盐穴地下储气库选址与评价新技术

New technologies for site selection and evaluation of salt-cavern underground gas storages

为了满足我国南方非油气主产区和天然气主要消费市场寻找有利盐矿建设盐穴地下储气库的需求,解决盐穴储气库库址筛选条件不清、建库条件评价的内容与深度不一致的问题,在分析国内外盐穴地下储气库资料的基础上,提出了地质、地表条件相结合的库址筛选原则,创建了盐穴地下储气库建库条件评价体系;然后利用上述筛选原则和评价体系对长江三角洲、中南地区、东南沿海等3大天然气主要消费市场的部分盐矿进行了筛选排序;进而对其中条件较好的淮安盐矿进行了建库条件评价。研究结果表明:①盐穴储气库库址筛选的原则包括构造、埋深、含盐地层厚度、氯化钠含量、顶板和储量等6项地质原则和地表条件、水源与卤水、与管网距离等3项其他原则,利用上述原则可以对筛选目标进行快速地优选排序;②建库条件评价体系包括对构造、含盐地层特征、密封性与稳固性、可溶性、储气规模以及地表条件等的综合评价。结论认为,所建立的评价新技术可以有效地指导盐穴地下储气库的选址与评价,为盐穴储气库的方案设计提供了依据和有力的技术支持,所提出的厚夹层利用先导性建议现场实施效果好;该项研究成果对于加快我国地下储气库的建设具有积极的意义。

In order to meet the demand of constructing salt-cavern underground gas storages (UGSs) in favorable salt mines for the regions that are neither major oil and gas production zones nor major natural gas consumer markets in South China, and solve the problems of unclear conditions for selecting salt-cavern gas storage sites and of inconsistent content and depth in evaluating gas storage conditions, based on investigation and analysis of salt-cavern UGS data in China and other countries, we proposed the principles of selecting gas storage sites in combination with geology and ground surface conditions, and developed a set of technologies in evaluating construction conditions for salt-cavern gas storages. By applying the selection principles of salt-cavern USGs, we selected and sorted some salt mines in the three major natural gas consumer markets (the Yangtze River Delta, Central–South China, and Southeast Coast of China), and evaluated the conditions of constructing a gas storage in the Huai'an salt mine with better conditions. The following findings were obtained. First, the principles of selecting gas storage sites can be applied to quickly optimize and sort the selected targets, including 6 items of geological factors such as structure, burial depth, salt-bearing layer thickness, NaCl content, top rock, and reserves, and 3 other items such as ground surface conditions, water source and brine, distance from pipeline networks. Second, the evaluation system of UGS construction conditions integrates features of structure and salt-bearing strata, tightness, firmness, dissolubility evaluation, prediction of gas storage scale, and analysis of cavity making condition. In conclusion, the new evaluation technologies can not only effectively guide the site selection and evaluation of salt-cavern USGs but provide foundation and power support for their scheme designs, and the presented pilot proposal for utilizing thick interlayers has achieved a perfect on-site application effect. This study is of great significance for constructing UGSs in China.