Porosity map of a reservpoir obtained from seismic. RMS Impedance amplitude was extracted across the reservoir from seismic, and calibrated into porosity using a simple linear regression. On the map, color is porosity (in fractions) obtained from seismic, white numbers indicate porosity from well logs. Notice the generally good correspondence. Anomalously low values (blue) near  a large fault along the southern edge of the reservoir fault need to be disregarded because the original seismic imaging was distorted, resulting in undreliable porosity estimates.