A Digital Speckle Experiment on the Cross-Couples Propagation of Artificial Fracture with Bedding Plane. Issue 199 (13th June 2019)

• Record Type: Journal Article
• Authors: Wang, Suling; Li, Jinbo; Dong, Kangxing; Wang, Xuefei; Song, Jian
• Is Part Of: Integrated ferroelectrics. Issue 199(2019)
• Page Start: 148
• Page End: 159
• Publication Date: 2019-06-13
• Subjects: Artificial fracture -- bedding plane -- intersection and propagation -- digital speckle -- fracture re-orientation; Ferroelectric devices -- Periodicals; Integrated circuits -- Periodicals; 537.244805
• DOI: 10.1080/10584587.2019.1592609
• Languages: English
• ISSNs: 1058-4587

Abstract

Abstract: The key to improving the hydraulic fracturing effect is to activate the weak bedding planes and form complicated fractures in an unconventional shale reservoir. In this paper, an experimental method, based on the digital speckle correlation technique, is put forward to measure the fracture tip displacement field when a type I fracture is cross-coupled with a weak bedding plane; the experimental specimen is similar to the material of a shale reservoir. Through observing the fracture tip displacement field, we can determine the location of the fracture tip and calculate the fracture tip stress intensity factor. This can reveal the changing characteristics of fracture tips after the artificial fracture intersects with the bedding plane. Experimental results show that the weak bedding plane is easily activated to form a shearing slip and fracture blunting, and then the fracture type changes from a type I to type I–II composite fracture and extends along the bedding plane. A weaker bedding plane, results in a bigger angle of the bedding plane, a bigger lateral load, larger angle of the crack turned, making it easier for the bedding to be activated and allowing more complex fracture morphology.