Forward Analysis Of Gas-liquid Two-phase Flow Pattern In Horizontal Wells

Because the horizontal well production has the advantages of expanding mining range and enhancing oil recovery,most of the horizontal wells have been put into mining and production with the most oilfields on the land entered the middle and late stages of development.Production profile logging interpretation is an important means of enhancing oil recovery,but most of the current production profile logging interpretation models are derived from vertical wells.In the horizontal wells,because the oil-gas-water three-phase flow is different in density and the flow is completely different from that in the vertical well.It is important to establish a production profile interpretation model of the horizontal well.The determination of the flow pattern is the premise of the production profile logging interpretation,which affects the selection of the interpretation model.For the study of gas-water two-phase flow patterns,experimental methods and numerical simulation methods are mainstream research methods.But the experimental methods are affected by many artificial factors,and the experimental conditions are limited.The numerical simulation method is based on the theory of fluid mechanics,and it is not combined with the practical data.So it can not ensure its correctness and accuracy.In this paper,the experimental method is used to simulate the gas-water two-phase flow in the horizontal section and the inclined upward 5 degree section.The method used to observe the recorded flow pattern is the visual method,while the experimental data need to be collected.Then numerical simulation method is used to simulat the gas-water two-phase flow under the same conditions,and factors need to be studied and analyzed(water content,flow rate of each phase,inclination angle of the section,etc.).With comparing the flow patterns and holdup of the numerical simulation results and the experimental results,the correlation is good.The study found that the flow pattern of gas-water two-phase flow in horizontal section is affected by the total flow under the normal temperature and pressure.When the total flow is small,the gas-water two-phase flow pattern in the horizontal section is a stratified flow,including smooth stratified flow and wavy stratified flow.When the total flow rate is large,the gas-water two-phase flow pattern in the horizontal section is a slug flow and a bubble flow.The flow pattern of gas-water two-phase flow in horizontal section is also affected by the volume flow of each phase.When the volume flow of water is constant,the flow pattern will change from stratified flow to bubble flow and slug flow as the volume flow of gas increases.When the volume flow of air is constant,the flow pattern will also change from a stratified flow to a bubble flow and a slug flow as the volume flow of water increases.It is found that the flow pattern of gas-water two-phase flow is also affected by the inclination angle of the pipe section.In the inclined upward 5 degree section,the gas-water two-phase flow pattern have not appear the stratified flow without cosidering the the total flow volume.The flow patternsis the slug flow and bubble flow,in which the slug flow is mostly.And when the total flow rate is constant,the slug unit length of the slug flow will gradually become smaller as the water content increases.When the total flow reaches a certain value,the slug flow will change to the bubble flow.At the same time,the key problem of production profile interpretation is to determine the holdup,physical property parameters,superfacial velocity,average flow velocity,flow rate,etc.The methods of requesting water holdup and the slippage velocity are mostly based on experimental data ane the theory.This paper provides a new idea for the holdup and the slippage velocity by post-processing the numerical simulation results,and also analyzes each phase velocity field on the flow section,which provides the guidance for the research and measurement locations of logging instrument.