Abstract
Production Log analysis is based on the calculation of fluid flow velocity, usually from a spinner, some fluid identification sensors to work out the holdups of fluids along the wellbore with a lookup of the slippage between the fluid phases from a correlation. The fluid rates are a result of the calculations and very dependent on the attributed slippage velocities. There are a number of slippage correlations in the Emeraude Production Logging (PL) analysis program from Kappa. The choice can be significant as the results from using different correlations may move the apparent water production from one zone to another. Usually the analyst just uses the correlation that gives the result closest to the surface test and keeps that correlation for all other zones.
The object of this paper is to find a more systematic way to pick the flow correlation to use in a 3-phase well. In Emeraude there are 7 Oil-Water (O-W) correlations and 2 full 3-phase flow correlations. For the O-W correlations, one has to pick a Gas-Liquid (G-L) correlation first. We used the correlation recommended by our previous study (Jongkittinarukorn and Kerr, 2011) to work out the G-L slippage and then used a similar statistical technique to determine which correlation works best determine the O-W slippage.
This study finds that 3-Phase G-L correlations perform better than 3-Phase correlations do. Choquette, ABB-Deviated, and Stanford Drift Flux LL correlations are the best three flow correlations and are recommended for PL analysis in a 3-phase well. The results of the statistical analysis indicate that gas rate, oil rate, and water cut are critical for flow correlation selection.
