Study on Identification of Carbonate Lithology Using Converted Wave Seismic Data

Aimed at the reflection feature difference between the two kinds of seismic data(P-wave and converted wave), by multi-wave modelling and lithology interpretation, it is probably determined that the target layer amplitude difference between P-wave and converted-wave section is a reflection of weak lithology change ,that is the existence of argillaceous limestone in limestone background. The lithology interface is further confirmed by the comparison of P-wave and converted wave section. According to the multi-wave seismic response analysis of the gas-producing well, the gas-bearing dolomite reservoir is characterized by low frequency and weak amplitude on P-wave section, while weak peak feature on converted wave section. Finally, we carry out the research of lithology prediction using amplitude attribute of converted wave. Compared with P-wave, the lithology prediction result based on converted wave is more consistent with reservoir prediction result, and the favorable lithology (dolomite) area basically corresponds to the reservoir development area, which shows the advantages of converted wave data in fine lithology identification.