摘要
在进行孔隙度地层覆压校正中 ,传统方法是在实验室测得岩心在有效覆压下的三轴孔隙度 ,再利用经验公式将三轴孔隙度转换为单轴孔隙度。在转换过程中 ,用到与岩石泊松比有关的转换因子。文章介绍的方法 ,避开转换关系式 ,通过实验室测定岩心在不同覆压下单轴孔隙度和三轴孔隙度的变化规律 ,确定与地层有效覆压等效的静水压力。在等效地层有效覆压下 ,测定岩心的三轴孔隙度 ,该孔隙度即为岩心在有效地层覆压下的单轴孔隙度。通过在香四气藏岩心实验的基础上 ,建立了该气藏孔隙度覆压校正模型。该方法测定的孔隙度与传统方法相当 ,可以用于储量计算。
In proceeding porosity correction by overburden pressure, the traditional method is to measure the core triaxial porosity in laboratory under effective overburden pressure, and again transform the triaxial porosity into uniaxial porosity by using the empiric formula, the transformation factor relevant to rock Poisson's ratio is used in transforming process. The paper introduces another method, i.e. avoiding the transforming relational expression, through the change rule of uniaxial- and triaxial-porosities measured from laboratory cores under different overburden pressure to determine the hydrostatic pressure equivalent to effective overburden pressure of strata, and to measure the core triaxial porosity under the effective overburden pressure of equivalent strata, this porosity is thus the core uniaxial porosity under effective overburden pressure. On the basis of core experiment from Xiang-4 gas pool, the model of this pool porosity corrected by overburden pressure is founded, this method of measuring porosity corresponding to the traditional one may be used in reserves calculation.
出处
《天然气勘探与开发》
2004年第2期47-49,4-5,共3页
Natural Gas Exploration and Development
