【摘要】 Narr和Lerche（1984）提出的地下天然裂缝间距指数估测方法存在一定局限性，不能估测较大的裂缝间距指数；且由于它未考虑岩心中观察到的裂缝数对裂缝间距指数的影响，亦未考虑岩层厚度与裂缝数的关系，因而估测的准确度不高。针对该方法的缺陷，提出在岩心直径、钻孔与岩层夹角、裂缝侧伏角为已知时，根据岩层厚度和各层在岩心中所含有裂缝数估测裂缝间距指数。新方法适用范围更广，即使只有单个钻孔资料，也可以获得较准确的估测结集。更多还原

【Abstract】 The authors in this paper put forward a new method to estimate natural subsurface fracture spacing index based on regulardistribution of fracture and core data. Core diameter, bed dip, fracture pitch, bed thicknesses and the number of fracture in abed in the core are required for calculation. The method gives rise to more accurate result even in one-drill case than that ofNarr and Lerche (1984 ).更多还原