定压稳态气测渗透率仪的研制

Development of Steady-state Gas Permeability Measuring Instrument

为保证测定结果的唯一性和稳定性,借鉴了储气筒活塞均匀移动稳压的原理,采用高精度玻璃筒代替传统的外接高压气瓶供气,气筒中密封可移动活塞,活塞在储气筒中匀速移动时受力平衡,储气筒中气体压力不变,通过对储气筒活塞加重块重量的设定,可以改变测量压差。在测定岩石渗透率的过程中,出口端压力为大气压,气体以稳定的状态通过岩心,得到相对稳定的渗透率值。虽然测定中采用的进口压力不同,结果有很大差异,然而当岩心在同一压差下测量时,测得的渗透率的误差可以保持在1%范围内,对不同的岩心在同一压差下测得的渗透率值大小也有了可对比性。

A stable result can be in the principle that when piston in motion with constant velocity in the air reservoir the pressure is invari- ant. Outlet pressure is atmospheric pressure. When the gas goes through the core in a stable situation, a stable permeabihty will come out. Although the results varied under the different inlet pressure, the error of core permeability can be maintained at range of 1% under the same differential pressure.