Monitoring the CO2 enhanced oil recovery process at the nanoscale: an in situ neutron scattering study

Konstantinos L Stefanopoulos,Georgios N Karanikolos,Waleed Alameri,Vassilios C Kelessidis,Tristan G A Youngs,Daniel T Bowron,Evangelos P Favvas

doi:10.1039/d1ya00058f

Abstract

Monitoring the dynamics of CO2-EOR, the pore accessibility and the structural properties of confined CO2 with neutron scattering.

Highlights

Paper capture and storage enhanced oil recovery (CCS-Enhanced oil recovery (EOR)) can be balanced with the dual objective of enhanced oil recovery whilst at the same time storing some of the injected CO2 permanently in the depleted reservoir.[6,7,8,9,10,11] in a recent review study it was suggested that it is feasible to use CO2 Enhanced Oil Recovery (CO2-EOR) to enhance shale gas recovery instead of using conventional water-based fracturing fluids
This means that the supercritical CO2 injection reduces the scattering contrast and, the scattered intensity between the limestone matrix and the carbon dioxide
A methodology has been established for monitoring the CO2-EOR process in real time at the nanoscale

Summary

Introduction

Paper capture and storage enhanced oil recovery (CCS-EOR) can be balanced with the dual objective of enhanced oil recovery whilst at the same time storing some of the injected CO2 permanently in the depleted reservoir.[6,7,8,9,10,11] in a recent review study it was suggested that it is feasible to use CO2-EOR to enhance shale gas recovery instead of using conventional water-based fracturing fluids. In the case of the miscible CO2-EOR process, the reservoir pressure is above the MMP and the higher and intermediate molecular weight reservoir oil hydrocarbons vaporize into the CO2, whilst part of the pressurised CO2 dissolves into the oil. This mass transfer between the oil and CO2 allows the miscibility of the two phases without any interface; as a result, a transition miscible zone is developed with the CO2 in the back and the oil in the front.[14] In most cases the miscible CO2-EOR mode is preferable because it achieves higher oil recoveries compared to the immiscible methodology. From this point of view, it is important to develop an in-depth understanding of the structural properties of both the porous host and the pore-confined CO2 during the CO2-EOR process at the nanoscale

Methods

Results

Conclusion