Evolution of Friction and Permeability in a Propped Fracture under Shear

Journal Article · Mon Dec 04 00:00:00 EST 2017 · Geofluids

DOI:https://doi.org/10.1155/2017/2063747· OSTI ID:1427991

Zhang, Fengshou ^[1]; Fang, Yi  ^[2]; Elsworth, Derek ^[3]; Wang, Chaoyi ^[2]; Yang, Xiaofeng ^[4]

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1. Tongji Univ., Shanghai (China). Key Lab. of Geotechnical & Underground Engineering of Ministry of Education. Dept. of Geotechnical Engineering
2. Pennsylvania State Univ., University Park, PA (United States). Dept. of Energy and Mineral Engineering. EMS Energy Inst. G3 Center
3. Pennsylvania State Univ., University Park, PA (United States). Dept. of Energy and Mineral Engineering. EMS Energy Inst. G3 Center. Dept. of Geosciences
4. China Univ. of Mining and Technology, Beijing (China). School of Mechanics and Civil Engineering

We explore the evolution of friction and permeability of a propped fracture under shear. We examine the effects of normal stress, proppant thickness, proppant size, and fracture wall texture on the frictional and transport response of proppant packs confined between planar fracture surfaces. The proppant-absent and proppant-filled fractures show different frictional strength. For fractures with proppants, the frictional response is mainly controlled by the normal stress and proppant thickness. The depth of shearing-concurrent striations on fracture surfaces suggests that the magnitude of proppant embedment is controlled by the applied normal stress. Under high normal stress, the reduced friction implies that shear slip is more likely to occur on propped fractures in deeper reservoirs. The increase in the number of proppant layers, from monolayer to triple layers, significantly increases the friction of the propped fracture due to the interlocking of the particles and jamming. Permeability of the propped fracture is mainly controlled by the magnitude of the normal stress, the proppant thickness, and the proppant grain size. Permeability of the propped fracture decreases during shearing due to proppant particle crushing and related clogging. Proppants are prone to crushing if the shear loading evolves concurrently with the normal loading.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States); Tongji Univ., Shanghai (China); China Univ. of Mining and Technology, Beijing (China)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE); Young 1000 Talent Program of China; Tongji Civil Engineering Peak Discipline Plan (CEPDP) (China); National Natural Science Foundation of China (NSFC)
• Grant/Contract Number: FE0023354; 41772286; 51674267
• OSTI ID: 1427991
• Journal Information: Geofluids, Vol. 2017; ISSN 1468-8115
• Publisher: Wiley
• Country of Publication: United States
• Language: English

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