白云凹陷深水区重力流砂岩储层反演与定量解释  

Inversion and quantitative interpretation of gravity-flow deposition reservoir in deep-water area of Baiyun sag

作　　者：王迪 张益明 刘春成 牛聪 叶云飞 黄饶 WANG Di;ZHANG Yiming;LIU Chuncheng;NIU Cong;YE Yunfei;HUANG Rao(CNOOC Research Institute Co., Ltd., Beijing 100028, China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《物探化探计算技术》2021年第4期406-412,共7页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：珠江口盆地白云凹陷深水区A气田在珠江组发育重力流砂岩储层,勘探潜力大。由于受到泥质充填和钙质胶结的影响,气层在叠后剖面上振幅强弱差异大,叠前道集AVO响应特征多变,储层及油气预测多解性强。为此,开展储层敏感弹性参数分析,认识到纵波阻抗和纵横波速度比交会能够有效区分该区岩性和含油气性,通过叠前反演能够解决储层预测与烃类检测问题。进一步建立深水区重力流沉积环境下的岩石物理量版,对反演结果进行定量解释,实现了A气田砂体厚度、孔隙度和含气性平面展布规律的预测。预测结果与已钻井吻合率高,孔隙度和气层厚度定量预测值与实际钻探值误差小于15%。同时,弱振幅气层得到有效识别,研究成果为精确计算气田储量规模提供借鉴,并有效指导该区下一步勘探部署。A gas field in deep-water area of Baiyun sag,Pearl River Mouth basin,develops gravity-flow deposition sandstones in Zhujiang Formation,which have great exploration potential.Due to the influence of shale filling and calcite cementation,the reservoirs behave complicated amplitude responses and AVO characteristics,which brings uncertainty for reservoir prediction and hydrocarbon detection.In this paper,based on detailed rock physics analysis,it is observed that combination of P-impedance and Vp/Vs can effectively distinguish lithology and fluid type.Pre-stack simultaneous inversion method is applied.Furthermore,a rock physics template is built up to establish the relationship between elastic parameters and rock properties,which can be used to quantitatively interpret the inversion results.The spatial distribution of regularity of the sandstone thickness,sandstone porosity and gas reservoir thickness is predicted.The predicted result is proved to be well consistent with the drilling data,and then the gas reservoirs with weak amplitude can be recognized.The error of predicted porosity and gas thickness is smaller than 15 percent,which lay solid foundation for precise reserves calculation and guide the next exploration deployment.

关 键 词：白云凹陷 重力流沉积 弱振幅 叠前反演 岩石物理量版 定量解释 

分 类 号：P631.4[天文地球—地质矿产勘探]