Application of “Virtual Pressure Gauge” for The Selection of Vertical Multiphase Flow Correlation in the Gas Lifted Well to Achieve Proper Tubing Outflow Analysis

Abstract

Tubing outflow analyses are performed to predict pressure losses up the production tubing based on the production rate, flowing wellhead pressure, physical features of the well and produced fluids in question. An outflow/vertical lift curve is used to show how the flowing bottom hole pressure varies as function of production rate. Reliable and accurate mean to predict pressure losses in vertical multiphase flow is essential to properly design well completions and artificial-lift systems, optimize production performance, and troubleshoot well problems.
The most important vertical multiphase flow correlations today are Duns-and-Ross, FancherBrown, Gray, Hagedorn-Brown, Orkiszewski, and Beggs-and-Brill. Selecting the best multiphase flow correlation for a specific application is an art, as well as science. There is no universal multiphase flow correlation that works in all applications. Each correlation has its strengths and weaknesses. To determine the most suitable vertical multiphase flow correlation, it shall be compared against measured pressure survey data. Then, the selected multiphase flow correlation should be tuned to match the measured pressure drop between the deepest pressure measurement and the wellhead. The pressure survey data can be taken from permanent downhole gauge installed in the production tubing. When the permanent gauge is not available, the temporary gauge has to be run into the well by wireline to acquire pressure data at various depths in the wellbore which can add operational cost of the well and increase the risk of well failure due to wireline operation failure.
vertical multiphase flow correlation and calibrate the selected vertical multiphase flow correlation in the gas lifted well without running the pressure gauge into the well. To check the accuracy of this technique, the comparison between common technique with actual measured pressure data and virtual gauge technique will be discussed. The comparison of those two techniques shows that virtual gauge application can be used as an alternative to select and tune vertical multiphase flow correlation under certain conditions and assumptions when running wireline gauge into the well is not possible to be performed.