Study On The Variation Of Heat Storage Temperature In Bohai Bay Basin

In order to cope with the energy crisis and environmental pollution since the 20 th century,people pay more and more attention to the development of clean energy.Geothermal energy,as an excellent renewable energy,is characterized by large reserves,no pollution,renewable energy and high utilization rate,and is becoming the focus of renewable energy development in north China.At present,the research on the thermal resources in Bohai Bay area is still in the stage of resource exploration and evaluation,and the research on the uplift and depression in the basin is still in the primary stage.This paper studies the geothermal law and causes of the heat reservoir in Qingfeng area to provide basic information and reference for the development and utilization of geothermal resources in the whole region.Qingfeng area is located at the northeast of Henan Province and Bohai Bay Basin.This paper mainly uses the logging data and geological exploration results in this area.The overall temperature and hydrochemical properties of heat storage are studied by using three methods of heat storage temperature estimation.Secondly,through the study of well logging data,the vertical and plane distribution characteristics of the geothermal field are obtained,and according to the geological data,the cover reservoir of the heat reservoir is divided.On this basis,the 3D geological model is established by COMSOL Multiphysics software.Finally,the temperature characteristics of the heat reservoir in Qingfeng area are obtained through the above research,and the formation mechanism is analyzed.The study shows that Qingfeng area can be divided into QY,XB and XY area,and the characteristics and differences of thermal storage and accumulation in the three areas are analyzed and compared.The distribution characteristics of heat storage temperature in the three areas are different under the condition of consistent tectonic activities in a large range.The characteristics of QY area are the development of multiple small faults,heat conduction is the main heat transfer mode,and the heat convection in the reservoir is controlled.The temperature of heat storage in XB is the highest and there is obvious water supply.The cap rock temperature is high and the reservoir temperature is low in XY area,but the temperature changes gently.In order to confirm the reasons for the differences in temperature characteristics of three communities in Qingfeng area,this paper studies the mechanism of thermal storage warehouse in Qingfeng area.The geothermal system in China can be divided into two categories and four subcategories: convective high temperature hot water type,convective medium low temperature hot water type,conduction low temperature hot water type,and conduction low pressure hot water type.These geothermal systems are divided according to tectonic activity,terrestrial heat flow,geothermal gradient of cap rock,reservoir temperature,heat source,water source,etc.Based on the above studies,the factors of thermal storage and accumulation in Qingfeng area are obtained,and it is confirmed that Qingfeng area belongs to the conduction type of medium-low temperature geothermal system.The tectonic evolution of Bohai Bay Basin is the basis of heat storage and accumulation.The heat reservoir in Qingfeng area is composed of high thermal conductivity strata covered with low thermal conductivity cap rocks.A few faults affect the heat transfer of local strata.A few faults affect the heat transfer of local strata.The heat source is mainly supplied by the mantle heating,and the meteoric precipitation is less than evaporation.The water source is mainly supplied by the surrounding strata through the faults near the reservoir,and the source is the Taihang Mountain in the northwest and the Southwest Shandong uplift in the east.The complete reservoir structure and abundant heat source and water supply in Qingfeng area are the strong guarantee of heat storage and reservoir formation.