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The ability of biodegradation on heavy components in heavy oil is still a controversial issue, and the effect of biosurfactants on resins is unclear. Four strains and biosurfactant were used to investigate the degradation ability of resins using gas chromatography-mass spectrometry (GC–MS) and negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) by a stimulated aerobic biodegradation experiment. Results showed that the biosurfactant improved biodegradation rates for saturates, aromatics, resins, and asphaltenes by 115–231%, 130–168%, 116–161%, and 135–217%, respectively. The A/C value (the sum of relative abundance of the acyclic O2 species divided by the sum of relative abundance of the mono, di- and tri-cyclic acids) indicated that biosurfactants could accelerate the biodegradation process. Results also showed that the utilization preference of O-containing and N-containing compounds varies from different strains by analysing their distribution. A reduction in the relative abundance of N1O1 class was detected in all samples containing microorganisms only. A significant decrease in C27H48O and C28H50O was observed in all samples with the biosurfactant. Carbazoles, benzocarbazoles and dibenzocarbazaoles could be effectively used by the strain J2 with biosurfactant. The relative abundance of O1 class increased when treated with microorganisms only. However, it decreased in the presence of biosurfactants. Therefore, biosurfactant could alter the preference that microorganism utilized heteroatom compounds.

In recent 30 years, Th/U ratio has been using widely in evaluating the paleoredox conditions during the depositions of source rocks. However, there are few studies on the preconditions of the use of Th/U ratio for evaluating the paleoredox conditions. In many areas, the evaluation results of redox conditions in paleoenvironment obtained by Th/U ratio is different from that reflected by other parameters. The accuracy of judgment of paleoredox conditions by Th/U ratio is questioned. In this paper, the weathering degree of source rocks during the deposition are determined by chemical index of alteration (CIA) and Al2O3-CaO, NaO-K2O (A-CN-K) ternary diagram, whereas the lithologies of parent rocks during source rocks depositions are determined by A-CN-K ternary diagram, Al2O3/TiO2 ratio and REEs. Furthermore, the effects of the weathering degree, the properties of parent rocks and sedimentation rate on Th/U ratio to evaluate the accuracy of paleoredox conditions are analyzed. The results show that in lacustrine basins, although the content of uranium (U) gradually increased with the decrease of oxygen content in the water column, the obvious enrichment of thorium (Th) in sediments because of parent rock undergoing strong weathering and relative fast sedimentation rate influences the accuracy of Th/U ratio for evaluating the paleoredox conditions. Additionally, the different initial content of U, Th and Th/U ratio in different lithologies also influence the accuracy of Th/U ratio for evaluating the paleoredox conditions. The distribution characteristics of Th/U ratio are the result of the comprehensive influence of various conditions, not just paleoredox condition. When evaluating the redox condition of paleolake water by the enrichment factors of redox sensitive elements (RSEs) and bimetal ratio, the effect of weathering, lithologies of parent rocks and sedimentation rate should be taken into consideration on distributions of parameters.

Antibiotic pollution has become a global problem threatening human health. Ofloxacin is one of the more widely used antibiotics, but reports on the reaction of plant to ofloxacin pollution are limited. In this study, using adversity-resistant (R), adversity-sensitive (S) and grafted plant S/R as models, we investigated the biological response of tomato to exogenous ofloxacin residues. The results showed that lower levels of ofloxacin treatment (5 mg L−1 and 10 mg L−1) promoted tomato growth, and 10 mg L−1 ofloxacin was the critical dose to stimulate growth among the different treatments. In addition, the photosynthetic and fluorescence parameters, antioxidant enzyme activities and transcription-level expression of the enzymes were stimulated by low ofloxacin treatment. However, high ofloxacin treatment (20 mg L−1 and 40 mg L−1) exhibited a significantly negative effect on plant growth, photosynthesis, fluorescence parameters, antioxidant enzyme activities and transcript levels expression. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels increased with increasing ofloxacin concentrations, indicating that the oxidative damage of plants was severe with increasing doses. In contrast, the role of antioxidant enzymes in the antibiotic response was limited at high ofloxacin concentrations. The grafting experiment demonstrated that grafted plants had the ability to alleviate ofloxacin stress. In conclusion, ofloxacin can damage the photosynthetic machinery by promoting ROS accumulation, which results in the etiolation of tomato leaves and inhibits plant growth, but grafting can reduce its.

The world is undergoing a substantial transition in its energy supply. Examining the possibilities to recover and use fossil fuel energy without emitting carbon dioxide to the surface, H2S was considered as an alternative energy vector to deliver a carbon free fuel from petroleum reservoirs to the surface. In this study, we investigated the high P-T chemical oxidation of crude oil with a suite of inorganic sulfur compounds. Tested inorganic sulfur compounds can be ordered by their ability to promote chemical changes to the oil matrix with the concomitant production of hydrogen sulfide, with a reactivity series, listed in order of decreasing reactivity as: S0 > S2O32− ~ S4O62− > SO32− > SO42−. The reaction mechanisms proposed in the study also light on likely key intermediate reactants and the geological timescale process of thermochemical sulfate reduction. Polysulfide species (containing S-S bond structures), such as thiosulfate and tetrathionate, may be reactive intermediates during the redox reaction. However, the early stage of thermochemical sulfate reduction may also involve labile organic sulfur functional groups converting to more stable molecules with aromatic structural units, such as dibenzothiophenes (DBT) and benzonaphthothiophenes (BNT). The apparent formation of saturated fatty acids and O2, NO and NO2 aromatic heteroatom species indicates the oxidation of saturated and aromatic hydrocarbons or heteroatom compounds. The oxidation of aromatic species may lead to aromatic ring-opening, followed by decarboxylation forming CO2 as final products.

Immature oils were proved to be existed in Es4u reservoirs based on GC-MS and carbon isotope analysis of oil sand and source rocks in Qingdong sag. By comprehensive discussion with compositional data from different sags in China, bicyclic sesquiterpenoids are related to thermal maturity and can be used in oil maturity identification. A new indicator, 4,4,8,9,9-pentamethyl decahydronaphthalene /8β(H)-homodrimane, is proposed for distinguishing immature and mature oils in the study area. It signifies mature when this ratio value is higher than 0.34, and immature when the value is lower than 0.34. The varying structures of the two compounds determines their stability.

Seismic data show that a set of Eocene lacustrine source rocks exists in the Qiongdongnan (QDN) Basin, northern South China Sea (SCS). The high content of C30 4-methylsteranes detected in the crude oil suggests the existence and the effectiveness of the lacustrine source rocks, and these compounds were not found in the Oligocene and Miocene source rocks. The above date indicates that the Eocene source rocks are effective and oil-prone. Lacustrine source rocks in faulted period have high organic matter abundance and better organic matter types in the SCS and other typical passive continental margin basins in the world. Lacustrine source rocks in the Eocene source rocks (E2w) from the Baiyun Sag of the Pearl River Mouth Basin have relatively high total organic content (TOC) values, which can be explained by moderate to high paleoproductivity and anoxic environment. Therefore, it can be speculated that the Eocene source rocks have good hydrocarbon potential in the QDN Basin. The developmental pattern of Eoce...

This article discussed the paleoenvironment and its control on Oligocene source rock formation in the deep water area of the northern South China Sea (SCS), including the deep water area of the Qiongdongnan (QDN) Basin and Baiyun Sag of the Pearl River Mouth (PRM) Basin. During E3y and E3l deposition, the terrigenous detrital matter (TDM) inputs were moderate to high and moderate respectively, as indicated by TiO2 values and SiO2/Al2O3 ratios, which accordingly diluted primary production, causing low to moderate and moderate productivity, respectively. The bottom water was oxic because of abundant TDM input, which was unbeneficial for organic matter accumulation. In this environment, algal organic matter could not be preserved. Terrigenous organic matter (TOM) is the main controlling factor of Oligocene source rock formation in the deep-water area of the QDN basin. Source rocks with high organic matter content in the Yacheng Formation could not be formed, although there was moderate to high TOM input in t...

Organosulphur compounds (OSCs) play important roles in the formation, preservation, and thermal degradation of sedimentary organic matter associated with petroleum generation. However, with the ongoing develop of hydrocarbon prospecting in ultra-deep reservoirs, the thermal maturation and geochemical behaviours of OSCs in deep sedimentary basins during the metagenesis stage of thermal maturation has not been well understood. In this study, we modelled the thermal maturation of OSCs by a combination of gold-tube hydrous pyrolysis studies and quantum mechanics calculations based on density functional theory (DFT) to investigate the reaction pathways and kinetic properties. Dibenzothiophene (DBT) was selected as an over-mature model molecule due to its high degree of aromaticity and lack of side chains. The energy barrier of aryl-aryl bonding is estimated to be approximately 60 kcal/mol. Dehydrogenation of OSCs through aryl-aryl bonding mainly occurs in the Easy%Ro range of 2.3%–3.8%. We modeled the contribution of OSCs to organic-derived H2S at advanced maturity based on numerical simulations in MATLAB. The contribution of OSCs to H2S can be quantitatively predicted based on specific thermal histories and the kinetics of H release from biaryl formation. Taking the Sinian reservoirs in the central uplift of the Sichuan Basin as an example, the yield of organic-derived H2S contributed from S-rich solid bitumen (S/C atomic ratio ~0.06) was estimated to be approximately 1.58 mg/g. These results suggested that OSCs participated as carriers of organic S from the surface to deep strata. Desulphurisation of OSCs together with thermochemical sulphate reduction, could contribute to the subsurface accumulation of H2S, to the detriment of. the quality of hydrocarbon reservoirs and the durability of the drill.

Source rock formation influenced by river-delta system, especially in continental margin basins, is still poorly understood. This article aimed to reveal the effect of river-delta system on the formation of the source rock by taking the Baiyun Sag of the Pearl River Mouth Basin for example. Paleo-Pearl River began to develop since the Enping Formation, providing abundant organic matter beneficial for the formation of the source rocks in the Baiyun Sag. The main controlling factor of source rock formation in the Baiyun Sag is terrestrial organic matter supply rather than the paleoproductivity or redox conditions. Low Al/Ti and P/Ti ratios suggest low marine productivity, which may be associated with a large number of terrigenous detritus input, occupying about 43.04%–94.91%. There is a positive correlation between the oleanane/C30hopane ratio and the TOC value, showing that terrigenous organic matter controls the source rock formation. The size of the delta below Pearl River estuary determines the extent of terrestrial organic matter supply. Source rocks with high organic matter abundance mainly formed in delta environment, and those in neritic environment in Enping and Zhuhai Formations also have high TOC values as a result of adequate terrestrial organic matter supply.

Geochemical experiments on 11 cores and 14 crude oil/oil sand samples from Qingdong sag have been performed. The oils range from immature to mature and some of the oils suffered biodegradation. The Es3l member of the Shahejie Formation (group A) deposits under fresh water. The Es4u member (group B) mainly deposits in brackish-saline evaporate environment, generating both immature and mature oils. Results show the nonbiodegraded oils in Es3l reservoirs in the north of the sag (group I) come from mature Es3l member (group A), while those in Es4u reservoirs (group III) come from mature Es3l (group A) and Es4u (group B1) members in the north; the less biodegraded oils (group II) in the western slope are the admixture of immature and mature oils of Es4u member (group B2) in the north; immature oils (group V) in the south are from the neighboring low mature Es4u member (group B3), and the most severely biodegraded oils (group IV) in the southern come from Dongying sag, except oils from well QD-8 that ha...

The main source rocks for gas reservoirs in Huangqiao area of Lower Yangtze region in south China are Permian-Lower Triassic marine strata with high maturity, including carbonate and clastic rocks. A series of geochemical experiments have been carried out in order to reveal the forming mechanism of large gas reservoirs. Geochemical characteristics of crude oils show the source kitchen, which contributes to the large gas reservoir formation, has changed from kerogen cracking to oil cracking. Based on the results of geological evidences, abnormal distribution of vitrinite reflectance, and fluid inclusion characteristics, magmatic hydrothermal is believed to be existed in Huangqiao area. The magmatic hydrothermal changes the source kitchen in two ways. First, the source rock evolution is accelerated by thermal provided by magmatic hydrothermal. Second, it provides hydrogen in the water contained in magmatic hydrothermal to improve liquid hydrocarbons transforming into gases. Thus, the magmatic hydrot...

Magnetic localization is an appropriate method for tracing an intra-body capsule object because of its satisfactory accuracy and efficiency. In this method, the capsule is enclosed in a ring magnet, which establishes a magnetic field around the human body. By using a sensor array system with a number of triaxial magnetic sensors, the magnetic flux densities can be measured, and the magnet can be localized by an appropriate algorithm. However, a problem for such a system is that the movements of the human body have interferences on the localization. Therefore, in order to compensate the interferences, we propose a three-magnet localization method. Here, in addition to the capsule object magnet, two other magnets are fixed on the surface of the human body to serve as reference objects. The position and orientation parameters of all the three magnets are determined by applying the optimal algorithm on the sensing data from the sensor array. Then, a reference coordinate system is built based on the two reference objects, and the capsule magnet is relatively tracked with respect to this reference system in human body. The experimental results show that the average localization error caused by the body movement interference is reduced from 30.1 mm (in the original coordinate system) to 3.82 mm (in reference coordinate system) and the average direction error reduced from 17.7° to 2.2°.

The oxygenated non-hydrocarbon compounds are widely distributed in soil. To investigate the distribution and origin of these compounds in topsoil of Beijing, their contents and compositions were measured in topsoil from 62 sites in Beijing. The research results showed that oxygenated non-hydrocarbons were composed primarily of C6∼C28 n-fatty acids, C12∼C28 n-fatty alcohols, n-fatty acid methyl esters, phthalates, sterols, and dehydroabietic acid in the topsoil of Beijing. The contents and compositions of these compounds varied with the sampling site. The concentrations of n-fatty acids and phthalate esters were the highest at all sites, followed by sterols, n-fatty acid methyl esters, fatty alcohols, and dehydroabietic acid in order. The n-fatty acids had a main peak of C16, followed by C18. An odd or even carbon number predominance was not observed in the low-molecular-weight n-fatty acids, indicating a fossil fuel or organic matter source. However, some high-molecular-weight n-fatty acids with an even carbon predominance may derive from a biomass. The n-fatty alcohols showed a main peak of C22 and were predominated by an even carbon number, suggesting plant, microbial, or other natural origins. Phthalates, including diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and dimethylphthalate (DMP), were detected. The content of phthalate esters was higher in the samples collected from dense human activity areas. The concentrations of DBP, DEHP, and DIBP were relatively high, indicating an anthropogenic source. The sterols (predominantly β-sitosterol) originated from biological sources, especially plants. The n-fatty acid methyl esters and dehydroabietic acid in topsoil showed apparent even carbon predominance with the former mainly derived from microorganisms or plants and the latter from cork combustion products.

Eocene lacustrine organic-rich shales, mudstones and shales in the middle member of Liushagang Formation (designated as LS2) are the most important source rocks in the Beibuwan Basin located in the northwest of the South China Sea. In this study, we explored the mechanisms responsible for the accumulation of organic matter in source rocks from LS2 of Weixinan Sag by investigating the paleoclimate, paleoredox, paleoproductivity and lithological characteristics of the parent rocks using biomarkers and elemental geochemistry data. Based on our analytical data, the deposition of the source rocks from LS2 occurred in a warm, humid paleoclimate with moderate chemical weathering, as indicated by CIA indexes and Sr/Cu ratios. The Sr/Ba ratios and gammacerane indexes indicated that the source rocks from LS2 were deposited in a freshwater paleolake. The Corg/P ratios and Redox Sensitive Elements (RSEs) -TOC bivariate diagrams demonstrated that the organic-rich shales and mudstones/shales deposited under anoxic and oxic-suboxic conditions, respectively. The levels of TOC, copper (Cu), molybdenum (Mo) and C30 4-methylsterance index in the organic-rich shales were higher than those of the mudstones and shales, indicating greater algae bloom and paleoproductivity during the deposition of the organic-rich shales compared to during the sedimentation of the mudstones and shales. Combined with La/Yb-∑REE, SiO2–TiO2, Al2O3/TiO2, Nb/Ta and Cr/Co ratios, it is considered that the parent rocks of the organic-rich shales were granite of relatively intermediate lithological compositions, with greater levels of nutrients such as phosphorus (P), Mo, Cu, compared to those of the mudstones and shales. Large-scale decomposition of dead algae led to oxygen depletion, which created favorable conditions for the preservation of organic matter and the release of P from the sediments to water. The increased content of P in water subsequently aggravated algal blooms. Such a positive feedback loop was conducive to the formation of organic-rich shales. The inter-relationships of algal blooms (controlled by P), paleoproductivity and paleoredox conditions play an important role in the accumulation of organic matter in organic-rich shales from LS2 of Weixinan Sag, Beibuwan Basin.

The risk of soils transferring polycyclic aromatic hydrocarbons (PAHs) into groundwater has caused widespread concern. Research on the leaching behavior of PAHs in soil profiles is very important for assessing this risk. Column leaching tests were carried out to provide insight into the effect of TOC and leaching water volume on leaching behavior of PAHs. Four groups were leached intermittently by deionized water under the same leaching rate for 10 d, 30 d, 90 d and 120 d. These four leaching periods are equivalent to 1 yr, 3 yr, 9 yr and 12 yr of rainfall time under natural conditions, respectively. The results showed that residual concentrations of PAHs on the surface of soil (0–5 cm) in three columns after 30 d of leaching were 37.9 μg/g, 18.5 μg/g and 3.7 μg/g, respectively, which was consistent with their TOC contents. According to the correlation analysis, both residual concentrations of ∑16PAHs and PAHs with different ring numbers were significantly correlated with the TOC content at depths of 5–100 cm after 30 d of leaching. With increased leaching water volume, PAH migration rates significantly decreased (from 3.13 μg/g/d to 0.005 μg/g/d) from 10 d to 120 d, which indicates that the initial period of the leaching process has a stronger effect on PAH vertical migration than the later stages of the process. Under long-term leaching, PAHs that were not leached previously were capable of migrating deeper into the soil profile. Therefore, it has the risk of PAH-contaminated soils transferring PAHs into groundwater.

Oil biodegradation studies using the powerful surfactant have mainly focused on saturated hydrocarbons or parent aromatic hydrocarbons, but not specifically on the position or degree of alkyl substitution of aromatic hydrocarbons. Removal of substituted aromatic hydrocarbons remains a controversial topic in biodegradation. In this study, the effect of surfactin addition on specific alkylated aromatic isomers and saturated hydrocarbons was observed in aerobic biodegradation experiments with four species of bacteria. The relative susceptibility of the individual alkylphenanthrene, alkyldibenzothiophene and methyltriaromatic steroid isomers to biodegradation was determined by their depletion rates. The results show that different bacteria induce removal of alkylated aromatic hydrocarbons and alteration of other petroleum hydrocarbons in various ways. Bacillus amyloliquefaciens strain BC is the best for biodegradation of general petroleum hydrocarbons, because it can convert n-alkanes, n-alkylcyclohexanes, isoprenoids, and aromatic hydrocarbons. Achromobacter strain J3 can degrade methylphenanthrenes, methyltriaromatic steroids, triaromatic steroids, and steranes better than other bacteria. Citrobacter sp strain J1 induces the highest degradation rate for dimethylphenanthrenes, trimethylphenanthrenes, and dimethyldibenzothiophenes, and Brucella melitensis strain J2 selectively degrades methyldibenzothiophenes. Surfactin addition increases the biodegradation rate of alkylaromatic hydrocarbons by 1.5–87.2%, and can significantly enhance the biodegradation of alkylphenanthrenes, alkyldibenzothiophenes and methyltriaromatic steroids. Alkyldibenzothiophenes can be used as markers for determining the levels of biodegradation of crude oils, and when used in conjunction with triaromatic steroids are a powerful indicator of the biodegradation of petroleum. The use of surfactin for enhancing the removal of aromatic hydrocarbons provides a wide range of applications in the environmental remediation and petroleum industry.

Drought is the main meteorological threat to plants and limits plant growth, development, and adaptation to environmental changes. However, root-shoot communication plays a vital role in improving tomato plant drought tolerance, especially when cultivars are grafted onto drought-tolerant rootstock. In this study, the relationship between photosynthetic capacity and reactive oxygen species (ROS) in response to drought stress was studied in tomato grafted with different drought-resistant tomato seedlings. To determine the drought-relieving effect of drought-tolerant rootstocks, we measured the effects of grafting on plant growth, net photosynthetic rate (Pn), ROS accumulation, and antioxidant enzyme activities in tomato leaves and roots under drought stress. Plant growth and Pn were significantly inhibited by drought, but ROS accumulation and antioxidant enzyme activities were significantly increased. Treatment with drought-tolerant tomato seedlings significantly increased plant growth and increased Pn under water-deficit conditions compared with those grafted with drought-susceptible rootstock. In addition, the plants grafted with drought-tolerant seedlings had increased activities of partial antioxidant enzymes, leading to decreased ROS production. Our results indicate that tomato grafted with drought-tolerant seedlings alleviated the phytotoxicity and oxidative damage caused by drought by regulating antioxidant enzymes under drought stress.

s The organic-rich sediments of the Fengcheng Formation in the Halaalate area, Junggar Basin, China are important source rocks and significant tight oil exploration targets. However, their geochemical characteristics have not been well documented. The hydrocarbon generation potential, genetic type of kerogen, organic matter (OM) sources, depositional conditions, and thermal maturity have been investigated based on a sample set of 11 mudstones. These source rock samples represent good to very good hydrocarbon generation potential, and primarily contain type I to II kerogen. The major organic input sources to the Fengcheng Formation from algae and bacteria were identified using stable carbon isotopes and biomarkers. Limited higher plant input can be inferred from trace amount of terrigenous OM biomarkers and minor contents of vitrinites and inertinites. The Fengcheng sediments were deposited under hypersaline and anoxic environments. Paleoclimate was arid during the deposition of the Fengcheng Formation. The presence of evaporites, mineral-bituminous groundmasses (MBG), alginites and microbial mats also supports these conclusions about depositional environments and biological source. The OM enrichment in the studied samples are attributed to the reducing environments, the booming of algae and the important bacterial contribution. Vitrinite reflectance and Tmax suggest a low thermal maturity of the studied Fengcheng sediments, in agreement with maturity-related hopane and sterane ratios and detection of hop-17(21)-enes. In a consideration of the quantity, quality and maturity of OM and their large thickness, the Fengcheng sediments have a good petroleum exploration potential.

Through the analysis of ocean organisms, the distribution characteristics and enrichment of organic matters in modern marine sediments and ancient marine strata, this paper shows that the main factors influencing the formation of excellent marine source rocks are the paleoclimate, biologic productivity, terrestrial organic matter, oxidation–reduction environment, sedimentation rate, and the type of the basin. In addition to those factors, high biologic productivity or high content of terrestrial organic matter input is a requirement for the enrichment of the organic matter in a marine environment. Reducing environment was favorable for organic matter accumulation and preservation in depositing and early diagenesis stage, which is an important element for the formation of high-quality marine source rocks. Paleoclimate also influences the marine source rocks formation, as humid subtropical and tropical climates are the most favorable regimes for the formation of marine source rocks. Wind transports some vascular plant materials into the marine environment. Furthermore, upwellings driven by steady wind can cause high biologic productivity, thus forming organic-C-rich mud. Suitable sedimentation rate is beneficial for marine organic matter accumulation. Moreover, the type of the basin also plays an important role in the development of marine source rocks. Silled basins with a positive water balance often act as nutrient traps, thus enhancing both productivity and organic matter preservations, while in open oceans, organic matter enrichment in sediments has just been found in the oxygen minimum layers.

The saturated and aromatic hydrocarbon maturity characteristics of crude oils from the eastern Chepaizi High in the Junggar Basin of northwest China were analyzed in detail. The results show that sterane maturity parameters for light oils from the Neogene Shawan Formation differ from other maturity parameters. Sterane αααC 29 20S/(20S + 20R) and C 29 ββ/(ββ + αα) ratios indicate low maturity, while aromatic hydrocarbons indicate high maturity. We infer that light oils from the Shawan Formation have higher maturity than Cretaceous and Jurassic crude oils and were generated at equivalent vitrinite reflectance of ∼0.9–1.2%. It can be concluded that the Shawan light oils originated mainly from deeply buried, highly mature Jurassic source rocks, southeast of Sikeshu Sag, southwest of Shawan Sag, and west of Huomatu Anticline Belt. During upward migration, crude oils generated from Jurassic source rock dissolved less mature Cretaceous bitumen resulting in a mixture with apparently conflicting parameters. Phase fractionation during migration also could have contributed to the anomalously low sterane maturity parameters.

This paper presented a system design review of fuel cell hybrid vehicle. Fuel supply, hydrogen storage, DC/DC converters, fuel cell system and fuel cell hybrid electric vehicle configurations were also reviewed. We explained the difference of fuel supply requirement between hydrogen vehicle and conventional vehicles. Three different types of hydrogen storage system for fuel supply are briefly introduced: high pressure, liquid storage and metal oxides storage. Considering of the potential risk of explosion, a security hydrogen storage system is designed to restrict gas pressure in the safe range. Due to the poor dynamic performance of fuel cells, DC/DC converters were added in hybrid vehicle system to improve response to the changes of power demand. Requirements that in order to select a suitable DC/DC converter for fuel-cell vehicles design were listed. We also discussed three different configurations of fuel-cell hybrid vehicles: “FC + B”, “FC + C”, and “FC + B + C”, describing both disadvantages and advantages. “FC + B + C” structure has a better performance among three structures because it could provide or absorb peak current during acceleration and emergency braking. Finally, the energy management strategies of fuel cell and were proposed and the automotive energy power requirement of an application example was calculated.

The research of natural gas is limited in the Upper Triassic to Lower Jurassic in the northeastern Sichuan Basin for a long time, with the source and accumulation of natural gas still being controversial. Based on a case study of the northeastern Sichuan Basin, the source of natural gas is discussed through the analysis of fluid inclusion and biomarker data, and the hydrocarbon accumulation is analyzed. It reveals that the gas is mainly from Permian marine source rocks in the Changxing Formation and Triassic terrestrial source rocks in the Xujiahe Formation. Two filling models of the hydrocarbon are put forward. One filling stage dated from the Middle to Late Jurassic, natural gas, generated in marine strata, accumulated in the reservoir of the Xujiahe Formation through the large boundary faults. The other filling stage is in the early Cretaceous, a large amount of natural gas generated by source rocks in the Xujiahe Formation, accumulated in the reservoirs of the same formation, and natural gas, generated by marine source rocks, can also be accumulated in reservoirs of Xujiahe Formation through the boundary faults.

Grafting cultivation could enhance the resistance to many biotic and abiotic stresses in tomato grafted seedlings. In order to further study the molecular mechanism of ABA signaling regulation in tomatoes grafted onto different rootstocks under drought stress, the different drought-resistance tomato varieties named drought-tolerant genotypes (T) and drought-sensitive genotypes (S), were selected for grafting with each other as rootstock or scion, and the response to drought stress were tested. And then whole transcriptome sequencing performed with the leaves and roots of S/T and S/S grafted tomato seedlings under drought stress. The results showed that, compared with seedlings grafted with S, the growth rate and stomatal aperture of seedlings grafted onto T were not significantly inhibited by drought and the ABA content increased after 15 days of drought stress. The roots had more DEGs in the functional category associated with plant hormone signal transduction than the leaves, and most of the genes were upregulated in S/T vs. S/S. The DEGs involved in ABA biosynthesis and ABA signaling both had impact on the drought resistance of grafted tomato with different rootstocks. Compared with ABA biosynthesis, there were more DEGs related to ABA signal transduction in different grafting treatments. They together regulated ABA content and stomatal aperture of the plant and allow it adapt to drought stress in time.

Horizontal well technology has been widely used in developing oil fields. Very commonly, these wells are hydraulically fractured to improve productivity in low permeability reservoirs. The productivity of a multifractured horizontal well is mainly affected by reservoir properties and fracture parameters. A simple and accurate method for evaluating and optimizing productivity of this type of wells is not available and is highly desirable to reservoir engineers. The authors analyzed the equipressure contour, velocity vector distributions, and the influence of factors such as ratio of vertical permeability to horizontal permeability, anisotropy of plane permeability, hydraulic fracturing angle, fracture distribution, and morphology on horizontal well's productivity by finite element numerical simulation method. The results show that optimizing the well trajectory and direction can reduce the degree of reservoir permeability anisotropy influencing on the productivity of well. Hydraulic fracture tilt or angles...

In this paper, a novel method is proposed to recover and extract the original signal parameters from the saturated multifrequency sinusoid wave signals. It makes use of the zero-crossing characteristics of the multifrequency sinusoid signals, to collect valid samples in unsaturated parts of the signals. On these valid samples, the amplitudes and phases of the specific original ac sensing signals can be linearly computed by applying the least square method. The simulation results show that the proposed method has satisfactory accuracy even with very large saturation ( ~ 10 times of the saturation limit) and large dc offset, which frees us from the restriction to avoid the signal saturation problem in the signal acquisition. The method is realized by the software algorithm, and no longer requires the common used hardware-the phase sensitive detection circuit. Hence when it is applied to the magnetic coupling system, we will obtain much simpler system composition, higher accuracy, and high execution speed.

Mutually enhanced Tm 3+ 1470 nm and Dy 3+ 1330 nm near-infrared (NIR) emissions are observed in Dy 3+ /Tm 3+ co-doped 70GeS 2 –10Ga 2 S 3 –20CsCl (mol%) chalcohalide glasses. With the optimized concentration of dopant ions, the NIR emission in a range from 1250 to 1550 nm shows the largest full-width-at-half-maximum (FWHM) of ~230 nm. The mechanism responsible for the mutually enhanced NIR emission is discussed. The present work demonstrates a promising way to realize superbroadband NIR emissions by rare-earth codoping.

The effect of copper ion doping on the γ-ray irradiation resistance of Mn2+ and Pr3+ doped phosphate glasses has been studied. UV-visible transmission spectra and photoluminescence spectra have been measured before and after γ-irradiation to characterize the radiation-induced defects. The electron paramagnetic resonance spectra of the irradiated samples with, and without Cu ions have been compared to show the ability of Cu ions to suppress the generation of radiation-induced color centers. The differential transmission spectra and the radiation-induced absorption coefficients have also been calculated for discussion of the observed phenomena. The much improved γ-irradiation resistance of Mn2+ and Pr3+ doped phosphate glasses has been demonstrated through CuO co-doping. © 2013 Elsevier B.V. All rights reserved.

From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology method, the microscope features of the sedimentary organic matter were studied. The results indicate that three types of kerogens present in the measured samples. Kerogen type I consists of the laminate algainite, abundant sporinite and only little content of cutinite, which can mainly generate oil. The generation hydrocarbon components of the type II kerogen are dominated by the sporinite, cutinite and little the exinite debris. The type III kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation. Through the analysis of the experiments, the organic kerogen of the Lucaogou formation is mostly comprised of the type I, partially type II, and particularly type III. In Hongyanchi formation, the organic type is mixed by the types II and III. The plot of the (S1+S2) or TOC value and the content of exinite show two trends. From the evolution of burial and the Permian source rocks in Changji Depression, the Permian formation source rock has ended the generation of hydrocarbon. A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation. The Lucaogou formation for kerogen type I has better potential hydrocarbon generation. It can reach the oil peak with Ro ratio of 0.9%. For the kerogen II, the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen I. For type III, it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%. In a word, the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.

Coals developed in the Oligocene Yacheng and Lingshui formations in the Qiongdongnan Basin have high organic matter abundance, and the dark mudstones in the two formations have reached a good source rock standard but with strong heterogeneity. Through the analysis of trace elements, organic macerals and biomarkers, it is indicated that plankton has made little contribution to Oligocene source rocks compared with the terrestrial higher plants. The organic matter preservation depends on hydrodynamics and the redox environment, and the former is the major factor in the study area. During the sedimentary period of the Yacheng Formation, tidal fiats were developed in the central uplift zone, where the hydrodynamic conditions were weak and the input of terrestrial organic matter was abundant. So the Yacheng Salient of the central uplift zone is the most favorable area for the development of source rocks, followed by the central depression zone. During the sedimentary period of the Lingshui Formation, the organic matter input was sufficient in the central depression zone due to multiple sources of sediments. The semi-enclosed environment was favorable for organic matter accumulation, so high quality source rocks could be easily formed in this area, followed by the Yacheng salient of central uplift zone. Source rocks were less developed in the northern depression zone owing to poor preservation conditions.

A multiprocess bioremediation approach was applied to treat petroleum-contaminated soil from Dagang Oilfield, China. The bioremediation processes involved the use of four exogenous microbial strains and six herbage plants screened from a large number of species to remove low levels of total petroleum hydrocarbons (TPH) in contaminated soil. The experimental results indicated that the reduction of TPH increased with the improved community structure from the exogenous petroleum-degrading bacteria by over 35% as compared with that using the indigenous bacterial community. The refreshed microbial consortium was also able to accelerate the reduction of TPH via plant roots (phytoremediation) by over 47%. The TPH reduction rate diminished over time. Molecular biomarker ratios such as Ph/nC17, Pr/nC18 increased during the experiment but the ratio of Pr/Ph decreased. The results suggested that the multi-process bioremediation may significantly shorten the bioremediation duration and can be quite effective for trea...

In the Yongjin oilfield of southern Junggar Basin, many wells have been drilled to produce industrial oils. Based on the analysis of fluid inclusions in the reservoirs, in combination with the geological and thermal evolution, the charge history in this area has been studied. The results indicate that the Jurassic Formation and Cretaceous Formation reservoirs contain abundant oil and gas inclusions, and four types of fluid inclusions have been distinguished. According to the homogenization temperatures of the fluid inclusions, the hydrocarbons charged the Cretaceous Formation for two periods, one ranges from the Late Cretaceous period to the Eogene period, and the other ranges from the Neocene period to the present. The oil filling history is correlated with the oil source correlation analysis, which is controlled by the movement of the Che-Mo plaeo uplift. Overall, oil accumulation is characterized by the superposition of two sets of source rocks for two stages in the Shawan depression.

According to the drilling results, there are three sets of source rocks of the Cenozoic Group in the Qiongdongnan Basin, including the Yacheng Formation transitional facies mudstone, the Oligocene Lingshui Formation semi-enclosed marine facies mudstone, and the Miocene neritic-bathyal facies mudstone. The hydrocarbon generating conditions of the source rocks in the study area are mainly controlled by sedimentary environment and organic matter input. The abundance of organic matter in the Oligocene source rocks which were formed in a low-energy back shore environment is confined by organic matter input and hydrodynamic condition. The Miocene source rocks formed in the open marine environment lack terrestrial organic matter input, whose organic matter abundance is constrained by the primary production of the ocean and the preservation condition of organic matter. In addition, the redox conditions are also significant to the formation of source rocks in the study area. According to the differences in key factors controlling the development of source rocks in different time periods and structural belts revealed by drilling practice, three development patterns of source rocks have been put forward. The first one is the transitional facies model featuring a great deal of terrestrial organic matter and weakly hydrodynamic conditions which are apt to develop high effective source rocks in the Yacheng Formation. The second one is the semi-enclosed marine facies featuring abundant terrestrial organic matter, weakly hydrodynamic condition and fine preservation condition in the central depression zone, which are apt to form fine-quality source rocks in the Lingshui Formation. The third one is the marine facies model featuring strong hydrodynamics in the shore-shallow area of northern continental shelf and the lack of benthic algae which are against the development of source rocks. It can be predicted that the continental slope is the perfect place to form source rocks where adequate amounts of light favor the photosynthesis of plants, besides the fine preservation and weakly hydrodynamic conditions. In the deep sea area, although accompanied with weakly hydrodynamic conditions and a reduction environment, it is not suitable for the development of source rocks on account of less aquatic organisms causing low primary production.

Drilling wells reveal that the organic matter abundance of Miocene marine source rocks in shallow water area of the Qiongdongnan Basin is relatively low with poor hydrocarbon generation potential. However, in some drilling wells of deep water area close to the central depression belt, Miocene marine source rocks with better organic matter abundance and hydrocarbon generation have been found, which have achieved better source rock standard based on the analysis of geochemical characteristics. Although there are no exploratory wells in deep water area of the research region, through the comparative analysis of geochemical data of several typical exploratory wells respectively from shallow water area in the basin, central depression belt margin in deep-water area of the basin and Site 1148 of deep sea drilling in the South China Sea Basin, it reveals that the tendency of the quality of source rocks becomes positive gradually from delta to bathyal environment, which then becomes negative as in deep oceanic environment. Owing to the lack of terrestrial organic matter input, the important controlling factors of Miocene marine source rocks in the Qiongdongnan Basin are ocean productivity and preservation conditions of organic matter. The element geochemistry data indicate that the tendency of the paleoproductivity and the preservation conditions of organic matter become positive as water depth increase from shallow area to bathyal area close to central depression belt. So it is speculated that there must exist high quality source rocks in the central depression area where the preservation conditions of organic matter are much better. Besides, in theory, in oxygen-poor zone of oceanic environment at the water depth 400–1 000 m, the preservation conditions of organic matter are well thus forming high-quality marine source rocks. The resulting speculation, it is reasonable to consider that there are high hydrocarbon generation potential source rocks in bathyal environment of the Qiongdongnan Basin, especially at the water depth 400–1 000 m.

The Lower Yangtze region is one of the important marine sedimentation areas of oil and gas distribution in southern China, for its favorable source rocks, reservoirs and covers. However, the intense tectonic movements and complex hydrocarbon generation process made it highly impossible to form large-sized oil and gas reservoirs. So it was divided to different hydrocarbon-bearing preservation units in oil-gas exploration. Recent study shows that the Permian and Lower Triassic source rocks in the Lower Yangtze region are complicated in lithology. The hydrocarbon generation potential of limestone there is low while argillaceous source rocks are overall of high abundance with excellent organic types, now in the process of hydrocarbon generation, so differences in high maturity influence the evaluation of organic matter abundance and type. Biomarker characteristics indicate a reductive environment. n-alkanes are marked by a single peak, with no odd-even predominance. The composition and distribution of the carbon numbers of n-alkanes, and the high abundance of long-chain tricyclic terpanes are indicative of marine sedimentation. The high contents of pregnane, homopregnane, rearranged hopane suggest that the source rocks are of high maturity. There is a good linear correlation between methylphenanthrene index and vitrinite reflectance. The correlation of oil-source rocks indicated that the oil of Well HT-3 may come from the Permian Longtan Formation in the Huangqiao area, the oil of Wells Rong-2 and Juping-1 came from the Lower Triassic Qinglong Formation in the Jurong area. The exploration here is promising in those different source rocks which all have great potential in hydrocarbon generating, and oil and gas were produced in the late stage of hydrocarbon generation.

Along with the rapid development of oil industries internationally, petroleum prospecting and exploitation activities are growing intensively. Especially in China, with the fastest economic growth in the world and shortage of petroleum resources, we are leading the practices of petroleum deep exploitation. Obviously, the risk of damage to the natural environment from these activities is high. Oil contamination in soils and groundwater is becoming a big issue along with pesticide pollution, which makes organic pollution prevention and control (OPPC) much more complex. In this paper, based on recent research on oil-contaminated soil at home and abroad, we make comments on the remediation technologies for polluted soil, emphasizing bioremediation techniques and degradation mechanisms in order to push forward research into bound organic pollution prevention and control (OPPC), especially in China.

A strain capable of oxidizing alkanes up to C36 was isolated from petroleum-contaminated soils. The strain was able to utilize paraffinic wax and liquid paraffin as the sole carbon sources for growth, and the growth with paraffinic wax was accompanied by the production of an unknown emulsifying agent. The ranges of pH value and temperature for satisfactory growth of strain W cells were from 4.0 to 8.0 and 10°C to 45°C, respectively. The kinetics of n-eicosane, n-triacontane, and n-hexatriacontane biodegradation was investigated with initial concentrations of 1,000 mg L−1. First-order kinetics could be fitted to the biodegradation of solid hydrocarbons by strain W at initial concentrations of 1,000 mg L−1. The first-order oxidation constant decreased with increasing chain length. When C36 was used as the sole carbon source, a wide variety of metabolites including fatty acids were formed and identified. Results could offer useful information for the application of strain W in bioremediation of petr...

The Moxizhuang field is a small oil field in the central Junggar Basin containing several low-saturation, low-resistivity oil reservoirs, which display a complex correlation between oil saturation and porosity and permeability that is atypical of both the filled and drained reservoirs. Biomarker associations of crude oil and grains containing oil inclusions (GOIs) of both the present-day water-bearing zones (water zones) and the oil- and water-bearing zones (low-oil-saturation pay zones) were analyzed to investigate the mechanisms for the formation of the low-saturation, low-resistivity oil accumulations. The biomarker assemblage and hierarchical cluster analysis indicate that oil in the Moxizhuang field was mostly generated from Permian source rock deposited in brackish to hypersaline anoxic environments. The pay zones and several water zones display GOI values as much as 38%, greater than the generally accepted threshold GOI value for an oil column (5%). These GOI values are similar to those for high-saturation oil reservoirs in the Bohai Bay Basin and oil zone samples from Australian basins, suggesting that both pay zones and water zones were high-saturation oil reservoirs in the geologic past. Geologic history analysis shows that the Moxizhuang field was located on the north wing of a paleoanticline during oil charge in the Late Cretaceous to Paleogene. This anticline has gradually evolved into a south-dipping monocline since the Neogene, causing northward remigration of accumulated oil. Differential lateral leakage of accumulated oil in different sandstone layers during the remigration phase led to the formation of the water zones with high GOI values (completely drained reservoirs) and the low-saturation, low-resistivity pay zones (partially preserved reservoirs) and caused the complex correlation between oil saturation and porosity and permeability. Compared with other postaccumulation physicochemical alteration processes, lateral leakage has rarely been recognized. Recognizing differential lateral leakage of accumulated petroleum with the existence of high-quality unfaulted cap rocks has important implication for petroleum exploration in sedimentary basins having complex evolution histories.

Through natural gas exploration in the Changling Fault Depression, abundant natural gas flows were obtained and high-quality source rocks were also reveiled. Based on bulk analyses, organic matter abundance, organic matter type and thermal maturity of the source rocks were studied systematically. At the same time, gas generating intensity and gas generating quantity were quantitatively analyzed by using basin modeling technologies. The results indicated that gas source rocks of the Shahezi Formation are characterized by abundant organic matter and dark mudstone distributions and high-over thermal maturity. They possess high gas generating intensity with the biggest value surpassing 500×108 m3/km2, and large gas generating quantity, accounting from 74.40% of the total amount. The Yingcheng Formation has good gas-source rocks with moderate dark mudstone and relatively high organic matter. It has type-III organic matter and low-over thermal maturity. The gas generating intensity is moderate, between 20×108 and 60×108 m3/km2. The gas generating quantity is 13.63% of the total amount. The Huoshiling Formation has relatively good source rocks with limited dark mudstone and low organic matter. It has type-III kerogen and over-thermal maturity. The gas generating quantity is 7.10% of the total amount. The Denglouku Formation has poor-gas source rocks, and is characterized by undeveloped dark mudstone and low organic matter abundance. It has type-III organic matter and low-high thermal maturity. Hydrocarbon gases in the Changling Fault Depression mainly originated from the Shahezi Formation, and secondarily from the Yingcheng Formation. The contribution of the Huoshiling Formation gas source rocks is relatively small.

A large number of disinfectants and insecticides were used on a large scale after the Wenchuan 5.12 Violent Earthquake. The disinfectants and insecticides, including HCH (hexachlorocyclohexane) and DDT (dichlorodiphenyltrichoroethane) as representative OCPs, could lead to serious environmental problems. In order to disclose the residues of HCH and DDT in soils following the Wenchuan 5.12 Violent Earthquake, surface soils in Dujiangyan City and Beichuan County were sampled in 2009. The samples were analyzed by GC/MS after pre-treatment by ultrasonic solvent extraction. It has been found that the concentrations of γ-HCH, β-HCH and 4,4′-DDT in soils of Beichuan County were 94–102.4, 14.1–36.1 and 2.9–4.3 times high their concentrations in those of the Wolong Nature Reserve, and the concentrations in soils of Dujiangyan City were 52.4–61.6, 8.8–45.3 and 5.4–6.2 times high their concentrations in soils of the Wolong Nature Reserve, respectively. According to the isomers of HCHs and metabolites of DDTs, it could be concluded that these areas may have additional inputs of lindane and 4,4′-DDT.

Recently, volcanic gas reservoirs in Yaoyingtai (腰英台) and Daerhan (达尔罕) tectonic belts in Changling (长岭) faulted depression of southeastern Songliao (松辽) basin have been discovered. Based on the compositions and isotopic values, the natural gas is characterized by high content of methane, low content of C2+, and C1/C1–5 beyond 0.95. Also, the natural gas contains nonhydrocarbons including carbon dioxide with the content from 20% to 40% and minor amount of N2. Combined with the isotopic values, the natural gas is generated by humic kerogen and coal-derived type, but in Daerhan, the natural gas is probably mixed by oil type gas. From the measurement of lithology and fluid inclusions in volcanic rocks, the bitumen, liquid hydrocarbon, and gas hydrocarbon inclusions are present. Through the analysis of the single gas inclusion in volcanic reservoir, the content of carbon dioxide is low, so the carbon dioxide and hydrocarbon gas of the reservoirs are not accumulated at the same time. In addition, minor amount of bitumen in the reservoirs is formed by thermal evolution of the crude oils sourced from the Yingcheng (842557CE) Formation mudstones through the characterizations of the biomarkers. The distribution of homogenization temperatures presents two peaks, one with the liquid hydrocarbon filling stage, and the other with gas filling stage. However, in Daerhan tectonic belt, the second peak is gas and carbon dioxide mixed filling period probably. Combined with the homogenization temperatures of salt water inclusions, the oil and gas filling period is from Qingshankou (青山口) Formation to Nenjiang (嫩江) Formation in the research area. During the charging period, minor amount of inorganic carbon dioxide filled into the trap, but plenty of inorganic carbon dioxide from the end of Sifangtai (四方台) to Eogene periods was related with the structural movement.

Geochemical composition characteristics of light oils from the Tertiary in the west of the Chepaizi uplift in the Junggar basin, northwest China, are distinct from those of biodegraded oils derived from the Permian in the study area and crude oils from some adjacent oil fields such as the Chepaizi and Xiaoguai oilfields. Oil source correlation shows that light oils in the study area have similar n-alkane and isoprenoid distribution patterns and carbon isotope compositions with the coal-derived oils from the Jurassic, and display obvious discrepancy on biomarker composition characteristics with the Cretaceous source rock extracts, inferring that they are probably the mixed oils from the Jurassic coal measures and Cretaceous source rocks. In this study, combined with the geochemical data of coal-derived oils from the Jurassic and Cretaceous source rocks or crude oils from the Cretaceous, the source and commingling features of the Tertiary crude oils of Well Pai 2 and Well Pai 8 were investigated. The proportion of the two sources in the mixed crude oils was estimated, and the hydrocarbon accumulation pattern of reservoirs in the study area was established.

In the hinterland of the Junggar Basin, there are multiple depressions with multiple sets of source rocks. Therefore, the conditions of hydrocarbon sources are complex, and the geochemical characteristics and sources of hydrocarbon vary in different structural belts. The evolution of the Che-Mo palaeohigh affected the formation of hydrocarbon source kitchens and hydrocarbon migration. We studied the combination and superimposition of hydrocarbon source kitchens, using as an example the hinterland of the Junggar Basin (including the Yongjin, Zhengshacun, Moxizhuang and Luliang uplift areas). The study was based on geochemical analyses of crude oil and fluid inclusions, and the histories of tectonic evolution and hydrocarbon generation. The results indicated that before the Paleogene there were two hydrocarbon-generating depressions: the Western Well Pen1 depression and the Changji depression on the south and north sides of the Che-Mo palaeohigh, respectively. The Permian source kitchen had been generating hydrocarbon continuously since Triassic and reached high maturity stage in the Cretaceous period. After Paleogene, the adjustment of the Che-Mo palaeohigh led to the subsidence of the Changji depression and the Jurassic source rocks reached mature stage and became the main source kitchens. However, the Jurassic source rocks in the Western Well Pen1 depression were still in a low maturity stage and did not generate oil because of the adjustment of tectonic movements. As a result, in the central and southern parts of the Junggar Basin, Jurassic source rocks generated oil, but in the Luliang uplift, the crude oil was from the Permian source rocks in the Western Well Pen1 depression and the Jurassic source rocks did not contribute. The crude oil in the central Zhengshacun-Moxizhuang belt was from the Permian source rocks in two depressions, and partially from the Jurassic source rocks. The crude oil in the Luliang uplift was from the source rocks of the lower Permian Fengcheng Formation and middle Permian Wuerhe Formation, which is characterized by superimposition of two sets of source kitchens and three accumulation stages. The crude oil in the Yongjin tectonic belt was from the lower Permian, middle Permian and Jurassic source rocks, which is characterized by superimposition of three sets of source kitchens and two accumulation stages. The crude oil in the Zhengshacun tectonic belt was from a combination of source kitchens of lower Permian and middle Permian in the Western Well Pen1 depression in the early stage and from the superimposition of Jurassic source rocks in the Changji depression in the late stage.

Stable carbon isotopes were used together with molecular markers to constrain genetic relationships between sandstone extracts and potential source rocks in the pre-Tertiary in the Huanghua Depression, North China. Comparison of the extracts from Permo-Carboniferous terrigenous mudstones and Ordovician marine carbonates indicated that their prominent differences are in stable carbon isotopes, molecular markers and thermal maturity. Although the extracts of the Mesozoic and Lower Permian Xiashihezi Formation sandstones have some similar isotopic characteristics, molecular markers data provide a good correlation between the Upper Jurassic-Lower Creta-ceous oils and the Upper Carboniferous Taiyuan Formation mudstones, and between the Lower Permian Xiashihezi Formation oils and the Lower Permian mudstones. The results showed that the Upper Jurassic-Lower Cretaceous sandstone oils were derived chiefly from the Upper Carboniferous Taiyuan Formation terrigenous mudstones and that the Lower Permian Xiashihezi Formation oils were sourced from the Lower Permian Shanxi Formation and Xiashihezi Formation terrigenous mudstones.