长江经济带岩盐矿特征与盐穴储库适宜性评价

长江经济带包括上海、江苏、浙江、安徽、江西、湖北、湖南、四川、重庆、云南和贵州11个省(直辖市),是我国重要的经济发展区域,油气资源长期安全可靠的储存对于该区经济可持续发展至关重要。基于长江经济带战略油气储库基地建设规划布局的需求,在充分收集利用前人地质调查和研究成果的基础上,对区内岩盐矿床进行了综合研究和分析,建立了层次结构模型,评价了盐穴油气储库建设的可行性。长江经济带除上海和贵州外,其余9省(直辖市)均发现了大量的岩盐矿床,主要成盐时代为震旦纪、三叠纪、白垩纪和古近纪; 成盐盆地范围0.29~10 000 km²,盐层累计厚度3~1 050 m,矿体埋藏深度40~3 400 m; 矿石中NaCl含量20%~99.86%; 矿体顶底板及夹层岩石主要为泥岩、粉砂质泥岩及泥质粉砂岩。地质调查揭示出区内大部分地下盐穴远离地震活动带,构造稳定,因此可以改造为石油储库。考虑储气库的密闭性及安全性,江苏金坛盆地等6个盐矿埋深适中,建穴地质条件较好,适合建造储气盐穴库; 江苏淮安等14个盆地的局部地区适合建造天然气储库; 重庆垫江等11个盐矿埋深较大,可以建造储气盐穴库,但建造成本较高; 湖南澧县等21个盐矿埋藏偏浅,应选择更深部的盐层空间建造油气储库。建议在江苏金坛、淮安、赵集和丰县,江西清江和会昌,湖北云应、天门小板和潜江等盐矿地区优先开发利用盐穴。

Characteristics of rock salt mines and suitability evaluation of salt cave storages in Yangtze River Economic Zone

Yangtze River Economic Zone, which includes 11 provinces (cities) of Shanghai, Jiangsu, Zhejiang, Anhui, Jiangxi, Hubei, Hunan, Sichuan, Chongqing, Yunnan and Guizhou, is an important economic development area in China, and the long-term safety and reliable storage of oil and gas resources is very important for the sustainable development of this region. According to the demand of construction planning and layout of strategic oil storage and gas storage base in Yangtze River Economic Zone, on the basis of fully collecting and utilizing the previous geological survey and research results, the authors comprehensively researched and analyzed the rock salt mines in the study area. Hierarchy structure model was built to evaluate the suitability of salt cave storages construction. Except Shanghai and Guizhou, the rock salt deposits were found in the 9 provinces (cities) of Yangtze River Economic Zone. The main salt-forming age was Sinian, Triassic, Cretaceous and Paleogene. The range of salt-forming basins is 0.29~10 000 km², with accumulated salt layers thickness of 3~1 050 m, and the ore body burial depth is 40~3400 m. Nacl content of ores is 20%~99.86%, and the rocks of top-bottom plate and interlayer of orebody are mainly mudstone, powder sandy mudstone and muddy powder sandstone. Geological survey shows that most of the underground salt caves in the region are far away from earthquake belt and have stable tectonic background, which can be used as oil storage. According to the sealing and safety of gas storage, 6 salt mines such as Jintan Basin in Jiangsu are of moderate buried depth and better geological conditions, which are suitable for the construction of salt cave gas storage. Regional areas in 14 basins such as Huai’an Basin in Jiangsu can also be built for natural gas storage. 11 salt mines such as Dianjiang, Chongqing, are of larger buried depth, which are also suitable for salt cave storages of natural gas, while their construction costs may increase. Some layers of 21 salt mines such as Lixiang, Hunan, are of shallow buried depth, but their deeper salt layers space should be selected. It is suggested that the salt caverns can be exploited first in the salt mine of Jintan, Huai’an, Zhaoji and Fengxian in Jiangsu Province, Qingjiang and Huichang in Jiangxi Province, and Yunying, Tianmen Xiaoban and Qianjiang in Hubei Province.