CAJ | 학술논문

地温梯度和大地热流是揭示盆地现今热状态的重要参数,它们对理解盆地的构造一热演化过程及油气资源评价等方面均具有重要意义.利用塔里木盆地约470口井的地层测试温度资料和941块岩石热导率数据,本文计算了塔里木盆地38个新的大地热流数据,进而揭示了该盆地现今地热分布特征.研究表明,塔里木盆地现今地温梯度变化范围为17～32℃/km,平均为22.6±3.0℃/km;大地热流变化范围为26.2～65.4 mW/m~2,平均为43.0±8.5mW/m~2.与我国其他大中型沉积盆地相比,它表现为低地温、低大地热流的冷盆的热状态,但仍具有与世界上典型克拉通盆地相似的地热背景.整体而言,盆地隆起区地温梯度和热流相对较高,坳陷区地温梯度和热流则偏低.此外,我们还发现塔里木盆地现有的油气田区一般位于高地温梯度区域,这可能与下部热流体的向上运移和聚集有关.影响塔里木盆地现今地热特征的因素包括盆地深部结构、构造演化、岩石热物理性质、盆地基底构造形态和烃类聚集等.
지온제도화대지열류시게시분지현금열상태적중요삼수,타문대리해분지적구조일열연화과정급유기자원평개등방면균구유중요의의.이용탑리목분지약470구정적지층측시온도자료화941괴암석열도솔수거,본문계산료탑리목분지38개신적대지열류수거,진이게시료해분지현금지열분포특정.연구표명,탑리목분지현금지온제도변화범위위17～32℃/km,평균위22.6±3.0℃/km;대지열류변화범위위26.2～65.4 mW/m~2,평균위43.0±8.5mW/m~2.여아국기타대중형침적분지상비,타표현위저지온、저대지열류적랭분적열상태,단잉구유여세계상전형극랍통분지상사적지열배경.정체이언,분지륭기구지온제도화열류상대교고,요함구지온제도화열류칙편저.차외,아문환발현탑리목분지현유적유기전구일반위우고지온제도구역,저가능여하부열류체적향상운이화취집유관.영향탑리목분지현금지열특정적인소포괄분지심부결구、구조연화、암석열물이성질、분지기저구조형태화경류취집등.
Geothermal gradient and terrestrial heat flow are key parameters that describe the thermal regime of sedimentary basin,and are so vital for understanding the tectono-thermal evolution and associated hydrocarbon resource potential assessment of oil and gas bearing basin.Here we show the distribution pattern of the updated present-day geothermal gradient and calculate 38 terrestrial heat flow values in the Tarim basin,one of the biggest sedimentary basins in China,based on the formation temperature data from approximately 470 wells and 941 thermal conductivity of rocks within this basin.Our results show that the present-day geothermal gradient of Tarim basin varies between 17~32 ℃/km with a mean value of 22.6±3.0 ℃/km, and the terrestrial heat flow ranges from 26.2 to 65.4 Mw/m~2 with a mean of 43.0±8.5 Mw/m~2,suggesting a thermal regime of cold basin with low temperature and low heat flow,as compared with other large-middle scale sedimentary basins in China.This low thermal regime also makes Tarim basin to share the similar geothermal characteristics of other typical craton basins in the world.Generally,the geothermal gradient and terrestrial heat flow in uplift areas are usually larger than those in the depressions.We also find that the discovered oil and gas fields in Tarim are usually with relatively large geothermal gradient,the cause for this coincidence is not clear but the upward movement and accumulation of hot fluid below is speculated to account for this positive geothermal anomaly.Finally,we summarize the factors that influence the geothermal distribution of basin as deep structure,tectonic evolution and basement pattern of basin,thermal physical properties of rocks and hydrocarbon accumulation as well.