAPG Search and Discovery Article #90915©2000 AAPG Rocky Mountain Section, Albuquerque, New Mexico