采用球面调和函数刻画岩心孔隙形态研究

Characterization of the Pore Morphology of 3D Rock Models Using Spherical Harmonic Functions

摘要:

针对统计特征函数和传统的球面调和函数不能有效刻画岩心三维模型形态特征的问题，提出了一种岩心球面调和函数。首先将三维岩心分解成同心球模型，并根据同心球的不同半径得到一系列的球面函数。然后对生成的球面函数进行调和分析获得形态特征描述子。最后通过相似性判定函数比较形态特征描述子获得不同岩心三维模型的形态相似性。利用多组砂岩岩心样本进行了比较实验，结果表明新算法能够有效描述岩心三维模型的形态特征，并且比统计特征函数和传统的球面调和函数具有更为准确的刻画能力。

Abstract:

Aiming at the statistical characteristic function and conventional spherical harmonic functions could not effectively describe 3D rock models, rock spherical harmonic functions were proposed. This algorithm was an improvement on the conventional spherical harmonic functions used in 3D model retrieval. Firstly, the 3D rock model was decomposed into a series of concentric spheres. On each sphere, a spherical function was obtained. By restricting the spheres to different radii, a collection of spherical functions could be obtained. Then, spherical harmonic transform was used on these functions to get morphological characteristics descriptor. Finally, a similarity comparison function was used to measure the similarity between each 3D rock models .Experiments on multi-group sandstone core samples show that the proposed algorithm is efficient in describing 3D rock models, and that the depicting ability of the new algorithm is exacter than the statistical characteristic function and the conventional spherical harmonic functions.