Calculation of bottom-hole flowing pressure of gas well using density iteration method

According to the functional relationship between borehole pressure of gas well and the density and moisture of gas in the borehole,the bottom-hole flowing pressure is calculated by density iterating from the well head to the well bottom. The bottom-hole flowing pressure of 8 gas wells which are of measured bottom-hole flowing pressure data is calculated under no considering the moisture of borehole gas,and the calculated data are compared with the measured data. It is shown that the average relative error of the calculated bottom-hole flowing pressure of 8 wells is only 4. 89%. The maximum error between the calculated bottom-hole flowing pressure under different gas moisture and the measured bottom-hole flowing pressure is 1. 369 1%. The calculated bottom-hole flowing pressure using the density iteration method,empirical formula and RTA separately is compared with the measured data,and it is shown that the calculation error of the density iteration method is the least. In addition,calculating bottom-hole flowing pressure using the density iteration method does not influence the normal production of gas well,the method is suitable to the calculation of bottom-hole flowing pressure in the whole production process of gas wells.