Prediction of Thin Bed Reservoirs Below ¼ Wavelength Tuning Thickness Using Full Bandwidth Inverted Seismic Impedance

Although conventional 3D reflection seismic data has been<br>invaluable in the exploration and development of oil and gas<br>fields worldwide, the stand-alone technology fundamentally<br>lacks the resolution required to adequately characterize<br>complex, thin-bedded hydrocarbon reservoirs. Limited vertical<br>seismic resolution, implicitly defined at ¼ wavelength tuning<br>thickness, can become particularly problematic when<br>predicting reservoir dimensions, and ultimately for risk and<br>reserve evaluation. Widess (1973) observed that thickness<br>estimation of a “thin-bed”, below ¼ wavelength tuning, can be<br>detected (or is encoded) within the amplitude of the composite<br>amplitude, which results from the increasing constructive<br>interference of the top and base reflections as the bed thins.<br>Herein, a methodology is introduced whereby aggregate<br>reservoir sandstone thickness is successfully predicted away<br>from well control via full bandwidth (0 to 25 Hz) inverted<br>seismic impedance.