Temperature Prediction Of Stratified Thermal Storage Under The Background Of Normal Earth Heat Flow

According to the type of heat source,geothermal systems can be divided into waste heat of magma chamber,radioactive heat of rocks,normal or slightly high terrestrial heat flow,and the normal or slightly high geothermal flow can be divided into two subclasses: thermal conduction by fault and thermal conduction by stratum.In general,geothermal display is obviously abnormal and the thermal storage temperature is higher in the first two type and thermal conduction by fault in normal terrestrial heat flow.For the thermal conduction by stratum in normal terrestrial heat flow,the ground surface is basically free of geothermal anomalies and the thermal storage temperature is also low.Previous researchers have been studied to a certain extent on the formation of layered thermal reservoirs in the normal terrestrial heat flow,but little research has been done on the geothermal field mathematical prediction model of geothermal reservoirs.Geothermal gradient method is widely used in the study of thermal storage temperature,but practice shows that there is a certain error in the geothermal gradient method.This article re-predicts the temperature from the perspective of historical heating method and corrects the geothermal gradient method.Therefore,this paper has a more profound understanding based on previous researches,and establishes a geothermal field mathematical prediction model of layered thermal reservoirs in the thermal conduction by stratum in normal terrestrial heat flow.It can provide reasonable and scientific guidance for the development and utilization of this type of geothermal resources.In this paper,by collecting and sorting out the geothermal data in Yunnan,we have explored the basic characteristics of geothermal formation,distribution,formation mechanism,and reservoir forms under the normal geothermal flow conditions,and established a heat storage model under the background of normal geothermal flow.On this basis,the characteristics of the geothermal field are studied,and the mathematical model of the thermal storage temperature calculation is established according to the conservation of energy and the Fourier law.In the process of solving the analytical solution of the mathematical model,statistical principles are used to find out the relationship between the required parameters and the known parameters.In this paper,there is a positive correlation between the increase of heat flux in heat reservoirs and the heat flow in the earth;there is a negative correlation between the thermal conductivity of the cover and the thickness of the cover.The linear regression analysis of these parameters was performed using spss software,and the mathematical relationship between them was obtained,and then the formula for calculating the temperature of the thermal reservoir was obtained.The calculation formulas obtained in this study were verified using the good thermal reserve,the poor cap thermal reserve,the multi-layer thermal storage and the heat storage affected by the fault.The verification results of single-layer and multi-layer heat reserve are basically consistent with the actual well temperature logs.The verification results of the poor cap layered heat storage model are not much different from the actual well temperature logs,but the verification results of the poor cap layer affected by the fault zone the heat storage model are quite different from the actual results.