盐穴储气库回溶造腔技术研究

Back-leaching Technology in The Construction of Underground Salt Cavern Gas Storage

为提高地下盐穴储气库的经济性,在确保运行安全前提下,开发企业要求盐穴储气库地下净体积尽可能大,而在造腔过程中由于地质情况、工程故障以及认识不到位等原因导致腔体部分盐层未得到充分溶蚀,体积没有达到最优,为充分利用日渐匮乏的适合建库盐层,有必要进行回溶造腔,提高单腔有效体积。利用注气排卤管柱,在注气排卤后,回注淡水,驱顶天然气使卤水界面至设计深度,对界面下盐层进行回溶扩腔。为此,建立了回溶造腔数学模型,并针对金坛储气库L井进行回溶造腔模拟研究。结果表明,L井回溶造腔一个轮次可有效提高腔体有效体积13.04%,效果显著。研究结果对提高盐层利用率和已有腔体有效体积等具有重要意义。

In order to improve the economic efficiency,the developer always requires to maximize the net volume of the underground gas storage facilities on the premise of operation safety. However,due to geological reasons,engineering failures and inadequate comprehemsion,some salt layers often fail to dissolve during the storage-building process. To make the best use of the increasingly deficient salt formations suitable for underground gas storage facilities,back-leaching can be used to optimize the volume of the gas storage facility. After gas-injection and debrining,fresh water is injected by tubing strings to push the interface of the brine and gas at the designed depth. By doing that the salt formations below the interface can be leached again,which will enlarge the volume of the leached caverns. We established the back-leaching mathematic models and wrote calculation program. The pilot back-leaching in well-L in Jintan project shows the effective volume of the cavern can be raised by 13.04 percent. This research is important for enhancing the efficiency of the use of salt formations and will improve the effective volume of the built caverns.