裂隙性储层孔隙度与饱和度计算方法

New method to calculate the porosity and saturation of fractured reservoir

裂隙性储层孔隙度与饱和度是油气藏评价的两个重要参数.本文提出利用裂隙介质AVO属性计算裂隙性储层孔隙度与饱和度的新方法.运用等效理论将裂隙介质等效为各向异性介质,得到裂隙介质的AVO响应即得到裂隙介质各向异性截距与梯度,根据各向异性截距梯度与孔隙度饱和度的关系得到裂隙介质的孔隙度和饱和度.本文建立裂隙介质(TTI介质)梯度截距和孔隙度饱和度的关系,可以根据地震数据直接求取裂隙介质的孔隙度和饱和度.模型试算表明,该方法能得到裂隙介质准确的孔隙度和饱和度,且稳定性较好.

Porosity and saturation of fractured reservoir are the two important parameters for reservoir evaluation. The paper proposes a new method that using AVO attributes of fractured reservoir to calculate porosity and saturation. First fractured medium is equivalent to the anisotropic medium using the equivalent theory,then obtaining the AVO attributes of fractured medium that obtaining the anisotropic intercept and gradient of fractured medium,last we can get the porosity and saturation of fractured medium based on the relationship between the anisotropic intercept gradient and porosity saturation. In this paper,the relationship between the anisotropic intercept gradient and porosity saturation of TTI medium is established. So we can obtain the porosity and saturation from seismic data. The numerical examples proved that we can get the accurate porosity and saturation of the fractured medium and the method is very stable.