Linking multi-scale 3D microstructure to potential enhanced natural gas recovery and subsurface CO2storage for Bowland shale, UK

Lin Ma,Peter D Lee,Paul Ashby,Kevin Taylor,Ronny Pini,Humera Ansari,Anne-Laure Fauchille,Michael Chandler

doi:10.1039/d0ee03651j

Abstract

This paper quantitatively characterises the microstructure in shales across five scales in 3D, builds a multi-scale model of CH4and CO2flow pathways and storage, and assesses the potential of enhanced gas recovery and CO2 storage simultaneously.

Highlights

Climate change has resulted in many countries aiming to reach net-zero greenhouse gas emissions by 2050
Artificial fractures were quantified at 10–100 mm scale; sample fabric, including the distribution of granular minerals, clay minerals, organic matter particles and heavy minerals, were characterised at low-resolution micro-scale (1–10 mm scale); the grain sizes and higher-resolution distribution of these porous phases were further characterised and quantified at high-resolution micron-scale (100 nm–1 mm scale); macropores (450 nm) within these phases were quantified at low-resolution nano-scale (10–100 nm scale) and mesopores (2–50 nm) were characterised at high-resolution nano-scale (1–10 nm scale)
The major compositions are identified as granular minerals (GM), clay minerals (CM), organic matter (OM) and heavy minerals (HM)

Summary

Introduction

Climate change has resulted in many countries aiming to reach net-zero greenhouse gas emissions by 2050. Natural gas produced from shales is considered to be a relatively ‘clean’ energy source, which could increase the energy supply and reduce CO2 emissions significantly, when compared with oil.[1] it is generally accepted that to meet net-zero, carbon capture, utilisation and storage is needed. The concept of CO2 injection into shale reservoirs has the potential to achieve these two goals of enhanced natural gas extraction and carbon sequestration simultaneously e.g. ref. Recent experimental results by Song et al, (2019) suggest that using CO2 as a fracturing fluid rather than water may have a significant impact driven by a lower fracturing pressure, while leading to a denser network of largely shearmode fractures

Methods

Results

Conclusion