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The article discusses a study on fluid of Mengqiguer uranium deposit in China. It mentions that fluid inclusions located in quartz fragment fracture contain liquid brine and hydrocarbon-containing aqueous solution. It states that vitrinite reflectance on organic matter in sand bodies is ranged from 0.40 percent to 0.74 percent. It also mentions that ore-forming fluid consists of mineral water containing oxygen and uranium and reducing hydrocarbon.

Abstract: Vitrinite reflectance (VR, Ro%) measurements from residual kerogen of pyrolysis experiments were performed on immature Maoming Oil Shale substituted the samples for the gas-prone source rocks of Yacheng formation of the Qiongdongnan Basin in the South China Sea. The work was focused on determination an upper limit of maturity for gas generation (ULMGG) or “the deadline of natural gas generation”. Ro values at given temperatures increase with increasing temperature and prolonged heating time, but ΔRo-value, given a definition of the difference of all values for VR related to higher temperature and adjacent lower temperature in open-system non-isothermal experiment at the heating rate of 20°C/min, is better than VR. And representative examples are presented in this paper. It indicates that the range of natural gas generation for Ro in the main gas generation period is from 0.96% to 2.74%, in which ΔRo is in concordance with the stage for the onset and end of the main gas generation period corresponding to 0.02% up to 0.30% and from 0.30% up to 0.80%, respectively. After the main gas generation period of 0.96–2.74%, the evolution of VR approach to the ULMGG of the whole rock for type II kerogen. It is equal to 4.38% of VR, where the gas generation rates change little with the increase of maturation, ΔRo is the maximum of 0.83% corresponding to VR of 4.38%Ro, and the source rock does not nearly occur in the end process of hydrocarbon gas generation while Ro is over 4.38%. It shows that it is the same the ULMGG from the whole rock for type II kerogen as the method with both comparison and kinetics. By comparing to both the conclusions of pyrolysis experiments and the data of VR from the source rock of Yacheng formation on a series of selected eight wells in the shallow-water continental shelf area, it indicate that the most hydrocarbon source rock is still far from reaching ULMGG from the whole rock for type II kerogen. The source rock of Yacheng formation in the local areas of the deepwater continental slope basin have still preferable natural gas generative potential, especially in the local along the central depression belt (namely the Ledong, Lingshui, Songnan and Baodao sags from southwest to northeast) from the depocenter to both the margin and its adjacent areas. It help to evaluate the resource potential for oil and gas of the hydrocarbon source rock in the deepwater continental slope of the Qiongdongnan Basin or other basins with lower exploration in the northern of the South China Sea and to reduce the risk in exploration. [Copyright &y& Elsevier]

The Cenozoic rift basins in eastern China show a clear temporal and spatial zonation and episodic tectonic evolution, which control their episodic hydrocarbon generation and zonal accumulation. In this paper, based on the study of depositional architecture, hydrocarbon migration system and dynamic evolution in the rift basins, combinations of hydrocarbon accumulation elements were analyzed using sequence stratigraphy. Hydrocarbon distribution in system tracts with different sequence orders was further studied. And we summarized stacking patterns and horizontal combination relationships for different types of reservoirs, such as lithological, tectonic-lithological, tectonic and stratigraphical reservoirs which can be observed from depression center to basin margin. The result reveals that various scales of pools exhibit significant distribution and evolution orderliness in different pool-forming units, i.e., depositional systems, plays and depressions. The regular distribution of various scales of pools is closely related to tectonic evolution and depositional filling in the rift basins. The result can be applied to the fine petroleum exploration in rift basins in eastern China. It will promote the scientific prediction and evaluation of reservoir types and their spatial distribution, lead to the active shifts of exploration targets in different zones, and thus support the stable progress of fine exploration in mature exploration areas. [ABSTRACT FROM AUTHOR]

Abstract: Based on analysis of the characteristics of unconventional hydrocarbon resources, this paper assesses the potential for unconventional hydrocarbons in China, summarizes the key technical progress in exploration and development, and discusses the prospects and developing strategies of unconventional hydrocarbons. The resources of unconventional oil and gas in China are abundant. The recoverable tight gas ranges from 8.8×1012 m3 to 12.1×1012 m3, the recoverable shale gas is from 15×1012 m3 to 25×1012 m3, the recoverable coalbed methane 10.9×1012 m3, the recoverable tight oil from 13×108 t to 14×108 t, and the recoverable shale oil 160×108 t. There is also some resource potential for oil sand. Such key techniques as the full-digital seismic exploration, low permeability and low resistivity reservoirs identification have been developed and their applications in oil and gas fields have achieved good results. Tight gas and tight oil are the most realistic resources to develop in China and the development and utilization of coalbed methane and shale gas are at a pioneer stage. In the next ten or twenty years, the production of unconventional hydrocarbon in China will increase considerably and play a major role in national hydrocarbon resources. [Copyright &y& Elsevier]

Abstract: The Daxing conglomerate reservoir has become an important exploration target in the Langgu Depression of the Bohai Bay Basin. In this paper, gravel composition, void space, poroperm characteristics and hydrocarbon productivity of the Daxing conglomerate in the third member of the Oligocene Shahejie Formation (Es3) are studied in detail to understand the impact of gravel type on reservoir quality based on cores, petrographic thin-sections, scanning electron microscope (SEM) photos, porosity, permeability and well test data. The Daxing conglomerate is composed of limestone and dolomite gravels. The void space of the Daxing conglomerate includes intragravel and intergravel pores as well as fissures. Intragravel pores are dominated by gravel type. They develop as intergranular pores, intergranular dissolved pores, intragranular dissolved pores and few intercrystalline pores in limestone gravels, whereas in dolomite gravels they develop as intercrystalline pores, intercrystalline dissolved pores, dissolved pores and cavities, few intergranular pores and intergranular dissolved pores. The analysis shows that dolomite conglomerates provide better reservoir quality than limestone conglomerates. Microscopically, areal porosity in dolomite gravels is higher than that in limestone gravels. Macroscopically, porosity and permeability of conglomerates that are dominated by dolomite gravels (dolomite conglomerates) are better than those of conglomerates dominated by limestone gravels (limestone conglomerates). The dolomite conglomerates are superior to the limestone conglomerate with regard to hydrocarbon productivity at the level of parent rock and gravel properties. Poroperm characteristics and hydrocarbon productivity of dolomite reservoirs in the middle Proterozoic Changcheng and Jixian Systems (parent rocks of dolomite gravels) are better than those of the limestone reservoirs in the lower Paleozoic, Cambrian and Ordovician (parent rocks of limestone gravels). Gravel properties, including grain structure, physical nature and dissolution velocity cause the dolomite conglomerates to have more intercrystalline pores, fissures and secondary dissolved pores than limestone conglomerates. [Copyright &y& Elsevier]

The article presents a paper on the current status of Central Asia in the energy market. Tables are presented including ranking of the Central Asian countries in energy production and export forecasts for Central Asian gas to China until 2030. Topics include the hydrocarbon future for the Caspian states, multivectoral gas pipeline policy, and the potential risks of a possible U.S. attack in Iran to the fuel and energy complexes in Central Asia.

Abstract: Vertical distributions of air pollutants are crucial for understanding the key processes of atmospheric transport and for evaluating chemical transport models. In this paper, we present measurements of non-methane hydrocarbons (NMHCs) and halocarbons obtained from an intensive aircraft study over northeast (NE) China in summer 2007. Most compounds exhibited a typical negative profile of decreasing mixing ratios with increasing altitude, although the gradients differed with different species. Three regional plumes with enhanced VOC mixing ratios were discerned and characterized. An aged plume transported from the northern part of the densely populated North China Plain (NCP; i.e. Beijing–Tianjin area) showed relatively higher levels of HCFC-22, 1,2-dichloroethane (1,2-DCE) and toluene. In comparison, the plume originating from Korea had higher abundances of CFC-12, tetrachloroethene (C2Cl4) and methyl chloride (CH3Cl), while regional air masses from NE China contained more abundant light alkanes. By comparing these results with the earlier PEM-West B (1994) and TRACE-P (2001) aircraft measurements, continuing declining trends were derived for methyl chloroform (CH3CCl3), tetrachloromethane (CCl4) and C2Cl4 over the greater China–northwestern Pacific region, indicating the accomplishment of China in reducing these compounds under the Montreal protocol. However, the study also provided evidence for the continuing emissions of several halocarbons in China in 2007, such as CFCs (mainly from materials in stock) and HCFCs. [Copyright &y& Elsevier]

The ancient structure characteristic, correlation of the oil and the hydrocarbon source rock characteristics, hydrocarbon migration trace, types and conditions of traps, migration passages and characteristic of hydrocarbon accumulation are researched in this paper. It is shown through the analysis that two main large tectonic activities after the Early Hercynian orogeny resulted in different tectonic patterns in the study area. Two main hydrocarbon infills occurred in the Donghetang Formation, the first occurred in the Early Hercynian resulting in the ancient hydrocarbon accumulation in the northern Tahe, the second infill was a large amount that occurred in places beneficial for hydrocarbon accumulation, such as structural traps and structural-stratigraphic traps formed in the Early Himalayan orogeny after migration along the faults through source rocks and other passages. Before the earlier period of the Himalayan orogeny, the petroleum mainly migrated to the north, whereas petroleum migrated to the south and southeast because of the structural reverse in the Himalayan orogeny, so the middle and later period of the Himalayan orogeny is the key period for hydrocarbon accumulation. The model of 'oil generation formed early, hydrocarbon accumulation controlled by the faults through source rocks and structures formed late' is proposed. It is pointed out that the south of the research area is currently the beneficial district for hydrocarbon accumulation, which provides the basis for future petroleum exploration. [ABSTRACT FROM AUTHOR]

Abstract: Natural gas exploration and discovery of hydrocarbons in the Xujiahe Formation in the Sichuan Basin are mainly concentrated in the Xu-2, 4 and 6 Members. The discovered gas reservoirs are characterized by a low filling degree, high water saturation in lower intervals, low levels of produced reserves and a limited number of gas-bearing reservoirs. The Xu-1, 3 and 5 Members are identified as source rocks. Based on the study of natural gas accumulations and several gas production wells in the Xu-1, 3 and 5 Members, this paper proposes that large scale sand bodies are developed in the Xu-1, 3 and 5 Members in the northwest, southwest and central parts of the Sichuan Basin. In each member, the favorable gas bearing area is about 5 000-11 000 km2, the reservoir rocks have good continuity with single layer extensions of up to 15-20 km. It is believed that these sand bodies have favorable conditions for gas accumulation within source kitchens to form lithologic or structural-lithologic gas reservoirs and have better accumulation potential and higher gas-bearing abundance than that of the Xu-2, 4 and 6 Members. Exploration practices have revealed that economic gas reserves may be generated. It is suggested that more efforts be made to study the gas accumulation conditions in the Xu-1, 3 and 5 Members (especially the Xu-3 and Xu-5 Members) and more exploration work be conducted in these strata. [Copyright &y& Elsevier]

Abstract: Greenhouse gas (GHG) emission from geological sources such as volcanic activity, seabed gas hydrate release, hydrocarbon seepage as well as uncontrolled combustion of fossil fuels is erratic and difficult to quantify. In this paper we assess the GHG emission due to spontaneous combustion of in-situ coal deposits (‘coal fires’). This problem is aggravated by human intervention (mining activities) which on the other hand allows better constrained estimations and improved reduction strategies, provided modern mining practices are employed. In this study we present three case studies on coal fire-related GHG emission quantification on provincial scale in China, and we propose an integrated quantification aimed at the joint analyses of local knowledge, geophysical data, and remote sensing data with the objective to retrieve unbiased numbers. As a first estimate, we conclude that the emissions of GHGs from coal fires in China account for well less than 0.22% of all global fossil fuel related CO2 emissions, most likely even less than 0.1%. This is much less than the previously estimated 2–3%. [Copyright &y& Elsevier]

Abstract: With Sichuan Basin as focus, this paper introduces the depositional environment, geochemical and reservoir characteristics, gas concentration and prospective resource potential of three different types of shale in China: marine shale, marine-terrigenous shale and terrigenous shale. Marine shale features high organic abundance (TOC: 1.0%–5.5%), high-over maturity (R o: 2%–5%), rich accumulation of shale gas (gas concentration: 1.17–6.02 m3/t) and mainly continental shelf deposition, mainly distributed in the Paleozoic in the Yangtze area, Southern China, the Paleozoic in Northern China Platform and the Cambrian-Ordovician in Tarim Basin; Marine-terrigenous coalbed carbonaceous shale has high organic abundance (TOC: 2.6%–5.4%) and medium maturity (R o: 1.1%–2.5%); terrigenous shale in the Mesozoic and Cenozoic has high organic abundance (TOC: 0.5%–22.0%) and mid-low maturity (R o: 0.6–1.5%). The study on shale reservoirs in the Lower Paleozoic in Sichuan Basin discoveried nanometer-sized pores for the first time, and Cambrian and Silurian marine shale developed lots of micro- and nanometer-sized pores (100–200 nm), which is quite similar to the conditions in North America. Through comprehensive evaluation, it is thought that several shale gas intervals in Sichuan Basin are the practical targets for shale gas exploration and development, and that the Weiyuan-Changning area in the Mid-South of Sichuan Basin, which is characterized by high thermal evolution degree (R o: 2.0%–4.0%), high porosity (3.0%–4.8%), high gas concentration (2.82–3.28 m3/t), high brittle mineral content (40%–80%) and proper burial depth (1500–4500 m), is the core area for shale gas exploration and development, the daily gas production for Well Wei 201 is 1×104–2×104 m3. [Copyright &y& Elsevier]

Abstract: The continuing increases in oil prices have renewed the argument over the real culprits behind these movements. The growth in demand for oil in international markets, especially from the United States and China, is often identified as the main source of consumption pressure on prices, and thus the upward trend in oil prices. This paper uses unit root tests with two endogenous breaks to analyze the characteristics of oil prices, production, and consumption for several countries. By taking into account structural breaks, we find that many countries’ oil consumption and oil prices are stationary, while other countries are not. We also perform causality tests to determine the direction of any possible relationship between oil price and oil consumption and production. Our statistical analysis reveals that production variables cause oil prices, while oil prices tend to cause consumption. As a result, we claim that the blame for the recent fluctuations in oil prices is more appropriately associated with supply factors, not consumption influences. [ABSTRACT FROM AUTHOR]

So far there has been no common opinion on oil source of the Chepaizi swell in the Junggar Basin. Therefore, it is difficult to determine the pathway system and trend of hydrocarbon migration, and this resulted in difficulties in study of oil-gas accumulation patterns. In this paper, study of nitrogen compounds distribution in oils from Chepaizi was carried out in order to classify source rocks of oils stored in different reservoirs in the study area. Then, migration characteristics of oils from the same source were investigated by using nitrogen compounds parameters. The results of nitrogen compounds in a group of oil/oil sand samples from the same source indicate that the oils trapped in the Chepaizi swell experienced an obvious vertical migration. With increasing migration distance, amounts and indices of carbazoles have a regular changing pattern (in a fine linear relationship). By using nitrogen compounds techniques, the analyzed oil/oil sand samples of Chepaizi can be classified into two groups. One is the samples stored in reservoir beds of the Cretaceous and Tertiary, and these oils came from mainly Jurassic source rock with a small amount of Cretaceous rock; the other is those stored in the Jurassic, Permian and Carboniferous beds, and they originated from the Permian source. In addition, a sample of oil from an upper Jurassic reservoir (Well Ka 6), which was generated from Jurassic coal source rock, has a totally different nitrogen compound distribution from those of the above-mentioned two groups of samples, which were generated from mudstone sources. Because of influence from fractionation of oil migration, amounts and ratios of nitrogen compounds with different structures and polarities change regularly with increasing migrating distance, and as a result the samples with the same source follow a good linear relationship in content and ratio, while the oil samples of different sources have obviously different nitrogen compound distribution owing to different organic matter types of their source rocks. These conclusions of oil source study are identical with those obtained by other geochemical bio-markers. Therefore, nitrogen compounds are of great significance in oil type classification and oil/source correlation. [ABSTRACT FROM AUTHOR]

Abstract: The Yuka depression is located in the north margin in Qaidam Basin, Qaidam Basin is an interior formed primarily in the Mesozoic and Cenozoic. There are extensive distribution of good source rocks of middle Jurassic, which have undergone non-uniform uplift, twisting and deep burying. There are different hydrocarbon generation (HG) evolutions. We have studied the history of burying, heating, and hydrocarbon generation of the Jurassic source rocks not just on the basis of tectonic disturbance and deep burying in detail. Meanwhile, Combining with fluid inclusion measurements and the numerical simulation of EASY%Ro, We analysis the evolution process, the tectonic stages and the intensity of the HG of middle Jurassic source rock. The hydrocarbon generation occurred in Yanshanian and Early Himalayan since the middle Jurassic formation. The paper discusses tarp formation and destroys of the oil & gas in Yuka depression. At last, we suggest that the thrust fault of Late Himalayan must be pay more attention, .and the middle or small sizes of oil & gas fields will be discovered in the future exploration. [Copyright &y& Elsevier]

Abstract: The light hydrocarbons of oils play an important role in their geochemistry, especially in mixed oils. The database of the Key Laboratory of Petroleum Geochemistry, China National Petroleum Corporation has accumulated 824 oil sample records. The oil samples represent most of the oil areas of China. In this paper the light hydrocarbons of salt lake derived oils from Jianghan basin, China, were studied. These oils are characterized by high toluene contents and high K 1 [K 1 =(2-MH+2,3-DMP)/(3-MH+2,4-DMP)] values. The reason is unclear but may be related to the high salinity environment of the source. [Copyright &y& Elsevier]

Abstract: Hydrocarbon migration pathways are the linkage between hydrocarbon source areas and accumulation sites. Modeling accurately the pathways of hydrocarbon migration is of important significance in determining the location of favorable petroleum exploration targets. In this paper, GIS-based modeling algorithms are presented for searching the pathways of secondary hydrocarbon migration by considering the geologic mechanisms. These algorithms are constructed on a raster digital elevation model (DEM) of the top boundary of a carrier bed, in which secondary migration occurred. On the DEM, a 3×3 pixel sized window is used for searching. The center of the search window is initially assumed at a point on the boundary of a hydrocarbon source area, from which the secondary hydrocarbon migration starts. The altitude values in the eight adjoining pixels enclosing the central pixel of the search window are compared, and the pixel with an altitude value not only larger than the central pixel but also the largest of the eight surrounding pixels is the next target pixel where the search window will move to. Each searched path will terminate at either a convex point, which indicates the existence of a trap for hydrocarbon accumulation, or a point on the boundary of the DEM, which suggests that the pathway of hydrocarbon migration extends outside the DEM. In addition, a concourse point of two paths is also considered as a termination point of either path. The algorithms were successfully applied in the modeling of the secondary migration pathways in the northern Songliao Basin, northeast China. The modeled results matched well with drilling data, suggesting the robustness of the algorithms. [Copyright &y& Elsevier]

The nano-scale pore structure of shale is closely related to the self-generated and self-accumulated shale oil and gas. The Bohai Bay Basin is a crucial oil-bearing basin in eastern China, and the Paleogene Shahejie Formation is the most important source rock section in this area. In order to study the internal relationship between hydrocarbon generation evolution and pore structure characteristics of source rocks, we conducted hydrocarbon generation simulation tests with a closed gold tube system, and heated up original rocks from Shahejie Formation in Laizhou Bay Sag, southern Bohai Bay Basin, from 290 °C to 440°C at different heating rates. Besides, we carried out low-temperature N2 adsorption experiments on sample residues, and measured their pore structure characteristic parameters. The results show that with the increase of simulated temperature, the specific surface area and pore volume of nano-pores below 10 nm (which are mainly organic pores) decrease first and then increase, while those of nano-pores above 10 nm increase all the way. The evolution trend of total specific surface area and pore volume is mainly controlled by pores below 10 nm which are mainly organic pores, especially micropores below 2 nm. There are two main factors affecting the development of inorganic pores: (1) Dissolution of organic acids produced by pyrolysis of organic matter in hydrocarbon-generation evolution; (2) Deformation of crystal structure of mineral components under the combined action of temperature and pressure. The experimental results at different heating rates demonstrate that rapid settlement under geological conditions is not conducive to the development of nano-pores, especially micro-pores composed of organic pores. [ABSTRACT FROM AUTHOR]

This study seeks to understand the ambient levels, gas/particle partitioning, and sources of nonpolar organic molecular makers (OMMs) at a suburban site in Nanjing, China. Particle‐ and gas‐phase OMMs were collected using a medium volume sampler equipped with two quartz filters in series and a polyurethane foam (PUF)/XAD‐4/PUF (PXP) adsorbent sandwich. More than 100 pairs of filter and PXP samples were collected diurnally from September 2018 to September 2019. The concentration profiles of total n‐alkanes and polycyclic aromatic hydrocarbons were peaking at n‐C12–n‐C17 homologs (9.98 ± 5.43–38.4 ± 17.7 ng m−3) and naphthalene (92.5 ± 56.7 ng m−3), respectively, followed by decreasing concentrations with further increases in molecular weight. Three artifact correction methods with different pre‐assumptions on relative contributions of evaporation loss to backup filter measurements were used to separate particle‐ and gas‐phase OMMs. The resulting particle‐phase fractions showed significant differences for OMMs with vapor pressure <10−9 atm at 298.15 K. Absorptive gas/particle partitioning coefficients of OMMs were empirically calculated based on measurements and theoretically predicted for comparison. The results obtained under the three artifact correction methods suggested growing importance of evaporation loss with decreased vapor pressure. Positive matrix factorization (PMF) was performed for source apportionment using total (PMFtotal) and particle‐phase (PMFparticle) OMMs data, respectively. Besides eliminating the influence of gas/particle partitioning, the involvements of more volatile species and gaseous OMMs data improved the identification of specific emission sources, supporting the usage of total OMMs data over a wide vapor pressure range for PMF source apportionment. Key Points: The particulate fractions of organic molecular markers attained their minima in summer, when the total concentrations increasedEvaporation loss might be the main sampling artifact of particulate organics when the vapor pressure is lower than 10−10 atmTotal concentrations of organic molecular markers over a wide vapor pressure range should be used for positive matrix factorization analysis [ABSTRACT FROM AUTHOR]

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Ordos Basin, a large lacustrine basin in the Triassic, possesses amounts of conventional and unconventional petroleum. In the basin, the Chang 7 shales have been studied extensively. Recent studies suggested that the crude oils accumulated in the Triassic Chang 9–8 should be mainly sourced by the Chang 9 shales [including the delta plain shale (DPS), delta front shale (DFS), and deep lake shale (DLS)]. The source rock (SR) potential, hydrocarbon generation (HG), and hydrocarbon expulsion (HE) characters of the Chang 9 shales should be analysed to make a comprehensive source rock evaluation. The shales are evaluated as excellent source rock potential, and the DLS is evaluated as the best potential. The HG–HE of the shales are analysed by utilizing two (closed and open systems) pyrolysis experiments. The DLS activation energy (Ea) shows the narrowest distribution and has the lowest average value of 219.00 kJ/mol. The HG onsets and total amounts of the DFS, DPS, and DLS have been determined (165 Ma and 200 × 103 t/km2, 157 Ma and 305 × 103 t/km2, 154 Ma and 430 × 103 t/km2), and the peak generation of the shales happened at 125–117 Ma, 127–100 Ma, and 125–100 Ma, respectively. The Chang 9 DFS, DPS, and DLS have reached the HE threshold at depths of 2,250, 2,500, and 2050 m, respectively, indicating large amounts of hydrocarbons have been expelled into the Lower Yanchang Formation (LYF). The tight sandstone oil reservoirs (TSORs) are mainly located in the areas where the organic‐rich shales are developed, especially in the northeastern study area. The areas between high‐value zones of source rock properties (e.g., thickness, Ro, total organic carbon, HG–HE intensity) are the sweet spots. [ABSTRACT FROM AUTHOR]

The coastal region off Macao is a known depositional zone for persistent organic pollutants (POPs) in the Pearl River Delta and Estuary of southern China and an important gateway for the regional contributions of contamination to the globe. This paper presents a comprehensive assessment of the input sources and transport pathways of polycyclic aromatic hydrocarbons (PAHs) found in the coastal sediments of Macao, based on measurements of 48 2-7 ring PAHs and 7 sulfur/oxygentated (S/O) PAH derivatives in 45 sediment, 13 street dust, and 68 aerosol samples. Total sediment PAHs concentrations ranged from 294 to 12 741 ng/g, categorized as moderate contamination compared to other regions of Asia and the world. In addition, the PAH compounds appeared to be bound more strongly to aromatics-rich soot particles than to natural organic matter, implying a prevailing atmospheric transport route for PAHs to Macao's coast. Compositional analysis and principal component analysis (PCA) suggested that different classes of PAHs in the coastal sediments of Macao may have been derived from different input sources via various transport pathways. For example, alkylated and S/O PAHs were likely derived from fossil fuel leakage and transported to sediments by both aerosols particles and street runoff. High-molecular-weight parent PAHs were predominantly originated form automobile exhausts and distributed by direct and indirect atmospheric deposition. Sow-molecular-weight parent PAHs, on the other hand, may have stemmed from lower temperature combustion and fossil fuel (such as diesel) spillage from ships and boats and were transported to sediments by river runoff or direct discharge as well as by air- water exchange. [ABSTRACT FROM AUTHOR]

Emission contributions from cookstoves to indoor, regional, and global air pollution largely depend on stove and fuel types. This paper presents a database on emission factors of speciated non-methane hydrocarbons (NMHCs) for 16 fuel/stove combinations burning 2 types of crop residue, wood, 4 types of coal, kerosene, and 3 types of gaseous fuels. The emission factors are presented both on a fuel mass basis (compound mass per fuel mass) and on a cooking task basis (compound mass per unit energy delivered to the pot). These fuel/stove combinations cover a large spectrum of the cookstoves used in both urban and rural households in China. Up to 54 hydrocarbons were identified, some of which are reactive precursors of photochemical smog. Based on published maximum incremental reactivity (MIR) values for NMHCs, we estimated stove-specific and fuel-specific ozone forming potentials (OFPs). The results indicate that raw coal powder, wood, and crop residues have higher OFP values than the other types of fuels tested. Strikingly, burning the coal briquette and honeycomb coal briquette produced OFP values more than 2 orders of magnitude lower than burning unprocessed (raw) coal, even in the same vented metal stove, for every 1 MJ delivered to the pot. [ABSTRACT FROM AUTHOR]

Reports that the Lunnan area in the Tarim Basin has become an important onshore oil production base in China. Statement that the formation of the oil and gas pools in the low uplift of Lunnan has experienced a comparatively complex process of dynamics; Reference to the fact that, based on the hydrocarbon generation period of source rocks, the formation period of cap rocks and traps, the analysis of organic inclusion and the analysis of bitumen in the reservoir, this paper draws the conclusion that the low uplift area of Lunnan has experienced three pool formation periods: the Permian period, the Cretaceous-Early Tertiary period and the Late Tertiary-Quaternary period and two oil and gas reservoir adjustment periods: the Late Permian period and the Late Tertiary-Quaternary period; Indication of the comprehensive study that the large-scale Ordovician buried hill, formed in Early Hercynian, became the reservoir during the Permian period, because the Cambrian-Lower Ordovician oil was discharged laterally into the reservoir along the top of the Ordovician weathering crust from south to north; Claim that the reservoir experienced a complicated process—reconstruction in the end of Permian, adjustment in Cretaceous-Early Tertiary and re-discharging process in Late Tertiary-Quaternary, leading to the early original heavy oil reservoir of marine facies and the late original light oil reservoir and gas pool; Statement that carboniferous, Triassic and Jurassic oil and gas reservoirs result from upward adjustment and re-distribution of Ordovician oil and gas reservoirs; Reference to the fact that, of those results, the formation of Triassic-Jurassic oil and gas pools came under the influence of the northward-tilting structure; Vertical migration of the oil and gas sourcing from the different hydrocarbon source rock intervals into the base unconformity of Triassic system; Migration of the the oil and gas laterally from north to south and accumulated into th

Reports that, based on detailed studies, this paper proposes that in the Tarim Basin, hydrocarbon reservoirs widespread either in vertical sequences or in plane and high-porosity and high-permeability reservoirs are developed all over the basin. Claim that obvious difference and heterogeneity exist among different kinds of reservoirs; Statement that the lithologic characteristics, reservoir space types and reservoir properties in various strata have been probed; Result indicating that although the Paleozoic carbonates have been deeply buried for a long period, high-quality reservoirs with the porosity of up to 5% -8% (12% as the maximum) and the permeability of 10x10&sup-3;–100x10&sup-3; µm² (1000x10&sup-3; µm² as the maximum) can be found in certain areas; Inclusion of the area with the development of reefs and carbonate beaches, the weathered-crust buried-hill belts that have undergone the long-term exposure, weathering and leaching, the area with the development of dolomitization, and those areas that have experienced the resolution of carbonic acid and organic acid generated by the maturity of the organic matter; Thorough investigation of the genesis of the high-porosity and high-permeability reservoirs in deep-buried conditions (with the depth more than 3500 m).

Leping coal (including barkinite-rich coal) is a unique kind of coal, which is widely distributed in the Late Permian Longtan Formation, South China. In this paper, Rock-Eval, Py-GC and simulation experiment via an open-system were used to study the hydrocarbon-generating potential, hydrocarbon composition, and hydrocarbon-generating model of barkinite-rich coals from the Shuicheng coal field of Guizhou Province, Southwest China. The results show that barkinite-rich coals have high hydrocarbon-generating potential, with S[sub 1] + S[sub 2] being 211 - 311mg/g, and can produce large amounts of hydrocarbon at the high-maturity stage, mostly within the temperature range of 420 - 450°C (corresponding to VR[sub 0] 1.1 - 1.5%); barkinite-rich coal is one of the better oil sources and light hydrocarbon and wet gas are the major hydrocarbon components, which account for 45% and 33% of the total hydrocarbons, respectively. These characteristics are of importance for exploring oil and gas resources in the Late Permian Longtan Formation coals, Southwest China. [ABSTRACT FROM AUTHOR]

The current research aims to unlock the temporal and spatial distribution of sand‐bodies and their relationship with hydrocarbon accumulation in the mid‐deep layer of basin margins, located in the eastern part of the Liuzan area of the Nanpu Sag, Bohai Bay Basin, China. Through this study, the main target interval of the area was divided into two fourth‐order sequences. The lean sand mixed sedimentary belt with great importance in controlling hydrocarbon accumulation was identified through the comprehensive use of 3D seismic data, logging data, lithological data and seismic inversion data. A detailed analysis of sand‐body development characteristics and their role in controlling hydrocarbon accumulation was conducted. The results reveal that the study area mainly develops two distinct fan‐delta lobes from the NE‐trending sediment supply direction. Due to the relatively high influence of the lacustrine transgression event, the scale of the lean sand mixed sedimentary belt within the SQ1‐1 (the lacustrine transgressive systems tract) is relatively small, showing a relatively continuous distribution of sand bodies in the plane. Conversely, due to the relatively high impact of the lacustrine regression event, the scale of the lean sand mixed sedimentary belt developed within the SQ1‐2 (the highstand systems tract) is relatively large, the two east sets of fan‐delta sedimentary systems being clearly separated. The lean sand mixed sedimentary belt formed a good lateral occlusion belt in favor of hydrocarbon accumulation. Through composite analysis of structural interpretation results, sand‐body distribution and well test data, it is evident that the lean sand mixed sedimentary belt located in the structural high is not a favorable zone for hydrocarbon accumulation. In contrast, the wing of the high part of the structure is the zone of sand‐bearing bodies and is a favorable zone of hydrocarbon accumulation. [ABSTRACT FROM AUTHOR]

The Upper Ediacaran to Lower Cambrian of the Sichuan Basin in South China has long been considered to be dominated by shallow‐water deposition. Hydrocarbon exploration, however, has revealed that a NW‐SE trending intraplatform trough formed in the basin during the same period. Although different models have been proposed, the formation and evolution of the trough are still not fully understood. In this study, we investigate both the origin of the intraplatform trough and the formation of the Sichuan Basin by integrating seismic interpretation, well correlation and tectonic subsidence analysis. The seismic and well data clearly show three stages of development of the trough. The first stage, in the early Late Ediacaran, is characterized by considerable thinning of the lower two members of the Upper Ediacaran from the platform margins to the trough. In the second stage, in the late Late Ediacaran, the platform margins backstepped and the extent of the trough expanded significantly to a width of ca. ~400 km. The third stage, in the early Early Cambrian, was dominated by gradual filling of the trough and onlapping of the platform margins. Backstripped tectonic subsidence curves show one, or two closely spaced episodes of linear subsidence starting at ~550 Ma and then decreasing exponentially until ~450 Ma. The shape of the subsidence curves is consistent with formation of the Sichuan Basin by low, and slow amounts of lithospheric stretching of thickened cratonic lithosphere. The tectonic subsidence increases from the centre to the NW of the basin. Interestingly the margins of the trough do not correlate with contoured values of increased tectonic subsidence and we infer that the trough was a palaeogeographic embayment in a large carbonate platform that developed in a broad, ramp‐like area of slow and low subsidence tilting down to the proto‐Tethyan ocean located to the NW of the basin. [ABSTRACT FROM AUTHOR]

As the main substance in some traditional Chinese medicines, cucurbitacins have been used to treat hepatitis for decades in China. Currently, the use of cucurbitacins against cancer and other diseases has achieved towering popularity among researchers worldwide, as detailed in this review with summarized tables. Numerous studies have reported the potential tumor-killing activities of cucurbitacins in multiple aspects of human malignancies. Continuous research on its anticancer activity mechanisms also brings a glimmer of light to the treatment of patients with lung cancer. In line with the promising roles of cucurbitacins against cancer, through various molecular signaling pathways, it is justifiable to propose the use of cucurbitacins as a potential mainline chemotherapy before the onset and after the diagnosis of lung cancers. Here, this article mainly summarized the findings about the biological functions and underlying mechanisms of cucurbitacins on lung cancer pathogenesis and treatment. In addition, we also discussed the safety and efficacy of their application for further research and even clinical practice. [ABSTRACT FROM AUTHOR]

Tar mats were firstly discovered and determined accurately in terrestrial oil and gas reservoirs associated with Lower Tertiary sandstone reservoirs in the Yaha field of the Tarim Basin, China, by thin-layer chromatography-flame ionization detector (TLC-FID) and Rock-Eval analysis. The relative content of asphaltene in gross composition of tar mat extracts accounts for more than 30%, that in the corresponding oil leg less than 20%. In the geochemical description profile of oil and gas reservoirs, drastic changes in asphaltene contents between tar mats and oil legs could be discovered. This is an important marker to determine tar mats. Distribution characteristics of saturated and aromatic hydrocarbons from reservoir core extracts and crude oils in the Yaha oil and gas reservoirs in the Tarim Basin are described systematically in this paper, and the results show there are similarities among n-alkane distribution characteristics, biomarker distribution characteristics and their combined characteristics of saturated hydrocarbons, and the geochemical characteristics of aromatic hydrocarbons for tar mats, oil leg, asphaltic sand and crude oil. These characteristics suggest the hydrocarbons in these samples were originated from the common source rocks. However, the geochemical characteristics of tar mats revealed that the mechanism of formation of tar mats is the precipitation of asphaltene from crude oils in petroleum reservoirs caused by increased dissolved gas in oil legs (gas injection). [ABSTRACT FROM AUTHOR]

Red-bed basins with rich hydrocarbon source rocks are widely distributed in south China, such as Banshi Basin in southern Jiangxi, which may have very good prospects for oil and gas exploration. However, due to poor ground conditions, and complex geological structures, seismic exploration and conventional electromagnetic methods cannot provide useful information for hydrocarbon evaluation. This study uses the wide field electromagnetic (WFEM) method to investigate the distribution and geoelectric characteristics of the target stratum of a red-bed basin in Jiangxi province, China. The inversion results demonstrate that the WFEM method could quickly delineate the favorable area and determine the location of the parametric well, confirming that the WFEM method is an effective geophysical exploration method for evaluating hydrocarbon resources in red-bed basins. [ABSTRACT FROM AUTHOR]

Significant progress in tight oil exploration has been reported in the second member of the Qiketai Formation (J2q2) in the Shengbei area of the Turpan–Hami Basin. Geochemical analyses were conducted to assess the quality of the J2q2 source rocks. The improved hydrocarbon generation potential method was utilized to quantify the hydrocarbon generation and expulsion features of the source rocks. The results showed that J2q2 source rocks were deposited in a reduced lacustrine setting with a high palaeoproductivity. The J2q2 source rocks are widely distributed (approximately 1,000 km2) and have a thickness that varies from 50 to 130 m. Moreover, they can be identified as a set of high‐quality source rocks (thermally mature rocks with Ro values >0.5%, consisting mainly of types I and II kerogen and possessing an average total organic carbon content of 2.68%). The oil–source correlation results reveal that the source of crude oil in the studied area is J2q2. The improved hydrocarbon generation potential method is established for different kerogen types to limit the influence of the kerogen type on the calculation. The hydrocarbon expulsion threshold of the type I model is located at Ro = 0.6%. The type II kerogen rocks have different characteristics, and the hydrocarbon expulsion threshold is located at Ro = 0.62%. The maximum hydrocarbon generation and expulsion intensities are 700 × 104 t/km2 and 400 × 104 t/km2, respectively. The hydrocarbon generation and expulsion amount of the J2q2 source rocks are 21.4 × 108 t and 12.3 × 108 t, respectively. The tight oil potential of the J2q2 tight oil in the Shengbei area is 4.09 × 108 t. The SB10 and SB6 well areas are favourable J2q2 tight oil exploration areas in the Shengbei area. The SB10 well area has the highest hydrocarbon generation and expulsion intensities in the study area and is the best tight oil exploration target. [ABSTRACT FROM AUTHOR]

Large-scale lacustrine basins in compressional settings are an important type of petroliferous basin, and the study of the characteristics of hydrocarbon accumulation in such basins is of great significance. This synthesis paper takes the Mesozoic Ordos Basin (central China) as a case study to establish lateral and vertical hydrocarbon accumulation patterns in this basin type, and highlights how facies and fluid potential control hydrocarbon accumulation in such basins. Based on systematic analyses of the Mesozoic source rocks, sedimentary facies, migration and accumulation patterns, and characteristics of the oil reservoirs, the hydrocarbon accumulation characteristics in the Mesozoic Ordos Basin are discussed. The analysis indicates that sedimentary facies controlled the characteristics and distribution of hydrocarbon source rocks and reservoirs, while diagenetic facies controlled the quality and distribution of the reservoirs. Excess pressure and fluid potential controlled hydrocarbon migration directions and paths, whereas facies and potential controlled the locations of oil accumulations and traps. It is concluded that source rocks controlled oil-bearing regions, sedimentary facies controlled oil-bearing plays, and fluid potential controlled the locations of accumulations. For shallow intervals, because fluid migration is mainly controlled by buoyancy, paleotopographic highs played an important role in controlling hydrocarbon accumulations. For deep layers (Chang 7 to Chang 10 members), since buoyancy is less than the capillary pressure, excess pressure caused by the undercompaction of mudstone and hydrocarbon generation at depth provides the driving force for lateral and vertical migration of oil, and becomes the main migration force. The reservoir accumulation characteristics differ laterally between regions of the basin; at the periphery of the basin, reservoir units are stacked in a step-wise manner, whereas at the center of the basin, multiple reservoir intervals are vertically stacked in the form of multistorey accumulations. Vertically, layers with different burial depths have different accumulation characteristics; the paleotopography controlled hydrocarbon accumulation in shallow intervals; instead excess pressure, fluid potential, and paleotopography controlled accumulation in deep intervals. This understanding could be used to inform prospecting in other large-scale lacustrine petroliferous basins in compressional settings such as the Eocene Green River Basin in the U.S.A. and the Middle Triassic Gunnedah Basin in Australia. Image 1 • Accumulation patterns in large-scale lacustrine petroliferous basins are defined. • Controls on oil accumulation by facies and potential in Ordos Basin are explored. • Patterns of hydrocarbon accumulation vary vertically and laterally. [ABSTRACT FROM AUTHOR]

The Dongying depression is an important oil-producing area in northeastern China, where the Paleogene Shahejie Formation is the main oil-bearing feature. Although petroleum migration and accumulation in the Dongying depression have been extensively studied, the charging history is still unclear. This paper defines the timeframe of petroleum migration on the basis of a comprehensive investigation of fluid inclusions coupled with basin modeling. According to the petrography and microthermometry of the fluid inclusions, types of fluid inclusion with low-peak-range distributions of the homogenization temperature (T h) (85–95 °C for the Niuzhuang sag and 90–105 °C for the Lijin sag) and high-peak-range T h distributions (105–120 °C for the Niuzhuang sag and 115–130 °C for the Lijin sag) were identified. By recovering the burial and thermal histories of Niuzhuang and Lijin sags with pressure–volume–temperature–composition simulation and one-dimensional basin modeling, it can be inferred that the trapping pressures of two types of hydrocarbon inclusions were higher than the corresponding paleopressure. (42.4 and 42.0 MPa, respectively), indicating rapid hydrocarbon charging resulting from abnormally high pressure. Two hydrocarbon charging events associated with the regional tectonic evolution of the Dongying depression, namely, continuous deposition and tectonics in the Paleogene Dongying Formation (Ed) and rapid deposition and tectonics in the Paleogene Minghuazhen Formation (Em), were inferred. The direction of oil charging was traced from the center to the margin in the north, and from the center to the central fault in the southeastern part of the depression in general, as indicated by the molecular maturity parameters, which roughly coincided with the abnormal pressure. • The investigation of fluid inclusions showed two oil-charging episodes in Sha 3 reservoirs. • The basin modeling suggested each reservoir was charged during the Late Paleogene and Early Neogene respectively. • The oils are charged along with the central faults and from the center to the edge of the depression. [ABSTRACT FROM AUTHOR]

The study of transtensional faults is significantly important for analysing migration and accumulation of hydrocarbons in petroliferous basins. The purpose of this study is to present disparities in the temporal and spatial evolution of two boundary transtensional faults (northern Linshang Fault and southern Xiakou Fault) in the Huimin Depression by 2D structural restoration and quantitative calculations of fault activity. This paper also reveals the controls of transtensional faults on the migration and accumulation of hydrocarbons by considering the stress normal to the fault plane (P), the shale gouge ratio (SGR) of the fault zone, and models of migration pathways. The results show that the transtensional systems within the Huimin Depression were generated from the reactivation of basement faults under an oblique extensional stress field. The Linshang Fault linked two initially separated segments and then behaved as a single fault since the Ek period, whereas the Xiakou Fault retained significant three-segment growth properties during the Paleogene. During the hydrocarbon charging period, the weak activity and strong vertical sealing restricted the occurrence of vertical migration around the Xiakou Fault, while the relatively strong movement and weak vertical sealing resulted in multilayer hydrocarbon accumulations around the Linshang Fault. Meanwhile, the vertically closed fault with high SGR (>0.6) acted as barriers and trapped hydrocarbons on the lateral migration pathways, whereas the vertically closed fault with low SGR (<0.6) served as conduits for further lateral migration into structurally higher positions. The discovered hydrocarbons are concentrated around transtensional fault systems, and the divergent E-W-striking brush-shaped secondary faults trapped abundant hydrocarbons within the hanging wall, demonstrating the important controls of the transtensional faults on the migration and accumulation of hydrocarbons in the Huimin Depression. • Movement characteristics and evolution process of the transtensional fault systems. • Activity intensity and vertical sealing during the charging period control the vertical hydrocarbon migration. • The lateral sealing variations during fault evolution control the lateral hydrocarbon migration and accumulation. • Closed brush-shaped secondary faults in the transtensional fault system are beneficial for trapping hydrocarbon. [ABSTRACT FROM AUTHOR]

Natural gas and condensate derived from Carboniferous-Permian (C-P) coaly source rocks discovered in the Dagang Oilfield in the Bohai Bay Basin (east China) have important implications for the potential exploration of C-P coaly source rocks. This study analyzed the secondary, tertiary, and dynamic characteristics of hydrocarbon generation in order to predict the hydrocarbon potentials of different exploration areas in the Dagang Oilfield. The results indicated that C-P oil and gas were generated from coaly source rocks by secondary or tertiary hydrocarbon generation and characterized by notably different hydrocarbon products and generation dynamics. Secondary hydrocarbon generation was completed when the maturity reached vitrinite reflectance (Ro) of 0.7%–0.9% before uplift prior to the Eocene. Tertiary hydrocarbon generation from the source rocks was limited in deep buried sags in the Oligocene, where the products consisted of light oil and gas. The activation energies for secondary and tertiary hydrocarbon generation were 260–280 kJ/mol and 300–330 kJ/mol, respectively, indicating that each instance of hydrocarbon generation required higher temperature or deeper burial than the previous instance. Locations with secondary or tertiary hydrocarbon generation from C-P coaly source rocks were interpreted as potential oil and gas exploration regions. [ABSTRACT FROM AUTHOR]

Aimed at the application situation of light hydrocarbon plant of northwestern Sichuan Gas District of PetoChina Southwest Oil & Gasfield Company, this paper deeply analyzed the factors affecting the light hydrocarbon yield. hen, a series of reform measures to improve the light hydrocarbon yield were proposed, which included expander amelioration, expansion rate adjustment, pressure of the seal gas control and opening degree of nozzle adjustment. The result showed hat the obvious effect can be obtained after taking above measures. [ABSTRACT FROM AUTHOR]

The Chengzikou Uplift (CZKU) is a second-order structure surrounded by several hydrocarbon generative kitchens in the Bohai Bay Basin. However, six recently drilled wells on the CZKU failed to prove hydrocarbon occurrences, which causes confusion for the understanding of hydrocarbon migration and accumulation on the CZKU. Mainly based on the seismic database, this paper attempted to determine the hydrocarbon migration pathways and enrichment mechanisms on the CZKU. The results show that the lateral and vertical hydrocarbon migration seems to take place through a stepped pathway system consisting of permeable layers within unconformities, permeable carrier beds, and faults. Through a simple 3D modeling considering topography changes only, the hydrocarbons tend to migrate from the northern sags to the southern slope and uplift with parallel mainstreams and accumulate with convergent mainstreams. The potential hydrocarbon traps mainly include stratigraphic, structural, and structural-lithologic traps, most of which have been confirmed by previous explorations. Subsequently, two preliminary interpretations for the dry well on the CZKU are made: the first is hydrocarbons mainly accumulated in the Paleogene stratigraphic (onlapping) traps within the sag and slope area, conducting no further migration to the uplift; the other is hydrocarbons may migrate to the slope and uplift but were trapped in structural-lithologic traps associated with faults beyond the area of the dry wells. Moreover, favorable hydrocarbon accumulation targets are predicted to reduce exploration risk. • Hydrocarbons migrate via a stepped pathway system from sag to slope and uplift. • Preliminary interpretations for the dry holes on the uplift are made. • Hydrocarbon migration and accumulation mechanisms are discussed by analogy with adjacent slope belts. • Paleogene and Neogene exploration targets are predicted respectively. [ABSTRACT FROM AUTHOR]

Hydrocarbon saturation is an important petrophysical parameter in reservoir evaluation and reserve calculation. Dielectric dispersion logs have been widely used to estimate the hydrocarbon saturation, especially in high salinity shale formations. However, there is still room to improve the accuracy of interpretation of dielectric dispersion logs. In this paper, we used two interpretation models combined four dielectric permittivity and four conductivity logs measured by Array Dielectric Tool (ADT) at four frequencies to predict the hydrocarbon saturation in shale oil reservoirs, Triassic Yanchang Formation, Ordos Basin, China. The logs measured at the highest frequency are interpreted by the Complex Refractive Index (CRIM) model. And the other three frequencies measured logs are processed by the shaly sandstone (SHSD) model. Based on the two models, simulated annealing algorithm is selected to calculate water saturation and rock textual parameter, the dispersive phase fraction, and water salinity. Besides, accurate porosity, dielectric permittivity of rock matrix, and temperature are input information to the proposed method. The proposed method is applied to shale oil reservoirs of Triassic Yanchang Formation in two wells. The effectiveness and reliability of proposed model is verified by synthetic log responses. The mean relative error between synthetic and field logs is small. The predicted hydrocarbon saturation is consistent with core data, and its variation is consistent with characteristics of NMR T 2 distributions, verifying the accuracy and reliability of proposed method and inversion results. Our estimated hydrocarbon saturation of the two wells is about 30%, showing a good oil generation potential of the studied shale oil reservoirs. [ABSTRACT FROM AUTHOR]

The exploration of deeply buried hydrocarbon is still a challenge for the petroleum geology. The Shunbei area is a newly discovered oil fields, located in the center of the Tarim Basin. The oil is mainly yielded from the Middle–Lower Ordovician carbonate reservoirs with depth > 7000 m in the Shunbei No. 1 and No. 5 fault zones. Calcite cements filled in vugs (v-calcite) and fractures (f-calcite) are identified in limestones and dolostones of the carbonate reservoirs. F-calcites in the Shunbei No. 1 fault zone trap secondary inclusions in trails, which comprise liquid-dominated biphase aqueous inclusions, liquid-dominated biphase oil inclusions, and/or oil-bearing triphase inclusions. F-calcite and v-calcite in the No. 5 fault zone trap secondary inclusions in trails, which consist of liquid-only monophase aqueous inclusions, liquid-dominated biphase aqueous inclusions, liquid-dominated biphase oil inclusions, liquid-only monophase oil inclusions, and/or oil-bearing triphase inclusions. The ranges of the homogenization temperature ( T h ) and ice-melting temperature ( T m − ice ) in the Shunbei No. 1 fault zone are, respectively, 130–150°C and -2.1–-1.5°C. The coexistence of liquid-only and liquid-dominated aqueous inclusions in the Shunbei No. 5 fault zone indicates that the aqueous inclusions are trapped at low temperatures. The aqueous inclusions in the Shunbei No. 5 fault zone show a range from -0.4 to -0.2°C in T m − ice which is very close to the meteoric fluid. In the context of the burial-thermal history and the Cambrian source rock evolution, the charging process of hydrocarbon in the Shunbei No. 1 and No. 5 fault zones corresponds to the Silurian and Middle Ordovician, respectively. Results of fluid inclusions indicate a tightly coupling relationship between the hydrocarbon charging process and fault system evolution in the Shunbei area. This study reveals the application of fluid inclusion under the systemically petrographic constraints to decipher the charging history of hydrocarbon, especially for the deeply buried reservoirs. [ABSTRACT FROM AUTHOR]

Analysis of apatite fission‐track and vitrinite reflectance combined with 1‐D basin modelling was used to reconstruct the thermo‐tectonic history of the northeast Sichuan Basin, China. The study indicates that the basin has evolved through multi‐phase tectonic regimes involving a series of subsidence and tectonic uplift phases exerting significant control on the thermal history. Heating and cooling processes were largely related to deep burial and intense exhumation, respectively. Exhumation that extended from 122 to 2.5 Ma has resulted in at least 4 km of sedimentary removal. The rate of exhumation and removal (denudation) was found to have reached 58 and 35 m/Myr, respectively. The results show that the denudation magnitude is significantly higher in the eastern part reaching 5.5 km, compared with 2.2 km in the western part of the study area. The fission‐track ages demonstrate the occurrence of three cooling phases: initial‐gradually increasing (~120–70 Ma), stagnant (70–15 Ma), and rapid (15 Ma to present). This suggests that cooling was associated with different compressive thermo‐structural events that began in the mid‐Lower Cretaceous (~122 Ma) marking the subsidence climax period. With the sedimentary section approximating 8‐km thickness by the time of maximum burial, the modelled average maximum temperature and vitrinite reflectivity coefficient reached roughly 232°C, and 3.5% for the Lower Triassic Feixianguan Formation (T1f1), thus indicating the conditions of dry gas generation. The Meso‐Cenozoic thermo‐structural evolution that postdated the onset of hydrocarbon generation has been critical for the evolution of the petroleum play, including the Feixianguan Formation in the marine carbonates of the Early Triassic and the Xujiahe Formation in the non‐marine sandstones of the Upper Triassic. This resulted in the modification of primary hydrocarbon accumulations, mostly in the lower petroleum play, and development of secondary accumulation in the newly formed structural traps in the upper petroleum play. Therefore, accurate thermo‐tectonic history reconstruction is valuable for understanding the geological history and hydrocarbon prospectivity. [ABSTRACT FROM AUTHOR]

Three new compounds, namely massonside C (1), massonianoside F (2), and 3, 8-dimethyl- herbacetin-7-O-β-D-glucopyranoside (3), together with five known compounds (4–8), were isolated from the fresh needles of Pinus massoniana. Their structures were established by 1D, 2D NMR, HRMS and comparison with the literature data. The absolute configuration of 1 was confirmed by a combination of X-ray single crystal analysis. All isolated compounds were evaluated for the protective effect of human umbilical vein endothelial cells against oxidative damage. [ABSTRACT FROM AUTHOR]

31 natural gases in the western Qaidam Basin of China were collected and analyzed for gas composition including light hydrocarbons (C5-C7) and carbon isotopic characteristics. Based on genetic type obtained from C1-C3 and C7 fractions, four types of gases are identified: oil-type gas, coal-type gas, biodegraded gas, and mixed gas. The oil-type gas is the predominant-type gas in the western Qaidam Basin; coal-type gas is mainly distributed in the Zhahaquan and Nanyishan fields; mixed gas is mainly in the Zhahaquan, Wunan, and Nanyishan fields; and biodegraded gas is mainly distributed in the Huatugou and Yuejinerhao fields. According to the empirical relationship between δ13C1 and the equivalent vitrinite reflectance ( R o , %) of source rock, the R o values of gas range from 0.6% to 1.5%, with an average value of 0.9%. The generation temperatures of major reservoired hydrocarbons (GTMRH) calculated from the C7 components range from 115.6°C to 141.7°C, with an average value of 126.5°C. These two maturity indicators have relatively positive correlation and reveal that the maturity of gas increases from west to east in the southwestern Qaidam Basin. Moreover, combining GTMRH with the homogenous temperature of petroleum inclusions, it is inferred that major petroleum charge in the western Qaidam Basin mainly occurred during the late period of the Himalayan movement. Deep hydrocarbon fluid sources were found in the Shizigou, Yingdong, Zhahaquan, and Nanyishan fields; thus, the deep reservoirs of paleouplifts adjacent to the hydrocarbon-generating depressions are estimated as a favorable area for further exploration in the western Qaidam Basin. [ABSTRACT FROM AUTHOR]

A rare super-large fractured karst aquifer located in Zibo city, Shandong Province of Northern China was polluted by petroleum hydrocarbons from a petrochemical company. Over the last 30 years, it has been the focus of several remediation efforts. In this study, the contamination and natural attenuation characteristics of the petroleum hydrocarbons were elucidated using hydrogeochemical indicators (DO, DOC, Cl−, HCO3−, pH, NO3−, and SO42−), petroleum hydrocarbons elements and environmental isotopes (δ15NNO3, δ18ONO3, δ13CDIC, and δ13CDOC). With the aid of GIS, statistical analyses, as well as first-order decay model and electron-acceptor-limited kinetic model, the spatio-temporal evolution characteristics of the petroleum hydrocarbons were modeled. Results showed a positive natural attenuation trend over the last 3 decades where intrinsic biodegradation mechanism was found to be the most important factor driving the degradation of hydrocarbons in the aquifer system. The hydrogeochemical association between the indicators and petroleum hydrocarbons provided the evidences of biodegradation and also served as markers, highlighting the occurrence of anaerobic respiration without methanogenic activities within the heterogenous karst media. Furthermore, the mean natural attenuation rate of petroleum hydrocarbons was calculated to be 3.76 × 10−3/day whereby the current highest petroleum hydrocarbons concentration (361.13 μg/L) is estimated to be degraded completely in 6 years under the present hydrogeological and environmental conditions. [ABSTRACT FROM AUTHOR]

CO2 flooding has been widely studied and applied to improve oil recovery from low permeability reservoirs. Both the experimental results and the oilfield production data indicate that produced oil components (POC) will vary during CO2 flooding in low permeability reservoirs. However, the present researches fail to explain the variation reason and rule. In this study, the physical model of the POC variation during CO2 flooding in low permeability reservoir was established, and the variation reason and rule were defined. To verify the correctness of the physical model, the interaction rule of the oil-CO2 system was studied by related experiments. The numerical model, including 34 components, was established based on the precise experiments matching, and simulated the POC variation during CO2 flooding in low permeability reservoir at different inter-well reservoir characteristics. The POC monitoring data of the CO2 flooding pilot test area in northeastern China were analyzed, and the POC variation rule during the oilfield production was obtained. The research results indicated that the existence of the inter-well channeling-path and the permeability difference between matrix and channeling-path are the main reasons for the POC variation during CO2 flooding in low permeability reservoirs. The POC variation rules are not the same at different inter-well reservoir characteristics. For the low permeability reservoirs with homogeneous inter-well reservoir, the variation of the light hydrocarbon content in POC increases initially followed by a decrease, while the variation of the heavy hydrocarbon content in POC is completely opposite. The carbon number of the most abundant component in POC will gradually increase. For the low permeability reservoirs with the channeling-path existing in the inter-well reservoir, the variation rule of the light hydrocarbon content in POC is increase-decrease-increase-decrease, while the variation rule of the heavy hydrocarbon content in POC is completely opposite. The carbon number variation rule of the most abundant component in POC is increase-decrease-increase. [ABSTRACT FROM AUTHOR]

We conducted a study in the Wulan‐Hua Sag, a Mesozoic relic sag in the Erlian Basin to analyse and determine the period of its hydrocarbon accumulation. Estimation of erosional thickness is carried out from sonic well logs and seismic velocity data, followed by defining burial history of the Wulan‐Hua Sag together with thermal history through basin modelling. Fluid inclusions and pore fluid microthermometric data of 37 samples from clastic reservoir in the Wulan‐Hua Sag are available for detailed correlation and analysis. The reconstructed erosion thickness indicates that first of all, differential uplift that is characterized by seesaw uplift‐erosion initiated at the north sub‐sag. Secondly, largest erosion degree appears in Tumu'er and Saiwusu tectonic belts. Thirdly, the thickness of sedimentary rocks removed by erosion in the south sub‐sag progressively increases from its subsiding centre outwardly. Burial history of the Wulan‐Hua Sag belongs to type of late‐period intensive uplift‐erosion. Two types of fluid inclusion are recognized in the Wulan‐Hua Sag indicating two hydrocarbon accumulation periods for reservoirs in LK1bt1 (lower interval in first member of Tengge'er Formation), which is middle depositing period of K1bt1 (first member of Tengge'er Formation) to early depositing period of K1bt2 (second member of Tengge'er Formation) and early K1bt2 to middle K1bs (Saihantala Formation) depositing period, respectively. Reservoir in the K1ba and upper interval of K1bt1 appears to have experienced one hydrocarbon accumulation period, which is early K1bt1 to early K1bt2 depositing period. And reservoir in the UK1bt1 (upper interval in first member of Tengge'er Formation) also has one hydrocarbon accumulation period, which is late K1bt2 depositing period to the Late Cretaceous (K2). Hydrocarbon accumulation model of the Wulan‐Hua Sag consists of two oil‐reservoir types including "upward‐charging" and "self‐sourced." Reservoir in lower interval of K1bt1 and reservoir in the upper interval of K1bt1 are considered to have more hydrocarbon exploration potential. [ABSTRACT FROM AUTHOR]

The sedimentary, paleogeomorphological and reservoir characteristics of the Jurassic Yan'an Formation in the southwestern Ordos Basin, northwestern China, were studied by means of casting thin sections, scanning electron microscopy, inclusion analysis and identification of low‐amplitude structures. A model for reservoir formation is established, and the controlling effects of sedimentary facies, paleotopography, low‐amplitude structures and formation water on oil reservoirs are revealed. There are significant differences in the sedimentary characteristics, structural morphology and paleowater characteristics between the reservoirs above the Yan 10 Member and those in the Yan 9 to Yan 7 Members. The Yan 10 Member contains fluvial sediments, whereas the Yan 9 to Yan 7 members contain delta‐plain anastomosing‐river deposits. The distribution of high‐permeability reservoir is controlled by pre‐Jurassic paleogeomorphology and sedimentary facies. Some of these facies exhibit high porosity and high permeability in a low‐permeability background. The main hydrocarbon accumulation period was the late Early Cretaceous, filling was continuous, and the charging strength altered from weak to strong and then from strong to weak. The Yan 10 reservoir is mainly controlled by the paleogeomorphology: hydrocarbons migrated upward at a high speed through the unconformity surface, and accumulated in the favorable traps formed by paleogeomorphic structural units, such as gentle slopes or channel island. Furthermore, groundwater alternation in these areas was relatively stagnant, providing good reservoir preservation conditions. The reservoirs in the Yan 9 and higher members are controlled by the sedimentary facies, low‐amplitude structure and paleowater characteristics. Hydrocarbons migrated through the three‐dimensional delivery system, influenced by favorable sedimentary facies and high‐salinity groundwater, then accumulated in the favorable low‐amplitude structural traps that formed during the hydrocarbon production period. [ABSTRACT FROM AUTHOR]

The coexistence of Pb‐Zn deposits and oil/gas reservoirs demonstrates that a close genetic connection exists between them. The spatiotemporal relationship between Pb‐Zn mineralization and hydrocarbon accumulation is the key to understanding this genetic connection. The Mayuan large‐scale Pb‐Zn metallogenic belt is composed of a number of Mississippi Valley‐type (MVT) Pb‐Zn deposits that were recently discovered on the northern margin of the Yangtze Block, China. It is hosted in the dolostone of the Sinian (Ediacaran) Dengying Formation (Z2dn). In addition to the abundant bitumen in the Mayuan Pb‐Zn metallogenic belt, the paleo‐oil reservoir and the MVT Pb‐Zn deposit overlap in space. In this study, two precise ages of 468.3 ± 3.8 Ma and 206.0 ± 6.5 Ma were obtained via the Rb‐Sr isotopic dating of galena and sphalerite from the Mayuan Pb‐Zn metallogenic belt, respectively. The early metallogenic age of 468.3 ± 3.8 Ma is similar to the previously published age of 486 ± 12 Ma. The age of 206.0 ± 6.5 Ma is consistent with the age of the metallogenic event that occurred at 200 Ma in the Upper Yangtze Pb–Zn metallogenic province of the Sichuan‐Yunnan‐Guizhou polymetallic zone, which is located on the southwest margin of the Sichuan Basin, suggesting that the metallogenic effects of this period were regional in scale in the peripheral areas of the Sichuan Basin. Previous studies have shown that two periods of hydrocarbon accumulation occurred in the oil/gas reservoir that coexists with the Pb‐Zn deposits in the study area. The Pb‐Zn mineralization at 468.3 ± 3.8 Ma occurred during the first period of hydrocarbon accumulation, while the second mineralization at 206.0 ± 6.5 Ma occurred during the transformation of the paleo‐oil reservoir to a paleogas reservoir. The spatial relationship between the paleo‐oil/‐gas reservoir and the MVT Pb‐Zn deposits and the temporal relationship between mineralization and hydrocarbon accumulation show that a close genetic relationship exists between the MVT Pb‐Zn mineralization and hydrocarbon accumulation. Analysis of metals in the source rocks forming the paleo‐oil/‐gas reservoirs show that source rocks which formed paleo‐oil/‐gas reservoirs may have provided metals for Pb‐Zn mineralization. Both the paleo‐oil/‐gas reservoirs and Pb‐Zn mineralizing fluids had the same origin. [ABSTRACT FROM AUTHOR]

Based on the seismic data analysis, source rock geochemistry and reservoir physical properties, the source reservoir allocation and reservoir forming conditions in the Linhe-Jilantai area in Hetao Basin were studied. The results show that the source rocks of the Lower Cretaceous and the Oligocene in the study area reach the standard of fair-good source rocks, and the lithology of reservoirs is mainly feldspar sandstone and lithic feldspathic sandstone with good physical properties. Combined with vertical and lateral migration pathways, three hydrocarbon accumulation models of near source, far source and inside source are proposed. The research results can provide reference and guidance for the further hydrocarbon exploration in Hetao Basin. [ABSTRACT FROM AUTHOR]

The article presents a study which discusses differences in reservoir architecture characteristics occurring between distributary channel sandstones with contrasting channel style in Songliao Basin, China. It mentions depositional characteristics, geometry and heterogeneity of distributary channel sandstones with different channel type. It also reveals use of the method of hierarchical analysis and distribution patterns of remaining hydrocarbons.

Volcanic reservoirs, which may contain unconventional oil and gas, have attracted attention from petroleum geologists in recent years. The Carboniferous volcanic reservoirs in Kebai fault zone(KBFZ) are prolific and the earliest discovered in China. The most hydrocarbons of Carboniferous strata in KBFZ come from weathered volcanic rocks beneath the regional Carboniferous and Permian unconformity surfaces. But commercial oil is found recently in the deeper Carboniferous volcanic rock which is far beneath from the weathering crust. In this paper, the formation mechanisms of another type volcanic reservoirs, which is different from the weathered, has been detailed studied and contrasted with the weathered. The Carboniferous strata consist of one volcanic cycle and two volcanic-sedimentary cycles. From the first cycle at the bottom to the third cycle on the top, the geotectonic environment transforms from the island arc to the collision zone and the main types of volcanic rocks change from the subalkali series(basalt, basaltic andesite, andesite, and related pyroclastic rock) to the alkali series(trachy-basalt, basaltic trachy-andesite, trachy-andesite, and related pyroclastic rock). The weathering volcanic reservoirs are about 500 m beneath the unconformity, and the spaces are primarily freshwater dissolved pores and weathering-induced cracks. the deeper reservoir spaces are dominant by organic acid dissolved pores and tectonic-induced cracks. The cracks in these two type of reservoirs are the significant factor in connecting the pores. The degree and type of diagenetic processes, which includes compaction, filling of pores and fractures, cementation, and grain dissolution, controls reservoir quality and is the key of the differences of the two typical reservoirs. [ABSTRACT FROM AUTHOR]