一种基于数字岩心表面弛豫率确定的新方法

在三维数字岩心的基础上,利用随机游走方法模拟了岩石的核磁共振响应,探索了最大值法、峰值法、叠加法三种确定岩心表面弛豫率的思路。通过实验测得的核磁共振T2谱转换为伪毛管压力曲线与岩心恒速压汞曲线进行刻度以及模拟高孔、高渗砂岩样品的核磁共振响应相结合的办法来确定岩心的表面弛豫率,进而对上述三种方法的可靠性进行验证。最终提出了最大值法确定岩心表面弛豫率的新方法,为准确求取岩石孔隙半径分布打下了坚实的基础。

A new Method to Determine the Surface Relaxation Rate Based on Digital Core

On the basis of 3 D digital core, this paper using the method of random walk simulation of the nuclear magnetic resonance (NMR) response of rocks to explored the maximum method, peak method and the superposition method of three determine relaxation rate of the surface of the core ideas. By converting nuclear magnetic resonance (NMR) curve to pseudo capillary pressure compared with core mercury injection curves and simulating high pore combination of nuclear magnetic resonance response of the high permeability sandstone samples to determine the core surface relaxation rate, which validated the reliability of the above three methods. Finally we put forward a new method of maximum value method to determine the core surface relaxation rate, then laid a solid foundation to calculate the rock pore radius distribution accurately.