低渗透和高渗透储层都存在应力敏感性

Stress sensitivity consists in low permeability and middle-high permeability reservoirs

近几年,有人将岩石孔隙压缩系数与岩石压缩系数的概念混为一谈,导出了一个错误公式,并用其解释实验结果,得出了低渗透储层不存在强应力敏感性这一错误认识。为了澄清一些概念,阐述了有孔岩石在不同压力环境下的压缩系数的概念,并指出孔隙度与岩石孔隙有效压缩系数的关系和孔隙度与岩石压缩系数的关系不是一回事,从有孔岩石体积公式入手,导出岩石孔隙有效压缩系数公式,通过该公式可看出,岩石孔隙有效压缩系数随孔隙度的增大而减小,而岩石压缩系数随孔隙度的增大而增大。其关系与油藏工程中表征孔隙度和岩石孔隙体积有效压缩系数的Hall曲线一致,进而说明Hall曲线是正确的。强调指出:用错误的公式解释正确的试验,所得结论和认识同样是错误的。理论公式的结果需要实验验证,实验是科学研究中一门基础科学,实验和理论一样都是在一定条件下成立。国内外研究者通过实验和理论研究,提出低渗透油气储层比中高渗透储层更具有较强的应力敏感性,诸多研究者的实验数据是可信的,不是实验的系统误差所致,这已经是事实,是毋庸置疑的。

Some scholars confused two different concepts： compressibility of pore space of rock and compressibility of reservoir rock. Some mistake recognitions were opened because some experimental results were explained by one mistake derivative equation. In order to clarify the concepts compressibility concepts of pore rock under different pressure condition das expresses, different relationship between rock porosity with compressibility of pore space of rock and rock porosity with compressibility of reservoir rock was put forward. A new compressibility equation of pore space was derived based on a volume equation （total volume is equal to porous solid plus pore volume）. Compressibility of pore space of rock increases as porosity decrease, and compressibility of reservoir rock increase as porosity increase. The relationship accords with the Hall curve of describing relationship of porosity and compressibility of pore space, and further prove the Hall curve is correct. The paper emphasizes the mistakes conclusions and recognitions that come from the mistake equation, calculation results of the theoretic equations have to be proved by experimental methods. Experimental study is a basic science in science research. The experimental and theory results express their reasonability and correctable under a certain condition. Research results of laboratory in the world have proved that low permeability reservoir stress sensitivity is stronger than middle-high permeability reservoir; many experimental data of researchers are reliable, but not experimental errors of system.