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During the Paleogene–Neogene, the Qaidam Basin was a saline lacustrine basin so the biomarkers of hydrocarbon source rocks exhibited unique characteristics under the salinization conditions. Saturated hydrocarbons extracted from a large number of source-rock samples were analyzed using gas chromatography and mass spectrometry. The results showed that n-alkanes in the source rocks were evenly distributed between even and odd carbon numbers, isoprenoid alkenes were predominantly phytanes, and ratios of pristane to phytane (Pr/Ph) were low, mostly in the range from 0.2 to 0.8. Terpanes typically showed high contents of C35 homohopane and gammacerane. Overall, the ratios of gammacerane to C30 hopane (gammacerane/C30 hopane) and C35–C34 homohopane (C35/C34 homohopane) exhibited a positive correlation. Differing concentrations of oleanane were detected. The relative content of C27 and C29 steranes in the hydrocarbon source rocks varied from 25 to 75%, and the relative content of C28 sterane in a considerable number of samples was higher than 30%. C27–C29 steranes generally showed an asymmetric V-shaped distribution, and the distribution of sterane/hopane and Pr/Ph ratios showed negative correlations. The salinity and reducibility indexes of the southern area of the Western Qaidam Basin were significantly higher than those of the northern area of the basin during the Oligocene–Miocene. Source rocks in the northern area were formed in a low-salinity and weakly reductive environment with type II2–III kerogen, whereas the hydrocarbon source rocks in the southern area formed in a high salinity and strongly reductive environment. The sedimentary water salinity and reducibility of the different areas were reduced in the following order: Hongliuquan, Yuejin, Shizigou, and Wunan–Lvcaotan. The best source rocks in this basin were developed in the Hongliuquan, Yuejin, and Shizigou areas with type II1–II2 kerogen. This study lays a foundation for further understanding the geochemical distribution of the hydrocarbon source rocks and crude oil in addition to the characteristics of the oil source in Paleogene and Neogene. [ABSTRACT FROM AUTHOR]

Hydrocarbon migration mechanism in deep Ordovician reservoir of the Halahatang area, Tarim Basin, is investigated based on the analysis of the geological setting and geochemical parameters. The parameters successfully analyzed include oil–gas properties, crude oil maturity [Ts/(Ts + Tm) ratio], gas carbon isotopic ratios, and trace elements (B, V, Ni, and Cu) in crude oil. The results show that hydrocarbons migrate into the Ordovician of the Halahatang area from the Manjiaer Depression and the Halahatang area itself through unconformities and faults. The overall hydrocarbon migration orientation in the area is generally from south to north. The oil and gas migration process determine parameters vary regularly from south to north as follows: oil density, V/Ni ratio, Ni/Cu ratio, and concentrations of V, Ni and (Ni + B) in crude oil regularly increase, whereas Ts/(Ts + Tm), gas/oil ratio, and dryness coefficient gradually decrease, and methane show a trend toward depletion of heavy carbon isotopes. Additionally, there exist obvious anomalies of geochemical parameter values in the Repu3 well block, which indicates that a local fault intersection could provide a favorable hydrocarbon filling point. Based on these findings, further exploration activities in the deep Ordovician reservoir of the Halahatang area should be conducted in the southern part of the Halahatang area along the oil charging pathways, and fault intersection zones should be emphasized. [ABSTRACT FROM AUTHOR]

Ectopic elution is a commonly used method for remediation of petroleum hydrocarbon contaminated soil. In the work, surfactant was used to wash petroleum hydrocarbon contaminated soil. Then, we investigated the effects of different surfactant combination ratio and concentration, the auxiliary concentration and temperature on the removal efficiency of petroleum hydrocarbon pollutants. The results showed that the oil solubilization capacity of Tw-80 was higher than that of SDS (Sodium dodecyl sulphate, SDS), and the removal rate of oil was the highest when the compound ratio of SDS/Tw-80 was 50-60. With the increase of surfactant concentration and temperature, the oil removal rate increased. The increase of alkaline solution was in favour of heavy oil separation and removal of tricyclic aromatic compounds. Sodium chloride, calcium chloride and magnesium chloride reduced the removal rate of oil, while sodium sulfate, sodium bicarbonate, sodium bicarbonate, sodium silicate and sodium phosphate increased the removal rate of oil. [ABSTRACT FROM AUTHOR]

The Dongpu Depression, containing huge amounts of hydrocarbons, is a typical petroliferous province in the Bohai Bay Basin, east China. As one set of the main source rocks, the first member of Shahejie Formation (E2s1) shows huge exploration potential with approximately 0.83 × 108 t resources remaining to be discovered. However, the geochemical characteristics and thermal evolution history of E2s1 source rocks have still not been determined. In this study, the sedimentary features were firstly analysed based on the geological data. Then the organic matter abundance, kerogen type, and thermal maturity of E2s1 source rocks in the present day were evaluated according to the Rock‐Eval pyrolysis, micro‐components of kerogen, total organic carbon (TOC), and vitrinite reflectance analysis. Furthermore, the evolution of thermal history and hydrocarbon generation was determined using the PetroMod procedure. The results show that dark mudstones and salt rocks were well developed in E2s1, which are propitious for organic matter to grow and preserve. E2s1 source rocks contain abundant organic matter and moderate to good generative source rock potential. E2s1 source rocks mainly consist of Type II kerogen and have entered early to maturation stage for hydrocarbon generation. Due to the limited buried depth, E2s1 source rocks only attained lower thermal maturity and generated finite hydrocarbons. The initial rapid subsidence and the second rift after uplift erosion resulted in the higher geo‐temperature at the end of E3d and the present day. Corresponding to the geo‐temperature evolution, there are two stages of hydrocarbon generation for E2s1 source rocks: The first stage was in the late E3d period, and the late stage was from the late Neogene to the present day. Moreover, the hydrocarbon generation rate and quantity of the late stage are much higher than the first stage, indicating the major hydrocarbon generation stage. Due to the limited hydrocarbon generation capacity, oils generated from E2s1 source rocks are low maturity; thus, it cannot migrate for a long distance and only accumulated around the sag belts. [ABSTRACT FROM AUTHOR]

A new natural product, 3α,19-dihydroxyl-ent-pimara-8(14),15-diene (1), which possesses an α-orientation hydroxymethyl at C-4 and ∆8,14 groups, as well as eight known compounds, was isolated from the rhizomes of Ricinus communis. The structure of 1 was elucidated by extensive spectroscopic methods and its absolute configurations were confirmed by X-ray crystallographic analysis. The inhibitory rate of 1 against protein tyrosine phosphatase 1B (PTP1B) was 49.49% at the concentration of 6.58 × 10−5 mol/L. [ABSTRACT FROM AUTHOR]

This article analyses the three main hydrocarbon markets in North Asia (oil, pipeline gas and liquified natural gas) and outlines their historical development and future potential with regard to China's Belt and Road Initiative (BRI). It concludes that that the oil market may evolve towards a proper regional market even without strong support from the BRI. By contrast, the regional gas pipeline development remains embryonic, while China might be willing to intensify the development of liquefied natural gas (LNG) as opposed to pipeline gas. The long-term market trend indicates that capital-intensive infrastructure projects are not always necessary during an energy glut. Instead of pipeline investment, the BRI should focus on the emergence of a decentralised market for the supply of LNG. [ABSTRACT FROM AUTHOR]

According to the new quantitative model for original total organic carbon (TOCo) evolution and recovery of source rocks, The TOCo evolution of muddy source rocks with different TOCs (MSRDTOC) (0.5% < TOC ≤ 1.5%, 2.5% < TOC ≤ 3.5% and 4.0% < TOC ≤ 6.0%, and their average values were 1.0%, 3.0% and 5.0%, respectively) and type III kerogen were investigated in the Western Sichuan Depression (WSD) of Sichuan Basin, China, finally recovery coefficients of TOCo were calculated. Studies showed that TOCo evolution of the MSRDTOC have similarities and differences. The similarities reveal that with the increase of thermal evolution level, varied TOC all reduce gradually and the sharp reduction occurs at the stage of a large number of hydrocarbon generation and expulsion (0.7% ≤ vitrinite reflectance (VR) ≤ 1.3%). The differences indicate that the starting time and decrease range for varied TOC are different. For TOCo = 1.0%, 3.0% and 5.0%, their starting time of TOC reduction are VR = 1.05%, 0.80% and 0.60%, respectively. When VR reaches to 3.0%, their TOC decrease ranges are 30.54%, 38.52% and 44.00% and their recovery coefficients are 1.44, 1.63 and 1.79, respectively. The higher the TOC is, the earlier the starting time of TOC reduction is, the bigger the range of TOC reduction and recovery coefficient are. It must restore TOCo when we evaluate source rocks at high-over mature stage and predict oil and gas resources. The MSRDTOC and their TOCo recovery should be evaluated, respectively. [ABSTRACT FROM AUTHOR]

The Chang-7 shale of the Upper Triassic Yanchang Formation was deposited in a deep-lacustrine environment in the southwest part of the Ordos Basin. It is characterized by a strong lithological heterogeneity, consisting primarily of pure shale and sandy laminated shale. This study explored the impact of sandy laminae in the thick pure shale on hydrocarbon generation, retention, and expulsion, which were rarely considered in previous studies. Based on core observation, thin section, and geochemical analysis, the hydrocarbon generation, retention, and expulsion characteristics were obtained for both pure shale and sandy laminated shale. In general, the Chang-7 shale stays at low mature to mature thermal evolution stage and has good hydrocarbon generation potential. It contains mainly Type II kerogen with an average total organic carbon (TOC) of 2.9% and average (S1 + S2) of 8.2 mg/g. Compared with sandy laminated shale, pure shale contains more retained liquid hydrocarbon and has a higher amount of asphaltene and nitrogen-sulfur-oxygen (NSO) polarized components, indicating a relatively weak hydrocarbon expulsion process. The middle part of a thick pure shale retains more liquid hydrocarbon and has higher percentages of asphaltene and NSO polarized components than that of the top and basal part of the shale where sandy laminae occur. The difference in hydrocarbon retention capacity is interpreted to have been primarily caused by the comparatively higher reservoir quality of the sandy laminated shale, having higher amount of brittle minerals and larger pores than the pure shale. Polymer dissolution and nanopore adsorption are also key factors in hydrocarbon retention and component partition. Based on this study, we suggest that sandy laminated shale, which receives most of the hydrocarbon from adjacent pure shale, should be the current favorable shale oil exploration targets. Even though pure shale contains high hydrocarbon potential, its development is still pending improved technologies, which could solve the challenges caused by complicated geological conditions. [ABSTRACT FROM AUTHOR]

Introduction: Adjuvant docetaxel-based chemotherapy is frequently used in the treatment of operable early breast cancer (EBC). This study investigated patterns of docetaxel use in patients with EBC in real-world clinical practice in China.Methods: This was a multicenter, prospective, observational study of Chinese women with operable breast cancer in tier 1 non-oncology-specific hospitals and other city hospitals in China. Adult Chinese female patients (≥ 18 years) with newly diagnosed breast cancer who underwent surgery and received docetaxel-containing adjuvant chemotherapy were eligible for inclusion. The primary end point of the study was to assess patterns of docetaxel use for adjuvant therapy in Chinese clinical practice. Secondary end points included factors associated with treatment selection, patterns of G-CSF use and safety.Results: In total, 502 patients were enrolled, 475 of whom were included in the analysis. The results showed that 31.6% of patients received docetaxel and anthracyclines in combination, 47.2% received docetaxel and anthracyclines sequentially, 18.5% received docetaxel and other medication either in combination or sequentially and 2.7% received 'other' chemotherapy regimens. Factors influencing selection of docetaxel/anthracycline in combination versus sequentially included age, breast cancer subgroup, PR status, and preoperative neoadjuvant chemotherapy. A total of 258 (54.3%), 35 (7.4%), and 108 (22.7%) patients received G-CSF as primary prevention, secondary prevention and treatment, respectively. Treatment-emergent adverse events (TEAEs) occurred in 54.5% (259) of patients, and the most frequently reported TEAEs (≥ 5% of patients) included bone marrow failure (10.1%), granulocytopenia (9.9%), nausea (8.8%) and vomiting (6.9%). Neutropenia and febrile neutropenia were reported by 10 and 12 patients, respectively.Conclusion: Docetaxel for adjuvant chemotherapy of operable EBC in China was most commonly given in combination or sequentially with anthracyclines. The study also showed that in China G-CSF is most frequently used as primary prophylactic, and no unexpected safety events were observed during docetaxel treatment.Funding: Sanofi (China). [ABSTRACT FROM AUTHOR]

Abnormal pressure commonly exists in the foreland basins which closely related to the oil and gas reservoir. Deep understanding of the distribution of abnormal pressure in reservoir and characterizing types of abnormal high pressure gas reservoir is a supplement to the theory of the fluid storage tank. ln this paper, the characteristics of abnormal high pressure distribution in typical foreland basins both at home and abroad and their relationship with gas reservoirs were analyzed in detail. Three types of abnormal high-pressure gas reservoirs are identified, including box type, top seal type and pressure transfer type. The box type is mainly characterized by the reservoir of source reservoir superposition with stable structure. The abnormal high pressure occurs in the reservoir and the cap rock, which mainly results from hydrocarbon supercharging and under-compacting deposition. The top seal type is predominated by high pressure in the cap rock, while the pressure in the reservoir is normal or abnormal high pressure. The abnormal high pressure may be caused by under-compacted deposition, strong oil and gas filling and tectonic compression. The pressure transfer type is dominated by secondary gas reservoirs With active tectonic. The pressure has a decreasing trend from deep to shallow, which is mainly sourced from the formation of pressure conduction caused by pressure relief or deterioration of storage conditions and lithological changes caused by fracture. The types of abnormal high-pressure gas reservoirs have a great significance to the exploration of abnormal high-pressure gas reservoirs and avoid accidents of drilling in foreland basins. [ABSTRACT FROM AUTHOR]

The Lower Cretaceous shales of Chagan Sag, Yingen‐Ejinaqi Basin, are considered as the source rocks of hydrocarbons discovered in the sag. Borehole shales from the Lower Cretaceous were subjected to comprehensive geochemical study to evaluate the quality of source rock, to reconstruct the paleodepositional environment and to determine the controlling factors of organic matter enrichment. Content of present‐day total organic carbon, and hydrogen index, averaging 1.4% and 259.2 mg hydrocarbon/g total organic carbon, respectively reveal poor to fair quality of organic matter. Average value of vitrinite reflectance (Ro) of 1.0% indicates mature organic matter. Maceral composition and biomarker analysis provide evidence for a mixed aquatic and terrigeous organic matter input. Based on Sr/Cu, Sr/Ba, and gammacerane index, we propose that organic matter was deposited in closed hypersaline under hot and arid climate conditions. The ratios of V/(V + Ni), and pristane/phytane (Pr/Ph), as well as the presence of β‐carotene suggest a stratified water column with anoxic bottom water condition. Low to moderate productivity as a result of deficient nutrient supply, the excellent organic matter preservation condition under stratified anoxic water column and high sedimentary rate controlled the quality of source rock. In addition, influence of factors such as content of clay minerals on organic matter enrichment cannot be ignored. [ABSTRACT FROM AUTHOR]

A suite of 27 oils from the Qinjiatun-Qikeshu oilfields in the Lishu Fault Depression of the Songliao Basin was analyzed using whole oil gas chromatography. In combination with the relative distribution of C27, C28, and C29 regular steranes, detailed geochemical analyses of light hydrocarbons in oil samples revealed crude oils characterized by the dual input of lower aquatic organisms and higher terrestrial plants. Several light hydrocarbon indicators suggest that the liquid hydrocarbons have maturities equivalent to vitrinite reflectances of around 0.78%-0.93%. This is consistent with the maturity determination of steranes C29 20S/(20S + 20R) and C29 ααβ/(ααα + αββ). Crude oils derived from the two distinct oilfields likely both have source rocks deposited in a lacustrine environment based on light hydrocarbon parameters and on higher molecular weight hydrocarbon parameters. The results show that light hydrocarbon data in crude oils can provide important information for understanding the geochemical characteristics of the Qinjiatun-Qikeshu oils during geologic evolution. [ABSTRACT FROM AUTHOR]

In order to study the mechanism of gas generation from the asphaltene, the thermal pyrolysis simulation experiment of the asphaltene is carried out by using high temperature and high pressure closed system. During asphaltene pyrolysis, the amount of methane is constantly increased but those of ethane, propane, and butane + pentane are all first increased and then decreased and eventually go to zero with the increase of the experiment temperature. And the dynamic parameters of gaseous hydrocarbon generation can be used to analyze the dynamic procedure of the asphaltene pyrolysis at the geological scale. The experimental results can perfect the theory of the origin of natural gas and provide an evidence for source judgment and resource evaluation of natural gas in marine strata in China. [ABSTRACT FROM AUTHOR]

The Anyue giant gasfield was discovered in the Sinian-Cambrian Central Sichuan region of the Sichuan Basin in 2013, with geological reserves up to 1×1012m3, which is the first time for the exploration of natural gas paleo-reservoirs in the world. The gas source studies suggest that the Sinian natural gas is originated from the Sinian and Cambrian hydrocarbon source rocks, and the systematical study on the Sinian and Cambrian ancient source rocks has important scientific and practical significance for the global oil and gas geologic domain of the ancient stratum. Based on the drilling data and field profile observation of Sinian and Cambrian in Sichuan Basin, with adoption of the interpretation data of 28 000 km-seismic and new drilling data, combined with geochemical analysis of source rocks of 2 315 samples, this paper systematically studied the high quality hydrocarbon source rock center, where the source rocks are mainly distributed along the Mianzhu-Changning craton inner rift, with a accumulative thickness reaching 200-450m, and 50-100m for the thickness of source rocks in other areas. The hydrocarbon source rocks of the Sinian-Cambrian contributed about 56%-63% of natural gas resources of the whole basin. Systematical evaluations have been conducted to the mudstone source rocks and their distribution in the Ⅲ-section of Sinian Dengying Formation, where TOC value is ranging from 0.04% to 4.73%, with an average of 0.65%. The thickness of the source rocks in central Sichuan region is ranging from 10 to 30 m. The oldest Sinian source rocks that can form large gasfields in China were systematically studied for the first time,and the total gas production intensity of the Sinian source rocks in the great central Sichuan region is (15-28)×108m3/km2, where the gas source conditions for the formation of large gasfields are available. By using the genetic method and analogy method, the amount of natural gas resources of the Sinian-Cambrian in the basin are re-evaluated as (4.65-5.58)×1012m3, and the resources potential of natural gas is huge. The amount of natural gas resources in the central Sichuan block accounts for about 66% of the total basin resources, which is the preferred selection for current exploration. [ABSTRACT FROM AUTHOR]

The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient (the ratio of the actual pore pressure versus hydrostatic pressure at the same depth) over 2.27. However, there exists a widespread low-overpressure interval between the strong overpressure intervals in the Yanan Sag of western basin. The mechanisms of the low-overpressure interval are not well understood. Three main approaches, pore pressure test data and well-log analysis, pressure prediction based on the relationship between the deviation of the velocity and the pressure coefficients, and numerical modeling, were employed to illustrate the distribution and evolution of the low-overpressure interval. And we analyzed and explained the phenomenon of the low-overpressure interval that is both underlain and overlain by high overpressure internal. The low-overpressure interval between the strong overpressure intervals can be identified and modelled by drilling data of P-wave sonic and the mud weight, and the numerical modeling using the PetroMod software. Results show that the low-overpressure interval is mainly composed of sandstone sediments. The porosities of sandstone in the low-overpressure interval primarily range from 15%-20%, and the permeabilities range from 10–100 md. Analysis of the geochemical parameters of C1, iC4/nC4, ΔR3, and numerical modeling shows that oil and gas migrated upward into the sandstone in the low-overpressure interval, and then migrated along the sandstone of low-overpressure interval into the Yacheng uplift. The low-overpressure both underlain and overlain by overpressure resulted from the fluids migrating along the sandstones in the low-overpressure interval into the Yacheng uplift since 1.9Ma. The mudstone in the strong overpressure interval is good cap overlain the sandstone of low-overpressure interval, therefore up-dip pinchouts or isolated sandstone in the low-overpressure interval locating the migration path of oil and gas are good plays for hydrocarbon exploration. [ABSTRACT FROM AUTHOR]

The faults that developed in the Liaoxi Depression can be classified into three types according to their extent and connectivity with the source and reservoir rocks (i.e. type I faults, type II faults and type III faults). These faults played different roles in controlling the basin geomorphology; the formation and evolution of the source rocks, reservoir rocks, cap rocks and traps; and the migration and accumulation of hydrocarbons in the Liaoxi Depression. Extending from the basement to the Neogene strata, type I faults, which are the largest in the basin, mainly controlled the development and basin-scale geomorphology; type II faults mainly controlled the sub-tectonic zones; and type III faults mainly controlled the formation and evolution of the traps. The movements of type I and type II faults during the hydrocarbon expulsion period were closely related to oil and gas migration. The rates of fault activity varied among the different sags of the Liaoxi Depression. Type I faults in both the northern and southern sags appear to have moved considerably during the hydrocarbon generation and expulsion stages, which strongly promoted hydrocarbon migration, whereas weakly active type I faults in the central sag made limited contributions to hydrocarbon migration. The sealing behaviour of the faults controlled the hydrocarbon migration directions and locations, and the good lateral sealing ability of the type I faults in the northern and southern sags confined the accumulation of hydrocarbons within the sags independently. However, the type I faults in the central sag partially opened laterally, which increased the likelihood of hydrocarbon migration from the sag centre to the uplift and reduced the likelihood of hydrocarbon accumulation within the sag centre. Therefore, the oil- and gas-enrichment patterns in the Liaoxi Depression are closely related to the characteristics of the faults, with traps near types I and II faults showing an increased likelihood of oil- and gas-field formation, as observed with the JZ9-3, LD4-2 and LD5-2 wells, and traps located in the sags remote from types I and II faults showing a reduced likelihood of oil and gas accumulation. [ABSTRACT FROM PUBLISHER]

A new brominated polyacetylene, xestonariene I (1), along with three known related analogues (2–4), was obtained from Chinese marine spongeXestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and by comparison with literature data. Compound4exhibited significant inhibitory activity against pancreatic lipase, which plays a key role in preventing obesity, with an IC50value of 0.61 μM, being comparable to that of the positive control orlistat (IC50 = 0.78 μM). [ABSTRACT FROM PUBLISHER]

Tectonic uplift is the most direct manifestation of tectonic activity, and tectonic deformation strength can be quantitatively shown through uplift height and speed. In this study, balanced rebound and oxygen isotope method are adopted to calculate maximum paleoelevation of stratum uplift of southeastern area of Sichuan Basin since Late Cretaceous due to tectonic activities. And based on current surface elevation of the target area, stratum erosion thickness of southeastern Sichuan during this period is calculated, thereby providing technical support for evaluation of the regional oil and gas exploration. Studies have shown that maximum paleoelevation of southeastern Sichuan uplift is gradually increased from NW to SE, which can maximally achieve 3813 m. Denudation quantity from Sichuan Basin to Qiyushang is gradually increased, and region with greater erosion thickness is above 2800 m. Since the Late Cretaceous, southeastern Sichuan stratum uplift makes oil and gas in Dingshan block gradually dissipate. Also, overlying rock unloading results in fault development, early fault activation, and expansion, which further exacerbates destroy of oil and gas reservoir in Dingshan block of southeastern Sichuan, China. [ABSTRACT FROM AUTHOR]

Deep fluids in a petroliferous basin generally come from the deep crust or mantle beneath the basin basement, and they transport deep substances (gases and aqueous solutions) as well as heat to sedimentary strata through deep faults. These deep fluids not only lead to large-scale accumulations of CO2, CH4, H2, He and other gases, but also significantly impact hydrocarbon generation and accumulation through organic-inorganic interactions. With the development of deep faults and magmatic-volcanic activities in different periods, most Chinese petroliferous basins have experienced strong impacts associated with deep fluid activity. In the Songliao, Bohai Bay, Northern Jiangsu, Sanshui, Yinggehai and Pearl Mouth Basins in China, a series of CO2 reservoirs have been discovered. The CO2 content is up to 99%, with δ13CCO2 values ranging from -4.1‰ to -0.37‰ and 3He/4He ratios of up to 5.5 Ra. The abiogenic hydrocarbon gas reservoirs with commercial reserves, such as the Changde, Wanjinta, Zhaozhou, and Chaoyanggou reservoirs, are mainly distributed in the Xujiaweizi faulted depression of the Songliao Basin. The δ13CCH4 values of the abiogenic alkane gases are generally >-30‰ and exhibit an inverse carbon isotope sequence of δ13CCH4>δ13CC2H6>δ13CC3H8>δ13CC4H10. According to laboratory experiments, introducing external H2 can improve the rate of hydrocarbon generation by up to 147% through the kerogen hydrogenation process. During the migration from deep to shallow depth, CO2 can significantly alter reservoir rocks. In clastic reservoirs, feldspar is easily altered by CO2-rich fluids, leading to the formation of dawsonite, a typical mineral in high CO2 partial pressure environments, as well as the creation of secondary porosity. In carbonate reservoirs, CO2-rich fluids predominately cause dissolution or precipitation of carbonate minerals. The minerals, e.g., calcite and dolomite, show some typical features, such as higher homogenization temperatures than the burial temperature, relatively high concentrations of Fe and Mn, positive Eu anomalies, depletion of 18O and enrichment of radiogenic 87Sr. Due to CO2-rich fluids, the development of high-quality carbonate reservoirs is extended to deep strata. For example, the Well TS1 in the northern Tarim Basin revealed a high-quality Cambrian dolomite reservoir with a porosity of 9.1% at 8408 m, and the Well ZS1C in the central Tarim Basin revealed a large petroleum reserve in a Cambrian dolomite reservoir at ∼6900 m. During the upward migration from deep to shallow basin strata, large volumes of supercritical CO2 may extract petroleum components from hydrocarbon source rocks or deep reservoirs and facilitate their migration to shallow reservoirs, where the petroleum accumulates with the CO2. Many reservoirs containing both supercritical CO2 and petroleum have been discovered in the Songliao, Bohaiwan, Northern Jiangsu, Pearl River Mouth and Yinggehai Basins. The components of the petroleum trapped with CO2 are dominated by low molecular weight saturated hydrocarbons. [ABSTRACT FROM AUTHOR]

The different agreements on oil and natural gas signed by Russian and Chinese companies testify to the profound changes in the oil and gas policies of both Russia and China. We stress the importance of the contractual norms which structure the energy interdependency of the countries involved. As there is no international multilateral framework able to manage energy supply security, the way the countries involved construct their energy interdependence to an extent defines models of sectoral governance. [ABSTRACT FROM PUBLISHER]

The mechanism of hydrogen sulfide (HS) generation plays a key role in the exploration and development of marine high-sulfur natural gas, of which the major targets are the composition and isotope characteristics of sulfur-containing compounds. Hydrocarbon source rocks, reservoir rocks, natural gases and water-soluble gases from Sichuan Basin have been analyzed with an online method for the content of HS and isotopic composition of different sulfur-containing compounds. The results of comparative analysis show that the sulfur-containing compounds in the source rocks are mainly formed by bacterial sulfate reduction (BSR), and the sulfur compounds in natural gas, water and reservoir are mainly formed by thermal sulfate reduction (TSR). Moreover, it has been shown that the isotopically reversion for methane and ethane in high sulfur content gas is caused by TSR. The sulfur isotopic composition of HS in natural gas is inherited from the gypsum or brine of the same or adjacent layer, indicating that the generation and accumulation of HS have the characteristics of either a self-generated source or a near-source. [ABSTRACT FROM AUTHOR]

To achieve a better understanding of Holocene climate change in the monsoon regions of China, we investigated the molecular distributions and carbon and hydrogen isotope compositions (δ13C and δD values) of long-chain n-alkanes in a peat core from the Shiwangutian (SWGT) peatland, south China over the last 9 ka. By comparisons with other climate records, we found that the δ13C values of the long-chain n-alkanes can be a proxy for humidity, while the δD values of the long-chain n-alkanes primarily recorded the moisture source δD signal during 9–1.8 ka BP and responded to the dry climate during 1.8–0.3 ka BP. Together with the average chain length (ACL) and the carbon preference index (CPI) data, the climate evolution over last 9 ka in the SWGT peatland can be divided into three stages. During the first stage (9–5 ka BP), the δ13C values were depleted and CPI and Paq values were low, while ACL values were high. They reveal a period of warm and wet climate, which is regarded as the Holocene optimum. The second stage (5–1.8 ka BP) witnessed a shift to relatively cool and dry climate, as indicated by the more positive δ13C values and lower ACL values. During the third stage (1.8–0.3 ka BP), the δ13C, δD, CPI and Paq values showed marked increase and ACL values varied greatly, implying an abrupt change to cold and dry conditions. This climate pattern corresponds to the broad decline in Asian monsoon intensity through the latter part of the Holocene. Our results do not support a later Holocene optimum in south China as suggested by previous studies. [ABSTRACT FROM AUTHOR]

In 2013, a great breakthrough of deep petroleum exploration was achieved in the Cambrian pre-salt intervals of Wells Zhongshen1 (ZS1) and Zhongshen1C (ZS1C), Tazhong Uplift. However, the hydrocarbon discovery in the Cambrian pre-salt intervals has triggered extensive controversy regarding the source of marine oils in the Tarim Basin. The geochemistry and origin of the Cambrian pre-salt hydrocarbons in Wells ZS1 and ZS1C were investigated using GC, GC-MS and stable carbon isotope technique. These hydrocarbons can be easily distinguished into two genetic families based on their geochemical and carbon isotopic compositions. The oil and natural gases from the Awatage Formation of Well ZS1 are derived from Middle- Upper Ordovician source rocks. In contrast, the condensate and gases from the Xiaoerbulake Formation of Wells ZS1 and ZS1C probably originate from Cambrian source rocks. The recent discovery of these hydrocarbons with two different sources in Wells ZS1 and ZS1C suggests that both Middle-Upper Ordovician-sourced hydrocarbons and Cambrian-sourced petroleums are accumulated in the Tazhong Uplift, presenting a great exploration potential. [ABSTRACT FROM AUTHOR]

Background: Since the novel H7N9 avian influenza outbreak occurred in China in 2013, neuraminidase inhibitors (NAIs) such as oseltamivir and peramivir have been used as first-line drugs to treat the influenza virus infection. This study aimed to compare the efficacy of oseltamivir-peramivir combination therapy versus oseltamivir monotherapy.Methods: A retrospective study of 82 H7N9 confirmed patients was conducted by reviewing medical charts at the First Affiliated Hospital of ZheJiang University in China from April 1, 2013 to Feb 28, 2014. The patients' clinical information was collected systematically, and we compared the virology and clinical data between oseltamivir monotherapy group (43 patients) and oseltamivir-peramivir combination group (39 patients).Results: The median duration from NAIs administration to H7N9 virus-negative in oseltamivir monotherapy group and oseltamivir-peramivir combination group was 6.50 and 7.00 days (p >0.05), respectively. The median decline of Day 2 to Day 0 (initiation of NAIs therapy) viral load was 0.00 and 0.69 log10 copies/μl (p >0.05) respectively in the monotherapy vs. combination therapy groups. The incidence of new Acute Respiratory Distress Syndrome during NAI administration was 63.89 and 77.78 % (p >0.05); while the mortality rates were 25.58 and 43.59 % (p >0.05) in the oseltamivir group vs. oseltamivir-peramivir group.Conclusions: Our results suggest that in adults with H7N9 virus infection, the use of oseltamivir-peramivir combination therapy was not superior to oseltamivir monotherapy. [ABSTRACT FROM AUTHOR]

Cost overruns are prevalent in hydrocarbon (oil and gas) megaprojects. A recent report indicates that 64% of ongoing megaprojects globally are facing cost overruns. Despite their increasing occurrence, there has been limited published research in the mainstream literature that has specifically examined why and how they occur. Consequently, suggestions regarding how to constructively address cost overruns in hydrocarbon megaprojects are scant. To better understand the causal nature of cost overruns in hydrocarbon megaprojects, this article provides a critical review of the extant literature. Findings from the research indicate that complex interactions between project characteristics, people, technology, and structure and culture contribute to cost overruns occurring. As a result, it is suggested that chaos theory can be used to explain how cost overruns arise in hydrocarbon megaprojects. This article provides a reference point for engendering future research in this pervasive and fertile area. [ABSTRACT FROM AUTHOR]

Cholestasis causes hepatic accumulation of bile acids leading to liver injury, fibrosis and liver failure. Paeoniflorin, the major active compound isolated from the roots of Paeonia lactiflora pall and Paeonia veitchii Lynch, is extensively used for liver diseases treatment in China. However, the mechanism of paeoniflorin's hepatoprotective effect on cholestasis has not been investigated yet. In this study, we administered paeoniflorin to rats for 3 days prior to alpha-naphthylisothiocyanate (ANIT) administration for once, then went on administering paeoniflorin to rats for 3 days. The data demonstrated that paeoniflorin significantly prevented ANIT-induced change in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP), serum total bilirubin (TBIL), direct bilirubin (DBIL), total bile acid (TBA) and gamma-glutamyl transpeptidase (γ-GT). Histology examination revealed that paeoniflorin treatment rats relieved more liver injury and bile duct proliferation than ANIT-administered rats. Moreover, our data indicated that paeoniflorin could restore glutathione (GSH) and its related synthase glutamate-cysteine ligase catalytic subunit (GCLc) and glutamate-cysteine ligase modifier subunit (GCLm) in ANIT-treated group. In addition, the RNA and protein expression of Akt and nuclear factor-E2-related factor-2 (Nrf2) were also activated by paeoniflorin in ANIT-induced rats. These findings indicated that paeoniflorin protected ANIT-induced cholestasis and increased GSH synthesis by activating Nrf2 through PI3K/Akt-dependent pathway. Therefore, paeoniflorin might be a potential therapeutic agent for cholestasis. [ABSTRACT FROM AUTHOR]

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Data on the physicochemical properties and the hydrocarbon and trace-element compositions of hydrocarbon fluids from various oil and gas basins in China have been analyzed and summarized. The distribution of a wide range of hydrocarbon biomarkers in crude oils has been correlated with the salinity of lacustrine sediments. The variety of facies that characterize the burial and transformation of the original hydrocarbon-generating organic matter is reflected in particular features of oil composition. The parameters identified are recommended for geochemical correlation of crude oils with rock organic matter and for prediction of the physicochemical properties or the hydrocarbon and trace-element compositions of oil accumulations. [ABSTRACT FROM AUTHOR]

The effects of high pressures on the yield and kinetics of gas generated by the cracking of crude oil were investigated in laboratory simulation experiments. Samples of a low-maturity non-marine oil were recovered from the Paleogene Shahejie Formation in the Dongying depression, Bohai Bay Basin, eastern China. The oils were cracked to gas under different pressure and temperature conditions in an autoclave. Initial temperatures of 300 °C were increased to 650 °C at rates of either 30 or 100 °C/h. Reaction products were analysed at the end of each 50 °C temperature increase. Pressure conditions were either 0.1 MPa (i.e. atmospheric) or 20 MPa. Results show that high pressures inhibit or delay oil-to-gas cracking and retard the initiation of the cracking process. The temperature at which oil was cracked and the activation energy of the formation of C1-5 hydrocarbons increased under high pressure conditions, demonstrating the effects of pressure on the kinetics of the oil-to-gas cracking process. High pressures and high temperatures inhibited the conversion of C2-5 hydrocarbons to methane during secondary cracking. In addition, high pressures retarded the generation of N2, H2 and CO during cracking of oil. The presence of water increased the yields of total cracked gas, C2-5 hydrocarbons and CO2 in high-pressure conditions. The simulation results show that CO2 and C2-5 hydrocarbons have similar yields during oil-to-gas cracking. Using the kinetic parameters determined from the laboratory experiments, the yield and production rate of gas generated during the cracking of oil from Member 4 of the Paleogene Shahejie Formation in the Minfeng-Lijin sag (Dongying depression) were calculated. The results indicate that only limited volumes of natural gas in this area were derived from the cracking of oil, and that most of the gas was derived from the thermal decomposition of kerogen. [ABSTRACT FROM AUTHOR]

The Pearl River Canyon system is a typical canyon system on the northern continental slope of the South China Sea, which has significant implications for hydrocarbon exploration. Through swath bathymetry in the canyon area combined with different types of seismic data, we have studied the morphotectonics and controlling factors of the canyon by analyzing its morphology and sedimentary structure, as well as the main features of the continental slope around the canyon. Results show that the Pearl River Canyon can be separated into three segments with different orientations. The upper reach is NW-oriented with a shallowly incised course, whereas the middle and lower reaches, that are located mainly in the Baiyun Sag, have a broad U-shape and have experienced consistent deposition. Seventeen deeply-cut canyons have developed in the slope north of the Baiyun Sag, playing an important role in the sedimentary processes of the middle and lower reaches of the Pearl River Canyon. These canyons display both asymmetrical V- and U-shapes along their lengths. Numerous buried channels can be identified below the modern canyons with unidirectionally migrating stacking patterns, suggesting that the canyons have experienced a cyclic evolution with several cut and fill phases of varying magnitude. These long established canyons, rather than the upper reach of the Pearl River Canyon, are the main conduits for the transport of terrigenous materials to the lower slope and abyssal basin during lowstand stage, and have contributed to the formation of vertically stacked deep-water fans in the middle reach. Canyon morphology is interpreted as a result of erosive sediment flows. The Pearl River Canyon and the 17 canyons in the slope area north of the Baiyun Sag probably have developed since the Miocene. Cenozoic tectonics, sea level change and sediment supply jointly control the morphology and sedimentary structure. The middle and lower reaches of the Pearl River Canyon developed on the paleo-terrain of the Baiyun Sag, which has been a persistently rapid depositional environment, receiving most of the materials transported via the canyons. [ABSTRACT FROM AUTHOR]

Northward subduction of the Cenozoic Tethys ocean caused the convergence and collision of Eurasia-Indian Plates, resulting in the lower crust thickening, the upper crust thrusting, and the Qinghai-Tibet uplifting, and forming the plateau landscape. In company with uplifting and northward extruding of the Tibetan plateau, the contractional tectonic deformations persistently spread outward, building a gigantic basin-range system around the Tibetan plateau. This system is herein termed as the Circum-Tibetan Plateau Basin-Range System, in which the global largest diffuse and the most energetic intra-continental deformations were involved, and populations of inheritance foreland basins or thrust belts were developed along the margins of ancient cratonic plates due to the effects of the cratonic amalgamation, crust differentiation, orogen rejuvenation, and basin subsidence. There are three primary tectonic units in the Circum-Tibet Plateau Basin-Range System, which are the reactivated ancient orogens, the foreland thrust belts, and the miniature cratonic basins. The Circum-Tibetan Plateau Basin-Range System is a gigantic deformation system and particular Himalayan tectonic domain in central-western China and is comparable to the Tibetan Plateau. In this system, northward and eastward developments of thrust deformations exhibit an arc-shaped area along the Kunlun-Altyn-Qilian-Longmenshan mountain belts, and further expand outward to the Altai-Yinshan-Luliangshan-Huayingshan mountain belts during the Late Cenozoic sustained collision of Indo-Asia. Intense intra-continental deformations lead ancient orogens to rejuvenate, young foreland basins to form in-between orogens and cratons, and thrusts to propagate from orogens to cratons in successive order. Driven by the Eurasia-Indian collision and its far field effects, both deformation and basin-range couplings in the arc-shaped area decrease from south to north. When a single basin-range unit is focused on, deformations become younger and younger together with more and more simple structural styles from piedmonts to craton interiors. In the Circum-Tibetan Plateau Basin-Range System, it presents three segmented tectonic deformational patterns: propagating in the west, growth-overthrusting in the middle, and slip-uplifting in the east. For natural gas exploration, two tectonic units, both the Paleozoic cratonic basins and the Cenozoic foreland thrust belts, are important because hydrocarbon in central-western China is preserved mainly in the Paleozoic cratonic paleo-highs and the Meso-Cenozoic foreland thrust belts, together with characteristics of multiphrase hydrocarbon generation but late accumulation and enrichment. [ABSTRACT FROM AUTHOR]

In order to investigate the distribution of the total petroleum hydrocarbons (TPH) in groundwater and soil, a total of 71 groundwater samples (26 unconfined groundwater samples, 37 confined groundwater samples, and 8 deeper confined groundwater samples) and 80 soil samples were collected in the Songyuan oilfield, Northeast China, and the vertical variation and spatial variability of TPH in groundwater and soil were assessed. For the groundwater from the unconfined aquifer, petroleum hydrocarbons were not detected in three samples, and for the other 23 samples, concentrations were in the range 0.01-1.74 mg/l. In the groundwater from the confined aquifer, petroleum hydrocarbons were not detected in two samples, and in the other 35 samples, the concentrations were 0.04-0.82 mg/l. The TPH concentration in unconfined aquifer may be influenced by polluted surface water and polluted soil; for confined aquifer, the injection wells leakage and left open hole wells may be mainly responsible for the pollution. For soils, the concentrations of TPH varied with sampling depth and were 0-15 cm (average concentration, 0.63 mg/g), >40-55 cm (average concentration, 0.36 mg/g), >100-115 cm (average concentration, 0.29 mg/g), and >500-515 cm (average concentration, 0.26 mg/g). The results showed that oil spillage and losses were possibly the main sources of TPH in soil. The consequences concluded here suggested that counter measures such as remediation and long-term monitoring should be commenced in the near future, and effective measures should be taken to assure that the oilfields area would not be a threat to human health. [ABSTRACT FROM AUTHOR]

The chemical characteristics of Ordovician formation water and its relationship with hydrocarbons in the Halahatang depression (Tabei Uplift, Tarim Basin, NW China) were analyzed on the basis of the detailed formation water test data. The formation water in the Halahatang depression can be characterized as CaCl2 type with high total dissolved solids (TDS) generally. The TDS concentration has a weak negative relationship with the depth, and is above 200 g/L in the North Region (north of the pinch-out line), then gradually decreases to the south, but is still greater than 50 g/L. The ion-proportionality coefficients of formation water, including the sodium-chlorine coefficient, desulfurization coefficient and metamorphic coefficient, reflect that the present strata are well sealed and had once experienced strong water-rock interactions. Furthermore, the source and evolution of the formation water presents a closed relationship with the hydrocarbon accumulation. The meteoric source of the formation water indicates the denuding by the Ordovician formation and the damage from the previous oil and gas reservoirs. The reservoir quality was also improved due to the strong karstification during the denudation, which was beneficial for hydrocarbon accumulation. The distribution of the TDS concentration is controlled by the caprock (Sangtamu Formation) and the high salinity fluids from overlying strata and adjacent regions. A geological model was established, the high salinity fluids penetrated the Ordovician strata resulting in the TDS increases in the northern part. Whereas, the South Region (south of the pinch-out line) was less affected due to the shielding layer of the O3s. The favorable preservation conditions reflected by the high TDS and ion-proportionality coefficients correspond to the stable subsidence of strata since the Triassic era, the oil and gas reservoirs formed in the Himalayan can be preserved. [ABSTRACT FROM AUTHOR]

Terrestrial faulted lacustrine basin is considered as a favorable place for the development of source rocks, especially the fault basins in eastern China. Based on molecular composition study of saturated and aromatic hydrocarbons in the extracts of source rocks of the Yingcheng and Shahezi formations in the Lishu Fault Depression, it is revealed that the extracts of source rocks are provided with low ratio of Pr/Ph, low content of C tetracyclic terpanes, high content of tricyclic terpanes and gammacerane, relatively high content of C steranes in the sag belt and its periphery; relatively high ratio of Pr/Ph, relatively high content of tetracyclic terpanes and gammacerane, low content of C steranes and obvious advantages of C steranes in its gentle slope belt; with high ratio of Pr/Ph, high content of C, C tricyclic and C tetracyclic terpanes, very low content of gammacerane and C steranes, and high content of C steranes in the edge of fault depression. According to the organic matter input and sedimentary environment, three types of source rocks have been established, which, respectively, are the mode of mixing organic matter input in deep and semi-deep lake, the advantage of terrigenous input in shallow lake and terrigenous input in shore-shallow lacustrine. The first mode is supposed to generate oil and gas, while the second one tends to generate oil. The distribution characteristics of oil and gas in the Lishu Fault Depression are very likely to be controlled by hydrocarbon generating characteristic of different source rock types. [ABSTRACT FROM AUTHOR]

The article presents abstracts on geological topics which include the relationship between earthquakes and hydrocarbon accumulation, the morphology of the Pearl River Canyon in China, and the structure of the Sichuan basin, China.

The Chipu Mississippi Valley-type (MVT) deposit is located on the southwest (SW) margin of the Sichuan Basin. Occurrence of plentiful organic matter (bitumen) at this deposit and abundant hydrocarbon reservoirs in the SW Sichuan Basin implies a link between lead–zinc mineralization and hydrocarbon systems in this area. The high δ34S values of most metal sulphides from the different ore stages suggest that H2S-bearing gases and/or thermochemical sulphate reduction (TSR) by organic matter could have been the source of reduced sulphur involved in ore formation. Sulphides with small positive to negative δ34S values can be attributed to organically bound sulphur at the Chipu deposit. Carbon and oxygen isotopic compositions from sparry carbonates suggest mixing of organic carbon with seawater-derived carbon in the mineralization process. From the early to the later ore stages, δ13CPDBvalues of ore-hosting carbonates are increasingly more negative, which indicates strengthening of the TSR role during mineralization. Hydrogen and oxygen isotopes in fluid inclusions in the quartz gangue indicate the provenance of the ore-forming fluids in the hydrocarbons. Moreover, some extremely low hydrogen isotope values suggest the addition of hydrogen from the same source. The low H/C ratios and high non-hydrocarbon component of the bitumen (Zhanget al. 2010) also suggest that the organic matter may have been involved in TSR and subjected to a strong oxidation by ore-bearing fluids. This study attempts to explain the lead–zinc mineralization process and the role of organic matter in it. As there is a demonstrable relationship between the evolution of the hydrocarbons and regional lead–zinc mineralization along the SW edge of the Sichuan Basin, we propose a possible model in which the MVT mineralization coincided with the degradation of hydrocarbon reservoirs due to the large-scale migration of basinal fluids, most likely driven by the late Indosinian orogeny in response to the closure of the Palaeo-Tethys Ocean. [ABSTRACT FROM AUTHOR]

Here we present six key parameters that have been applied to evaluate the Silurian Longmaxi shale gas accumulations of southern Sichuan Province. These parameters include richness of organic matter, single layer shale thickness, burial depth of the shale, maturity, shale properties, and brittle mineral content. In combination with drilling data, the lower limits of these six parameters for marine shale gas have been evaluated and the following conclusions are drawn: (1) Organic carbon recovery, gas content inversion, and production tests have been applied for the first time to measure the lower limit of TOC, which is determined to be 1.0%. (2) Based on the hydrocarbon generation and expulsion theory for source rocks and the characteristics of Longmaxi shale, the lower limit of the single-layer thickness is estimated to be 30 m, of which a thickness of at least 15 m should contain high-quality shale. (3) Based on the correlation of TOC and porosity, the lower limit of gas-filled porosity is 1.2%. (4) Other parameters, such as maturity, burial depth, and brittle mineral content have also been studied with regard to the geologic conditions of southern Sichuan. Based on the study results, an evaluation index system has been established for highly evolved marine shale gas, and the system has been applied successfully to geologically screened shale gas occurrences in southern Sichuan Province. [ABSTRACT FROM AUTHOR]

The Tahe-Lunnan hydrocarbon province is China's largest region with oil-and-gas-producing marine carbonate rocks. However, in terms of multi-source hydrocarbon generation, multi-episode reservoir adjustment and reconstruction, it remains unsettled how to determine the geological period of primary hydrocarbon filling of the Ordovician reservoir in this region. Based on the analysis of distribution and properties of reservoir, hydrocarbon filling of the Cambrian source rocks in the Late Caledon stage has largely been destroyed. However, hydrocarbon filling of the Middle Ordovician source rocks in the Early Carboniferous resulted in the major body of crude oil. During the charging process, the hydrocarbons were oxidatively degraded to heavy oil due to the poor closure conditions, which is corroborated by homogenization temperature of inclusions. Moreover, the capturing of hydrocarbon inclusions with high-temperature does not represent the filling of mature petroleum in the later period, but represents the result of the natural gas containing light fraction. Therefore, the Tahe-Lunnan area underwent two hydrocarbon filling processes, and the invasion of excessive dry gas led to a gas-washing fractionation upon the original Ordovician reservoirs. [ABSTRACT FROM AUTHOR]

The Xiangjiang River (XR), located in Hunan province in south-central China, is the second largest tributary of the Yangtze River. The occurrence, and sources of the polycyclic aromatic hydrocarbons (PAHs) in the 20 surface sediment samples from XR were analyzed, and the biological risks of the PAHs on the benthic organisms were assessed using sediment quality guidelines. The results showed that the occurrence level of the 16 USEPA priority PAHs in the surface sediments ranged from 190 to 983 ng/g (dry weight) with a mean concentration of 452 ± 215 ng/g. The concentration of phenanthrene was the highest with a mean concentration of 104 ± 44 ng/g. The compositions and principal components analysis indicated that the PAHs in the sediments in XR were mainly from pyrogenic sources which could be attributed to the open burning of rice straws and coal combustion of the local industries in the XR basin. The PAH contamination in the sediments was considered to be moderate, and has posed a small adverse biological effect on the benthic organisms. [ABSTRACT FROM AUTHOR]

The semi-closed pyrolysis simulation system under constant pressure was conducted to explore the characteristics and mechanisms of hydrocarbon generation from Xiamaling Formation shale in Xiahuayuan, North China. The experiment results indicate the oil generated by the Xiamaling Formation shale in oil window should be classified as 'aromatic-intermediate' type, whereas the decreasing of dry coefficient can be ascribed to the cracking of residual bitumen in source rock in the stage of high to post maturity. The amount of hydrocarbon gas generated from residual bitumen can be up to 1-2 m per ton rock in high to post mature stage by calculating hydrogen contents in the kerogen, the expelled hydrocarbon, and the residual hydrocarbon. This reveals the importance of residual bitumen as a gas source during high to post mature stage of the kerogen evolution, and also as the broad exploration prospect of these gases. This research highlights the attention should be paid to oil/gas reservoirs sourced from residual bitumen of organic-rich source rock in high mature stage, even the primary oil/gas reservoirs considered as the main exploration targets in middle-upper Proterozoic sediments of North China. [ABSTRACT FROM AUTHOR]

The Sinian Dengying Formation in China hosts one of the oldest gas-bearing reservoirs in the world. With a long geological history, it has developed into the reservoir rocks, whose quality depends on chemical dissolution and cementation. Despite presence of cavities and pores in the algal dolomites of the Dengying Formation, they were mostly filled with various forms of dolomite cements. Therefore, the investigation of these dolomites and their evolution is significant for analyzing the mechanism of pore space preservation. There are five types of cements in the Dengying Formation, which were well sampled for lab measurements such as thin section, cathodeluminescence, minor elements, isotope analysis of carbon, oxygen and strontium, in attempt to explore the fillers' geochemical characteristics and the diagenetic fluids. They are characterized as follows: firstly, fibrous rim dolomite cement is a typical product formed at sea bottom, and geochemically very similar to the matrix (micrite and microcrystalline dolomite), which could be a reflection of the geochemical characteristics of water at that time; secondly, the diagenetic fluids of the foliated dolomite cements tend to be inheriting, derived from the shallow burial 'imprisoned' seawater; thirdly, fine- to medium-grained dolomite cements with fairly high strontium isotopes and low carbon and oxygen isotopes were precipitated chiefly in freshwater during the period of uplifting caused by Tongwan tectonic movement; fourthly, coarse-grained dolomite cements bear a relatively high percentage of Mn element, but low in Fe and Sr, with carbon and oxygen isotopes remarkably shifted to negative values, which all show that they are related to hydrocarbon maturation and migration, and corresponding Thermochemical Sulfate Reduction; lastly, saddle-shaped dolomite cements are hydrothermally associated, and they were formed in high-temperature brine, which had passed through the areas rich in radioactive strontium isotopes. [ABSTRACT FROM AUTHOR]

The characteristics and sources of major hydrocarbons and halocarbons in the wintertime ambient air of urban center of Shanghai, a mega city of China, were investigated. Propane, toluene, ethyl acetate, and benzene were the most abundant hydrocarbons. The majority of species showed significant variability in mixing ratios with occasional episodic increases. The more common use of liquefied petroleum gas fuel for taxis and light motorcycles was believed to lead to high levels of ambient propane over the urban center of Shanghai. Correlating with toluene, dichloromethane, and 1,2-dichloroethane (1,2-DCE), abundant chloromethane (up to a daily mean of 1.61 ± 0.99 ppbv and a maximum of 5.34 ppbv) was mainly associated with industrial emissions, although biomass burnings exist widely in east China. The Chinese New Year (CNY) holiday period with no industrial activity over China provides a platform for the study of industrial emissions over the urban atmosphere of Shanghai. The normal weekly cycles were characterized by higher and more variable mixing ratios during weekdays which dropped during weekends. Enhanced mixing ratios were observed in the fortnight before the CNY holidays due to increased industrial emissions as a result of overtime production to make up for the holiday losses. During the CNY holidays, lower level and less variable mixing ratios were observed. A benzene/toluene (B/T) ratio of 0.6 ± 0.4 (mean ± std.) for the morning rush hour samples was identified to be the characteristic ratio of vehicular emissions. However, a B/T ratio of 0.4 ± 0.2 from vehicles and other sources was derived for the ambient air. [ABSTRACT FROM AUTHOR]

Based on the systematic analyses of fifteen typical crude oils and ten typical potential source rocks collected from the Qaidam, Tarim and Turpan basins, Northwest China, the geochemical characteristics of the oils and source rocks were investigated and oil-source rock correlations undertaken. The oils and source rocks deposited in saline lacustrine environment from the western Qaidam Basin were characterized by n-alkanes with even carbon-number preference in the C-C range, low pristane/phytane (Pr/Ph) ratios (less than 0.5), and high abundances of C steranes, gammacerane and C hopanes. The oils and source rocks deposited in marine environment from the Tarim Basin were characterized by n-alkanes with even carbon-number preference in the C-C range, relatively low Pr/Ph ratios (near to 1), high abundance of C steranes, and relatively high gammacerane. In contrast, the oils and source rocks deposited in terrigenous bog environment from the Turpan Basin were characterized by relatively high Pr/Ph ratios (oil samples greater than 6) high abundance of C steranes, and relatively low gammacerane and C hopanes. The higher amounts of C and C n-alkanes of source rocks from the western Qaidam Basin and the Tarim Basin suggest an origin of these alkanes from functionalized C and C n-alkadienes and alkenones in prymnesiophytes living in lacustrine and marine environments. Oil-source rock correlations suggest oils in the western Qaidam Basin were derived from the Oligocene Lower Ganchaigou Formation (E), oils in the Tabei and Tazhong uplifts from the Tarim Basin have a genetic relationship with the Middle-Upper Ordovician source beds. Oils in the Turpan Basin generally fall into two genetic types. Most oils in the Taibei depression from the Turpan Basin were derived from the Lower-Middle Jurassic coal measures, but the fewer oils in this region are a mixed source derived from the Lower-Middle Jurassic coal measure and the Upper Permian source rocks. [ABSTRACT FROM AUTHOR]

We identified a Neogene rapid uplift-denudation event of the South Tianshan based on apatite (U-Th)/He and apatite fission track (AFT) ages in Tertiary rocks of the Tarim basin, using borehole samples. The (U-Th)/He thermochronology can be used to reveal the tectono-thermal events with lower temperature than that of AFT thermochronology and has not been used previously to study the uplift of the Tianshan Mountain. Using these data, we show the relationship between the uplift of the South Tianshan and the subsidence/deposition of the northern Tarim basin during the Neogene. The apatite helium ages reveal the migration of uplift, erosion and deposition in the northern Tarim basin. A rapid uplift of the South Tianshan during the Miocene and a corresponding rapid subsidence in the northern Tarim basin occurred. However, in the Pliocene, the Kuqa Depression and South Tianshan uplifted and eroded at the same time and in turn provided the detrital source rocks for the Northern Uplift of the Tarim basin. In contrast to earlier studies, we arrive at the conclusion that the South Tianshan experienced rapid uplift in the Miocene based on (U-Th)/He data of apatite obtained from borehole samples collected in the Tarim basin itself, and not from the bordering mountain chain. Combined apatite (U-Th)/He and fission track thermochronometry enables reconstruction of thermal histories of sedimentary rocks between 40 and 120°C, and this has implications for the generation of liquid hydrocarbon in the 65-120°C range in the basin. Thermal and burial histories of typical samples were also modelled to show the rapid uplift in our study. Our works not only provide a new evidence for the South Tianshan uplift but also indicate that there is a coupling between uplift and subsidence in the South Tianshan and adjacent northern part of the Tarim basin, which controlled hydrocarbon accumulation in the Kuqa Depression and Northern Uplift of the Tarim basin. [ABSTRACT FROM AUTHOR]

Ordovician black shales are widely distributed in the Tarim Basin and its peripheral regions, and some of them may serve as potential hydrocarbon source rocks. The present study of the Ordovician graptolite fauna from these shales, together with the yielded conodonts and chitinozoans etc., permits a refined correlation of the rocks. Based mainly on a new collecting of the graptolites and a study of the faunas in Kalpin and Kuruktag regions, and the successful identification of the new graptolite material from a few drill cores within the basin, we are able to update our knowledge of the Ordovician in the regions, and draw some conclusions: (1) The most widespread distribution of the black shales in the Tarim Basin and its peripheral regions, which correspond to the Nemagraptus gracilis Zone, may be related to a global sea-level rise during this time interval. (2) Black shales of Ordovician occur most frequently and extensively in the Kuruktag (also spelled as Quruq Tagh) region in eastern Tianshan Mountains, spanning Tremadocian to mid-Katian ( D. spiniferus Zone) temporally and extending southeastwards into Manjiaer Depression. The black shales of the D. spiniferus Zone may even extend into the central Tarim Basin. (3) Three different bio- and litho-facies belts (Bachu: carbonate platform and reef belt; Kalpin-Aksu: marginal platform and upper slope belt; Wushi: slope belt) are recognized in the northwestern Tarim Basin. (4) The internationally well-correlated Saergan black shale, which has been considered to possess high potential for hydrocarbon source rock, may possess a restricted distribution in the Kalpin and Aksu areas. [ABSTRACT FROM AUTHOR]

The structural framework and evolution processes of the giant superimposed Tarim basin in Paleozoic Era are controlled by three main factors: (1) features and structures of the basin basement; (2) deep mantle dynamics process (such as the Sinian rifting and the Permian plume-related magmatic activities); (3) the powerful regional compressional or compresso-shear stress regime generated by the orogenic movement from surrounding regions. The latter of which occurring in multiple episodes is the most important factor for the Paleozoic Tarim basin evolution. Under the above tectonic background, the underlying lithosphere of the Tarim basin had been flexed, and then the upper crust was folded. The paleo-uplifts (e.g., Tabei (塔北) and Tazhong (塔中)) and depressions occurred in both of the flexural and folding processes, which are different with the models of foreland basin in stable and large cratons in the world. During the early evolution stage in Cambrian-Early Ordovician, low-relief paleo-uplifts, and open carbonate platforms formed in center area, while during the Late Ordovician compressional tectonic regime, the belted uplifts and restricted platforms formed in the contemporaneous folding processes. Denudated stages occurred during the strong tectonic events marked by the unconformities and karstified weathered crusts formed on platforms. All the discovered giant-middle oilfields are closely related to the paleo-uplift and karstified crust evolution. There are two main types of oil reservoir: paleo-karst type and reef-bank type on the carbonate platform in paleo-uplift areas. In Permian, plume-related massive magmatic activities led to geo-temperature increase and the regional uplifting in this basin, ending the marine deposit filling sequences and starting the formation of terrestrial deposits-dominated sequences. With abundant supply from giant hydrocarbon generation depressions, the most important oil fields formed in Tabei and Tazhong areas. To reveal the multi-stage evolution processes and the structural framework of the paleo-uplifts may be helpful for the prediction of new hydrocarbon domains. The integrated study on coupling relationship between the basin and surrounding orogens can provide an important approach for the superimposed basin dynamic research. [ABSTRACT FROM AUTHOR]

Using high pressure and geological condition simulation vessels, we conducted hydrous pyrolysis experiments of kerogen, solid bitumen and liquid hydrocarbons in southern China in order to study the processes of gas generation and derive geochemical indicators of gas genesis under approximate pressure and temperature. The results indicate that gas generation productivity of different marine material decreased in the order of crude oil (light oil and condensate), dispersed soluble organic matter (solid bitumen and heavy oil), and kerogen. Under identical temperature-pressure regimes, pyrolysates derived from kerogen and dispersed soluble organic matter display drastically different geochemical characteristics. For example, the $\delta ^{13} C_{CO_2 } - \delta ^{13} C_1 $ values of gaseous products from dispersed soluble organic matter are greater than 20‰, whereas those from kerogen are less than 20‰. The δC values of pyrolysates from different marine hydrocarbon sources generally increase with pyrolysis temperature, but are always lower than those of the source precursors. The δC values of ethane and propane in the pyrolysates also increase with increasing pyrolysis temperature, eventually approaching that of their sources, at peak hydrocarbon generation. At high-over mature stages, the δC values of ethane and propane are often greater than those of their sources but close to those of coal gases, and thus become ineffective as gas genetic indicators. Ln(C/C) can clearly distinguish kerogen degradation gas from oil cracking gas and Ln(C/C)-( δC− δC) can be an effective indicator for distinguishing oil cracking gas from dispersed soluble organic matter cracking gas. [ABSTRACT FROM AUTHOR]

The concentrations of PAHs in the surface waters from seven river basins in China were summarized from literature published from 2000-2010. Subsequently, the risks from individual PAHs and ΣPAHs in the surface waters of China were quantified by comparing the overlap between the probability distributions of exposure concentrations with the probability distributions of toxicity data. The results show that the concentrations of 15 PAHs in the surface waters ranged from 3.09 to 38139.00 ng L, with a geometric mean of 474.93 ng L. The significantly higher concentrations of the 15 PAHs occurred in the surface waters from northern China when compared with those from southern China. The concentrations of the 15 PAHs in Chinese surface waters were higher than those in other waters worldwide. The MOS (margin of safety) values were calculated at 90th percentile values of exposure concentrations and 10th percentile values of toxicity data, with 5.75, 0.17, 2.33, 0.30, 0.57, 1.74, 1.05, and 0.11 for Ace, Ant, Flu, BaP, Flua, Nap, Phe, and Pyr, respectively. The probabilities of the individual PAH concentrations exceeding the 10th percentile value of the toxicity data were 6.06%, 2.07%, 9.51%, and 2.07% for Nap, Ace, Phe, and Flu, respectively, suggesting minimal risk to aquatic organisms; however, the probabilities of BaP, Ant, Flua, and Pyr exceeding this value were 19.49%, 25.46%, 15.15%, and 30.50%, respectively, indicating potential risks. Among the individual PAHs, the ecological risk from Pyr was the highest, followed by, in descending order of risk, Ant, Bap, Flua, Phe, Nap, Flu, and Ace. Additionally, the combined ecological risk of ΣPAH8 in Chinese surface waters was significantly higher than any that of individual PAHs alone. The MOS values in the river basins were < 1, except for the Haihe River Basin, suggesting a potential combined risk from ΣPAH8 in the other six river basins. The probabilities calculation indicate that low to high ecological risk from ΣPAH8 for all aquatic species was reported in the Liaohe River Basin (65.58%), Huaihe River Basin (57.15%), Songhua River Basin (46.49%), Pearl River Basin (38.41%), Yangtze River Basin (25.98%), Yellow River Basin (15.92%), and Haihe River Basin (5.22%). [ABSTRACT FROM AUTHOR]