Changes

====Lab Based Core Sample Testing====

====Lab Based Core Sample Testing====

Cores are cylindrical rock samples that are collected during or after well drilling. They are sent to the laboratory for further testing. The Anelastic Strain Recovery (ASR) is a method used to determine the in-situ stresses and their orientation from cores by measuring the strain over time.

Cores are cylindrical rock samples that are collected during or after well drilling. They are sent to the laboratory for further testing. The Anelastic Strain Recovery (ASR) is a method used to determine the in-situ stresses and their orientation from cores by measuring the strain over time.

The core is placed in a container filled with silicon and the strain is monitored (see Figure 17). The change in the core dimension is related to the microcracks creation in the rock when in-situ stress is relieved. The alignment of these micro fractures depends on the direction of the principal stresses. When the stress is relieved, the core tends to expand most in the maximum stress relief direction, and least in the minimum stress relief direction. The volume of the microcracks is proportional to the values of the in-situ stresses.  

The core is placed in a container filled with silicon and the strain is monitored (see [[:File:GeoWikiWriteOff2021-Tayyib-Figure17.png|Figure 17]]). The change in the core dimension is related to the microcracks creation in the rock when in-situ stress is relieved. The alignment of these micro fractures depends on the direction of the principal stresses. When the stress is relieved, the core tends to expand most in the maximum stress relief direction, and least in the minimum stress relief direction. The volume of the microcracks is proportional to the values of the in-situ stresses.  

[[File:GeoWikiWriteOff2021-Tayyib-Figure17.png|center|framed|{{Figure number|17}}Anelastic Strain Recovery Apparatus (ASR) (from Lin, W. et al. 2007) [13]]]

[[File:GeoWikiWriteOff2021-Tayyib-Figure17.png|center|framed|{{Figure number|17}}Anelastic Strain Recovery Apparatus (ASR) (from Lin, W. et al. 2007) [13]]]

====Geological Method (Geologic Structure)====

====Geological Method (Geologic Structure)====