doi:10.16186/j.cnki.1673-9787.2019040053

Received:2019/04/13

Revised:2019/10/22

Published:2021/01/15

Calculation model of hydraulic fracturing initiation time considering reservoir rheology

WANG Zhirong, HU Kai, CHEN Lingxia, GUO Zhiwei

College of  Environmental and  Hydraulic  Engineering,Zhengzhou University,Zhengzhou 450001 ,Henan,China

Abstract:In allusion to the issues of time effect of the interaction between gas and rock mass in the hydraulic fracturing process and both coupling mechanism of fracturing stage between them,firstly,based on the results of creep test of gas containing soft coal,an improved six-component nonlinear viscoelastic plastic rheological model was established by using the generalized Kelvin model and fitting of  MATLAB least squares iteration. Secondly，according to the fracturing initiation pressure model of fractured reservoir in vertical well,combined with the six-component nonlinear viscoelastic-plastic creep model,the calculation model of fracturing initiation time of low-permeability soft coal was established. Finally,combined with the test well in Jiaozuo large water inflow mining area fracturing data and coal sample test results,the model was solved and verified. This research result has illustrated the scientific matching relation between the fracturing time and fracturing pressure,which provided a solid theoretical basis for the accurate control of initiation time and protection of the groundwater environment in the mining area.

Key words:vertical well;gas-containing soft coal;creep model;reservoir rheology;initiation pressure;initiation time

 考虑储层流变性的水力压裂起裂时间计算模型_王志荣.pdf