Application of Characteristic Curve Reconstruction Technique in Thin Interreservoir Prediction in Gulong Area

Daqing Oilfield has undergone more than 60 years of exploration and development, the favorable reservoir has changed from pure sandstone to thin interbed sand and mudstone. Thin interbeds of sand and mudstone are characterized by thin reservoir thickness, poor physical properties and inability to distinguish sand and mudstone by P-wave impedance. It restricts the accuracy of reservoir prediction and directly affects the success rate of well location deployment. Therefore, the feature curve reconstruction technique is introduced in this paper. Based on the wavelet transform reconstruction technology, the P-wave impedance is taken as the low frequency part, and the lithologic sensitive curve is taken as the high frequency part, and the multi-curve fusion is carried out to reconstruct a new characteristic curve. The characteristic curve is consistent with the seismic reflection characteristics and has a good response to the reservoir. The reconstruction technology of characteristic curve has good applicability for the thin interbed of sand and mudstone, effectively distinguishing the characteristics of sand and mudstone, which not only widens the effective frequency band of seismic, but also ensures the quality of well-seismic matching, combined with the seismic waveform indication inversion technology, the reservoir prediction accuracy is improved. The practical application of this technology in the Putaohua reservoir in Gulong area of Daqing Oilfield shows that the coincidence rate of post-test Wells is high, and the sand body plane distribution conforms to the geological law, which provides reliable basic data for well location deployment.