Dual Modality EIT-UTT for Water Dominate Three-Phase Material Imaging

Xi Duan,Panagiotis Koulountzios,Manuchehr Soleimani

doi:10.1109/access.2020.2966668

Xi Duan, Panagiotis Koulountzios + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.2966668

Copy DOI

Abstract

Three-phase material imaging such as oil, gas and water is a critical problem in many processes. Monitoring and separation of each phase before corresponding process can be a key to realise cost efficiency production. In the oil and gas industry such a tool can generate great environmental benefits. In recent years, several multi-modality imaging systems are being adapted for such an application. It is not possible to gain information on three phase flow using a single imaging modality that can be deployed in production field. For a three-phase flow dominated by water phase, this is more challenging. The capability of the majority of current dual-modality systems was only demonstrated under limited flow regime conditions. This paper presents a novel combined imaging system including electrical impedance tomography (EIT), and ultrasound transmission tomography (UTT) for mapping three-phase flow. In water dominate mode, the EIT is able to image the nonconductive phases of oil and gas in a water dominate background phase, but not able to separate oil and gas. The EIT two-phase imaging then complimented with the speed of sound imaging of the UTT, which can separate liquid (oil and water) and gas. A dual modality EIT-UTT system combining a 32-electrode EIT array and a 32-transducer UTT sensor array is developed to demonstrate this novel three-phase material imaging. The concept was demonstrated using simulation study and then shown with experimental lab tests. Measurement principles and method are described, experiment based on several three-phase flow scenarios are established, and the results show successful distinguishably for all three phases.

Highlights

In oil and gas industry, companies are increasingly facing the need to find ways of improving oil and gas production techniques, establishing production facilities in difficult location, reducing cost and transporting energy efficiently through pipelines
Because water is more mobile than petroleum, some of the surrounding water is bound to be pumped up when crude oil and natural gas are produced through wells
MEASUREMENT SYSTEM SETUP The experimental system includes a combined sensor, which includes both the 32-electrode electrical impedance tomography (EIT) sensor array and the 32-electrode ultrasound transmission tomography (UTT) sensor array, and two separate measurement system

Summary

INTRODUCTION

In oil and gas industry, companies are increasingly facing the need to find ways of improving oil and gas production techniques, establishing production facilities in difficult location, reducing cost and transporting energy efficiently through pipelines. X. Duan et al.: Dual Modality EIT-UTT for Water Dominate Three-Phase Material Imaging using measurements from electrodes placed on its boundary. It has been applied on industry to identify gas and oil in water depending on their conductivity properties, currently it is a relatively mature technique in two-phase flow [5]. Ultrasonic transmission tomography (UTT) [6], [7] has widely been applied in process industries, by measuring time of flight (TOF) of the signal, spatial distribution of acoustic impedance can be imaged, it is especially well-suited for identify gas from liquid phases [8], [9]. Other multi-modality tomographic systems have been applied and proposed for complex process industry applications such as gas-oil-water (three-phase) flow [1], [15], [16]. The measurement includes subtraction between reference and inclusion data for sound speed leading to the image of change of sound speed: m=S v (9)

IMAGE RECONSTRUCTION

DUAL MODALITY PROCEDURE

CONCLUSION