咸阳地热田钻孔温度测量及水动力系统  

Borehole temperature logging and water dynamic system in the Xianyang geothermal field, Northwest China

作　　者：饶松[1,2] 李卫卫[2] 姜光政 唐晓音[2] 罗璐[2] 王建存[3] 

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,武汉430100 [2]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [3]中国石化集团新星石油有限责任公司,北京100083

出　　处：《地质科学》2015年第3期982-1000,共19页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国石化集团新星石油有限责任公司科学技术研究开发项目“我国典型地热田成因分析、资源评价与优化开采研究”（编号：51460960）资助.

摘　　要：地热田温度场分析，不仅为地热田类型划分和热源机理研究提供科学根据，而且可以为确定地热田有利开采区域和深度提供直接依据。本文报道了咸阳地热田13口钻孔的系统（准）稳态测温数据，对研究区温度的垂向分布特征做了初步分析，并据此划分了地热田水动力系统。结果表明，咸阳地热田属于以传导为主的沉积盆地型地热田，地温梯度为26．2～40．1℃／km，平均为32．4℃／km。然而，与典型的传导型地热田相比，咸阳地热田的地温场特征又存在特殊性，表现为钻孔温度-深度曲线分段性明显：浅部受地表水流动对温度场的影响，地温曲线呈现出锯齿形波动；钻孔中上部受地表水和深部水热活动影响较小，温度曲线为传导性地热特征；井孔中下部测温曲线明显“下凹”，揭示了地下水沿渭河断裂侧向补给的同时使地层温度降低；井孔下部温度随深度异常增大，表明存在异常压力流体封存箱。测温资料揭示了咸阳地热田水动力系统在垂向上存在多层结构：浅部为垂向重力驱动型，中上部为正常压实型，中下部为侧向重力驱动型，下部为封闭型。基于咸阳地热田水动力系统的多层结构，建议将各系统赋存的地热资源分别进行规划和开发。Research of temperature pattern of geothermal field, is not only the important basis for the classification and source mechanism study, but also provides direct evidence for the identification of advantageous thermal field area and depth. This paper reports the systemic （quasi-） steady temperature data of 13 boreholes in Xianyang geothermal field. Then, the vertical temperature distribution characteristics and the fluid dynamic system have been analyzed. The results show that the Xianyang geothermal field is a conduction-dominated geothermal field in sedimentary basins, with the geothermal gradient between 26.2 ~ 40.1 ~C/km, and 32.4 ~C/kin for average. Rut compared with the typical conductive geothermal field, the Xianyang geothermal field shows the special properties on the borehole temperature-depth curve. On the whole, there are four segments on the borehole temperature- depth curve. The shallow region of the temperature-depth curve exhibits a marked serration which is clearly related to the activity of surface water. The upper region is characterized by linear temperature-depth curve and conductive geothermal pattern by the lack of infiltration of shallow surface water and deep hydrothermal upwelling. The concave temperature-depth curve in the lower region reveals that the infiltration and lateral flow of the ground water along the Weihe faul has reduced formation temperature along with the water supplement to the geothermal field. At the bottom of the boreholes, the temperature anomaly increases with depth, which indicates the presence of fluid compartment with abnormal pressure. The high resolution temperature data reveal that the Xianyang geothermal field has multilayer structure of fluid dynamic system in vertical, that is vertical gravity-driven flow in the shallow region, normal compaction-driven flow in the upper region, lateral gravity-driven in the lower part and fluid compartment at the borehole bottom. Therefore, planning and exploitation separately according to the fluid dynamic system layers

关 键 词：钻井地温测量 地温梯度 水动力系统 咸阳地热田 

分 类 号：P314[天文地球—固体地球物理学]