Abstract:The mechanical relation built based on sedimentary compaction process showed that the pore-fluid pressure Peis related to overburden pressure Pe and effective pressure Pe, among which the Ph can be gained by the density of formation,Pe by stack velocity. It considered by the analysis of sensibility of predicted precision of formation pressure in Shandong area of Jiyang depression that the change of seismic velocity and overburden pressure gradient are sensitive to formation pressure,so that the data of interval transient time and real-measured pressure of 100 wells in Jiyang depression have been counted up and the data of seismic velocity spectrum of 1000 positions in that area have been interpreted,that basically clarified the factors caused anomaly of seismic velocity spectrum in the area and built the model of correcting the interference resulted from anomaly of seismic velocity spectrum data; the computations of models of normal formation pressure for three sags have been finished separately by logging density and average density, forming a set of predicting methods for formation pressure characterized by advanced technology,easy to operation and good practicality. Application of these methods to predict the formation pressure of 15 prospecting wells,the absolute errors between the predicted results and the formation pressure coefficient of real drilling data are less than 0.1g/cm3 and the maximum relative errors are less than 10%,overcoming unstable and big skip's shortcomings the former prediction of formation pressure had,which met the demands of prospecting drilling for the prediction of formation pressure.