基于Biot相洽理论的致密砂岩弹性参数计算方法

Elastic parameters calculation for tight sand reservoir based on Biotconsistent theory

中国石油大学(华东)地球科学与技术学院，山东青岛266580

Yin Xingyao, School of Geosciences,China University of Petroleum (East China),Qingdao 266580,China

致密砂岩储层中速度孔隙度关系复杂，针对致密砂岩中孔隙/裂隙并存的特点，提出了一种致密砂岩储层弹性参数的计算方法。根据Biot相洽理论，引入岩石骨架泊松比，在Biot相洽条件下对其进行求取，用于岩石骨架弹性模量的计算；结合约束反演求取的裂隙孔隙度，在Biot理论框架下求取孔隙和裂隙并存时致密砂岩的弹性参数。该方法无需对除裂隙以外的孔隙进行描述，避免了孔隙参数选取不合理带来的计算误差。使用该方法计算实际致密砂岩储层的弹性参数，用于横波速度计算以及流体敏感参数交会分析，取得了较好的效果，证明了方法的有效性。

The coexistence of pores and cracks in tight sandstone causes the absence of correlation between velocity and porosity and the wide range in velocity variation.A method to calculate elastic parameters of tight sandstone reservoirs was proposed.According to Biotconsistent theory,Poissons ratio of rock frame is introduced.When the Biotconsistent condition is satisfied,the elastic modulus of the rock frame is calculated.Then combined with the volume fraction of cracks obtained by constrained inversion,the elastic parameters of tight sandstone containing both pores and cracks are calculated in the framework of Biot theory.The method is free of pores except for cracks and avoids the calculated errors caused by the inappropriate choice of porous parameters.The calculated elastic parameters of actual tight sandstone reservoirs provide favorable elastic parameters for Swave velocity calculation and fluid sensitive parameters crossplot analysis.Meanwhile,it shows a good result and proves the feasibility of the method.

国家重点基础研究发展计划(973)项目(2013CB228604)、国家科技重大专项(2011ZX05030004002，2011ZX05019003)和国家自然科学基金项目(41004050)共同资助。

10.3969/j.issn.10001441.2013.05.001