井孔水温动态变化的影响因素探讨

本文主要通过对近两年来在北京塔院井、 四川西昌太和井不同深度上取得的水温观测资料的对比研究, 得到以下认识: ① 塔院井有套管封闭, 温度梯度变化较小的区段内, 梯度是水温动态的主要影响因素, 梯度变化较大的上部, 水温动态无明显的规律性, 梯度变化较小的下部, 正梯度段内水温潮汐与水位同向变化; ② 塔院井负温度梯度段对其下部旧探头震后变化形态有明显影响, 使得震后需要较长时间才能恢复; ③ 太和井位于观测含水层位范围内的探头由于受温度梯度和含水层进出水的共同影响, 使得其温度动态变化更为复杂。 研究结果表明, 分析水温资料和放置水温探头时, 充分了解井孔水文地质条件、 井孔结构和温度梯度分布是非常必要的。

Study on the Influencing Factors of Well Water-temperature Changes

In this paper, we mainly study water temperature changes at different depth of the Tayuan well, Beijing and the Taihe well, Xichang, Sichuan . It is shown that above the observed aquifer of the well, at sealed section with small temperature gradient, temperature gradient is the main factor of water temperature changes. In positive gradient belt, temperature tidal effects changes directly with water level tide. In negative gradient section, temperature tidal effects changes inversely with water level tide. And in the section at which temperature tidal effects can be observed, the larger the temperature gradient is, the larger the temperature tidal dynamic range. Negative gradient section of the Tayuan well also influences after-seismic temperature changes of geothermometer located under it, making temperature taking more time to come back to the normal level. Water temperature changes are more complicated when probe locates within the observed aquifer range. The result shows that it is necessary to fully understand hydro-geological conditions, well profile and temperature gradient when analyzing temperature changes and installing temperature probe.