基于随机缝洞介质理论模拟塔中北坡储层的地震响应

发布时间：2018-05-19 20:11

本文选题：随机缝洞介质 + 矢量自相关函数　；参考：《石油地球物理勘探》2016年06期

【摘要】：由于碳酸盐岩缝洞型储层自身的特点,岩石物理性质呈跳跃性变化,储集体形态变化也较剧烈,现有的随机介质模型并不适合对缝洞型储层的描述,且随机介质的非均匀尺度往往局限于水平方向和垂直方向,无法对地下任意方向的非均质特征进行描述。为此,在混合型自相关函数的基础上,通过引入方向因子给出了一种新的矢量自相关函数表达式,使产生的随机介质具有一定的方向性,在此基础上采用阈值截取法,通过给定缝洞发育的长、短半轴及局部发育密度构造具有不同统计特征的缝洞介质模型,实现了对不同尺度、发育密度、发育角度及不同充填速度的复杂缝洞的有效描述。结合塔中北坡实际钻井资料及测井解释成果,建立了符合该区实际地层结构的随机缝洞介质模型,利用非均匀介质条件下波动方程数值模拟,研究了不同参数情况下一间房组顶部储层的运动学及动力学特征。正演模拟结果表明,缝洞型储层发育尺度越大、发育密度越高及缝洞内充填速度越小,则对应T74界面波峰的反射能量越弱、低频特征越明显,从而为一间房组顶部缝洞型储层波场特征识别及储层预测提供了依据。在此基础上优选出对一间房组顶部缝洞型储层参数变化敏感的属性(均方根振幅及瞬时频率),大大提高了在界面强反射干扰下缝洞型储层预测的准确性。
[Abstract]:Because of the characteristics of carbonate fracture-cavernous reservoir, the physical properties of the rock show a jump change, and the reservoir morphology changes sharply. The existing stochastic media model is not suitable for the description of the fracture-cavernous reservoir. And the non-uniform scale of random media is usually confined to horizontal and vertical directions, so it is impossible to describe the heterogeneity in any direction of underground. On the basis of the mixed autocorrelation function, a new vector autocorrelation function expression is given by introducing the direction factor, which makes the random medium have certain directivity. On this basis, the threshold interception method is adopted. Based on the given long, short axis and local development density models with different statistical characteristics, the effective description of complex fractures and cavities with different scales, developmental densities, development angles and different filling velocities is achieved. Based on the actual drilling data and logging interpretation results on the north slope of Tarim Basin, a random fracture-cavity medium model is established in accordance with the actual formation structure in this area, and the wave equation is numerically simulated under the condition of non-uniform medium. The kinematic and dynamic characteristics of the top reservoir of a room group under different parameters are studied. The forward simulation results show that the larger the development scale, the higher the development density and the smaller the filling velocity, the weaker the reflection energy of the wave peak corresponding to the T74 interface is, and the more obvious the low frequency characteristic is. Thus, it provides a basis for the identification of wave field characteristics and reservoir prediction in the top fractured and cavernous reservoir of Yijianfang formation. On this basis, the attributes (RMS amplitude and instantaneous frequency) which are sensitive to the change of the parameters of the top fracture-cavity reservoir of a room group are selected, which greatly improves the accuracy of prediction of the fracture-cavity reservoir under the strong reflection interference of the interface.
【作者单位】：中国石化石油物探技术研究院;南京大学地球科学与工程学院;中国地质大学(武汉)地球物理与空间信息学院;中国石化西北油田分公司勘探开发研究院;江苏华东八一四地球物理勘查有限公司;
【基金】：国家“973”课题(2014CB239201) 国家重大科技专项(2016ZX05014001)联合资助
【分类号】：P618.13;P631.4

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