APPLICABILITY ESTIMATION OF FOUR METHODS OF CALCULATING THE DEVIATION FACTOR OF NATURAL GAS

The deviation factor of natural gas is a great significant parameter for the gas reservoir engineering calculation,which is mainly obtained by the Standing-Katz graphic solution or empirical formula calculation.The graphic solution is with great deviation when the parameters are manually read and is not convenient for computer application.The precision and applicability of the empirical formula calculation are difficult to confirm.To resolve the shortcomings mentioned above,firstly we digitize the Standing-Katz graph with digital software,then with the digital graph we analyze and evaluate the calculations' precision and application range of the 4 kinds of empirical formulas which are widely used for the present engineering calculation,finally the most accurate empirical formula is optimized to offer the reference for our research staff.