四川盆地致密砂岩地震岩石物理分析及储层预测方法优选  

Seismic rock physics analysis of tight sandstone and optimization of reservoir prediction methods in the Sichuan Basin

作　　者：纪智 JI Zhi(Exploration and Development Research Institute of Daqing Oilfield Company Limited,Daqing 163712,China)

机构地区：[1]大庆油田有限责任公司勘探开发研究院,大庆163712

出　　处：《物探化探计算技术》2024年第5期508-516,共9页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：中央引导地方科技发展专项“黑龙江省陆相页岩油重点实验室”(ZY20B13)。

摘　　要：四川盆地HC区块须家河组二段岩性是以岩屑长石砂岩和长石岩屑砂岩为主,具有低孔低渗的致密砂岩储层特征,储层物性变化大,纵波阻抗叠置,基于叠后反演方法进行储层预测多解性强。为降低勘探风险,提高井位部署成功率,利用地震岩石物理分析技术,优选Raymer层状模型建立地震岩石物理解释图版,采用Gassmann方程进行孔隙流体置换,并利用置换后的结果做AVO正演属性分析。通过以上详实分析,须二段含气储层顶面AVO类型为IV类AVO,孔隙流体变化不会引起AVO类型改变;同时明确了纵横波速度比和纵波阻抗双参数为储层敏感弹性参数,优选了储层预测方法。笔者的研究成果预测了四川盆地HC区块须二段致密砂岩含气储层厚度分布,并提交了两口井位,预测结果与实钻数据吻合较好,目前该方法已经在相似地质条件的致密砂岩储层中广泛应用。The lithology of the second member of the Xujiahe Formation in the HC block of the Sichuan Basin is mainly composed of lithic feldspar sandstone and feldspar lithic sandstone.It has the characteristics of tight sandstone reservoir with low porosity and low permeability,great changes in reservoir physical properties,and overlayed p-wave impedance.Reservoir prediction based on the post-stack inversion method has strong multi-solution.In order to reduce exploration risks and improve the success rate of well location deployment,seismic rock physics interpretation charts were established using a Raymer layered model based on seismic rock physics analysis techniques.Pore fluid displacement was carried out using the Gassmann equation,and AVO forward attribute analysis was performed using the displacement results.According to the above-detailed analysis,the AVO type of the upper surface of the gas-bearing reservoir of the second member of the Xujiahe Formation is Class IV.Affected by lithology and physical properties,pore fluid changes do not cause the change of AVO type.At the same time,the two parameters of p-wave velocity ratio and p-wave impedance are defined as sensitive elastic parameters of the reservoir,and the reservoir prediction method is optimized.The research results of this paper predict the thickness distribution of tight sandstone gas reservoir in the second member of Xujiahe Formation in the HC block of the Sichuan Basin,and submit two well locations.The predicted results are in good agreement with the actual drilling data.This method has been widely used in tight sandstone reservoirs with similar geological conditions.

关 键 词：四川盆地 岩石物理分析 储层预测 Raymer层状模型 流体置换 AVO属性 

分 类 号：P631.4[天文地球—地质矿产勘探]