Application of Seismic Frequency Expanding Processing Technology in the Jurassic Thin Reservoir Prediction of Jinlong Oilfield

The thickness of the Jurassic reservoir sand body in Jinlong Oilfield is thin, with rapid lateral changes and unclear spatial distribution patterns. It is difficult to identify conventional seismic data, and improving the resolution of seismic data for predicting thin sand body reservoirs has become the key to the exploration and development of Jurassic lithological oil and gas reservoirs. By using HFE high-resolution frequency extension processing method and combining with AIW acoustic impedance inversion technology, effective prediction of thin sand reservoir has been achieved. The results show that by utilizing HFE high-frequency expansion processing technology, the frequency band of target layer seismic data has been widened by 45 Hz (from 10～55 Hz to 10～100 Hz), improving the ability of seismic data to identify thin sand reservoirs and achieving effective characterization of thin sandstone layers larger than 8 m; At the same time, based on seismic frequency data, AIW wave impedance reservoir inversion was carried out to accurately predict and characterize the spatial distribution of the J₁s₂¹ sand body in the Jurassic Sangonghe Formation in the study area. Four favorable areas for oil and gas reservoirs were identified, with one favorable area having achieved high industrial oil and gas production through drilling. The actual drilling results are highly consistent with the reservoir prediction results, with a 100% accuracy rate for reservoir prediction drilling and an absolute error value of less than 4.29% for sand body thickness. This method is effective for predicting thin sand reservoirs in the Jurassic system, with obvious results and high drilling coincidence rate. It can be used as an effective method for predicting thin sand reservoirs and provide reliable technical support for predicting sand reservoirs in lithological oil and gas reservoirs.