Figure 2. PP amplitude attribute (a) and the depth-equivalent PS amplitude attribute (b) across the reservoir interval. PP amplitude facies cannot be related to productive and nonproductive reservoir facies. In contrast, PS amplitude facies tend to segregate productive facies (high amplitudes; yellow/red colors) from non-productive facies (low amplitudes; green/blue colors).Well AL-1 was drilled to test this PS amplitude-facies map.