The Study On The Mechanism Of Structural Geothermal Fields Of Wei Hai

Geothermal energy, also known as ‘heat from internal earth’, derives the friction heatfrom architectonic movement, the decay of radioactive substance and magma melt deep insidethe earth. In these days and ages, due to the traditional energy scarcity and the environmentalimpacts in their using processes, and the abundance sustainability and cleanness ofgeothermal energy, it has become a hotspot of academic world.There are nine geothermal fields in Weihai region, most of which are low-temperaturefields. The lack of management and planning for these fields caused damaging explorationand omen of geologic hazard. Using methods of structural geology, hydrogeology, physicsand chemistry and based on research history of geothermal exploration in Weihai, thegeological structure and characters (including heat storage character, water chemistrycharacter, source of supply, etc.) of geothermal fields in Weihai are discussed, the formingconditions and reasons of geothermal fields are analyzed, and formation mechanismhypothetical model of Weihai structural geothermal fields are established in this article.Most geothermal fields in Weihai are in the orogenic belt area of Jiaonan-Weihai, theirdistribution is controlled by rift structure: they are usually formed in the joint part of two ormore breakages. This geothermal region consists of low temperature geothermal fields, whosestore type is structural fissure thermal storage. According to the main chemical composition ingeothermal fluid, two geothermal fields could be classified: one has mineralization≤1g/L,including fields of Hongshuilan, Qili and Hulei, Xingcun; the other kind hasmineralization≤1g/L, including fields of Baoquan, Wenquan, Daying, Bei and Xiao. The hotstore bedrock and water-contained grit stone layer in the geothermal fields can help store andtransmit heat fluid, the sand and weathering goo sandy soil play a role of insulation. The mainsource of water supply to geothermal fields is rainfall, or the mixture of rainfall and seawater,which has a approximate geothermometer reservoir temperatures between70～120℃, fromwhich the depth of hot water cycle could be estimated as2000-4000m. Based on the analysisabout geological structure and characters of geothermal fields in Weihai area, a hypotheticalmodel is built to study the formation mechanism of Weihai structural geothermal fields.At the end, on existing foundation of knowing formation mechanism of Weihai structural geothermal fields, computational simulation and artificial recharge experiment are conductedto further explore and research Weihai geothermal fields, aiming to demonstrate theadvantages of geothermal energy for solving environmental impacts of energy application andto develop the society, economic and environment in Weihai.