Abstract

A study of Devonian Woodford Formation sediments and the oils they have generated in the Permian Basin indicates it is an excellent source for oil and gas for both conventional and unconventional plays. Woodford deposition occurred during upwelling conditions, as evidenced by its oils characteristics, resulting in excellent organic matter productivity. Additionally, and also contributing to its excellent source character, photic zone anoxic conditions allowed for significant organic matter accumulation and preservation in the underlying sediments. Maps of organic richness and hydrocarbon potential show these conditions generally existed over a very large part of the Permian Basin.

Maps of thermal maturity and oil distribution indicate that although the Woodford is at a present day gas maturity level in much of the Delaware Basin, oil generated and expelled from it prior to its present day maturity occurs in traps along the edge of the basin and on the Central Basin Platform. Woodford oils occur in reservoirs as young as Guadalupian and as old as Lower Ordovician indicating many different play types exist for this source to charge. Migrating Woodford oils commonly mix with oil from other sources, typically Wolfcamp/Cline.

Unconventional Woodford oil source/reservoir plays will occur most commonly in the Midland Basin. However, gas condensate plays are likely to also exist in the Delaware Basin in transition areas between oil and gas window maturities, and to the south in the Val Verde. To date the Midland Basin has been dominated by shallower Permian unconventional plays, but the Woodford represents a future target within reasonable drilling depths.