Ultrasonic method for measuring water holdup of low velocity and high-water-cut oil-water two-phase flow

Abstract

Oil reservoirs with low permeability and porosity that are in the middle and late exploitation periods in China's onshore oil fi elds are mostly in the high-water-cut production stage. This stage is associated with severely non-uniform local-velocity flow profiles and dispersed-phase concentration (of oil droplets) in oil-water two-phase flow, which makes it diffi cult to measure water holdup in oil wells. In this study, we use an ultrasonic method based on a transmission-type sensor in oil-water two-phase flow to measure water holdup in lowvelocity and high water-cut conditions. First, we optimize the excitation frequency of the ultrasonic sensor by calculating the sensitivity of the ultrasonic fi eld using the fi nite element method for multiphysics coupling. Then we calculate the change trend of sound pressure level attenuation ratio with the increase in oil holdup to verify the feasibility of the employed diameter for the ultrasonic sensor. Based on the results, we then investigate the effects of oildroplet diameter and distribution on the ultrasonic fi eld. To further understand the measurement characteristics of the ultrasonic sensor, we perform a flow loop test on vertical upward oilwater two-phase fl ow and measure the responses of the optimized ultrasonic sensor. The results show that the ultrasonic sensor yields poor resolution for a dispersed oil slug in water fl ow (D OS/W fl ow), but the resolution is favorable for dispersed oil in water fl ow (D O/W fl ow) and very fi ne dispersed oil in water fl ow (VFD O/W fl ow). This research demonstrates the potential application of a pulsed-transmission ultrasonic method for measuring the fraction of individual components in oil-water two-phase fl ow with a low mixture velocity and high water cut.

Void Fraction Measurement of Oil–Gas–Water Three-Phase Flow Using Mutually Perpendicular Ultrasonic Sensor

“…As for slug flow and churn flow, we will give the specific measurement scheme below. We used the ultrasonic sensor to measure oil-water two-phase flow in a previous work, and the results suggested that the attenuation of ultrasonic pulse is not significant when the diameter of the oil bubble is less than 1 mm [20]. In the oil-gas-water three-phase flow, due to the injection of gas, oil and water have been mixed into an emulsified state.…”

“…Focusing on void fraction measurement in oil-gas-water three-phase flow, because of the heterogeneous distribution of the gas phase. The ultrasonic sensor consisted of single receiver is insufficient to accurately measure void fraction [19,20]. In this paper, a mutually perpendicular ultrasonic sensor (MPUS) system composed of two pairs of ultrasonic transducers positioned opposite to each other was designed to measure the void fraction of heterogeneous flow in oil-gas-water three-phase flow.…”

Data-Driven Methodology for the Prediction of Fluid Flow in Ultrasonic Production Logging Data Processing

“…The oil-water two-phase flow in the oil well has complex flow regimes with random and variable oil-water interface, as well as a serious slip effect between the oil and water phases. These problems have caused major challenges to traditional production profile logging, such as spinner flowmeter responds poorly under low flow conditions, and the fluid capacitance has poor response under high water cut conditions [2]. Ultrasonic multiphase flow logging tool is a logging method that uses the ultrasonic Doppler effect and the difference in acoustic impedance between oil, gas, and water and uses the spectral characteristics of the discrete phase reflected sound waves to obtain the flow of fluids in each phase [3].…”

Sistema de Monitoramento Versátil de Conteúdo Líquido Aplicado em Separadores Primários

“…Exemplos de sensores comerciais são os visores ou medidores mecânicos de nível e sensores de pressão ou capacitivos montados internamente ao reservatório, além de sensores radioativos, eletrônicos, térmicos,ópticos e hidráulico. No entanto, um dos métodos que atendem os requisitos restritivos devidoà aplicação na indústria do petróleo utiliza propagação de ondas ultrassônicas empregando sensores montados externamente (Lee et al, 2005;Sakharov et al, 2003;Subhash and Balasubramaniam, 2014;Zhao et al, 2016). A aplicação do ultrassom em reservatórios de armazenamento e vasos de separaçãoóleoagua por segregação gravitacional para caracterização das interfaces entre os diversos fluídos no interior deles e identificação de suas propriedadesé um desafio que não foi totalmente superado pelas tecnologias existentes (Mukherjee et al, 2020;Alshaafi et al, 2020;Leal-Junior et al, 2018) Sensores de ultrassom são largamente utilizados na indústria de processos e as suas diversas técnicas atualmente empregadas em monitoramento fazem dessa uma aplicação promissora (Hauptmann et al, 2001).…”