Study On The Formation Conditions Of Layered Heat Storage In The Background Of Normal Geothermal Heat

The geotherm system can be divided into magmatic type, uplift fracture type subsidence basin cover type and the geothermal producted by normal terrestrial heat flow or higher sightly on heat source. In general, foregoing three types of geothermal reservoir can product high temperature, and their geothermal anomaly are common in Earth's surface. However, there is no unusual geothermal in earth's surface and the water's temperature producted is low on the last one which is not favored by experts. Consequently clarify the geothermal formed by normal or slightly higher terrestrial heat flow conditions can subserve to relieve the pressure on the requirement of geothermal resource.This article analyses heat storage, thermal channel, capping conditions and chemical characteristics of water of normal terrestrial heat flow heat geothermal systems by collecting and sorting predecessors'research data. It also combined with the field reconnaissance and geophysical exploration data.This text maks clear its formation conditions and genetic model and establish its conceptual model. Follows are main conclusions about it:(1) This type of geothermal system is heated by normal or slightly higher terrestrial heat flow, There is no existence of radioactive source by particularly high heat rate on shallow crust and there is no unconsolidated or are being cooled magma intrusion. There is no material flow can carry deep heat from beneath,either.(2) The geotherm system formed by normal terrestrial heat flow can be divided into three types:mountain prototype, sequestration erosion type, cover basins type. All of them are layered heat storage. Their conditions of storing are generally good and circulation of groundwater is weak.(3) Mountain prototype geothermal systems are generally weak on tectonic movement. Its cap rock is cositituted by bedrock can be impermeable and insulatinal. And its geothermal reservoirs is deep underground,almost no nudity,and have a good thermal conditions. Sequestration erosion type have intense tectonic movements, geothermal reservoirs local sites was lifted to the surface. There is a complete groundwater recharge, runoff, drainage circulatory system. And the spring exposed by tectonic control. Cover basins type geothermal system is more growed in garben basin. And its cover is unconsolidated formation or hypabyssal rock. Its base is water-rich,its heating time is short, and it can warm up quickly.(4) The geothermal system's genetic model formed by normal terrestrial heat flow can be summarized as below:Geothermal reservoirs was corrosioned or erosioned in the early days,and the groundwater were sealed in heat reservoirs. Then the bedrock or loose cover layer deposited. They Composite the cap rock, it also can be impermeable and insulatinal. The groundwater is heated by subject to normal or slightly higher terrestrial heat flow long time will lead to the thermal storage absorbed heat of the surrounding rock adequately and exchange heat in large area. Finally form low-temperature hot water. If intense tectonic movements aren't intensely after the formation of geothermal reservoirs, there is little spa exposed. If tectonic movements are intensely, heat reservoir is lifted to the surface to form a spring partially.