Evaluation of Shallow Seismic Reflection Resolution on an Outcrop Analog to Campos Basin (Brazil) Sandstones Reservoirs

Summary The use of the seismic reflection method to image targets with depths of 0–100 m has been increasing since the 1980’s. One of the most compromising issues of the using seismic reflection for shallow depths is its capacity to image structures with interpretable resolution. In this study, we use two modelling techniques, convolution and finite-difference acoustic modelling, to evaluate the feasibility of the seismic reflection method on an outcrop of the Volta Redonda Basin (Brazil) which is considered as an analog to poorly unconsolidated sandstones reservoirs in Brazil. The features of this outcrop were used to construct a 2D P-wave velocity model. Synthetic data, generated using three different dominant frequencies for the Ricker wavelet as the seismic source, were compared in order to access the resolution limits of the method. The synthetic sections yielded from the convolution served as guide to the acoustic modelling brute stacks. Raw shot gathers of the three frequencies were also analysed to recognize what features can be imaged and which frequency is capable of imaging them. The investigation of the synthetic dataset demonstrated that a minimum dominant frequency of 150 Hz is required to image the ultra shallow thin sedimentary beds present on the outcrop.