Abstract:

Based on the pipe flow model and rheological principle,the experiment programme about five different viscosity is designed,and the relationship between threshold pressure gradient and viscosity under the condition of diameter 1mm and the viscosity 340 to 44500mPa•s is acquired,which demonstrates the TPG macroscopically.Meanwhile,the sand packed model,with the permeability about 186.4 to 6698.0×10^-3μm²,and the viscosity about 10 to 450mPa•s, considering the microcosmic structure of pore and throat,is designed.The result shows that firstly,the lower the viscosity is,the smaller the TPG will be under the condition of the same gas permeability,secondly,with the same viscosity,initially the TPG decreases sharply as the increasing of gas permeability,but when the permeability exceeds 600×10^-3μm²,the increasing velocity slows down gradually.And the last,initially the TPG decreases sharply as the increasing of mobility but when it exceeds 25μm²/Pa•s,the speed slows down gradually,while the relationship shows power function.

Key words: ordinary heavy oil, threshold pressure gradient, physical simulation, sand packed model, rheological principle