Continuous Stress Tensor Determination from Wireline Logs
- Nicholas Harvey
- 4 hours ago
- 2 min read
Technical Presentation by Nick Harvey, Principal, Harvey Rock Physics
AusIMM Hunter Region Branch – July 2026 Tech Talk
EVENT DETAILS Date & Time: Wednesday, 8 July 2026 • 6:00 pm – 7:30 pm AEST Venue: Singleton Diggers Club, 49 Castlereagh Street, Singleton NSW 2330 Format: In-person • 1 Professional Development Hour • Free for AusIMM members |
Introduction
Nick Harvey, Principal of Harvey Rock Physics, will present a technical paper on a novel workflow for the continuous determination of the in-situ stress tensor using wireline log data at the AusIMM Hunter Region Branch July Tech Talk.
Accurate characterisation of the full stress tensor is fundamental to geomechanical design in mining, civil engineering and resource extraction. Conventional techniques such as overcoring deliver discrete point measurements that may not adequately capture spatial variability within heterogeneous rock masses. The workflow presented addresses this limitation by providing continuous, interval-by-interval estimates of stress orientation and magnitude.
Technical Approach
The method integrates three complementary wireline datasets:
Acoustic borehole image analysis – Utilisation of borehole ovality and breakout features to constrain stress orientations.
Full-wave sonic data – Provision of elastic moduli and anisotropy information for magnitude estimation.
Density logging – Supply of overburden stress and lithological constraints.
A proprietary tensor optimisation procedure is then applied to compute the principal stresses (σ₁, σ₂, σ₃) on a continuous basis throughout the logged interval. This yields a high-resolution stress profile that reveals vertical and lateral variations often overlooked by traditional discrete measurement techniques.
Demonstrated Application
The workflow has been applied to three boreholes drilled through heterogeneous lithologies in contrasting geological settings. In each case, the continuous stress profiles obtained compared favourably with available overcoring measurements while providing complete interval coverage. The results demonstrate the method’s ability to identify critical stress variability that point-scale techniques may miss, with direct implications for mine design, ground control and geotechnical risk assessment.
Industry Relevance
This presentation is particularly relevant to professionals engaged in mine design, ground control, geotechnical engineering and risk management within the mining sector. The approach offers a practical means of obtaining high-resolution stress information from existing or planned wireline logging programmes, supporting more informed decision-making in excavation design and stability analysis.
Event Information
Date: Wednesday, 8 July 2026
Time: 6:00 pm – 7:30 pm AEST
Venue: Singleton Diggers Club, 49 Castlereagh Street, Singleton NSW 2330
Format: In-person attendance
Professional Development: 1 PD Hour
Registration
Attendance is free for AusIMM members. Non-member registration is $20 and student registration is $5. To secure your place at this in-person technical session, please register via the official AusIMM events portal:
Early registration is recommended as capacity is limited.