Hydraulic fracturing experiment of coalbed methane well under triaxial stress

  • DONG Guang
  • Research Institute of Engineering and Technique, Huabei Sub-Company, Sinopec Group, Zhengzhou 450006, China

Received date: 2014-07-01

  Revised date: 2014-09-24

  Online published: 2015-02-02


For further understanding of hydraulic fracture initiation and propagation mechanisms of coalbeds, hydraulic fracturing experiments under triaxial stress were carried out on the raw coal specimens from a coalmine with a large-size true triaxial hydraulic fracturing test system. The initiation and propagation characteristics of coalbed hydraulic fracture were studied under different triaxial stress states. The experimental results indicate that the stress state and coal cleat had a direct effect on hydraulic fracture initiation and propagation. The existence of small-scale cleat caused the hydraulic fracture propagation pressure to fluctuate frequently within a narrow range. The swerve of many fracture propagation paths was observed, and the filtration of fracturing fluid led to loss of propagation pressure. These problems are not conducive to the formation of high conductivity hydraulic fracture. The coalbed hydraulic fracture will be more complex with lesser degree of principle stress difference, and horizontal and vertical fractures may be both generated. This experiment may provide references for further exploration of coalbed fracturing mechanisms.

Cite this article

DONG Guang . Hydraulic fracturing experiment of coalbed methane well under triaxial stress[J]. Science & Technology Review, 2015 , 33(1) : 43 -46 . DOI: 10.3981/j.issn.1000-7857.2015.01.007


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