# An Experimental Analysis of Gas Reduction in Multiphase Flow with a KMS Helical Static Mixer
## 6 Experimental Validation of the Numerical Result  
### Methodology  
Based on the numerical results, the improvement of the gas reduction was verified with a laboratory-scale platform based on the configuration in Figure 2, where an \(80([lt])\) mixture composed of 25% oil and 75% water, motivated again by the Nuvoil samples'  
Figure 11: X and Z bubble ratios’ performance at the output of the mixer for increasing velocities.  
Figure 10: Transversal sections at \(d_{l}=20\) mm with a rotating gas bubble.  
data, was complemented with dispersed gas injected into the flow at the entrance. The experiments allowed not only the validation of the gas isolation, but also verifying the sedimentation time of the phases and the resulting fraction of the volumes in the reservoir for both cases: with and without the KMS as the inlet device. In addition, a configuration of a 2-element KMS was studied and compared with the 4-element case.  
It is important to recall that the amount of gas in the mixture at the reservoir is deduced by characterizing the resulting volume with respect to the defined incoming liquid; the resulting difference implies disperse gas bubbles that contribute to a higher volume, which should converge to the original as the gas emerges to the surface by sedimentation.  
An additional parameter \(r\) describes the distance where the KMS is located with respect to the input of the horizontal separator and is considered to ensure a suitable pressure drop due to the mounting of the deviation tube. Regarding the location of the bubble at the end of the KMS, \(r\geq 20\) mm and two cases were tested. According to Equation (1) with \(K_{T}=1\), implying the flow without the KMS, \(r=100\) mm implies a drop pressure of \(\Delta P=0.0037\) Kg/cm\({}^{2}\), barely contributing to \(\Delta P_{sm}\), which is even lower for \(n=2\).  
Four different cases were studied as described in Table 3 and from which several experiments were carried out at room temperature. Case A describes the current operational scenario of the real case in the company, where foaming results in injection pumping issues.  
The analysis was addressed under two perspectives on the total mixture in the reservoir once having passed through the KMS. On the one hand, three samples spaced by 10 min were taken from the layer at the bottom of the reservoir, where a dominant water as the heaviest component was expected and, on the other hand, a vision system based on the lateral camera monitors the dynamics of an intermediate layer where a mixture is evolving in time because of the gravity separation. This intermediate mixture layer (IML) is particularly interesting because it includes the original mixture with different proportions over time and its thickness decreases since the water gets to the bottom layer, the oil emerges to the top layer, and the gas emerges from the mixture. Figure 12 depicts a capture of these layers in the reservoir, which vary over time in thickness depending on the configured case and the concentration of the involved phases, as studied in what follows.  
Figure 12: Layers in the horizontal reservoir permanently monitored by the vision system.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Case** & **KMS** & **r** & **d** \\ \hline A & NA & NA & NA \\ B & 4-element & 40 mm & 20 mm \\ C & 4-element & 100 mm & 20 mm \\ D & 2-element & 100 mm & 20 mm \\ \hline \hline \end{tabular}
\end{table}
Table 3: Experimental analysis cases.