The ultra-deep (deeper than 8 000 m) petroleum in the platform-basin zones of the Tarim Basin has been found mainly in the Lower Paleozoic reservoirs located to the east of the strike-slip fault F5 in the north depression. However, the source and exploration potential of the ultra-deep petroleum in the Cambrian on the west of F5 are still unclear. Through the analysis of lithofacies and biomarkers, it is revealed that there are at least three kinds of isochronous source rocks (SRs) in the Cambrian Newfoundland Series in Tarim Basin, which were deposited in three sedimentary environments, i.e. sulfide slope, deep-water shelf and restricted bay. In 2024, Well XT-1 in the western part of northern Tarim Basin has yielded a high production of condensate from the Cambrian. In the produced oil, entire aryl-isoprenoid alkane biomarkers were detected, but triaromatic dinosterane was absent. This finding is well consistent with the geochemical characteristics of the Newfoundland sulfidized slope SRs represented by those in wells LT-1 and QT-1, suggesting that the Newfoundland SRs are the main source of the Cambrian petroleum discovered in Well XT-1. Cambrian crude oil of Well XT-1 also presents the predominance of C29 steranes and is rich in long-chain tricyclic terpanes (up to C39), which can be the indicators for effectively distinguishing lithofacies such as siliceous mudstone and carbonate rock. Combined with the analysis of hydrocarbon accumulation in respect of conduction systems including thrust fault and strike-slip fault, it is found that the area to the west of F5 is possible to receive effective supply of hydrocarbons from the Cambrian Newfoundland SRs in Manxi hydrocarbon-generation center. This finding suggests that the area to the west of F5 will be a new target of exploration in the Cambrian ultra-deep structural-lithologic reservoirs in the Tarim Basin, in addition to the Cambrian ultra-deep platform-margin facies-controlled reservoirs in the eastern part of the basin.

In order to learn about the detection capability of GC (gas chromatography) and GC-MS (gas chromato-graphy-mass spectrometry) laboratories in the petroleum geology industry of China, improve the detection level of the laboratories and promote inter-industry exchanges, the Standardization Committee of Petroleum Geological Exploration organized a comparison study among the petroleum geology laboratories throughout the country. A total of 23 laboratories participated in this study. Total hydrocarbons, saturated hydrocarbon and aromatic hydrocarbon samples were selected, and the experimental method was specified according to relevant standards. The data quality of each laboratory was evaluated using the quartile robust statistical method. The results show that the data of the laboratories are stable and reliable, and the analysis results have good repeatability and reproducibility. The qualification rate of total hydrocarbons light hydrocarbon ratio parameters of GC is 95%, and the qualification rate of saturated hydrocarbon and aromatic hydrocarbon parameters is 97%. The qualification rate of saturated hydrocarbon parameters of GC-MS is 100%, and the qualification rate of aromatic parameters is 95%. The overall satisfaction rate is high. The main reasons for the problematic data and outliers of relevant parameters of some laboratories are the storage conditions, storage time, instrument model, test method, personnel operation errors, etc. It is suggested that the laboratories should strengthen quality control measures to further improve the GC and GC-MS detection capabilities.

Space nuclear reactor power,with the advantages of high energy density,high output power,long duration,and minimal influence from the external environment,is the preferred route for energy supply for future high-power long-life space missions and deep space exploration missions.Based on the developmental requirements and characteristics of different design options for megawatt-class space nuclear reactors,a technical scheme for a megawatt-class small lithium-cooled space reactor is designed.This scheme uses a lithium-cooled reactor coupled with a Brayton power conversion system that is lightweight and durable.The key technologies involved in the design are reviewed.Developmental progress of technical analysis and demonstration,verification prototype systems,and experimental platforms is presented.Suggestions and comments for developing high-power space nuclear power in China in the future are presented.

The Triassic Chang 7 shale in the Ordos Basin with considerable total organic carbon content (TOC) has been considered as an ideal target for in-situ conversion process (ICP) in China. However, the compositional kinetics for oil and gas generation from the Chang 7 organic matter during heating remain unclear, causing difficulty in the resource evaluation of shale oil and the temperature optimization in future ICP. In this study, the non isothermal pyrolysis of two Chang 7 kerogens at 2 and 20 degrees C/h were conducted to investigate the potential of individual components of products as well as their evolution kinetics. By using a comprehensive two-dimensional gas chromatography (GCxGC), the yields of individual components (including C1-5, C6-14 saturates, C6-14 aromatics, C15+ saturates, C15+ aromatics and NSOs) in pyrolysis products were measured. The maximum yields of oils and C1-5 from ZK-2 kerogen with hydrogen index (HI) of 471 mg/g TOC were 421.5 and 240.5 mg/g TOC, much higher than those from ZK-1 with HI of 332 mg/g TOC. Relatively, the temperature for giving maximum yield of C6-14 is significantly higher than those of C15+ and heteroatomic compounds (NSOs), which were decomposed to re-generate light hydrocarbons in the closed system. It showed that activation energies (Ea) for the generation and cracking of C6-14 and C2-5 were distributed in broader ranges compared with NSOs and C15+ components by kinetic fits. Meanwhile, the mass conversions of oil and gas from the Chang 7 kerogen in ICP at 0.5-10 degrees C/d were obtained. The temperatures giving maximum HC yield in ICP were predicted to be 330-368 degrees C. The oil and gas generation potentials of the Chang 7 shale in the Ordos Basin giving maximum HC yields were estimated as 542 x 10(8) t and 89.4 x 10(8) m(3), respectively. Finally, it is elucidated that heated temperatures of about 20 degrees C higher than those giving maximum oil yield result in GOR higher than 200 m(3)/m(3). These findings are beneficial for the economic production of shale oil in ICP.

空间核反应堆电源具有能量密度大、输出功率高、持续时间长、不受日照等环境影响的优点,是未来大功率长寿期航天任务及深空探测任务能源供应的优选路线.本文在综述国际空间堆电源发展历程与研究现状的基础上,归纳总结空间堆电源的技术发展趋势,针对固有安全、轻量化、长寿期的需求,提出一套兆瓦级小型锂冷空间堆电源方案,梳理锂冷空间堆电源发展需重点关注的研究内容,并介绍目前正在开展的可行性研究工作,为我国空间堆电源研究提供参考.

In recent years, petroleum exploration has extended from shallow to deep reservoirs in the globle petroliferous basins. In contrast to conventional carbonate reservoirs, the fractures and hydrotherm related karst reservoirs could mainly be developed in deep strata along the tectonic deformation and fault zone. The seismic imaging and tectonic analysis have been combined to identify the scale and features of the deep fault system in the Tarim Basin, NW China. It was found that the tectonic collision and movement generated a prevalent strike-slip fault system, which was conjugated and extended from paleo-uplift to the inside of the Manjar Sag (source kitchen) in the Tarim Basin. The micrograph of cores and images of well logging demonstrated that deep reservoirs are dominated by porosities, fractures, and hydrothermal minerals (e.g., fluorite, pyroxenite). Burial dissolution and thermohydrology along strike-slip fault have greatly contributed to the formation of deep carbonate reservoirs, meanwhile controled the accumulation and hydrocarbon properties in the deep carbonates reservoirs of Tarim Basin. The analysis of adamantane, dibenzothiophene, and carbon isotopes indicated that oil-cracking, thermochemical sulfate reduction (TSR), and gas-washing fractionation could be the main factors to control the sequential accumulation of various hydrocarbons around Manjar Sag. The formation and hydrocarbon accumulation of the deep carbonate reservoirs along this strike-slip fault system could provide important details regarding deep petroleum geological processes from both scientific and practical aspects. These findings could be applied to future studies and the exploration of deep potential marine reserves worldwide.

Diamondoids have attracted extensive attention from researchers because of their important application value in oil and gas exploration. Since diamondoids have complex molecular structures and a large number of isomers, the identification of certain diamondoids is still controversial. In this paper, a qualitative study of adamantane derivatives, such as 1-ethyl-3-methyladamantane and 1-ethyl-3,5,7-trimethyladamantane, was carried out using gas chromatography-mass spectrometry, gas chromatography-triple quadrupole mass spectrometry and two dimensional gas chromatography-time-of-flight mass spectrometry. The chromatography peak position of these compounds in different mass spectrograms was confirmed. In addition, with the help of MASS FRONTIER software, the fragmentation mechanism and the characteristic ions formed during electron ionization was interpreted for 1-ethyl-3,5,7-trimethyladamantane in the ion source.

运用全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)结合全二维气相色谱/氢火焰离子检测(GC×GC/FID)实现了对准噶尔盆地乌夏地区不同生物降解程度原油饱和烃复杂混合物成分的分析研究,提升了对生物降解原油组成及成因机理认识.结果显示:①乌夏地区生物降解原油中不可识别混合物主要由烷基取代环状化合物及其同系物组成,这些环状化合物主要以六元环为基本单元,包括单环烷烃(类胡萝卜烷)、双环烷烃(十氢化萘,脱-A,B环-甾烷)、三环烷烃(菲满类、三环萜烷、断甾烷)和金刚烷类、四环烷烃(甾烷、断藿烷、四环萜烷)和五环烷烃(藿烷、25-降藿烷)等六大类化合物;②不同生物降解原油中饱和烃总量变化不大,饱和烃中不同族系化合物随着生物降解作用增强呈现此消彼长的变化规律,在重度生物降解阶段,双环烷烃存在大量同系物及同分异构体,可能是微生物作用新生成的化合物,并且由于自身较强的抗生物降解能力,使双环烷烃成为饱和烃的优势成分,占饱和烃总量的50％左右,而多环烃类化合物含量随着生物降解程度逐渐增加,主要是由抗降解能力相对较强的高环数化合物的逐渐富集形成.

在用全二维气相色谱—飞行时间质谱定性石油样品中的金刚烷系列化合物基础上,建立了一套包括前处理方法在内的用全二维气相色谱—氢火焰离子化检测器定量分析石油样品中金刚烷类化合物的新方法.该方法利用全二维气相色谱正交分离的特点,使得常规的金刚烷系列化合物在色谱条件下就能很好地分离,实现了该类化合物的色谱定量分析.为减少前处理过程中低碳数金刚烷类化合物的挥发损失,新方法中对现有的石油样品饱和烃馏分的分离方法进行改进,建立了用小柱法分离收集饱和烃前馏分的方法,具有所需样品量少、分析时间短、实验耗材少的特点,金刚烷回收率满足色谱定量分析的需要.与传统的色谱—质谱定量方法相比,全二维色谱定量方法分离度高,重复性好,对内标物质要求低,7次实验的相对标准偏差小于5％,满足复杂体系的分析要求.

Thermal stability of liquid petroleum in the subsurface is closely linked to reservoir temperature. Most oil accumulations occur at temperatures <120 °C. Oil cracks into gas at temperatures >150–160 °C leading to the dominance of gas condensate and free gas accumulations in ultra-deep high-temperature reservoirs. The recently drilled Fuyuan-1 exploration well (northern Tarim basin) produced high-quality non-cracked single-phase (black) oil from a carbonate reservoir located at maximum depth 7711 m and temperature 172 °C. This is the deepest oil discovery in China to date and among the deepest in the world. The oil density (0.825 g/cm3 at 20 °C or API gravity 40°), relatively low gas/oil ratio (135 m3/m3 or 758 scf/bbl), low variety and abundance of adamantanes as well as lack of thiaadamantanes and dibenzothiophenes indicate that the oil was expelled from a source rock at moderate thermal maturity and has not been cracked. The molecular and isotopic composition of oil-associated gases are consistent with this interpretation. We suggest that the oil remained uncracked because the residence time at temperatures >150-160°C was relatively short (<5 my based on 1D modeling) and apparently insufficient for cracking. We conclude that there is potential for finding unaltered liquid petroleum in other high-temperature reservoirs with relatively low geothermal gradient and recent burial in the Tarim basin and around the world.

A number of condensate reservoirs with high concentrations of H2S have been discovered in the deep dolomite reservoirs of the lower Ordovician Yingshan Formation (O1y) in the Tazhong Uplift, where the formation water has a high pH value. In the O1y reservoir, the concentrations of Mg2+ and SO4 2− in the formation water are higher than those in the upper Ordovician formation. The concentration of H2S in the condensate reservoirs and the concentration of Mg2+ in the formation water correlate well in the O1y reservoirs of the Tazhong Uplift, which indicates a presumed thermochemical sulfate reduction (TSR) origin of H2S according to the oxidation theory of contact ion-pairs (CIPs). Besides, the pH values of the formation water are positively correlated with the concentration of H2S in the condensate reservoirs, which may indicate that high pH might be another factor to promote and maintain TSR. Oil–source correlation of biomarkers in the sulfuretted condensates indicates the Cambrian source rocks could be the origin of condensates. The formation water in the condensate reservoirs of O1y is similar to that in the Cambrian; therefore, the TSR of sulfate-CIPs likely occurred in the Cambrian. High H2S-bearing condensates are mainly located near the No. 1 Fault and NE-SW strike-slip faults, which are the major migration pathway of deep fluids in the Tazhong Uplift. The redox between sulfate-CIPs and hydrocarbons is the generation mechanism of H2S in the deep dolomite condensate reservoirs of the Tazhong Uplift. This finding should be helpful to predict the fluid properties of deep dolomite reservoirs.

The first exploratory well, the ZS1C well, with 158,545 m(3) daily gas production was discovered in 6861-6944 m deep strata of the Cambrian gypsolyte layer of the Tarim Basin, China in 2014. The discovery opens a new target for the Cambrian-reservoired oil and gas exploration, and directly leads to large-scale oil and gas exploration of the deep-reservoired Cambrian oil and gas fields in the Basin. Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry and a comprehensive two-dimensional gas chromatography flame ionization detector revealed the presence of abundant adamantane compounds, 2-thiaadamantanes and 2-thiadiamantanes, and a large amount of sulfur-containing compounds in the condensate oil. The formation of organic sulfur-containing compounds, such as 2-thiaadamantanes, is an indication of sulfur incorporation from the gypsum in the stratum into oil and gas in the course of TSR. This reservoir has apparently suffered severe TSR alteration because (1) High content of H2S, (2) H2S sulfur isotopes, (3) CO2 carbon isotopes, and others abundant data to support this findings. Similar sulfur isotopic composition of H2S, oil condensate and the gypsum in the Cambrian strata indicate that the produced condensate is experienced TSR alteration. Therefore, the deep-accumulated Cambrian oil reservoir has experienced severe TSR alteration, and accumulated natural gas and condensate contains high sulfur content. (C) 2015 Elsevier Ltd. All rights reserved.

The aromatic hydrocarbon fractions of five crude oils representing a natural sequence of increasing degree of biodegradation from the Liaohe Basin, NE, China, were analyzed using conventional gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional gas chromatography (GC×GC). Because of the limited peak capability and low resolution, compounds in the aromatic fraction of a heavily biodegraded crude oil that were analyzed by GC-MS appeared as unresolved complex mixtures (UCMs) or GC "humps". They could be separated based on their polarity by GC×GC. UCMs are composed mainly of aromatic biomarkers and aromatic hydrocarbons with branched alkanes or cycloalkanes substituents. The quantitative results achieved by GC×GC-FID were shown that monoaromatic hydrocarbons account for the largest number and mass of UCMs in the aromatic hydrocarbon fraction of heavily biodegraded crude oil, at 45% by mass. The number and mass of diaromatic hydrocarbons ranks second at 33% by mass, followed by the aromatic biomarker compounds, triaromatic, tetraaromatic, and pentaaromatic hydrocarbons, that account for 10%, 6%, 1.5%, and 0.01% of all aromatic compounds by mass, respectively. In the heavily biodegraded oil, compounds with monocyclic cycloalkane substituents account for the largest proportion of mono- and diaromatic hydrocarbons, respectively. The C4-substituted compounds account for the largest proportion of naphthalenes and the C3-substituted compounds account for the largest proportion of phenanthrenes, which is very different from non-biodegraded, slightly biodegraded, and moderately biodegraded crude oil. It is inferred that compounds of monoaromatic, diaromatic and triaromatic hydrocarbons are affected by biodegradation, that compounds with C1-, C2-substituents are affected by the increase in degree of biodegradation, and that their relative content decreased, whereas compounds with C3-substituents or more were affected slightly or unaffected, and their relative content also increased. The varying regularity of relative content of substituted compounds may be used to reflect the degree of degradation of heavy oil. Moreover, biomarkers for the aromatic hydrocarbons of heavily biodegraded crude oil are mainly aromatic steranes, aromatic secohopanes, aromatic pentacyclotriterpanes, and benzohopanes. According to resultant data, aromatic secohopanes could be used as a specific marker because of their relatively high concentration. This aromatic compound analysis of a series of biodegraded crude oil is useful for future research on the quantitative characterization of the degree of biodegradation of heavy oil, unconventional oil maturity evaluation, oil source correlation, depositional environment, and any other geochemical problems.

A continental condensate field, with the deepest burial depth (7084 m) so far in China, was recently discovered from the Cretaceous sandstone reservoir in the Bozi area of the Kuqa Depression, Tarim Basin. In this paper, we report general features of this field, including geochemistry of the condensates, their origin, and migration and accumulation. General geochemistry of the condensate reflects that it is an over pressured condensate reservoir. Analytical results by newly-developed high-resolution GC x GC-TOFMS method indicate that the condensate is rich in n-alkanes from nC(3) to nC(34) and in diamondoid hydrocarbons with a high content of adamantanes. The condensate has a high abundance of aromatic hydrocarbons. The gas delta C-13(2) values in these are -23.3 parts per thousand, which is characteristic of coal-derived gases. Compared with the contents of conventional condensate oils, the BZ1 well has a high content of aromatic hydrocarbons, suggesting that the condensate is in a stage of highly mature cracking. Analyses of oil biomarkers, carbon isotopes, gas compositions, etc., revealed that the condensate is dominantly sourced from the highly mature coals of the Jurassic Qiakemake Formation in the western Kuqa Depression. This set of coal source sequences has generated large quantities of condensate since 3 Ma, when the study area was subjected to a rapid subsidence with sediments over 2000 m and consequently attained at the condensate-generating stage. Such condensates then migrated vertically into the Cretaceous traps along faults. Therefore, the Bozi condensate field is a typical case of large-scale oil/gas field characterized by late-stage accumulation. Multiple elements favor the formation of this large-scale condensate field. The timing of trap formation accords with that of the condensate generation (since 3 Ma). The traps and source rocks are stacked vertically. Faults connect the source rock sequences and the reservoirs. The hydrocarbon charge is strong and efficient. Thick Paleogene gypsum beds act as an excellent cap rock, favoring the accumulation and preservation of the condensate. (C) 2015 Elsevier Ltd. All rights reserved.

In this paper, we analyse the Ordovician condensate in the Tazhong area of the Tarim Basin, NW China, using a new high-resolution comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC x GC-TOFMS). Results show that 4778 compounds at a signal-to-noise ratio of more than 100 were detected, reflecting the advantage of this method in the analysis of condensate. Abundant adamantane series compounds and some diamantane series compounds, as well as a series of sulphur-containing compounds (including the benzothiophene series, and the dibenzothiophene series) were detected for the first time in the study area. Combined with the results of a study on oil and gas sources and migration/accumulation, we address the origin of these compounds. It is implied that the diamondoids were not formed in-situ due to oil cracking (in reservoir approximately 5500 m deep at temperature around 139 degrees C), whereas the cracking of oil to gas may have occurred in the deeper-buried Cambrian dolomite reservoir at a reservoir temperature of 180-220 degrees C (8500-11,000 m depth). The oil-cracked gas (secondary cracking product) might have migrated to and accumulated in the shallower-buried Ordovician reservoir, accompanied by abundant diamondoids. The formation of sulphur-containing compounds may be related to thermochemical sulphate reduction (TSR), which, similar to the oil cracking, took place in the deeper-buried Cambrian reservoir. Under high-temperature TSR, SO42- in the formation water is reduced to H2S and organic sulphur compounds, leading to the enrichment of sulphur in crude oils (e.g., benzothiophene, and dibenzothiophene series). As such, it is implied that the Tazhong area could potentially be explored for deep-buried oil-cracked gas. (C) 2015 Elsevier Ltd. All rights reserved.

A series of pairwise alkyl-decahydronaphthalene isomers were identified in petroleum geological samples by GC × GC/TOFMS.

An analytical method for quantifying biomarker compounds of the sterane and the hopane existing in saturated hydrocarbons has been established by using comprehensive two-dimensional gas chromatography-flame ionization detector (GC×GC-FID) with optimized operating parameters. The new method achieves the quantification by using a GC×GC-FID system which is able to completely separate steranes from hopanes. The data obtained by the new method are of good repeatability and reliability. Compared with the original data, the relative standard deviations (RSDs) of 12 reference compounds are less than 5%. The RSDs of the quantitative results of the biomarkers based on seven separate analyses are also less than 5%. Compared with the traditional method of gas chromatography-mass spectrometry (GC-MS), the new method has a number of advantages, such as common internal standards (ISs), high resolution, no co-eluting peak, and no interference caused by diagnostic ion peaks. The new method provides petroleum geologists with an effective and scientific means in future researches.

A gas condensate from well ND1 in the Jizhong Depression of the Bohai Bay Basin, China is characterized by two-dimensional gas chromatography with flame ionization detector (GC x GC-FID) and time-of-flight mass spectrometry (GC x GC-TOFMS). This condensate is sourced from the fourth member of the Shahejie Formation (Es4) but reservoired in the Mesoproterozoic Wumishan Formation carbonate at a depth of 5641-6027 m and the reservoir temperature is 190-201 degrees C. It is the deepest and the highest temperature discovery in the basin to date. The API gravity of the condensate is 51 degrees and the sulfur content is < 0.04%. A total of 4955 compounds were detected and quantified. Saturated hydrocarbons, aromatic hydrocarbons and non-hydrocarbon account for 94.8%, 5.1% and 0.02% of the condensate mass, respectively. Some long chain alkylated cyclic alkanes, decahydronaphthalenes and diamondoids are tentatively identified in this condensate. The C-6-C-9 light hydrocarbon parameters show that the gas condensate was generated at relatively high maturity but its generation temperature derived from the dimethylpentane isomer ratio seems far lower than the current reservoir temperature. Some light hydrocarbon parameters indicate evaporative fractionation may also be involved due to multiple-charging and mixing. The diamondoid concentrations and gas oil ratio (GOR) suggest that the ND1 condensate results from 53.3-55% cracking. Since significant liquids remain, the exploration potential of ultra-deep buried hill fields in the Bohai Bay Basin remains high. (c) 2013 Elsevier Ltd. All rights reserved.