Device and method for measuring fluid saturation in nuclear magnetic resonance on-line displacement

A method for measuring fluid saturation in on-line displacement applied to a device for measuring fluid saturation in nuclear magnetic resonance (NMR) on-line displacement, characterized in comprising:

• measuring a nuclear magnetic resonance (NMR) T2 spectrum under the dead volume filling of the on-line displacement system as displacing phase fluid and the core to be measured as saturated nuclear magnetic detection phase fluid to generate a calibrated T2 spectrum;
• measuring a nuclear magnetic resonance (NMR) T2 spectrum of a process in which the core to be measured is converted from a saturated displaced phase fluid into a displacing phase fluid to generate a displacement process T2 spectrum;
• generating the fluid saturation of the on-line displacement system in real time according to the calibrated T2 spectrum and the displacement process T2 spectrum, wherein,
• the dead volume is the sum of the space of a liquid discharge end evacuation pipe, a liquid discharge end liquid discharge pipe, a liquid inlet end evacuation pipe, a liquid inlet end liquid inlet pipe and the space of the diversion trench of the core holder plug;
• the nuclear magnetic detection phase fluid is a phase fluid in which the influence of the nuclear magnetic resonance is difficult to eliminate, among the displacing phase fluid and the displaced phase fluid;
• the device for measuring fluid saturation in nuclear magnetic resonance (NMR) on-line displacement, comprising:
• an injection device, an intermediate container, a core holder, and a nuclear magnetic resonance (NMR) instrument, wherein,
• the injection device is connected to one end of the intermediate container through a first pipe, for injecting fluid into the intermediate container;
• the other end of the intermediate container is connected to the core holder by a second pipe, for injecting the fluid into the core in the core holder;
• the core holder is located in a central area of the magnetic field of the NMR instrument, for monitoring the NMR signal of the core to be measured;
• the core holder includes a sleeve, two fixed plugs, a liquid discharge end movable plug and a liquid inlet end movable plug, wherein,
• the two fixed plugs are arranged at two ends of the sleeve respectively;
• the liquid discharge end movable plug and the liquid inlet end movable plug pass through the fixed plugs and abut against both ends of the core, to fix the core axially;
• the liquid discharge end movable plug is provided with an evacuation pipe and a liquid discharge pipe;
• the liquid inlet end movable plug is provided with an evacuation pipe and a liquid inlet pipe;
• the liquid inlet pipe is connected to the intermediate container through the second pipe.