Transient Flow Pattern Characteristics Of Horizontal Oil-water Two-phase Flow In Flow-concentrating Pipe

Horizontal oil-water two-phase flow phenomena widely exist in petroleum industry. The developing of the transient horizontal oil-water two-phase flow pattern in flow-concentrating pipe, the measurement of the flow parameters and the dynamics characteristics of the horizontal oil-water two-phase flow are of great significance for production profile logging technologies. Because the horizontal oil-water two-phase flow structure in flow-concentrating pipe presents highly randomness, instability and polymorphism, the flow parameters are very difficult to measure. To address the complex issue, the annular conductance probe and the parallel conductance probe are designed. The dynamical experiment is carried out in Tianjin University multiphase flow loop facility. The following research results have been achieved.Firstly, it is necessary to simulate the different conditions of transient horizontal oil-water two-phase flow in flow-concentrating pipe with numerical simulation software FLUENT. Compare the simulation results with the measure results of the conductance probe, we can see that the numerical simulation software FLUENT can simulate six kinds of typical flow patterns in horizontal oil-water flow very well. Based on the simulation results, the time and space development of the transient flow pattern of horizontal oil-water two-phase in flow-concentrating pipe is studied. It is concluded that the transient flow pattern in flow-concentrating pipe reaching stability need 120 seconds and axial position 20cm.Secondly, use four parallel conductance probe sensors to measure the transient flow pattern of horizontal oil-water two-phase in flow-concentrating pipe. And validate that the simulation results are right with the analysis of the dynamics characteristics of the conductance probe sensors in different axial position.Thirdly, the two kinds of sensors'signals can reflect the global characteristics of flow patterns in horizontal oil-water flow, the four kinds of dispersed flow can be divided. The mixture velocity is calculated by the cross-correlation flow measurement technique. The result show that the parallel conductance probe have the better total flow measurement characteristics. The nonlinear dynamics characteristic of horizontal oil-water flow is studied using nonlinear analysis method. By analyzing the rules of two complexity measures with the changes of horizontal oil-water two-phase flow parameters, the results indicate that the two complexity measures are sensitive to the flow pattern transition in horizontal oil-water flow, and this method is an efficient, supplementary diagnostic tool to reveal the flow pattern transition mechanism of the horizontal oil-water flow.