水淹枯竭气藏型地下储气库盘库方法

地下储气库多周期运行盘库,是研究气库运行规律、分析漏失、进一步提高气库运行效率和降低气库运行成本的关键环节。已建立的未水淹气藏型地下储气库盘库数学模型却并不适用于水淹枯竭气藏型地下储气库,评价结果明显高于实际注采气量。为此,通过深入分析水淹枯竭气藏型地下储气库气驱排水扩容机理、多周期注采运行过程中气水两相宏观与微观运动规律及可能的分布状态,创新性提出了可动用库存量的概念,以注采气量与视地层压力在一个注采周期内满足定容压升降方程为评价准则,建立了水淹枯竭气藏型地下储气库盘库模型。实例验证结果表明,该模型计算的结果与实际吻合,可用于水淹枯竭气藏型地下储气库多周期运行盘库计算和分析。为储气库运行、管理及调整提供了依据。

Song Xianzhi, Li Gensheng, Wang Haizhu, Ding Guosheng, Tian Shouceng

In the construction process of multi interbedded rock salt cavity with water solution, the interbedded insoluble debris is apt to excessively deposit on the bottom of the cavity, which leads to the reduction of cavity dimension and salt dissolution rate, thus the construction quality and the schedule of underground gas storage will be badly influenced. Therefore, this paper first presents a new method of debris cleaning based on jet flow washing with high pressure rotating water, then explains its working principles by the jet flow and rotational flow actions. Thus, based on the multiphase flow theory, a mathematical model for this new method is established. By use of this model, a numerical simulation is made on the influences of the parameters, such as flow rate, debris size, and tool’s rotation velocity, etc., on the debris washing efficiency. The simulation results show that ①flow rate and debris size are the main influencing factors, i.e., the washing efficiency is greatly improved while the flow rate increases, whereas it is lowered down dramatically while the debris size increases; ②the optimal rotation velocity exists under specific conditions, but the influence of the rotation velocity on the washing efficiency scales down as the debris size rises. As a conclusion, this new method not only effectively improves the debris washing efficiency for the cavern underground gas storage but provides a new way for facilitating the salt cavern underground gas storage made through multi interbedded salt rocks safely, rapidly and with a high quality.