Study On Geothermal Reinjection Of Tracer Technology And Simulation Of Thermal Energy Storage

In the increasingly serious energy and environmental situation of today, no doubt that the clean geothermal resources have broad application prospects. However, because the mining is seriousiy disorder, reservoir pressure and temperature come down and resource depletion affecting the sustainable use of geothermal resources. Proved at home and abroad, geothermal water reinjection is the primary way to solve the problem. Therefore, through the geothermal reinjection experiment and simulation, study the effects heat recharge thermal response mechanism to explore the relationship between thermal breakthrough time and and geothermal geological environment.There will be significant for protection of geothermal resources, sustainable use of geothermal resources and geothermal field to extend the life of the development and utilization.Geothermal fields in Beijing urban area located in the North China plain. It is classified as rift basin medium-low conduction geothermal system. Taking 122#-123# geothermal double-wells as the research object, Summary Beijing City geothermal field distribution of the thermal storage, geothermal geological, hydrogeological data and other research results.Through reinjection tracer test and numerical simulation techniques, study on the evolution of geothermal reservoir simulation of temperature field.Understanding and results achieved as follows:From dual tracer test, the results showed that the signal receivers to capture high resolution, no background interference.We could see clear linear concentration curve peak of MO.Tracer breakthrough time can be clearly concluded that 68.66h, calculated flow rate of 3.35 m/h. Combination of pumping test data, the data structure used three descending deep Gauss-Seidel iterative equations.Then computer program solving the permeability coefficient K, reverse generation of measured data into the tracer test,getting the permeability of the aquifer thickness is 4.81m.Full use of tracer test calculation parameters serving temperature field simulation from medium-term to the final phase.The cold front is blocked from prophase to medium-term. In the final phase, mass exploitation of thermal energy storage resources made the cold front gradually advance to the pumping direction and located near the central axis, which is affected by heat flow heating and environmental temperature.Then the geothermal gradient value increases and the temperature contours intensive. Throughout the entire process there is no heat breakthrough phenomenon, but the trend of change still point out the direction of further research.Geothermal water level and temperature data processing as different time scales showed that thermal water supply quantity is closely related with the natural process of precipitation. Long-term exploitation of geothermal resources, thermal reservoir temperature display fluctuation with no significant downward trend.Geothermal double-well system(122#-123#) using underground thermal energy storage calculation method to evaluate resources.Through Integration calculating,the recoverable amount of hot water is 8.8×106m3 and geothermal resources is 2.73×1010KJ, equivalent to 933 tons of standard coal heat. In view of the fact that the system scope is much larger than thermal energy storage of calculating, recoverable reserves could satisfy heating demand for hot. If providing enough hot water, thermal reservoir energy storage will renew quickly and can be long-term exploited.