Reservoir characterization with high frequency bandwidth seismic data and coherence processing

摘要

Reservoir characterization is a crucial prerequisite to predict the economic potential of a hydrocarbon reservoir or to examine different production scenarios. Unfortunately, it is difficult to determine the exact reservoir properties at the required scale. Typical seismic data has a temporal resolution a-round 100 feet and a spatial resolution of about the same order. However, surface seismic is the only tool available to address the reservoir fields wide. Wells resolve the reservoir down to the inch scale, but only at single points in the field. A new method of enhancing the frequency bandwidth of seismic data and restoring high frequencies has been developed and can have a profound effect on better correlation with well logs and help bridge the scale gap. Referred to as Frequency Bandwidth Extension technologies (FBE) , this method increases the limit of resolution of seismic data by exploiting the limit of resolution in the frequency spectrum. This is different from any of the conventional methods practiced in the industry. This approach (pentent pending) results in sharper wavelets capable of I-dentifying thinner beds and subtle features.The application of 3-D Coherence processing is an extremely powerful tool to efficiently exploit the wealth of structural and stratigraphic information encapsulated in the seismic waveforms of 3-D seismic data volumes. This tool provides the oil industry with technology that significantly improves productivity, interpretation accuracy, and extracts a vast amount of information from the 3-D seismic data volume that would otherwise be overlooked. This technique allows the geoscientist to rapidly I-dentify both subtle structural and stratigraphic features throughout the field. In addition this technology is very powerful for recognizing subtle differences between 3D data sets processed with different parameters and technologies especially those which change the frequency of the waveform. Thus coherence is an excellent tool to evaluate both the structural and stratigraphic effects of increasing the frequency of seismic data as demonstrated here. The resultant data cube is equally useful to geo-physicists, geologists, and reservoir engineers to help build a more accurate picture of the subsurface, increasing the precision of reservoir modeling, and decreasing the risks associated with drill site selection. Processing geophysicists work closely with interpretation geoscientists to optimize the results of the coherence processing using the latest algorithms and parameters to focus on features of specific interest.