核磁共振可动流体实验最佳离心力确定新方法研究

在核磁共振实验中，一般通过高速离心的方法来区分可动流体和束缚流体，为了准确的测试可动流体饱和度，需要确定一个最佳离心力。传统的最佳离心力标定方法需要多次离心，并且离心力只能间断增加，改进的方法通过matlab数据拟合可以减少离心次数，并将该离心力-含水饱和度拟合曲线中，满足斜率为-69/500的点的纵坐标作为最佳离心力；更进一步地通过岩心理想毛细管模型，推出离心力与孔渗数据之间的理论关系，结合该理论关系与已经建立的最佳离心力标定方法，得到最佳离心力与孔渗数据之间的拟合曲线。该曲线给出了核磁可动流体饱和度实验中最佳离心力与岩心孔隙度和渗透率之间的函数关系，使最佳离心力可以通过岩心孔渗数据确定。

Research of New Method to Calibrate the Optimum Centrifugal Force for Nuclear Magnetic Resonance Movable Fluid Experiment

In NMR experiments, we usually distinguish the movable fluid and bound fluid by high-speed centrifugation method. In order to test accurately for the movable fluid saturation, you need to calibrate the optimum centrifugal force. The traditional method of calibrating optimum centrifugal force need centrifuge many times, and the centrifugal force only increase intermittently. The improved method can reduce the centrifugation times by matlab data fitting, and confirming the vertical coordinates of the points which slope is -69/500 is the optimum centrifugal force in the centrifugal force and the water saturation fitting curve. Furthermore a theoretical relationship was derived between the centrifugal force and the porosity-permeability data through the core ideal capillary model. And combining the theoretical relationship and the calibrating method of optimum centrifugal force, we find the fitting curve between the optimum centrifugal force and the porosity and permeability data. The curves show a functional relationship between the NMR movable fluid saturation optimum centrifugal force and the core porosity and permeability data which can calculate the optimum centrifugal force by the porosity and permeability.