Seismic Facies Analysis Seismic Sequence Analysis Mitchum et al., 1977b Key Stratigraphic Units Are Broken Out AAPG©1977reprinted with permission of the AAPG whose permission is required for further use. Seismic Facies Analysis Geometric Relations are Captured through ABC Mapping Other Seismic Features are Extracted as Seismic Attributes SLIDE 4 This slide shows a 'road map' for stratigraphic analysis First we perform seismic sequence analysis to map sequence boundaries using reflection terminations This subdivides the sediment fill into genetically related units – depositional sequences Second, we do seismic facies analysis, which has two elements We use a technique to capture geometric information We can also extract seismic attributes, any of a variety of measures of the seismic reflections A commonly used seismic attribute is reflection amplitude, another is reflection continuity We combine the geometric information with the seismic attributes to predict the environments of deposition (EODs) that influenced the types of deposits (e.g., a beach where clean sands may have been deposited) On the right, we have a portion of Line C from exercise 11a We talked about the shelf-edge carbonate build-up "reef” Below the seismic image is a map view for the youngest Jurassic depositional sequence The dark blue is the location of the "reef” To the right (landward) is a carbonate shelf To the left (basinward) is a carbonate slope Carbonate Shelf Edge Reef Carb. Slope Interpretation/Prediction Patterns are used to Interpret EODs Lithologies / stacking are predicted Courtesy of ExxonMobil L 11 – Stratigraphic Analysis