Multiphase holdup measurement of oil–gas–water flow using new dual receiver fiber-optical probe array multiphase logging tool

Abstract

To solve the problem of multiphase holdup measurement, a new dual-receiver fiber-optical probe array multiphase logging tool (NDRFOPA_MLT) is designed and developed. This paper first constructed the mechanism model of an NDRFOP for phase holdup measurement by using the ray tracing method and theoretically analyzed the feasibility of NDRFOP to measure phase holdup; considering the shortcomings of NDRFOP local measurement, a NDRFOPA sensor for oil production three-phase flow is designed and developed. At the same time, the volume of fluid model was used to simulate the distribution characteristics of the medium in the NDRFOPA_MLT measurement pipeline under the working conditions of oil–gas–water flow with a total flow rate range of 0.42–1.25 m3/h, water holdup range of 50%–80%, oil holdup range of 10%–30%, and gas holdup range of 10%–40%. In addition, the NDRFOPA_MLT measurement models for different multiphase flow conditions were established by the ZEMAX ray tracing method, and the sensitivity distribution, response characteristics, and phase holdup measurement methods were studied to obtain the phase holdup measurement results under multiphase flow conditions. Finally, a multiphase flow experimental platform with a measurement pipe diameter of 20 mm and a measurement pipe length of 300 mm was established, and experiments were conducted under multiphase flow conditions, such as a gas flow rate range of 0.04–0.16 m3/h, oil flow rate range of 0.64–1.70 m3/h, and water flow rate range of 0.53–2.58 m3/h. The experimental results showed that phase holdup measurement error was mainly kept within 10%.

Experimental Analysis of Gas Holdup Measured by Gas Array Tool in Gas–Water Two Phase of Horizontal Well

“…The six spring arms of the GAT are distributed in a circular shape at equal intervals, and an optical fiber probe is fixed in each spring arm, as shown in Figure 1. The head of the optical fiber probe is sapphire, and the refractive indices of light in sapphire, gas, water, and crude oil are 1.76, 1.00, 1.33, and 1.50, respectively [10][11][12][13]. As shown in Figure 2, when the optical fiber probe is in contact with gas, most of the light is reflected back due to the large difference in refractive index between the gas and the sapphire, and the intensity of the reflected light is the largest.…”

“…As shown in Figure 2, when the optical fiber probe is in contact with gas, most of the light is reflected back due to the large difference in refractive index between the gas and the sapphire, and the intensity of the reflected light is the largest. When the optical fiber probe The head of the optical fiber probe is sapphire, and the refractive indices of light in sapphire, gas, water, and crude oil are 1.76, 1.00, 1.33, and 1.50, respectively [10][11][12][13]. As shown in Figure 2, when the optical fiber probe is in contact with gas, most of the light is reflected back due to the large difference in refractive index between the gas and the sapphire, and the intensity of the reflected light is the largest.…”