Study On The Recovery And Recharge Ability Of Wells In Geothermal Fluid Exchange Development

Geothermal resources as environmentally friendly renewable resources,has broad application prospects.The geothermal exploitation methods including heat transfer and wellbore fluid exchange.The exchange of fluid type mining refers to the establishment of extraction and filling of wells,wells through the formation of hot water produced by heat,end through the formation of recharge well injection at present,the development of geothermal fluid exchange factors development effect and influence understanding is not perfect,it is particularly important to carry out research on prediction rules and the effects of the heat collecting capacity and recharge capacity.In this paper,using the method of numerical simulation in Shengli Oilfield L geothermal plant development project as the research object,establish the model of recharge of geothermal wells development concept,in the output of the temperature history fitting on the basis of formation pressure of geothermal exploitation,description and analysis of the temperature distribution.The output temperature and well group energy efficiency as evaluation index.Analysis of the influence of wellbore formation parameter and production parameters on the heat collecting capacity,and analyzed the factors influencing the sensitivity.By nonlinear multiple regression analysis method,the heat collecting capacity prediction model is established,and the model is verified.The recharge well natural recharge recharge conditions to analyze the influential factors sure,the natural recharge in full recharge and recharge time required to recharge pressure conditions,and the establishment of the recharge capacity prediction model.The research on extraction and filling well thermal recovery time and irrigation,The relationship between the distance between wells,through the analysis of the aquifer permeability,thickness of aquifer and the liquid depth and other parameters on therecharge capacity influence,established the calculation charts and extraction and filling well ratio optimization method to improve the ability of irrigation.At the end of the geothermal well recharge capacity of the recharge well swap,multi well recharge development mode are discussed.The output temperature of stratum formation heat capacity,thermal conductivity,increasing shaft depth decreases,and increases with the increasing of recharge rate,less affected by casing heat conduction coefficient and recharge temperature.Through the sensitivity analysis,to determine the various factors on the heat collecting capacity of the degree of influence is from: heat conduction coefficient,recirculation velocity,borehole depth,formation heat capacity,well spacing,casing heat conduction coefficient,recharge temperature,heat capacity of casing.Recharge capacity decreases with epidermal coefficient increase with the wellhead pressure,aquifer thickness,recharge rate,permeability increases.The influence of various factors on the recharge capacity from large to small: the thickness of skin factor,wellhead pressure,water recharge rate,permeability.In the mode of development,found that the recharge well swap mode can reduce the recharge pressure,but the resulting output temperature decreased,resulting in decreased energy efficiency,and can improve the extraction and filling ability.Select a recovery method,the optimal well pattern for the production well between two recharge well.Taking back filling ability and heat breakthrough,determine the optimal spacing for 160 m.