流体分布模式对碳酸盐岩储层地震波频散与衰减特性影响的定量研究

储层流体地震勘探与描述是碳酸盐岩油气藏勘探开发领域的重要研究内容。在地震波激励下，流体之间会发生振荡流动，导致能量损耗进而引发地震波频散和衰减，故可利用频散衰减特征刻画流体分布模式。然而，受测量频带限制，现有实验室测量数据及理论模型尚无法准确揭示碳酸盐岩中流体分布模式与频散和衰减特性间的定量关系。拟采用四种方式饱和样品，利用CT扫描流体分布，明确不同流体分布模式的定量表征方式；利用多频段岩石物理测量系统研究不同流体分布模式下的地震波频散和衰减变化规律，阐释流体分布影响地震波频散和衰减的物理机制；以流体分布模式和频散衰减实验数据为约束，在孔弹性框架下构建岩石物理数值模型，揭示流体分布模式、流体饱和度与地震波频散和衰减的定量关系。项目成果对于碳酸盐岩含气储层勘探、评价具有重要的研究意义和商业价值。同时，研究方法可用于监测/评估储层二氧化碳、煤层瓦斯含量等，为降低勘探风险和提高经济效益做出贡献。

Seismic detection and characterization of the fluid distribution is of importance in the exploration and production of carbonate reservoir. In response to the seismic wave, the fluid pressure may oscillate and generate multiphase flows, which results in energy dissipation causing seismic wave dispersion and attenuation. Therefore, the dispersion and attenuation may help identify fluid distribution. However, due to the bandwidth-limitation of laboratory measurement technologies, it is challenging to study the relationship between the fluid distribution and seismic dispersion over the full frequency range. Our project will first use four methods to saturate a carbonate rock sample to obtain different fluid distribution patterns. The fluid distribution will be characterized using a micro-CT scanner. The seismic dispersion and attenuation related to the different fluid distribution patterns will be measured using the multi-band measurement system. Finally, a numerical model will be built under the Biot poro-elastic framework as well as the constrains of the measurement to clarify the mechanisms, related to the fluid distribution, that affect the seismic response. The quantitative relationship that the study will outline, can be applied to constrain seismic pre-stack inversion of gas carbonate reservoir, monitoring/evaluation of stored carbon dioxide, methane and coal seam gas content in reservoirs, etc., contributing to reduction in exploration risks and improving economic benefits.