Numerical Simulation Of Temperature Field In Situ Modified By Electric Heating Of Oil Shale

China is a big oil consumer.Since 2012,domestic crude oil consumption has been on the rise.China’s energy supply is facing great challenges,the development of conventional energy has been difficult to meet the rapid development of China’s economic status.Oil and gas as non renewable energy,in the future for a long time,conventional energy crisis will be the most serious problem faced by most countries in the world.In order to find a substitute for crude oil,the rapid consumption of non renewable energy has triggered the upsurge of exploration and development of unconventional energy in the world.At present,the development and utilization of oil shale is mainly concentrated in the surface distillation stage.The surface distillation and decomposition of oil shale are carried out,and the waste residue is used for building materials.However,with the increase of mining time and scale,the "three wastes" problem highlighted by oil shale surface distillation technology has attracted more and more attention,and the surface distillation technology has strict requirements on rock strata,which is generally only applicable to the high oil shale with shallow burial and thick rock strata.In order to further more reasonable development and utilization of oil shale,it is necessary to clarify the influence of different heating well layout methods In this paper,we set up different well distribution methods: single well group,parallel Well Group,polygonal well group.The temperature field numerical simulation of oil shale in-situ mining is studied.(1)In the numerical simulation of single well group,it is found that the effective heating volume of thin oil shale increases the fastest in 1-3 years,and the temperature field basically reaches a stable state after 3 years of heating.If heating is continued,the economic benefit is not great.Its advantage is that it can have a larger cracking range in a short time range,with the characteristics of short cycle and fast oil production.The effective heating volume of thick oil shale model is less than 6 before heating The results show that the temperature of thick oil shale is kept at 6-9 hours,the heat loss of thick oil shale is small,and it can gain more profits in development,and the heating period is generally long,but the oil output is large because of the thick rock and large volume.(2)In the numerical simulation of parallel Well Group,through the research and analysis of 28 different models,it can be seen that when the distance between heating wells is the same,the effective heating volume of oil production increases with the increase of heating well power,the increase speed is faster in the early stage,and then gradually slows down;when the heating power is constant,the effective heating volume of oil production increases with the increase of heating well spacing,but the increase speed is slow With the expansion of heating range,the effective heating volume of oil production slows down due to the influence of heat transfer range;in order to improve the heating efficiency of oil shale and make better development and utilization of oil shale,based on the effective heating volume of oil production,in the horizontal well heating model of thin oil shale,the model is more accurate The heating effect is the best and the economic benefit is the highest.In the parallel well group model of thick oil shale,the economic benefit of model p10-6 is the best.(3)After the experiment of optimal well spacing in polygonal well group,it is found that the optimal well spacing changes with the heating time,and has a certain stage.The optimal well spacing increases with the heating time.In this experiment,after 1700 days of heating,the optimal well spacing is 15 m.