中国大陆干热岩地热资源潜力评估

 地热资源是一种极具竞争力的清洁可再生能源,按其成因和产出条件可分为水热型和干热岩型,其中,干热岩型地热资源以其分布的普遍性和高热储温度而更具开发潜力与前景。干热岩地热资源潜力评估是干热岩开发的基础工作。本文基于大量热流数据,编制了新版中国大陆地区热流图。进而依据岩石热物性数据库,计算评价了中国大陆地区干热岩地热资源。评价方法主要采用体积法,文中详细介绍了评价方法中各参数选取的原则与数据来源。计算结果表明,中国大陆(3—10km深度)干热岩地热资源总量为20.9×10⁶EJ,合714.9×10¹²t标准煤。若按2%的可开采资源量计算,是传统水热型地热资源量的168倍,相当于中国2010年能源消耗总量的4400倍。但是,囿于干热岩开发的经济性和现有技术条件,近期应着眼于4—7km深度段干热岩地热资源的开发,热储目标温度是150—250℃,干热岩开发的有利靶区包括藏南地区、云南西部(腾冲)、东南沿海(浙闽粤)、华北(渤海湾盆地)、鄂尔多斯盆地东南缘的汾渭地堑、东北(松辽盆地)等地区。最后,指出了现阶段干热岩研究的主要任务。

Estimate of Geothermal Resources Potential for Hot Dry Rock in the Continental Area of China

As one of the clean renewable energy, geothermal energy is very competitive. According to its genesis and exploration conditions, geothermal resources could be divided into two kinds, that is, one is hydrothermal resources and the other one is Hot Dry Rock (HDR) geothermal resources. Because of its universality and high temperature, HDR geothermal resources have great potential for projecting future development. The assessment of HDR geothermal resources potential is the base of HDR resources exploration. Here the heat flow map in the continental area of China is updated on the basis of more new heat flow data. Then the HDR geothermal resources are estimated using volume methods with a thermal physical access in the continental area of China (3 km —10 km). Results show that the total HDR geothermal energy is 20.9×10⁶EJ, which is equivalent to standard coal of 714.9×10¹²t. If the recoverable energy is 2% by computing, then it is 168 times of conventional hydrothermal energy, and it is equivalent to 4,400 times of total annual energy consumption during the year of 2010 in China. Nevertheless, due to the limitation of economics and technology, the HDR geothermal resources exploration within the depth of 4km—7km accompanied with an expected temperature of 150—250 ℃ should be conducted in the near future. Several target regions for HDR geothermal resources exploration are proposed, including South Tibet, West Yunnan (Tengchong), the southeast coast of China (Zhejiang, Fujian and Guangdong), North China (BBB basin), the southeast regions of Ordos Basin (Fenwei Graben), and Northeast China (Songliao Basin). Finally, the future tasks involving geothermal resources research are listed.