基于扰动弹性阻抗的裂缝参数反演方法

发布时间：2019-01-15 21:06

【摘要】：裂缝参数是裂缝型储层评价的重要指标,利用基于方位弹性阻抗的叠前地震反演方法可获取裂缝储层参数,而地震波方位反射系数方程是叠前方位反演的基础。为探寻稳健的裂缝参数反演方法,首先对比分析方位反射系数方程中各参数的敏感性,探讨裂缝参数反演结果不稳定的根本原因,同时发现裂缝是导致储层呈现方位差异性的主要因素;然后结合扰动反演思想,将方位各向异性弹性阻抗表示为背景介质弹性阻抗项与扰动弹性阻抗项之和,定义扰动弹性阻抗缘于储层裂缝的存在;最终构建了一种稳健的基于扰动弹性阻抗的裂缝参数反演方法。模型试算和实际资料试处理的结果均表明,利用本文方法能够得到合理的储层裂缝参数,尤其是较好地解决了裂缝参数反演不稳定的问题。
[Abstract]:Fracture parameter is an important index of fracture reservoir evaluation. Prestack seismic inversion method based on azimuth elastic impedance can be used to obtain fracture reservoir parameters, and seismic wave azimuth reflection coefficient equation is the basis of forward stack inversion. In order to find a robust inversion method for fracture parameters, the sensitivity of each parameter in the azimuth reflection coefficient equation is compared and analyzed, and the root cause of the instability of the inversion results of fracture parameters is discussed. At the same time, it is found that fracture is the main factor leading to the difference of reservoir azimuth. Then the azimuth anisotropic elastic impedance is expressed as the sum of the elastic impedance term of background medium and the disturbance elastic impedance term, and the disturbance elastic impedance is defined as the existence of reservoir fracture. Finally, a robust inversion method of fracture parameters based on perturbed elastic impedance is constructed. The results of model calculation and actual data processing show that reasonable reservoir fracture parameters can be obtained by using this method, especially the problem of unstable inversion of fracture parameters is well solved.
【作者单位】：中国石油大学(华东)地球科学与技术学院;
【基金】：国家“973”项目(2013CB228604) 国家科技重大专项课题(2011ZX05030-004-002、2011ZX05019-003)联合资助
【分类号】：P631.4

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