基于Biot-Gassmann方程的流体替换技术在番禺天然气区PY气田的应用

Application of fluid substitution method in PY gas field based on Biot-Gassmann equation in Panyu natural gas area

珠江口盆地番禺天然气区PY气田位于坡折带上,特殊的沉积环境导致该气田已钻探的各井T50储层泊松比关系异常,含油气性特征非常复杂。为更好的判断储层的含油气性,利用Biot-Gas-smann方程对坡折带储层的流体性质进行了替换,考查不同流体性质下储层的含油气响应特征。研究结果表明:Biot-Gassmann方程能有效的用于坡折带储层的流体替换研究;坡折带T50储层含水和含气时的AVO响应特征相近,但两者响应的幅值不同,含水砂岩的幅值更小。

The PY gas field of Panyu natural area in Pearl River Mouth Basin was located in slope break belt,where the special sedimentary environment led to the Poisson＇s ratio anomaly of T50 reservoir of drilled wells,and the hydrocarbon feature in very complication.In order to determine the hydrocarbon of reservoir,the authors used the Biot-Gassmann equation to do fluid substitution of slope break belt reservoir and test the reservoir hydrocarbon response characteristics under different fluid characteristics.The results showed that Biot-Gassmann equation can be more effectively applied into the fluid substitution work in slope break belt reservoir.The AVO response characteristics was similar of T50 reservoir containing water or gas,but the amplitude was different,the amplitude of water-bearing sandstone was smaller.