Application of Quantitative Description Method of Carbonate Cave Reservoir Based on Wave

The reservoir type of Yuqi mainly is cave type, which is not detailed description, and the filled and unfilled condition of it is not effectively distinguished. Therefore, quantitative description of carbonate cave reservoir is necessary.

According to the actual condition of Yuqi, the method is provided for describing carbonate cave reservoir quantitatively.

Firstly, geological models of cave reservoir are established considering different size and filling degree. Secondly, the technique of wave equation forward modelling is adopted for obtaining seismic response. The seismic multi-attribute analysis technique is used to choose the sensitive attribute of different modelling results. Then the quantities version is built by finding the relationship of sensitive attribute height/width, model height/width and filling degree of cave, which is finally used in effective reservoir quantitative description. The sensitive attributes for cave reservoir and unfilled cave reservoir separately are root-mean-square amplitude (RMS), and attenuation gradient.

By the application of quantitative description method, the relative error of RMS height/width and model height/width is less than 17%, which proves that this method of restoring cave reservoir size is reliable. Meanwhile, the predicted result of judging filling degree by attenuation gradient quantities version for practice well coheres with practice condition.