CO_2在岩石孔隙介质内相态特征的超声波探测与分析

Ultrasonic detection and analysis of phase behavior of CO_2 in porous media

岩心孔隙介质内的流体相态特征研究是实施CO2埋存及驱油的重要基础。本实验建立了一套超声波测试岩心孔隙介质内流体相态特征的新方法。通过声波探头及夹持器堵头一体化、端面抛光等手段,将声波探头直接作用于孔隙介质,解决了传统测试方法中探头不能承压、声波沿钢体绕射、能量损失过大等诸多问题,同时,自行研制了孔隙介质内流体相态探测声波发射、接收及信号处理软件,提高了测试精度,推动了超声波技术与油气田开发技术的交叉结合与应用发展。以吉林油田某区块天然岩心为例,测试了孔隙介质内CO2的相态特征,分析了孔隙介质对流体相态的影响。结果表明:该方法灵敏度高,数据可靠,避免了常规PVT方法中忽视孔隙介质影响的误差。

Study on phase behavior of fluids in porous media is an important foundation for both CO 2 sequestration and CO2 flooding. In this paper ,a new method for ultrasonic detection of phase behavior of fluids in porous media was established. Based on integration of ultrasonic sensors and holder plug and end face polishing ,ultrasonic sensors were directly acting on porous and problems of conventional methods like not bearing pressure for sensors ,wave diffraction along steel holder ,large energy loss would be solved. In addition ,transmitting ,receiving and signal processing software was programmed and test accuracy was in-creased. Taking the natural cores of Jilin oilfield as an example ,phase behavior of CO2 in porous media was detected and the impacts of porous media were analyzed. The results showed that the method is highly sensitive ,the data is reliable and the errors of ignoring the impacts of porous media in conventional meth-ods were avoided.