Abstract: According to the rock physical model, the variation rules of reservoir fluid seismic attributes were analyzed, and a new factor for reservoir fluid identification was presented. Based on the Gassmann equation and other effective rock physical theories, a method for calculating the new factor by using velocities of P wave and S wave (or impedances) was given. The sensitivity difference between the new factor and other factors were analyzed and compared quantitatively. The effects of porosity variation on the fluid identification factors were studied using the similar method. The new fluid identification factor, which is not affected by the porosity variation, has higher sensitivity than the traditional factors affected by the porosity variation. Thus, the new fluid identification factor is helpful to decrease uncertainty of reservoir fluid identification and improve reservoir drilling rate.

Key words: reservoir fluid, identification factor, sensitivity, seismic attribute, porosity, rock physical modeling

摘要： 根据岩石物理模型,分析了油藏流体地震属性的变化规律,提出了新的油藏流体识别因子。基于Gassmann方程和其他有效的岩石物理理论,详细阐述了利用纵波、横波速度(或阻抗)计算新流体识别因子的方法。利用流体识别因子敏感度定量分析方法,对比分析了新流体识别因子的敏感度与传统流体识别因子的差异,并定量分析了储层孔隙度变化对流体识别因子的影响。研究表明,虽然传统的流体识别因子敏感度不同,但都受储层孔隙度变化的影响;而新流体识别因子较传统流体识别因子敏感度更高,且不受储层孔隙度变化的影响。因此,新的流体识别因子对有效降低油藏流体识别的多解性及提高油藏钻探成功率具有重要意义。

关键词: 储层流体, 识别因子, 敏感度, 地震属性, 孔隙度, 岩石物理模拟