Research On Numerical Simulation And Gas Holdup Measurement Of Upward Oil-Gas-Water Three-Phase Flow

Three-phase flow is the most common flow of fluid in nature. It widely exists in the oil wells of developed in the middle and later stage. The understanding, description and prediction of oil-gas-water three-phase flow characteristics has become a research focus in the field of multiphase flow, Numerical simulation method is an effective way to study three-phase flow. Cross-section gas holdup detection is an urgent problem to solve in the field of multiphase flow. In this paper, we research the gas holdup logging tool of oil-gas-water three-phase flow based on optical fiber sensor.Firstly,an overview research of multiphase flow pattern and the current commonly used three-phase flow cross-section gas holdup measurement method are described in this article. And the optical fiber sensing technology is described.Secondly, the numerical simulation based on computational fluid dynamics software fluent for oil-gas-water three-phase flow on the inner diameter of 20mm vertical tube is excuted. The oil-gas-water three-phase flow pattern is to be divided based on oil-water interface features and the general characteristics of gas-liquid interface and has got the flow pattern map under the typical overall oil-gas-water three-phase flow. The distribution of the tube radial gas holdup is analyzed, the maximum gas holdup basically appears in the pipe center under various flow-type. Optical fiber sensor should be placed in the pipe center.Thirdly, aiming at the cross-section gas holdup measurement problems, the oil-gas-water three-phase flow gas holdup logging tool based on optical fiber sensor is designed. A theoretical feasibility analysis of measuring gas holdup based on optical fiber sensor is done, and consider that the optical fiber sensor can measure three-phase flow of gas holdup. Optical fiber sensor head using single-fiber cone-shaped sapphire right angle prism can effectively identify the gas and liquid phase. Hardware system and software control system sensor is designed.Lastly, the indoor experiment on the local gas holdup of oil-gas-water three-phase is performed based on optical fiber sensor system. And instruments measurement accuracy for gas holdup of three-phase flow is validated.