地震波场数值模拟是理解地震波在地下介质中的传播特点,帮助解释观测数据的有效手段,而提高计算精度和运算效率是所有波场数值模拟方法研究所追求的目标.有限差分技术是求解波动方程计算效率最高、应用最为广泛的方法之一.但传统的有限...地震波场数值模拟是理解地震波在地下介质中的传播特点,帮助解释观测数据的有效手段,而提高计算精度和运算效率是所有波场数值模拟方法研究所追求的目标.有限差分技术是求解波动方程计算效率最高、应用最为广泛的方法之一.但传统的有限差分技术计算过程中的数值频散问题影响了该技术的计算精度与计算效率.本文通过交错网格高阶有限差分技术与通量校正传输方法(Flux-corrected transport method,FCT)相结合,对横向各向同性介质(Transverse isotropic medium,TI)一阶速度-应力弹性波动方程组进行了数值求解研究.波场快照数值模拟结果表明,本文研究的数值模拟方法与波动方程二阶有限差分方法、交错网格四阶有限差分方法相比,在压制网格数值频散方面有明显的优势,计算精度提高,而且可以利用较大的空间步长,提高计算效率.展开更多
Strong heterogeneity and complex pore systems of carbonate reservoir rock make its rock physics model building and fluid substitution difficult and complex. However, rock physics models connect reservoir parameters wi...Strong heterogeneity and complex pore systems of carbonate reservoir rock make its rock physics model building and fluid substitution difficult and complex. However, rock physics models connect reservoir parameters with seismic parameters and fluid substitution is the most effective tool for reservoir prediction and quantitative characterization. On the basis of analyzing complex carbonate reservoir pore structures and heterogeneity at seismic scale, we use the gridding method to divide carbonate rock into homogeneous blocks with independent rock parameters and calculate the elastic moduli of dry rock units step by step using different rock physics models based on pore origin and structural feature. Then, the elastic moduli of rocks saturated with different fluids are obtained using fluid substitution based on different pore connectivity. Based on the calculated elastic moduli of rock units, the Hashin-Shtrikman-Walpole elastic boundary theory is adopted to calculate the carbonate elastic parameters at seismic scale. The calculation and analysis of carbonate models with different combinations of pore types demonstrate the effects of pore type on rock elastic parameters. The simulated result is consistent with our knowledge of real data.展开更多
文摘地震波场数值模拟是理解地震波在地下介质中的传播特点,帮助解释观测数据的有效手段,而提高计算精度和运算效率是所有波场数值模拟方法研究所追求的目标.有限差分技术是求解波动方程计算效率最高、应用最为广泛的方法之一.但传统的有限差分技术计算过程中的数值频散问题影响了该技术的计算精度与计算效率.本文通过交错网格高阶有限差分技术与通量校正传输方法(Flux-corrected transport method,FCT)相结合,对横向各向同性介质(Transverse isotropic medium,TI)一阶速度-应力弹性波动方程组进行了数值求解研究.波场快照数值模拟结果表明,本文研究的数值模拟方法与波动方程二阶有限差分方法、交错网格四阶有限差分方法相比,在压制网格数值频散方面有明显的优势,计算精度提高,而且可以利用较大的空间步长,提高计算效率.
基金sponsored jointly by the National Natural Science Foundation of China(No.41074098)the Key State Science and Technology Project(2011ZX05023-005-005)China University of Petroleum(Beijing) Fund(KYJJ2012-05-08)
文摘Strong heterogeneity and complex pore systems of carbonate reservoir rock make its rock physics model building and fluid substitution difficult and complex. However, rock physics models connect reservoir parameters with seismic parameters and fluid substitution is the most effective tool for reservoir prediction and quantitative characterization. On the basis of analyzing complex carbonate reservoir pore structures and heterogeneity at seismic scale, we use the gridding method to divide carbonate rock into homogeneous blocks with independent rock parameters and calculate the elastic moduli of dry rock units step by step using different rock physics models based on pore origin and structural feature. Then, the elastic moduli of rocks saturated with different fluids are obtained using fluid substitution based on different pore connectivity. Based on the calculated elastic moduli of rock units, the Hashin-Shtrikman-Walpole elastic boundary theory is adopted to calculate the carbonate elastic parameters at seismic scale. The calculation and analysis of carbonate models with different combinations of pore types demonstrate the effects of pore type on rock elastic parameters. The simulated result is consistent with our knowledge of real data.