Development of a user-interactive nodal analysis model and productivity analysis of Donghae-1 gas field

This study presents a user-interactive nodal analysis model based on Windows 95, 98 and NT using Delphi for investigating optimum production schemes in gas condensate fields. This program is capable of inputting the data as a file or sub-window. It is coded so that calculated results can be plotted on graphs attached to this program which makes it handy in the field. The developed model has been applied for Gorae V structure in Donghae-1 gas field located in the East Sea near Ulsan, Korea to analyze the production performances. The reservoir was assumed as dry gas or gas-condensate reservoirs. In the case of a gas-condensate reservoir, mist and transition flowing patterns were studied. In order to investigate the inflow performances of vertical as well as horizontal wells, we analyze the effects of horizontal well length, skin factor, formation permeability on productions. Also, the effects of tubing, surface flow line, and surface choke sizes have been examined on producing behaviors. Finally, the productivity analysis of the total production system has been performed using the interpreted data of DST(Drill stem test) conducted on Gorae V structure. (author). 7 refs., 2 tabs., 14 figs.