深部煤层伴生废热新模式开发及适用性分析

Development and Applicability Analysis of a New Model of Waste Heat Associated with Deep Coal Seams

现阶段深部煤层的开发过程中,煤层埋藏深、温度高,开发初期伴生地层水携高温废热开采至地面造成了部分能源浪费。基于资源综合利用角度上,为了使深部煤层开发中携带的废热用于热泵技术热源,提出废井改造地热井以降低钻井成本,以此设立深部煤层地热开发的工艺及热泵技术适用条件,从经济性及安全性两方面去分析深部煤层地热开发的可行性,给出了利用热泵系统进行煤层伴生废热开发的条件,最终建立出相关热泵系统模型,通过具体的示例环境参数进行计算。得出鄂尔多斯东缘神府地区某区块深部煤层伴生废热的单井制热量可达14.8 kW,热泵系统的制热性能系数(COP)可达到4.33~7.31,同时,煤层气井出口混合产物温降将近10℃。表明煤层伴生废热开发在提高了井上采收作业安全性的同时拥有较好的采热开发环境,扩展了废热可利用的经济性,提出一种深部煤层综合性开发的新型模式。

At the present stage of deep coal seam development,the coal seam is buried deep and the temperature is high.At the initial stage of development,the associated formation water was brought to the surface with high-temperature waste heat,which caused some energy waste.From the perspective of resources,in order to use the waste heat carried in the development of deep coal seams for the heat source of heat pump technology,waste wells was used to transform geothermal wells to reduce drilling costs,the process of deep seam geothermal development was established and the applicable conditions of heat pump technology the feasibility of deep coal seam geothermal development was analyzed,and the applicable development conditions and related technologies were given.Finally,the relevant heat pump system model was established,and the calculation was carried out through specific example environmental parameters.It is concluded that the single well heating capacity of the waste heat associated with the deep coal seam in a block in the Shenfu area of the eastern margin of Ordos can reach 14.8 kW,and the heat pump system coefficient of performance(COP)can reach 4.33~7.31.At the same time,the temperature drop of the mixed product at the exit of the coalbed methane well is nearly 10℃.It shows that the development of coal seam-associated waste heat improves the safety of uphole recovery operations and has a better heat development environment,expands the economy of waste heat utilization,and proposes a new model for comprehensive development of deep coal seams.