Figure 3
Typical stress indicators found in FMI logs. a). Axially oriented breakouts with blurry appearance in the directions of 90° and 270° TOH. b). Drilling-induced tensile fractures (DITFs) occurring as axial fractures in the directions of 180° and 355° TOH parallel to one principal stress. c). Drilling-enhanced natural fractures (DENF) appear as inclined non-continuous fractures (green line) next to continuous natural fractures (blue sinusoidal curve) in the directions of 190° and 15° TOH. Anderson (1951) shows the alignment of these features to existing natural fractures. Bedding planes (green dotted sinusoidal curve) crosscutting the fracture planes are unaffected by stress-induced borehole wall features.