【摘要】 在建立正演压力模型的基础上,讨论了孔隙压力从异常低压递增到极限压力的过程中,在游离气饱和度为20%时,游离气在孔隙中分别以均匀分布和块状分布这二种情况存在,利用理论模型Biot-Geerstma-Smith方程分别算出纵波和转换横波的速度。然后分析异常压力的变化对P波、PS波反射系数的影响,以及由此产生的AVO异常,并且得出可以用AVO曲线来预测异常高压的结论。更多还原

【Abstract】 Conceptual model of Biot-Geerstma-Smith equation,based on forward pressure model was adopted in the calculation of P-wave and converted shear wave under the two conditions of the free gas either evenly distributed or massively distributed in pores and of the free gas saturation being over 20% during the transforming process of pore pressure from subnormal value to threshold value. By analyzing the impact of abnormal pressure on P-wave and PS-wave reflection factors, and the consequently excited AVO anomaly, it can be concluded that AVO curve can be used to predict supper pressures.更多还原