Measurement Of The Properties Of Oil-Water Two-Phase Flow In Inclined And Horizontal Pipes

Inclined and horizontal oil-water two-phase flow phenomena widely exist in petroleum industry, and measurement of the flow parameters is of great significance for industrial production process and optimization. As oil-water two-phase flow structure presents highly randomness, instability and polymorphism, the flow parameters are difficult to measure. To address this complex issue, ring conductance probe and mini-conductance array probe are designed. As the conductance probe, and mini-conductance array probe signals can reflect global and local character of flow patterns in oil-water flows respectively, the dynamical experiment are carried out in Tianjin university multiphase flow loop facility. Flow parameters are measured, such as the flow pattern maps of inclined and horizontal oil-water two-phase, the cross-correlation velocity of oil-water mixtures and water volume fraction. The nonlinear dynamics characteristics of inclined oil-water flows are studied by using nonlinear analysis methods. The flow pattern transition in horizontal oil-water two phase flow are studied by using two fluid model and numerical simulation techniques. Water cut in horizontal oil-water flows are measured by combination of conductance and capacitance probe. The creative points of this study are as follows:1. The inclined oil-water two-phase flow structure information is extracted by the combined measurement of ring conductance probe and 5-channels axial mini-conductance array probes. Based on the measured signals, the flow pattern maps in large diameter oil-water flows are proposed at different inclined angles, and it can be concluded that the pipe diameter has great influence on flow pattern transitional boundaries. A new chaotic attractor morphological analysis method, perimeter measure analysis method, is proposed, which studied the variation of perimeter measure with the embedding delay time in phase space. The analysis results show that the growth rate of attractor area is an invariant feature to describe the attractor morphological characteristic, the perimeter measure is sensitive of flow pattern transition between dispersed oil in water pseudoslug and dispersed oil in water countercurrent flow, and a good identification results have been obtained for these two water dominated flow patterns. The perimeter measure will provide a new way to study the nonlinear dynamics mechanism of flow pattern evolution.2. The horizontal and near-horizontal oil-water two-phase flow structure information in 20 mm ID pipes is extracted by the combined measurement of ring conductance probe and 8-chanels radial mini-conductance array probes. Based on the measured signals, flow patterns maps including six kinds of typical flow patterns in horizontal oil-water flows are proposed. The flow pattern transitional boundaries are calculated by two fluid model, dispersed flow model and phase inversion model. The results show that the boundaries between ST and ST&MI flow pattern are different between experiments and physical model, while the experimental transitional boundaries between ST&MI and Semi-dispersed flow patterns (D O/W&W, D W/O&D O/W), and Semi-dispersed flow and Full-dispersed flow patterns (D O/W, D W/O) are consistent with the physical model, and the inclination angles will greatly enlarge the differences. The numerical simulation work in this study will provide a feasible method to understanding the flow pattern evolution.3. The measurement of partial phase flow rate in horizontal oil-water flows are investigated by using the combination instrument of conductance and capacitance probe during the production well logging in horizontal wells. As the conductance probe is sensitive to water continuous flow patterns, and the capacitance probe is sensitive to oil continuous flow patterns, considering the actual experimental response character, the following measurement solutions are proposed, for the total flow rate in the range of 20~50 m3/d(low flow rate range), the capacitance probe is used to measure partial phase flow rate, and for the total flow rate in the range of 100~200 m3/d(high flow rate range), the conductance probe is used. For the low flow rate range, where exist more slip effect between oil and water phase, we establish a variable coefficient drift flux model and the proposed model has better water cut prediction precision, combination with the statistical model in high flow rate range, water cut prediction precision is less than 3%. Finally we provide a reliable well logging interpretation method of horizontal well production profile based on the physical model.