盆地超压层段非幕式突破期的地热场模型数值解法

盆地超压层段的地热场模拟对超压成因研究及油气生成，排放机理分析有重要意义，但求解超压层段的热传递方程的数值解法至今仍没有被很好地解决，问题的关键在于确定超压流体速度场，由于超压流体发生幕式突破之前的排出速率极低，其速度场v=vxi vzk近似满足条件Эux/Эx Эuz/Эz＝0，可将其近似地视为稳定的不可压缩的无源流体，利用这一条件及相应的边界压力条件，可使整个计算过程得到简化，在此基础上所建立的地热场模型有限元数值解法和模拟软件，能够实现对含油气盆地在幕式突破之前的超压层段地热场进行动态模拟。     

Inversion of multiple thermal indicators: Quantitative methods of determining paleoheat flux and geological parameters. I. Theoretical development for paleoheat flux

The quantitative inversion of present-day downhole thermal indicator information enables (a) assessment of the effective paleoheat flux recorded by thermal indicators, and (b) determination of geological parameters related to the dynamical burial history of sedimentary strata. The logic of the general inversion scheme underlying seven thermal indicators, viz. vitrinite reflectance, sterane, and/or hopane isomers, sterane aromatization, optical rotation,³⁹Ar/⁴⁰Ar, pollen translucency, and fission scar tracks in apatite is presented, and their capability for resolving paleoheat flux is noted. In a second paper, determination of chemical and physical parameters, as well as several other quantities of geological interest (such as the sizes and erosion times of multiple unconformities, stratigraphic ages, paleo-overpressure, igneous intrusion timing, overthrust timing and frictional heat generation, fault and slump timing, thermal effects due to radioactive layer emplacement, and salt emplacement and dissolution timing) are discussed. Such events impact on both burial and thermal histories of sedimentary layers.Resolution problems are discussed also in the second paper, as is an attractive scheme called thermal indicator tomography for sorting out degrees of resolution, precision, and uniqueness of the relevant geological parameters for each process in combination with determination of the effective paleoheat flux. Detailed statements on the mechanics of implementing the tomographic approach are provided.     

Determination of paleoheat-flux using multiple thermal indicator tomography

Multiple thermal indicator tomography is a non-linear inversion procedure which permits simultaneous determination of geological, chemical kinetic, and thermal parameters in the burial and thermal histories of sediments. The procedure is based on inverting measurements with depth in a well of multiple thermal indicators, each of which must have experienced the same thermal history. For two wells from diverse geological settings, tomography is used to assess the paleoheat-flux variations with time most consistent with all the thermal indicator data. Resolution and sensitivity of the results are also addressed. For the case history of well X in the North Sea, with both vitrinite reflectance and sterane isomer thermal indicators, a generally decreasing heat flux from past to present is obtained roughly halving every 50 Ma. The activation energy for the sterane isomer is also determined simultaneously to be 42±20 kJ/mole. For the second case history of the Irma Mclean well in the onshore Gulf of Mexico, data from four thermal indicators are available: vitrinite reflectance, sterane and hopane isomers, and sterane aromaticity. A general decrease in paleoheat-flux from amount 2.8 heat flux units (HFU) at 100 MaBP to 1.25 HFU at the present day is obtained, the activation energy for the sterane isomer is simultaneously determined to be around 50±20 kJ/mole, while the corresponding values are around 80±20 kJ/mole for the hopane isomer, and around 65±20 kJ/mole for sterane aromatization.     

Thermal Backstripping from Vitrinite Reflectance Profiles in Comparison with an Extensional Model for Passive Continental Margin Basins on Northern Continental Shelf of South China Sea

INTRODUCTIONVitrinitereflectance(R.)canprovideagreatdealinfor-mationonthermalhistoryofabasin.Itisafunctionofmaximumpaleotemperatureandeffectiveheatingtime,inotherwords,afunctionofdepositionalrateandgeothermalgradientwithirreversiblecharacteristics.Butitalsohasacumulativeeffectthroughoutgeothermalevents.Paleotemperaturesaremainlycontro1ledbythebasalheatflowandheatgenerationfromradioactivesourceswithinthecrust.Themodelforde-terminingpaleoheatflowoflinearchangewithtimefr0mvitri-nitereflecta…     

定量动力地层学简述

定量动力地层学是应用数学定量方法研究沉积盆地的地质动力学、地层学、沉积学和水力学属性，最终获得盆地沉积相展布和地层分布模式的一门综合性学科。本文对定量动力地层学的提出、理论基础、研究方法等作了简要介绍，并用实例阐述了定量动力地层学的应用。     

利用多种古地温计研究松辽盆地东南隆起区的地热史

根据实测地温资料和岩石骨架热导率测试结果对本区今地温场的特征进行限分析，利用镜质体反射率反演古热流、成岩期原生矿物流体包裹体均一法测温和磷灰石裂变烃迹的热中分析研究了本区的地热演化，所获得的认识对松辽分地东南隆起区的油气地质研究和勘探评价很有意义。     

Inversion of multiple thermal indicators: Quantitative methods of determining paleoheat flux and geological parameters. II. Theoretical development for chemical, physical, and geological parameters

Using the logic for quantitative inversion of present-day downhole thermal indicators, the inversion procedure can be used to determine unknown, or poorly known, chemical and physical parameters as well as other geological quantities of interest which impact on burial history and thermal history of an evolving sedimentary basin. Some such quantities are: amount of erosion and timing of unconformities, paleo-overpressuring, stratigraphic age, timing of igneous intrusion and insertion temperature, overthrust timing and frictional heating, fault and slump timing, effects due to emplacement of a radiocative layer, and salt emplacement and dissolution timing. Combining a priori unknown values of these chemical/physical and geological parameters with unknown (a priori) paleoheat flux variations, a theoretical scheme, called thermal indicator tomography, is developed for the systematic determination of all parameters at the same time and on the same footing. Case histories will be discussed in subsequent papers in this series.     

东濮凹陷北部沙三段古压力恢复及油气运聚动力构成

综合应用流体包裹体法和盆地模拟法, 恢复了东濮凹陷北部沙三段古压力, 并分析了成藏期油气运聚动力构成。研究结果表明, 沙三段超压分布受构造格局、沉降中心、生烃中心控制明显, 超压幅度表现为洼陷区大、中央隆起带次之、西部斜坡带最小, 受盐岩层发育影响, 濮卫-文留地区盐岩下部层系表现为压力系数高值区。成藏期超压和浮力是研究区沙三段油气运聚的主要动力, 压力过渡带和正常压力带是油气的主要聚集场所。研究区主要存在超压驱动、超压-浮力联合驱动和浮力驱动等3种类型的驱动机制, 其中斜坡带和洼陷带等超压带主要为超压驱动, 部分中央隆起带上的压力过渡带为超压-浮力联合驱动, 西部斜坡带和部分中央隆起带等正常压力带主要为浮力驱动。      

湘南骑田岭地区锡多金属矿体的磁法找矿标志研究

中高山地区找矿的地质标志由于地面工作的困难而不易充分使用,如能利用物探特别是航空物探的指标作为有效的找矿标志,则具有实际的经济价值.文章分析骑田岭地区占总储量1/3的19号矿脉(体)的航磁异常时,发现较低精度的航磁异常的幅值不适于作为寻找该矿体的找矿标志;而利用航磁异常梯度刻画的磁结构则能完美地定位19号矿脉(体)的空间位置,"磁异常梯度矢量交汇处"是一个可能的有效的找矿标志.初步研究假设认为,流体的作用改变了区域岩石磁性的结构以及磁场的结构,磁异常梯度矢量与流体运移方向具有某种内在联系,利用磁异常梯度矢量可模拟研究区所发生过的成矿流体场的作用特征,找到成矿流体所可能的汇聚位置,从而确定成矿作用所发生的空间位置.     

伸展盆地地表热流值的模拟计算—以渤海湾盆地济阳坳陷为例

伸展盆地的大地热流值可以认为是由地幔热流，地壳内部和盆地沉积物生热效应以及岩石圈和沉积物导热性质等多个因素综合叠加的结果。本文根据传热学理论，分析了纯剪切模式条件下伸展盆地内的地表热流值贡献的分布规律及其与伸展因子的理想关系，认为深部热源的能量，伸展因子大小，地壳浅层的生热性质以及盆地构造位置是控制盆地热流高低和展布的关键因素。结合沉积地层的导热性质，放射性元素的生热效应，岩浆区的现今地表热流分布，得到了与正演模拟相接近的结果，验证了该方法思路的有效性。同时对该地区幕式伸展裂陷过程中的地表热流值变化趋势进行了模拟，认为在不同的伸展裂陷幕地表热流值表现为阶段式的升高，在末期达到最大值。     

Coalification anomalies induced by fluid flow at the Variscan thrust front: A numerical model of the palaeotemperature field

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