安塞特低渗透油藏水淹层饱和度解释模型改进及应用

Improvement and application of the water-saturation model for water out strata of ultra-low permeability reservoirs in Ansai Oilfield

以安塞三叠系延长组长6油层为例,针对"三低"油层储层致密、孔喉半径小、泥质含量高、油水分异弱等特征和水淹机理复杂的矛盾,在多模型对比研究的基础上提出淡化系数饱和度解释模型,并确定出淡化系数校正因子D均值在0.25～0.3左右。利用新方法对研究区20口生产井进行对比解释,水淹级别解释符合率达到88.0%以上,产水率平均差异7.91%。此方法解释符合率较高,适应性较好,可以作为该区水淹层饱和度解释模型。

Taking Chang 6 oil layers of Yanchang Formation as an example, and on the basis of the comparative study of multiple models,the saturation interpretation model for freshening factors was proposed by ＂three -low＂ oil reservoirs with tight reservoir, small pore throat radius, high mudstone content, weak oil -water differentiation, and complex contra- diction of water - out mechanism. The mean value of dilution correction factor D was determined to be 0.25 - 0.3. The new method was utilized to carry out comparative interpretation in 20 production wells of the studied area. The coincidence rate of water - out degree is over 88% ,and the mean differential of water production rate is 7.91%. As a result of high coinci- dence rate of the interpretation and good adaptability, the method can be used as the saturation interpretation model for wa- ter flooded reservoirs in the studied area.