Abstract:

The Carbonate reservoirs of Tahe Oilfield in North Tarim are characterized by large buried depth,week seismic reflection signal and high heterogineity.Three methods could be used to predict this kind of reservoirs:1.use seismic horizon flattening technique to restore fossil landform;use seismic attribute parameters to restor fossil water system.Then predict the karst reservoir developed position;2.use the parameters of coherence,amplitude,wave impedance inversion and constrained logging to analyze the validity of the reservoir;3.use pattern recognition technique to predict reservoir's oil and gas potential,including hystogram,2-D cross plot and 3-D cross plot.The practice has proved that the predicted distribution areas of available carbonate reservoirs fit well with the actural ones,and the coincidence is 70%～80%.

Key words: fossil landform, fossil water system, amplitude extraction, coherent calculation, wave impedance inversion, pattern recognition, multi parameter analysis