A New Multiphase Flow Model Predicts Pressure and Temperature Profiles in Wells

Abstract

ABSTRACT Since 1981, Elf Aquitaine, IFP and Total-CFP have been collaborating to establish a new calculation method predicting multiphase flow pressure drop in wells able to cope with any case of oil or gas production. A flow model has been developed by using fundamental equations of two-phase fluid mechanics. The mass and momentum balances for each phase are considered as well as interactions between phases related to every flow regime. The main flow patterns are taken into account and mechanistically – based relations determine transitions. The physical basis of this model has been provided by experiments carried out on test facilities generating fluid flow conditions similar to those encountered in production wells. The test loop consists of two 30 meter long flowlines (diameter 3 and 6 in), which can take any inclination from 0 to 90 degrees. The fluids used were condensate, heavy gas-oil, water and natural gas with pressure ranging from 5 to 50 bar. Experimentation and modelling resulted in the development of the program WELLSIM, which performs calculations of pressure and temperature profiles in vertical or deviated wells. Comparison with data gathered from wells offering widely different production characteristics shows good agreement over the whole range of parameters and the accuracy of the results is significantly better than with conventional methods.