PX气田高含硫气藏硫沉积实验研究

发布时间：2018-06-08 00:59

本文选题：高含硫天然气 + 有效应力　；参考：《西南石油大学》2017年硕士论文

【摘要】：随着高含硫气田开发的进行,地层中的能量逐渐衰竭,造成地层中高含硫天然气的硫溶解度发生改变,高含硫天然气中的元素硫逐渐以液态或者固态的形式析出,使得储层中的岩心渗透率和孔隙度的改变。硫的沉积对储层造成的伤害以及硫在气体中的溶解度是研究高含硫气田开发的两个重要问题,于是,本文以PX气田为例,针对这两个问题,进行了以下研究,并取得了一些认识:(1)通过对PX气田的基质岩心和裂缝岩心进行应力敏感性实验,实验结果说明:基质岩心的应力敏感性表现为中等,裂缝岩心的应力敏感性表现为强,随着有效应力的变化,裂缝岩心的渗透率损失比基质岩心更大。(2)利用PX气田的基质岩心和裂缝岩心的应力敏感性实验数据,综合考虑渗透率和效应应力之间的关系,建立了适用于PX气田的基质岩心和裂缝岩心渗透率预测经验模型;利用不同有效应力不同硫饱和度下基质岩心和裂缝岩心的实验数据,建立了不同饱和度下预测岩心渗透率的预测经验公式。(3)通过应力敏感和硫沉积共同作用对储层伤害实验,发现PX气田的裂缝岩心和基质岩心在受到硫沉积作用后,裂缝岩心的渗透率下降十分明显,而基质岩心的渗透率下降比较平缓;在孔隙度方面,利用NMR(核磁共振技术)测试发现,硫沉积作用对基质岩心的小孔隙影响较大,小孔隙数量明显减少,而对于裂缝岩心,其大孔隙数量明显减少,孔隙度下降幅度较大。(4)通过硫单质在甲烷、二氧化碳、硫化氢中的溶解度实验,得到了硫在三种气体中的溶解规律。通过BP神经网络和LIBSVM预测了在本文中的实验情况下,硫的溶解度数据,通过平均误差、均方差和标准差判断,支持向量机的预测结果精度要好于BP神经网络。
[Abstract]:With the development of the high-sulfur gas field, the energy in the formation gradually fails, which results in the change of the sulfur solubility of the high-sulfur gas in the formation, and the elemental sulfur in the high-sulfur gas gradually precipitates in the form of liquid or solid. Changes in core permeability and porosity in the reservoir. The damage caused by sulfur deposition to reservoirs and the solubility of sulfur in gas are two important problems in the development of high sulfur gas fields. Therefore, taking PX gas field as an example, the following studies are carried out in this paper. Through the stress sensitivity experiment of matrix core and fractured core in PX gas field, the experimental results show that the stress sensitivity of matrix core is medium, and that of fractured core is strong. With the change of effective stress, the permeability loss of fractured core is larger than that of matrix core.) based on the experimental data of stress sensitivity of matrix core and fractured core in PX gas field, the relationship between permeability and effect stress is considered synthetically. An empirical model of matrix core and fractured core permeability prediction for PX gas field is established, and the experimental data of matrix core and fractured core under different effective stress and different sulfur saturation are used. The empirical formula of predicting core permeability under different saturation is established. Through the experiments of stress sensitivity and sulfur deposition, it is found that the fractured core and matrix core of PX gas field are affected by sulfur deposition. The permeability of fractured core is obviously decreased, while that of matrix core is relatively gentle. In terms of porosity, it is found by NMRs that sulfur deposition has a great influence on the small porosity of matrix core. The number of small pores is obviously reduced, but for fractured cores, the number of macropores is obviously reduced, and the decrease of porosity is larger. 4) the solubility of sulfur in methane, carbon dioxide and hydrogen sulfide is tested by experiments. The dissolution of sulfur in three gases was obtained. In this paper, the solubility data of sulfur are predicted by BP neural network and LIBSVM. The accuracy of the prediction result of support vector machine is better than that of BP neural network through the judgment of average error, mean variance and standard deviation.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE311

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