复杂气藏AVO属性交会含气性检测应用研究

Predicting and detecting of the gas sand by AVO attributes crossplot in complex reservoir

乌审召地区沉积相带复杂多变、储层非均质性强、气层AVO响应多变,含气储层预测难度大.本文在精细岩石物理分析的基础上,选取具有明确岩石物理含义且对气层敏感的AVO属性,针对不同AVO分类井进行AVO正演建模和流体替代分析,研究该区AVO气层响应特征及属性交会规律,并确定了以NI和PR属性交会为核心的AVO气层检测方法及流程,为探索解决该区含气性预测难题提供了有价值的思路.利用这套方法,对该区储层进行了含气性检测,取得了良好效果.

WSZ area is characterized by complex sedimentary facies, strong heterogeneity and multiple AVO responses of gas sand, so it is very difficult in predicting gas reservoir in this area. In this paper, we choose appropriated AVO attributes with definite petrophysical implication and sensitive to gas sand according to detailed petrophysical analysis and proceed AVO forward modeling and fluid substitution analysis for different AVO class wells to acquire the properties of AVO response and crossplot of AVO attributes. By this way,we finally confirmed the methods to identify gas reservoir based on cmssplot of NI and PR,and succeeded in identifying gas sand in this area