Numerical Simulation Modeling of Hydrocarbon Migration into and Through Sand Reservoirs in the Pabst Field (Main Pass Block 259), Northern Gulf of Mexico

By

 Yuxian Li¹, Joel S. Watkins¹, Roger Sassen¹

(1) Texas A&M University, College Station, TX

 Numerical simulation modeling of hydrocarbons charging reservoir sands provides a better understanding of the distribution of hydrocarbons in reservoir compartments and assists in the development of numerical simulation models used during the development and production. Herein, we report results of numerical simulation modeling of migration of hydrocarbon liquids into the 10,300-ft sand of the Pabst field in the northern Gulf of Mexico. The model is based on and constrained by geochemical, seismic and well-log data. Seismic amplitudes serve as proxies for gas-condensate distribution.

Sands in the Pabst field appear to have been deposited as delta-toe or turbidites on an upper paleoslope. The field is complexly faulted. Three main NW-SE trending growth faults and numerous low-throw NE-SW trending faults divide the field into numerous compartments. The numerical simulation models indicate that the three major growth faults mainly seal. Some communication between two of the growth faults may have occurred across a local high-standing block. The NE-SW trending low-throw faults mainly form barriers. The main migration pathways appear to be the two structurally lower growth faults. Geochemical data shows that present condensate is highly mature and that it arrived late in the field, flushing the earlier, heavier liquids as it migrated. The 10,300-sand contains mainly condensates but other sands contain remnants of the earlier, heavier hydrocarbons.