Techniques And Application Of Prestack Seismic Inversion

With the more complex geological cases and the abruptly increasing cost of oil exploration, seismic technology is applied tectonic shape characterization and reservoir assessment. As a core technique of seismic exploration, seismic inversion plays a key role during oil exploration.The seismic inversion is all the time the key technique in the petroleum exploration. Especially with the more and more complex geological setting and the steep rise of exploration cost, and with the seismic technique application from the tectonic feature to reservoir evaluation and even to oil-bearing test, the seismic technique is becoming more and more crucial in the process of oil field prospecting and development.The following are the contents in the paper:1. The theory and its precedence of the prestack AVO inversion and the elastic impedance (EI) inversion are analyzed.2. On the basis of detailed analysis on petrophysics and the demonstration of inversion scheme, it is presented that the prestack seismic inversion can acquire a good effect in the reservoir prediction.3. Discussed are such new techniques of how to enhance the signal-noise ratio, resolution and fidelity in the prestack seismic processing as quality test and editing of field acquisition data, phase inversion deconvolution (PID), prestack time migration, phase normal moveout correction (PMO) and vector filtering (VFL) and so on, which provide base for EI inversion.4. In connection with the logging and drilling data of 6 exploratory wells, the longitudinal and transverse wave impedance inversions are performed on the 40 km2 prestack seismic data in the middle south of Biyang Sag. And the distribution of reservoir is obtained with a good effect.5. The wavelet absorption inversion of the 40 km2 prestack seismic data is performed to make the oil and gas test, which give a powerful proof for the trap evaluation and the determination of drill site.