山东省德州市德城区地热采灌工程合理井距与热突破时间推算

Calculation of Reasonable Well Spacing and Thermal Breakthrough Time for Geothermal Extraction and Irrigation Engineering in Decheng District in Dezhou City in Shandong Province

山东省德州市砂岩热储开发时间早,供暖工程数量较多,但受社区面积和布局的影响,采灌井距远近不一,过近的采灌井距,势必会加速热突破的发生。为指导今后区内地热工程建设,利用《砂岩热储地热尾水回灌技术规程》(DZ/T0330—2019)中合理井距公式,代入德城区地热地质参数,推导出该区合理井距经验公式。随着地热工程开采量增加,合理井距亦随之增加,当开采量为60 m 3/h时,合理井距不应低于181 m。根据计算,德城区51组采灌对井中,21组采灌对井将会发生热突破,且有8组采灌对井热突破时间不足10年,占比达到了19.6%。为保障采灌工程可持续运行,采灌井应及时调整布局。

Dezhou city in Shandong province has a long history of sandstone thermal storage development and a large number of heating projects.However,affected by the area and layout of the community,the distance between the production and irrigation wells varies.If the distance between the production and irrigation wells is too close,it is bound to accelerate the occurrence of thermal breakthrough.In order to guide the construction of geothermal engineering in the area,by using the formula for reasonable well spacing in the"Technical Specification for Geothermal Tailwater Reinjection of Sandstone Thermal Storage"(DZ/T03302019),the empirical formula of reasonable well spacing in Decheng District is derived by substituting the geothermal geological parameters in the area.It is showed that the reasonable well spacing will increases accompanying with the increase of mining output of geothermal engineering.When the mining output is 60m 3/h,the reasonable well spacing should not be less than 181m.According to the calculation,among the 51 groups of production and irrigation wells in Decheng district,21 groups of production and irrigation wells will have thermal breakthrough,and 8 groups of production and irrigation wells will have thermal breakthrough less than 10 years,and account for 19.6%.In order to ensure the sustainable operation of the mining and irrigation project,the mining and irrigation wells should be rearranged in a timely manner.