恒速压汞法不能确定孔喉比

Pore-throat ratio can not be determined by constant-speed mercury injection method

压汞法是研究岩石孔隙结构的重要方法。前人认为,常规压汞法只能确定岩石的孔隙大小及分布,恒速压汞法扩展了常规压汞法的功能,可以用来确定岩石孔隙的孔喉参数。根据本文的研究,恒速压汞法扩展的功能是对压力数据"噪音"的误读。岩石的孔隙为三维互连网络,不存在孔道和喉道的概念,每一个孔隙周围都有大小孔隙与其相连,汞液不会经过喉道才能进入孔道,而是先进入大孔隙,再进入小孔隙。恒速压汞曲线的锯齿状特征,也不是岩石孔喉特征的反映,而是压汞仪器的机械原因所产生的压力波动。油井从岩石孔隙中采油时压力也产生波动,但波动不是因为岩石孔隙的孔喉特征所致。

Mercury injection method is very important in research of pore structure of rocks. Conventional mercury injection method can be used to determine rock＇s pore size and its distribution. Constant-speed mercury injection method expanded the functions of conventional mercury injection method, and can determine pore＇s and throat＇s parameters of rocks. However, according to the study of this paper, the function expanded by the constant-speed mercury injection method is the misuse of the ＂noise＂ of pressure data. Pores of rocks build an interconnected 3D pore net. There are no concepts of pore body and pore throat. Every pore is connected with surrounding big pores and small pores. Mercury would not enter throats before entering pore bodies, which choose the bigger pores first and then the smaller pores to enter. The sawtooth-like curve of mercury injection is not the reflection of pore-throat structures of rocks, which is the pressure fluctuation caused by the mechanical process of mercury injection apparatus. The pressure fluctuation of oil wells in production process is also not caused by pore-throat structures of reservoir rocks.