Developing a new hydrate saturation calculation model for hydrate-bearing sediments
Developing a new hydrate saturation calculation model for hydrate-bearing sediments
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开发一种新的含水合物沉积物水合物饱和度计算模型
DOI：
10.1016/j.fuel.2019.03.038
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发表时间：
2019-07-15
期刊：
影响因子：
7.4
通讯作者：
Yan, Weichao
中科院分区：
文献类型：
--
作者：
Dong, Huaimin;Sun, Jianmeng;Yan, Weichao
本研究将X射线计算机断层扫描（CT）技术应用于过量气体条件下砂岩沉积物中氙水合物形成过程的现场观测。在利用扫描图像获取水合物微观分布信息的同时，利用有限元法计算了扫描图像获取的含水合物样品的电阻率。因此，观察到电阻率指数（RI）与水合物饱和度（S-h）数据与我们的新计算模型而不是简单的阿尔奇公式拟合模型（即实验拟合模型）更好地匹配。此外，我们计算了电阻率与水合物饱和度曲线的基础上的数字岩石模型与理想的水合物分布。分布类型有粘着型、粘固型和散在型。微观分布观察和模拟结果表明，电阻率随水合物饱和度的变化对于三种类型的水合物分布表现出一定的差异。我们还发现，饱和度指数（n）是一个函数的水合物饱和度（S-h），它可以应用在所提出的新的计算模型，以计算电阻率与水合物饱和度数据。这表明，所建立的模型是一个有用的方法饱和度计算和储层识别的目的在水合物沉积物。
This study incorporates X-ray computed tomography (CT) technology into the in-situ observation of the xenon hydrate formation process in sand sediments under excess gas conditions. While the scanning images were used to obtain microscopic distribution information of the hydrate, we implemented the finite element method (FEM) to calculate the resistivity of the hydrate-bearing samples obtained from scanning images. Consequently, it was observed that the resistivity index (RI) versus hydrate saturation (S-h) data matched better with our new calculation model rather than the simple Archie formula fitting model (i.e. experimental fitting model). Besides, we calculated the resistivity versus the hydrate saturation curves based on digital rock models with idealized hydrate distributions. These distributions included adhesive type, cemented type and scattered type. Observation of microscopic distribution and simulation results indicated that the resistivity versus hydrate saturation exhibited certain differences for the three types of hydrate distributions. We also found that saturation exponent (n) is a function of the hydrate saturation (S-h), which can be applied in the proposed new calculation model in order to calculate the resistivity versus hydrate saturation data. This suggests that the established model is a useful methodology for the purpose of saturation calculations and reservoir identification in hydrate-bearing sediments.