基于CT的数字岩心三维建模

为研究储层微观孔隙结构和建立微观渗流模型，本文通过对东营凹陷沙三中亚段H152井区的典型低渗透储层岩样进行CT（computed tomography）扫描及图像处理，建立了微观尺度的数字岩心模型；继而经过对该模型进行分析和计算，提取了储层孔喉网络模型，在三维空间上直观、清晰地显示了不同尺度的孔隙及喉道的形态、大小和分布；最后通过对孔隙结构特征、孔隙度、渗透率和压降等动静态参数的分析和计算，建立了储层岩样的微观渗流模型。根据算法对比和参数分析结果认为：与传统中值滤波相比，非局部均值滤波算法可在相似性比较的基础上进行滤波处理，从而提高模型的准确性；基于CT的数字岩心建模可为地质研究提供可靠的数字模型；根据近似等压面假设的微观渗流数值模拟分析了流体渗流特征，为揭示低渗透储层流体渗流规律提供了一种新的途径。

3D Modeling of Digital Core Based on X-ray Computed Tomography

In order to study the micropore structure of petroleum reservoir and develop 3D micro percolation model,CT (computed tomography)scanning and image processing of typical low-permeability reservoirs were carried out in the H152 area of the middle section of Shahejie Formation in Dongying depression,and a micro digital core model was established.Then,through the analysis and calculation of the model,the reservoir pore throat network model attributions of different scales of pores and throats were displayed intuitively and clearly in three-dimensional space.Based on the analysis and calculation of dynamic and static parameters such as pore structure,porosity,permeability and pressure drop,a micro percolation model of reservoir samples was established.According to the comparison of algorithm and analysis of the parameters,it is concluded that:Compared with the traditional median filter,the non-local-means filter algorithm that based on the comparison of similarity and the accuracy of the model is improved;The CT-based digital core can provide a reliable digital model for geological research;Based on the assumption of isobaric surface,the numerical simulation of percolation was carried out,and the characteristics of fluid transport were analyzed.The numerical simulation of percolation provides a new way to reveal the transport law of low permeability reservoir.