| Title | Use of Schmidt Hammer for Strength Heterogeneity Characterization, and a Way to Overcome the Lack of Mechanical Data |
|---|---|
| Authors | Jose Rogelio Hernandez Borbon, Anna Rogers, Lynette Liston |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Preliminary feasibility assessments for the development of an Eavor-Loop™ project may face challenges associated with limited data. Eavor-Loops ™ often target deep formations without existing research or offset well data. From a geomechanical perspective, the development of a preliminary wellbore stability model is particularly sensitive to rock property uncertainties, with uniaxial compressive strength (UCS) being a key example. Additionally, the high expense of laboratory testing can complicate efforts to accurately capture rock heterogeneity and assess wellbore stability. The Schmidt Hammer has long been used for the indirect estimation of rock strength, with numerous empirical correlation equations developed to estimate UCS from rebound values. Eavor has adopted this technique during early-stage field exploration by conducting extensive Schmidt Hammer testing on outcrops of the target formations. A limited number of core plugs can be then extracted and tested for UCS, which enables the local calibration of Schmidt Hammer rebound values and the development of comprehensive UCS datasets. This method not only facilitates preliminary UCS estimation but also provides insight into the spatial variability and heterogeneity of rock strength across a formation. In addition, it supports the study of the mechanical properties of basement rocks, which are critical targets in Eavor-Loops™ 2.0, yet rarely characterized in existing literature. By refining UCS estimates and capturing heterogeneity, this approach reduces uncertainty, enhances early-stage geomechanical modeling, and offers a practical solution to the lack of subsurface mechanical data in unexplored locations. |