Determination of rock fracture toughness KIIC and its relationship with tensile strength

Yan Jin, Jianbo Yuan, Mian Chen, Kangping Chen, Yunhu Lu, Huaiying Wang

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

Hydraulic fracture propagation is greatly influenced by mode-II fracture toughness since this is one of the factors which determine whether a fracture diverts. Direct measurement of rock fracture toughness is constrained by high cost, limited number of available cores and long turn around time. Therefore, to overcome these constrains, it is necessary to develop an effective mode-II fracture toughness test which can be used in a prediction analysis for deep rock formations. Consequently, a mode-II fracture toughness test system was designed for rocks using the straight-notched Brazilian disc (SNBD) test methodology. In the experiment, this system was used to test 20 rock samples from the WG oilfield. This enabled a fracture toughness prediction model to be established, based on an analysis of the test data. H341 acoustic, density and gamma-ray logging data were used to predict horizontal stresses and rock tensile strength. When combined with the mode-II fracture toughness prediction model, continuous values were predicted, which were successfully confirmed by field fracturing practices. It was confirmed, therefore, that this successful method met the need of providing continuous fracture toughness data during field fracturing operations.

Original languageEnglish (US)
Pages (from-to)621-627
Number of pages7
JournalRock Mechanics and Rock Engineering
Volume44
Issue number5
DOIs
StatePublished - Sep 1 2011

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Keywords

  • Fracture toughness prediction
  • Hydraulic fracturing
  • Mode-II fracture toughness
  • Rock mechanics
  • Straight-notched Brazilian disc test
  • Well logging

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Geotechnical Engineering and Engineering Geology
  • Geology

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