# An Experimental Analysis of Gas Reduction in Multiphase Flow with a KMS Helical Static Mixer
## 3 Problem Statement and Methodology Overview  
For a hydraulic ALS, one of the most common methods for separation in multiphase flows is the segregation by gravity by means of horizontal three-phase separators. As expected and since the process is applied into continuous flow, the separation could be inefficient without adequate equipment, particularly for those oil wells from which the extracted mixture has a high gas composition and foaming becomes an important challenge to deal with. The conventional three-phase separator, even without inlet devices, is quite enough for those oil wells where the gas concentration is not significant, achieving an acceptable performance in the separation of phases and recycling the water as the power fluid. Depending on the oil well, the concentration of the gaseous phase is an important parameter that impacts not only the separation, but also the efficiency in pumping; if the gas is not segregated from the water inside the horizontal separator, the electric pump to reinject the motor fluid into the oil well demands more energy. The focus of this work is two-fold: the first objective is the study of a KMS mixer as the inlet device to favor the gas reduction just before the multiphase mixture enters the horizontal separator; the second objective of the study is focused on the experimental analysis of the sedimentation times of the phases in the reservoir of the separator as a result of the remaining gas in the reservoir. Although the KMS was originally designed to generate a homogeneous mixture of miscible phases, for an incoming fluid with a high difference in density such as a liquid and gas, the mixer does not operate as expected, and the helical acceleration sends the liquid to the wall of the pipe. while the gas, the lightest component, remains at the center of the tube. The analysis performed in this work aims to characterize this phenomenon for determining the dynamics and geometric conditions for the implementation as a gas pre-separator in the oil extraction process. Once having defined these conditions, the dynamics of sedimentation is analyzed to describe the performance regarding the times and quality of the separation in the reservoir. The studies were developed in a scaled pilot platform where the KMS and the reservoir were assembled based on previous numerical analysis. The cyclonic phenomenon produced by the KMS is exploited to isolate the gas by means of a deviation strategy that should be characterized in location and geometry in the vertical pipeline just before the entrance to the three-phase separator, as depicted in Figure 2, to guarantee the casing of the concentrated gas. The parameters to be determined from the study to take full advantage of the phenomenon are the diameter \(d_{i}\) of the inner gas deviation pipe once in the stable region of the cyclone, the distance \(d\) where the KMS is located with respect to the deviation pipe allowing this capture, and the length \(L\) of the KMS, which is defined by \(n\) helical elements. Once the mixture is broken by the KMS, the gas should be guided to the output depicted in Figure 2, while the heaviest phase at the walls ends at the bottom of the horizontal separator, where, by sedimentation, the oil is segregated from water over time. The experimental performance is studied with the configuration from Figure 2, where the pipeline is set as in the oilfield, with \(D=44.8\) mm. In the pilot experimental platform, a \(1/2[HP]\) pump supplies the mixture to the system, making the fluid pass through a 3D-printed KMS of either 4 or 2 elements with \(l/D=1\) and a reservoir as the horizontal gravity separator, where the remaining mixture is accumulated. The induced cyclone phenomenon was captured by an endoscope full-HD camera with \(1920\times 1080\) pixels and 60 fps at the outlet section where the deviation pipe, with diameter \(d_{i}\), to be defined, is located for casing the gas and deviating it.