A New Evaluation Procedure of Rock Fracability Using Cluster Analysis of Well-Logged Petrophysical Properties of Facies
Xiaofeng Zhou1,2, Feng He3, Jianguang Wei1,2
1Northeast Petroleum University, Daqing 163318 China
2Research Institute of Unconventional Oil and Gas Resources, Daqing 163318 China
3Shale Gas Exploration and Recovery Department, CNPC Chuanqing Drilling Engineering, Chengdu, 610051 China
Keywords: Rock, fracability, cluster analysis, petro facies analysis
Abstract
The authors present a new rock fracability evaluation procedure using the cluster analysis of log data on petrophysical properties of facies. The effect of the physical and mechanical properties of rocks on the fracability evaluation results is analyzed in combination with the geophysical log data. The triaxial compression tests of cores are carried out to determine their brittleness indices. An entry-level classification of petrophysical properties of rock facies is implemented by the cluster analysis of the geophysical log curves. A new classification procedure is proposed for the petro facies analysis using the permeability index and brittleness index of rocks, and the profile of rock fracablity index is obtained. Application of the procedure is illustrated using core data from a reservoir in China. The fracability index of cores sampled in a horizontal well correlates well with the calculated profile of fracability index.
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