普通稠油启动压力梯度表征及物理模拟方法

基于管流模型及流变原理，分别设计了5种不同黏度原油实验方案，得到了管径1mm条件下原油黏度340～44500mPa•s范围内启动压力梯度随黏度变化关系，从宏观上验证了普通稠油存在启动压力梯度，同时在此基础上设计了考虑微观孔喉结构的填砂管模型，其中填砂管气测渗透率为（186.4～6698.0）×10^-3 μm²，原油黏度为10～450mPa•s,实验结果表明：在相同气测渗透率条件下原油黏度越小启动压力梯度越小，且两者呈较好的线性关系；在相同原油黏度条件下，开始随着气测渗透率的增加启动压力梯度迅速减小，当渗透率高于600×10^-3 μm²左右时，启动压力梯度随渗透率增加而减小的幅度趋于平缓；初始条件下随着流度的增加启动压力梯度迅速降低，当流度K/μ突破25 μm²/Pa•s后，随着流度的进一步增加，启动压力梯度降低速度趋于平缓，且二者呈幂函数关系

THE METHOD OF CHARACTERIZATION AND PHYSICAL SIMULATION OF TPG FOR ORDINARY HEAVY OIL

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.