| dc.description.abstract | In order to study the seismic signatures of abnormally pressured sections, three different reservoir traps were modeled using a 40-Hz, zero-phase, Ricker wavelet and a two millisecond sample rate. MODEL A, CASES 1-2 involved a typical Oligocene sequence of the Gulf Coast Province with discrete lenticular sands encased in shales at depths of 5,000-5,500 feet. In CASE 1, the sands were assumed to be geopressured, while in CASE 2, the sands were normally pressured. MODEL B, CASES 1-2 involved abnormally and normally pressured channel sands, representative of the Pennsylvanian sequences in the Mid-Continent, encased in shales at depths of 12,500-13,100 feet. Finally, MODEL C, CASES 1-4 represented a typical Miocene sequence of the Gulf Coast with a growth fault reservoir containing interbedded tight sands and shales and a single gas sand upthrown to the fault and with a relatively thick sand accumulation downthrown to the fault. Depths ranged from 7,000-7,800 feet. Variations in reflection coefficient, polarity, amplitude, frequency, travel-time thickness and seismic waveform character were studied for each of the above-mentioned models. It can be concluded that synthetic seismic models are useful in aiding in the prediction of geopressured gas zones, thereby reducing exploratory and developmental drilling costs as well as saving human lives. | en_US |
