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Re-exploration of cratonic basins using passive-margin sequence-stratigraphic concepts: examples from upper Paleozoic rocks, eastern margin, Midland basin

Conference · · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)
OSTI ID:6132132
Use of 5000 well logs and extensive outcrop information with a 22,000-mi/sup 2/ test region on the eastern margin of the Midland basin permitted delineation of 16 probably third-order type 1 depositional sequences. Sandstone-isolith maps of siliciclastic highstand and lowstand systems tracts show that most structural traps produce from highstand fluvial-deltaic reservoirs, but most stratigraphic traps discovered to date occur within lowstand depositional systems, principally incised valley fills and basin-floor fans. Hydrocarbons are rarely trapped in retrogradational (transgressive) systems tracts. Maps of lowstand tracts refocus attention on reservoirs that can be predicted to exist basinward of preexisting shelf edges. A basinward shift of exploration emphasis from incised valley-fill reservoirs to other lowstand elements - such as basin-floor fans, canyon and leveed-channel fills, and lowstand progradational deltaic wedges - could lead to plays where lenticular reservoir sandstones and marine-condensed source and seal shales exhibit the optimum conditions for pinch-out traps.
Research Organization:
Univ. of Texas, Austin (USA)
OSTI ID:
6132132
Report Number(s):
CONF-890404-
Conference Information:
Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) Journal Volume: 73:3
Country of Publication:
United States
Language:
English