| Popis: |
Four Pliocene to Pleistocene reservoirs of the East Breaks Block 160 field are interpreted as deep-water sand deposits of turbidite origin: the oldest (Globoquadrina altispira) is about 50 mi downslope from its age-equivalent shelf; the youngest (Trimosina A) is only 6-10 mi downslope from its shelf. Electric-log correlations and facies analysis for both reservoirs suggest channel-fed deposition of aggradational lobes with basal sheet sands. Biofacies indicate deposition at middle to upper bathyal water depths (> 600 ft). Seismic facies analysis shows the reservoir interval correlates with discontinuous, variable-amplitude, non-parallel reflection character. This sand-prone seismic facies has a lobate map pattern within the isochron thicks of the Block 160 salt-withdrawal basin. A depositional model for this system includes (1) deposition during a sea level lowstand, (2) sediment supplies from a shelf-edge deltaic system, (3) transport by gravity flow process through physiographic lows on the slope, and (4) deposition as intraslope basin fans consisting of sheet, lobe, and channel deposits. |
