The Application Of High Resolution Complex Trace Analysis Method To Oil Reservoir Description

The complex trace analysis method has been introduced into communication Theory long before, now this analysis method has also been an important application in reservoir description. The complex trace analysis method is a seismic data processing method, which is to use Hilbert transform to transform the real signal into a complex signal. And it can be more conveniently separated some parameters from the seismograms, such as the instantaneous amplitude, the instantaneous frequency, and instantaneous phase. Because of these parameters are beneficial to wave dynamics study, therefore it is also helpful to seismic lithology interpretation and hydrocarbon detection. Instantaneous amplitude also calls reflected intensity, amplitude envelope.And it and "bright spot" profile have a similar role. However, by comparison with the "bright spot" profile, "bright" degree of the instantaneous amplitude profile is more distinctive, and the reflection of profile detail is more obvious. Instantaneous amplitude reflects an instantaneous variety in the energy of the seismic wave, because instantaneous amplitude is on seismic wave phase irrelevant, so it can be used to infer the geological body of relating with lithology. Such as the unconformity surface, fault, thin layer, the oil and gas abundance zones. For different geological conditions, instantaneous amplitude profile may show the "bright spot" or the "dim spot". Usually people focus attention upon reservoir by its "bright spot" form, but often this "bright spot" is also a reflection of strong reflection of the rock's energy and thin-layer complex interference. Through exploration practice, people summed up the "dim spot" may also be a reflection of oil and gas. By using the characteristic of the instantaneous phase is on amplitude irrelevant, the instantaneous phase has the unique advantage to track the weak reflection of poor continuity and the reflection wave of polarity variety. For example, through tracking "flat spot", it may forecast oil and gas directly and research lithologic trap, such as overlapping, pinch-out and so on.thick reservoir beds rich in oil and gas, which will emerge a shadow of low frequency in the instantaneous frequency profile, this feature can be used to forecast oil and gas; the thin reservoir layer will be a reflection on the high or low frequency in the instantaneous frequency profile, and this phenomenon appear periodically. Therefore, making use of instantaneous frequency to speculate a thin layer of oil and gas, which also will acquire qualitative or quantitative results. Thus, complex analysis techniques are becoming the bridge linking seismic exploration and development of seismic.Seismic signal instantaneous characteristic parameters based on conventional complex trace analysis method for the conventional seismic interpretation and reservoir description, whose accuracy meets the requirements. But with the continuous deepening of oil and gas exploration, it is more necessary for seismic data of high signal-to-noise ratio and high-fidelity, high-resolution. So for the high-resolution seismic exploration, particularly on thin bed study, it's whose precision is inadequate.This paper, based on the full research on the conventional complex trace analysis algorithm and its application effect, a new high-resolution complex trace analysis method is proposed,it can be used to interpret the high-resolution seismic data. Basic principles are as follows:The differential character of Fourier transform and its corollary point out that calculating signal derivatives is equal to filtering signal, and can improve signal dominant frequency, the way has been applied in the field of signal processing already;The basic expression of complex trace may be known that the decisive factor of complex trace's resolution is the real signal's resolution. Therefore, improving real signal resolution can improve the resolution of complex trace, and the concept of resolution can be learned that the same band or widening band, improving dominant frequency can improve the signal's resolution. In addition, the signal to noise ratio and wavelet form also can affect signal resolution, on the premise of no noise disturbing,this paper makes using Lake-wavelet as a seismic wavelet.Finally, the numerical simulation and actual data processing results show that the method is effective to improve the resolution of the seismic data and can be well used in reservoir description.