周口凹陷区地温场特征及影响因素分析

Analysis of geothermal field characteristics and influencing factors in Zhoukou depression area

周口凹陷区有着丰富的地下热水资源。根据69个地热钻孔资料和实测热导率资料分析了周口凹陷区地温场特征及其影响因素,地温梯度变化在2.77~3.94℃/100 m之间,平均地温梯度为3.36℃/100 m,大地热流密度在43.6811~64.5884 mW/m 2之间,平均大地热流密度为55.7240 mW/m 2。周口凹陷区是一个中温型地温场,地温梯度和大地热流密度具有凸起区较高、凹陷区较低的特点,大地热流值与地温梯度分布规律相一致;而不同层位的地温分布规律则相反,即凹陷区内温度高,凸起和隆起上的温度低。基底构造形态、沉积盖层厚度、深大断裂、地下水等因素决定了该凹陷区总体地温特征。

Zhoukou depression area is rich in underground hot water resources.According to 69 geothermal drilling data and measured thermal conductivity data,the geothermal field characteristics and influencing factors of Zhoukou depression are analyzed.The geothermal gradient varies from 2.77 to 3.94℃/100 m,and the average geothermal gradient is 3.36℃/100 m.Geothermal flow density from 43.6811 to 64.5884 mW/m 2,the average geothermal heat flux is 55.7240 mW/m 2.Zhoukou depression area is a medium-temperature geothermal field.The geothermal gradient and geothermal flow density are characterized by higher elevation and lower depression.The geothermal flow value is consistent with the geothermal gradient distribution law.The geothermal distribution of different horizons is opposite.That is,the temperature inside the recess is high,and the temperature on the bump and the ridge is low.Basement structure morphology,sedimentary caprock thickness,deep and large faults,groundwater and other factors determine the overall geothermal characteristics of the depression.