基于双相介质渐进方程的油气识别

发布时间：2018-07-10 13:53

本文选题：双相介质 + 渐进方程　；参考：《成都理工大学》2017年硕士论文

【摘要】：对于储层的流体识别,是地震勘探中一项非常重要的技术,国内外在这项工作中都有不少成功的实例。但是,以往的储层流体识别都是基于砂岩储层和碳酸盐岩储层的地震弹性波理论上,这些理论仅仅适用于单相介质储层,但是碳烃储层和许多沉积岩是流体饱和的双相介质储层。这些双相介质的弹性性质可以用孔隙弹性理论来描述。经典的Biot的孔隙弹性理论不适合地震频带,只适用于Biot特征频率以上的频带,通常为0.1 MHz或更高。此外,大多数孔隙弹性研究集中在速度分散和衰减。因此,本文期望从两个双相介质之间的界面获得反射系数的简单形式的分析表达式。虽然对任意入射角非常复杂,但是对于法向入射,问题大大简化。基于双相介质的渐进方程,进行双相介质孔隙介质储层的油气识别。通过对渐进方程公式构建,且利用孔隙介质岩石骨架的弹性模量,储层的渗透率,流相流体的相关参数,得出了渐进方程与波动方程之间的关系。通过对胡克定律,动量和质量的平衡方程以及对动态达西定律的推导,对经典的孔隙介质理论的参数给予了新的物理解释。并且通过设立参数ε,表达了流体参数和地震频率所建立的联系。在渐进分析中,对一些参数进行去耦,使其独立,并将相关的一些高阶项舍去,从而得到一个储层介质界面的平面波的反射系数和透射系数的渐进表达式。通过渐进方程表达式进行岩石物理模拟研究,建立了快波的频变反射系数表达式。通过建立目标函数,对流体参数项B进行反演,反演所用方法为模拟退火算法,推过对算法的参数控制和选择,达到范围空间内的最小值,求得最优解。B参数的振幅异常越强,说明目标储层含有可流动的流体。再对B参数进行加权,从而使含气含油储层的响应相对于含水储层的响应更加敏感,从而达到流体识别的目的。
[Abstract]:The identification of reservoir fluid is a very important technique in seismic exploration, and there are many successful examples in this work at home and abroad. However, in the past, reservoir fluid identification was based on seismic elastic wave theory of sandstone reservoir and carbonate reservoir, and these theories are only suitable for single-phase medium reservoir. However, hydrocarbon reservoirs and many sedimentary rocks are fluid-saturated dual-phase reservoirs. The elastic properties of these two-phase media can be described by pore elasticity theory. The classical Biot's pore elasticity theory is not suitable for the seismic frequency band, but only for the frequency band above the Biot characteristic frequency, usually 0.1 MHz or higher. In addition, most pore elasticity studies focus on velocity dispersion and attenuation. Therefore, this paper expects to obtain a simple analytical expression of reflection coefficient from the interface between two biphase media. Although it is very complicated for any angle of incidence, the problem of normal incidence is greatly simplified. Based on the progressive equation of dual phase medium, oil and gas identification of porous medium reservoir in dual phase medium is carried out. The relationship between the asymptotic equation and the wave equation is obtained by constructing the formula of the progressive equation and using the elastic modulus of the rock skeleton of the porous medium, the permeability of the reservoir, and the relevant parameters of the fluid flow phase. Through the derivation of Hooke's law, momentum and mass equilibrium equations and dynamic Darcy's law, a new physical interpretation of the parameters of classical pore media theory is given. The relation between fluid parameters and seismic frequency is expressed by setting parameters 蔚. In the asymptotic analysis, some parameters are decoupled to make them independent, and some higher order terms are removed, thus the progressive expressions of reflection coefficient and transmission coefficient of plane wave at a reservoir interface are obtained. In this paper, the equation of fast wave reflection coefficient with frequency variation is established through the study of rock physics simulation by the asymptotic equation expression. By establishing objective function, inversion of fluid parameter term B is carried out. The inversion method is simulated annealing algorithm. The parameter control and selection of the algorithm is pushed to the minimum value in the range space. The stronger the amplitude anomaly of the optimal solution. B parameter is obtained. This indicates that the target reservoir contains fluid that can flow. Then the B parameter is weighted to make the response of gas-bearing oil reservoir more sensitive than that of water-bearing reservoir, so as to achieve the purpose of fluid identification.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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