基于居里面深度对中国东北部大地热流的研究

大地热流值是表征地球热状态的重要参数,也是进行深部地温预测和评价一个地区地热资源的最基本数据。受钻孔测温的影响,盆地外的无钻孔测温地区缺少实测的大地热流值。目前的热流分布图都是依据相邻盆地的实测值进行插值绘制的,无钻孔区热流值可信度较低。由于岩石居里点与温度密切相关,可以通过居里面深度来研究地表热流值。本文依据东北地区现有的居里面深度分布图,结合实测的岩石热导率、岩石生热率数据和相应的地壳分层状况,计算了东北地区的大地热流值,重新绘制了中国东北地区精细的大地热流分布图。东北地区整体大地热流处于42.5~95 mW/m 2 之间,热流高值位于五大连池及敦化 密山断裂带海龙—牡丹江一带,松辽盆地内部、小兴安岭和长春 延吉缝合带也有局部的高热流值。热流高值与居里面隆起区域有较高的一致性,即居里面隆起处热流较高,而坳陷区热流较低。本次研究填补了中国东部地区热流实测值空白,为该区深部地温预测和地热资源评价提供了更加准确的参数。     

The origin and distribution of natural gas in the frontal uplift area of the Kuqa depression,Tarim Basin

The frontal uplift of the Kuqa depression is an important oil and gas producing area. In this study, the distribution and origin of natural gas were discussed based on natural gas components and isotope data. The main components of natural gas were hydrocarbons with relatively high contents of C2+ component. Most gases were de-rived from terrestrial source rocks, and some came from marine rocks. The contents of non-hydrocarbon gases were high in the central part of the frontal uplift area and low in the two terminals. The distribution of oil composition was similar to that of natural gas, which was mainly controlled by the types of source rocks. Dry coefficient and maturity of natural gas in the frontal uplift were lower than those of gas in the Kelasu tectonic belt of the Kuqa depression, which was mainly affected by the difference of tectonic movements in both areas. In the frontal uplift, the traps were formed in the early stage and could capture the early formed oil and gas, and structural adjustment was slight in later stages, so the oil and gas could be effectively preserved. Multiperiodic oil and gas filling led to the complex distribu-tion of natural gas.     

运城盆地不同构造单元埋藏与热演化史对比研究

正沉积盆地的埋藏和热演化史研究对盆地分析研究和油气勘探具有重要意义(Zuo et al,2011; Hu et al,2001; Qiu et al,2012)。在沉积盆地的热演化史研究中,区分埋藏过程中的加热事件和抬升剥蚀期间造成的冷却事件尤为重要。(U-Th)/He定年方法是一种放射性同位素低温定年方法,具有低温敏感性(磷灰石封闭温度为70℃,锆石封闭温度为180℃)和精度高的特点,是近年来国际上新发展     

Effects of transient uplift/erosion on the surface heat flow and heat generation relationship in presence of small scale asthenospheric convection

In this paper the effect of transient uplift/erosion on the relationship between surface heat flow and heat generation for truncated exponential model of radiogenic heat source distribution and basal asthenospheric convection is investigated. Asthenospheric convection is described by a parameterized model, in the form of a nonlinear heat flux boundary condition involving basal temperature and mantle internal temperature. This boundary condition has been linearized and the analytical solution of the problem is obtained by the eigenvalue-eigenfunction expansion method. The analytical solution is used to derive the nature of surface heat flow and heat generation relationship. The results show that the linear relationship is maintained during the uplift/erosion and the estimates of the slope of the linear relationship are different from the depth scale of the exponential model and increase with the rate of uplift/erosion. The estimates of the reduced heat flow also increase with the rate of uplift/erosion. These results would find applications in the interpretation of linear surface heat flow and heat generation relationship which is observed in different tectonic environment.     

内蒙古银额盆地西部路井凹陷油气地球化学特征与油气源

通过对银额盆地西部路井凹陷华力西晚期侵入岩、侏罗系、白垩系等不同层系所获原油的族组分、全油同位素、原油生物标记化合物、原油伴生气组分、同位素地球化学特征的分析,探讨了不同层系原油的生油母质类型、沉积环境和生烃母质的演化程度。对上石炭统—下二叠统干泉组、侏罗系、白垩系烃源岩沉积环境进行分析,并与上石炭统—下二叠统干泉组生物标志化合物的对比,认为路井凹陷不同层段所获得的原油与上石炭统—下二叠统干泉组烃源岩具有良好的亲缘关系,原油地球化学特征及生物标志化合物差异的原因是不同位置干泉组上段与下段烃源岩的贡献不同。     

鄂尔多斯盆地天环坳陷北段奥陶系烃源岩特征及成熟演化史

为研究天环坳陷北段下古生界天然气成藏规律,利用探井资料和有机地球化学方法,评价了天环坳陷北段奥陶系烃源岩特征并恢复其成熟演化史。天环坳陷北段奥陶系乌拉力克组和克里摩里组烃源岩有机碳含量和生烃潜量相对较高,烃源岩有机质丰度以中等—好为主,少部分为差烃源岩;三道坎组和桌子山组烃源岩以差为主。干酪根组分鉴定表明,天环坳陷北段奥陶系烃源岩主要为Ⅱ₁～Ⅰ型干酪根,热演化程度高,处于生干气阶段。成熟演化史模拟显示,古生代—中生代早期地温梯度低,地层埋藏浅,烃源岩成熟演化程度低。燕山期,由于构造热事件,地温梯度迅速升高,早白垩世烃源岩经历的最高温度超过200℃,达到生气高峰期,早白垩世是油气成藏的主要时期。早白垩世之后,鄂尔多斯盆地整体抬升,地温梯度减小,生烃作用停止。     

Research on the characteristics and influencing factors of terrestrial heat flow in Guizhou Province

Terrestrial heat flow is an important physical parameter in the study of heat transfer and thermal structure of the earth and it has great significance in the genesis and development and utilization potential of regional geothermal resources. Although several breakthroughs in geothermal exploration have been made in Guizhou Province. The terrestrial heat flow in this area has not been properly measured, restricting the development of geothermal resources in the province. For this reason, the terrestrial heat flow in Guizhou was measured in this study, during which the characteristics of heat flow were determined using borehole thermometry, geothermal monitoring and thermal property testing. Moreover, the influencing factors of the terrestrial heat flow were analyzed. The results show that the thermal conductivity of rocks ranges from 2.0 W/(m·K) to 5.0 W/(m·K), with an average of 3.399 W/(m·K); the heat flow varies from 30.27 mW/m² to 157.55 mW/m², with an average of 65.26 ± 20.93 mW/m², which is slightly higher than that of the average heat flow in entire land area in China. The heat flow in Guizhou generally follows a dumbbell-shaped distribution, with high values present in the east and west and low values occurring in the north and south. The terrestrial heat flow is related to the burial depths of the Moho and Curie surface. The basaltic eruptions in the Emeishan led to a thinner lithosphere, thicker crust and lateral emplacement, which dominated the basic pattern of heat flow distribution in Guizhou. In addition, the dichotomous structure of regional active faults and concealed deep faults jointly control the heat transfer channels and thus influence the terrestrial heat flow.     

Annual variations in the surface radiation budget and soil water and heat content in the Upper Yellow River area

Measurements taken between July 2006 to May 2007 at the Maqu station in the Upper Yellow River area were used to study the surface radiation budget and soil water and heat content in this area. These data revealed distinct seasonal variations in downward shortwave radiation, downward longwave radiation, upward longwave radiation and net radiation, with larger values in the summer than in winter because of solar altitudinal angle. The upward shortwave radiation factor is not obvious because of albedo (or snow). Surface albedo in the summer was lower than in the winter and was directly associated with soil moisture and solar altitudinal angle. The annual averaged albedo was 0.26. Soil heat flux, soil temperature and soil water content changed substantially with time and depth. The soil temperature gradient was positive from August to February and was related to the surface net radiation and the heat condition of the soil itself. There was a negative correlation between soil temperature gradient and net radiation, and the correlation coefficient achieved a significance level of 0.01. Because of frozen state of the soil, the maximum soil thermal conductivity value was 1.21 W m⁻¹°C⁻¹ in January 2007. In May 2007, soil thermal conductivity was 0.23 W m⁻¹°C⁻¹, which is the lowest value measured in the study, likely due to the fact that the soil was drier then than in other months. The soil thermal conductivity values for the four seasons were 0.27, 0.38, 0.55 and 0.83 W m⁻¹°C⁻¹, respectively.     

大地电磁技术测定的准噶尔盆地乌伦古坳陷至北隆起带石炭系及油气前景分析

【研究目的】 本文以准噶尔盆地乌伦古坳陷至乌伦古北隆起带为研究区,研究石炭纪地层沉积、分布特征,为该区地质结构研究和油气勘查工作提供了依据和参考。【研究方法】 采集大地电磁测深数据,结合以往重磁电震资料,采用二维共轭梯度反演、最优化电性分层等技术获取石炭纪地层、断裂构造展布特征,为火成岩覆盖区研究石炭纪地层提供了有效的方法。【研究结果】 利用大地电磁测深技术结合重磁电震资料开展综合处理分析,获得研究区石炭系厚度图、石炭系埋深图,初步确定了上下石炭统的分界面,查明了石炭纪地层的分布特征,索索泉凹陷、福海坳陷和扎河坝坳陷为3个石炭纪地层沉降中心,具有较好的油气勘查前景。【结论】 在火成岩覆盖区,采用大地电磁测深、重磁电震综合处理解释技术为石炭纪地层研究提供了有效的技术支撑。     

库车前陆冲断带盐下深层压力特征及其油气勘探意义

库车前陆冲断带盐下深层气藏埋深大, 普遍发育超压。通过收集大量盐下深层压力实测数据, 开展压力分布规律研究, 揭示其与气藏的形成及分布之间的联系。结果表明, 库车前陆冲断带盐下深层压力分布为85~127 MPa, 压力系数分布为1.5~1.9, 为超压特征。平面上, 地层压力和压力系数分布表现为南北分带、东西分段的特征。侏罗系烃源岩距白垩系巴什基奇克组砂岩顶部为1 500~4 000 m之间, 平均为3 000 m, 源储压差在70 MPa以上, 超压流体为天然气强充注成藏提供动力条件, 是形成高效气藏的必要条件。平面上, 盐下深层大气藏(田)的分布与超压分布区叠置;纵向上, 气藏群位于超压集中发育的封闭楔形冲断体内, 成排成带分布。