Fracturing tests on reservoir rocks: Analysis of AE events and radial strain evolution

TL;DR

This study investigates the fracturing behavior of reservoir rocks using acoustic emission monitoring and CT scans, revealing patterns in AE event distributions and strain evolution relevant for resource extraction and storage.

Contribution

It introduces combined AE and CT scan analysis on different reservoir rocks, providing new insights into fracture initiation and propagation patterns.

Findings

AE amplitudes follow an exponential distribution

AE energies follow a power law distribution

Radial strain evolution will be compared to fracture models

Abstract

Fracturing in reservoir rocks is an important issue for the petroleum industry - as productivity can be enhanced by a controlled fracturing operation. Fracturing also has a big impact on CO2 storage, geothermal installation and gas production at and from the reservoir rocks. Therefore, understanding the fracturing behavior of different types of reservoir rocks is a basic need for planning field operations towards these activities. In our study, the fracturing of rock sample is monitored by Acoustic Emission (AE) and post-experiment Computer Tomography (CT) scans. The fracturing experiments have been performed on hollow cylinder cores of different rocks - sandstones and chalks. Our analysis show that the amplitudes and energies of acoustic events clearly indicate initiation and propagation of the main fractures. The amplitudes of AE events follow an exponential distribution while the energies follow a power law distribution. Time-evolution of the radial strain measured in the fracturing-test will later be compared to model predictions of fracture size.