裂缝储层孔隙度、饱和度计算方法

A method to calculate porosity and saturation in fractured reservoirs

裂缝性储集层孔隙度和饱和度是评价油气藏的重要参数。本文提出了运用裂缝介质各向异性梯度计算裂缝介质孔隙度和饱和度的新方法,其流程为:1计算裂缝介质的截距与梯度;2计算裂缝介质的各向异性梯度;3固定两个参数(孔隙度、饱和度)中的一个参数计算另一个参数。虽然文中方法不可能同时反演出裂缝的孔隙度与饱和度,但是对于实际油田开发仍具有应用价值。模型试算结果表明,地震记录信噪比对反射系数有很大影响,但是对于孔隙度和饱和度计算结果影响不大,证明了方法的有效性和适应性。

Porosity and saturation are two important parameters for fractured reservoir evaluation.This paper proposes a new method to calculate porosity and saturation in fractured reservoirs using their anisotropic gradient.We first use the equivalent theory to calculate intercept and gradient,then calculate anisotropic gradient,and finally fix one of the two parameters(porosity or saturation)to calculate the other one.The proposed method is provided with application value for the oil field development,although it is impossible to simultaneously invert porosity and saturation of fractures.Model tests show that signal-to-noise ratio of seismic record has a great impact on reflection coefficients,but has little influence on the calculated porosity and saturation,which proves the validity and adaptability of the proposed method.