Visual lab tests: proppant transportation in a 3D printed vertical hydraulic fracture with two-sided rough surfaces

Jun Li, Pingli Liu, Shibo Kuang, Aibing Yu

Research output: Contribution to journalArticleResearchpeer-review


An effective proppant placement in a hydraulic fracture system is the key to increasing the gas production of unconventional reservoirs. The fracture surfaces are generally rough, however, assumed to be smooth or rough only on one side for visualization in existing experimental fracture models, which may generate unrealistic results. This paper presents a two-sided rough fracture model for studying the proppant placement. This was realized by combining the digitalization of rough surface and 3D printing technology. Using this new fracture model, some distinct piling-up and transportation mechanisms of proppants in a vertical fracture with two-sided rough surfaces were demonstrated against the counterpart of the fracture that considers only one-sided rough surface or smooth surfaces. Particularly, a finger-like piling of proppants resulting from the collective effect of proppant gliding, aggregation and saltation was present in the two-sided rough fracture. Meanwhile, high-speed channel, particle wormhole, cavity and isolated pillars also occurred locally. To quantify these mesostructures, the concept of channel ratio was introduced and correlated with fluid viscosity. All the results suggest that the new fracture model is useful not only to better understand the proppant placement but also to optimally design and control hydraulic fracture systems.

Original languageEnglish
Article number107738
Number of pages11
JournalJournal of Petroleum Science and Engineering
Publication statusPublished - Jan 2021


  • 3D printing technology
  • Hydraulic fracture
  • Particle wormhole
  • Proppant placement
  • Shale gas
  • Two-sided rough fracture model

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