The Formation Mechanism And Development Potential Of Hot Dry Rock

The demand for clean energy has increased dramatically with the rapid economic development and social progress in China. As a clean energy, Hot Dry Rock(HDR) has a great potential of development and caused wide attention.In order to study the HDR formation mechanism of sedimentary basin, find out the geothermal geological characteristics and evaluate the potential for exploitation. This paper discussed the impact of neotectonics on the formation of HDR, evaluated the HDR potential in Songliao Basin, established a suitable evaluation index system of HDR exploration regional selection for the sedimentary basin based on the Geothermal Geology theory and a large number of collected geological and geophysical data. Main results obtained from this research are as follows:(1) Based on the summary of regularities of HDR formation and Quaternary Geology, this research analyzed relationship between the topographic features, neotectonics, lithology and HDR, and the influence of the neotectonic movement on the HDR geothermal resources, summarized the forming mechanism of HDR, divided the HDR mechanism into four kinds and proposed four basic principles for the HDR regional selection.(2)The investigation and evaluation of potential for HDR in China is divided into five stages including National scale(Grade E), Basin scale(Grade D), Target scale(Grade C), Site scale(Grade B) and Injection scale(Grade A). The HDR evaluation investigation of Songliao Basin belongs to Grade D.(3) By summarizing the basic geological characteristics and geothermal geological conditions of Songliao Basin, this paper reasonably determine the basin heat reservoir geothermal geological parameters. The total of HDR geothermal energy resources is 91.01×104EJ, which is equivalent to standard coal of 31.04×1012t. According to the lower limit of 2%, the amount of recoverable resources is 0.62×104EJ, 0.62×1012t of standard coal.(4) In the paper established a suitable evaluation system of HDR exploration regional selection for sedimentary basins, which includes five indicator layers: the physical features of the earth, surface geothermal display of HDR, HDR geothermal geological condition, HDR resource potential and geological safety. The analytic hierarchy process and multi factor layer by layer superposition method was used to evaluate the Songliao basin. Results indicated that the HDR exploration development suitability is the lower middle level and the distribution trends of favorable prospecting area become better from the edge to the center.