Fracture Toughness
Overview:
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Fracture toughness is a measure of the energy required to extend a crack and is a crucial parameter required in hydraulic fracturing design.
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Most commercial fracture modeling software require fracture toughness as an input parameter.
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Mode I fracture toughness is measured in the laboratory using the ISRM recommended Cracked Chevron Notch Brazilian Disc (CCNBD) test.
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Anisotropy in fracture toughness can be captured by notching sample in different orientations with respect to bedding.
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Material requirements for CCNBD based fracture toughness are more economic than other recommended methods.
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Sample dimensions can be scaled while meeting the requisite geometrical considerations for optimal material utilization.
Recommended Sample Dimensions:
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Diameter – 2 inches or 1.5 inches
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Length – 0.8 inch or 0.6 inches