Fracture permeability estimation using seismic attenuation

天然裂缝控制着含水层或储油层的渗透性，因此发现和表征裂缝区域的能力是地震调查的一个主要挑战。任何储层表征的主要问题之一是预测流体对弹性性质的影响的能力。在裂缝性多孔储层中，饱和流体对弹性性质的影响是复杂的，因为流体影响岩石的弹性各向异性。在这种非均质多孔介质中，由于裂缝和流体流动而产生的尺度的存在，是地震波频散和衰减的原因。该项目的目的是开发一个完整描述有效弹性特性的理论模型和一种估算裂缝渗透率的方法。该模型是基于毕奥的孔隙弹性理论和裂缝建模为高度顺应性的非均质性。应用非均质多孔介质中波的传播方法，对波在孔隙和裂缝间的传播引起的衰减和频散进行了定量分析。这就产生了裂缝和背景渗透率的估计，这将验证碳酸盐含水层的现场数据。我们提出的方法的结果可以显着帮助钻井的规划和决策，这是水和油气勘探中最昂贵的部分之一。

Natural fractures control the permeability of aquifers or oil reservoirs, and hence the ability to find and characterize fractured areas represents a major challenge for seismic investigations. One of the main issues in the characterization of any reservoir is the ability to predict the effect of fluids on elastic properties. In fractured porous reservoirs the effect of the saturating fluid on elastic properties is complex, as fluids affect elastic anisotropy of the rock. The existence of scales caused by fractures and fluid flow in such heterogeneous porous media are the reasons for dispersion and attenuation of seismic waves. The aim of this project is to develop a theoretical model for the complete description of the effective elastic properties and a method for estimation of fracture permeability. The model is based on Biot s theory of poroelasticity and fractures are modeled as highly compliant heterogeneties. Applying methods for the wave propagation in heterogeneous porous materials, attenuation and dispersion, caused by wave-induced fluid flow between pores and fractures is quantified. This yields to the estimation of fracture and background permeability, which will be validated on field data from a carbonate aquifer. Outcomes from our proposed methodology can significantly help in planning and decision making in drilling, which is one of the most expensive parts of water and hydrocarbon exploration.