五大连池尾山地区存在干热岩资源的可能性探讨

 干热岩被视为未来的清洁能源,是地热资源的重要组成部分,极具研究价值和开发前景。中国现阶段干热岩调查研究应遵循"面上开展,点上突破"的原则。基于"点上突破"原则,本文选取中国最新的火山群--五大连池火山群开展前期研究,通过搜集分析区域地质条件、岩石地球化学、深部CO₂气体,区域地球物理资料,探讨了五大连池尾山地区存在干热岩的可能性。研究结果表明,五大连池火山属于非深源火山,具备存在干热岩的可能,热源机制属于岩浆余热型,第四纪火山岩浆囊所处的深度上限值为3.3~3.4 km。区内深部CO₂气体来源于地幔岩浆冷却成岩过程中的脱排气作用,是幔源岩浆囊中岩浆结晶分异的结果。W8勘探孔及附近供水井发现高浓度CO₂的事实表明,在尾山与五大连池农场七分场之间的地下可能存在正在冷却成岩的岩浆囊。

Possibility of hot dry rock resources in Weishan volcano area of Wudalianchi

As an important part of geothermal resources, hot dry rock(HDR) is regarded as a clean energy for future, with a great research value and development prospect. In the present stage, HDR study in China should not only be carried out across the country, but also be focused on some key spots for breakthrough. According to this principle, this paper takes Wudalianchi volcanic area as a key spot for pilot study. Through analysis of the collected materials including regional geological conditions, rock geochemistry, deep CO₂ gas, regional geophysical data, this paper discusses the existence possibility of HDR resources in Weishan volcanic area of Wudalianchi. The results show that Wudalianchi volcanoes are not deep volcanoes, which indicates the possibility of HDR existence with heat source from shallow residual magma. The ceiling of the quaternary volcanic magma capsule may possibly exist at a depth of 3.3~3.4 km or so. Deep source CO₂ gas, widely discovered in the Wudalianchi volcanic area, is proven to be derived from the exhaust function of mantle magma, which is a diagenetic and cooling process and resulted frommagmatic crystallizing differentiation. The fact that high concentrations of CO₂ are found around Well W8 indicates there may be cooling diagenetic magmatic capsule in the underground space between Weishan volcano and Wulianchi No.7 Farm.