The natural gas in the Wen'an slope buried-hill belts, Jizhong sub-basin has become an important target area for the deep and ultra-deep reservoir explorations in the Bohai Bay basin. However, the gas sources, charging history and gas accumulation…
The article discusses the results of biomonitoring research at the Underground Gas Storage (UGS). Hydrogen sulphide, as one of the products of microbiological reaction and transformation, as well as a product of chemical reactions in rocks, is a…
Hydrothermal diamond-anvil cell and Raman spectrograph were used to measure the hydrogen isotope fractionation factor between benzene and heavy water at high P-T condition. The isotope fractionation factor is determined when the isotope fractionation…
The U.S. Geological Survey assessed undiscovered unconventional hydrocarbon resources reservoired in the Upper Cretaceous Tuscaloosa marine shale (TMS) of southern Mississippi and adjacent Louisiana in 2018. As part of the assessment, oil-source rock…
The Re-Os geochronometer has been applied to many petroleum systems worldwide. However, it is debated if the Re-Os systematics in petroleumactually record the timing of oil generation. Here, we investigate the Re-Os isotope systematics of the…
Asphaltenes are unique molecules whose abundance and structure control physicochemical properties of petroleum. The structural appearance of asphaltenes (island versus archipelago architecture) is dependent upon the sample type and petroleum source,…
Context. Carbon fractionation has been studied from a theoretical point of view with different models of time-dependent chemistry, including both isotope-selective photodissociation and lowerature isotopic exchange reactions. Aims. Recent chemical…
In this study, pyrolysis experiments were conducted with a saturate-rich Tertiary source rock-derived oil from the South China Sea basin using a fixed-volume pressure vessel at temperatures from 350 to 425 C for 24 h (0.92-1.85% Easy R0) to…
A series of gold-tube isothermal laboratory experiments at 370 C and 50 MPa were carried out to investigate the stable carbon isotope fractionation during the formation of hydrocarbon gases from siderite reacting with the iron-bearing minerals, which…
Water (H2O) and minerals involved organic-inorganic reactions are critical for hydrocarbon evolution in sedimentary basins and deep in the Earth. The mechanism and isotope fractionation for H2O-mineral-hydrocarbon interactions remain unclear. In this…
Oligocene deep syn-rift lakes in the Gulf of Tonkin, Vietnam, represent exceptional paleoenvironmental archives, but their use for unravelling the regional paleoclimatic development has been hindered by poor dating. Here we present a high-resolution…
Iron (Fe) isotope is an effective tool for tracing Fe transformation, migration, and biogeochemical cycling in the Earth's surface system. In this study, the Fe content and stable isotope composition (56Fe/54Fe) in two Gleysol profiles (M1 and M2)…
In this work, Huadian oil shale was extracted by water at 350, 365, and 385 C with a time series (2-100 h) under a closed system to better investigate the carbon isotope fractionation character and its use in predicting the oil recovery rate (ORR).…
Inorganic sulfur (S) species including pyrite (FeS2) and sulfates may co-exist with organic matter (OM) in source rocks. Their inter-related effects on hydrocarbon generation and decomposition, and the 34S isotope fractionation during thermal…
Oil and condensate reservoirs frequently experienced later gas charging and cap gas leakage. The influences of these two processes on diamondoid concentrations and compositions are not well documented. To investigate these issues, quantitative GC,…
During the analysis of the 47 values of CO2 derived from carbonates, the acid fractionation factor not only allows 47 values produced from carbonates and reacted at different temperatures (usually 25 and 90 C) to be compared to one another, but also…
Maintaining and supporting complete biodegradation during remediation of petroleum hydrocarbon contaminated groundwater in constructed wetlands is vital for the final destruction and removal of contaminants. We aimed to compare and gain insight into…
BACKGROUND: The high frequency and wide distribution of oil spills pose serious threats to the marine environmental ecosystem and human health. Microbial degradation is considered to be the most applicable means to process oil spills. Carbon isotope…
Stable carbon and hydrogen isotope ratios of individual n-alkanes and acyclic isoprenoids are important tools in petroleum geochemistry. However, the analysis requires baseline separation and peak profiles using gas chromatographyisotope ratio mass…
Here we further demonstrate asphaltene to be the main carrier of Re and Os in crude oil and additionally show that generally the less soluble fractions of asphaltene contain higher concentrations of Re and Os, with the 187Os/188Os and 187Re/188Os…
The formation mechanism of 23 shale gas samples from the Fuling shale gas field in the Upper Ordovician Wufeng (O3w) Formation-Lower Silurian Longmaxi (S1l) Formation marine shales was investigated based on the carbon and hydrogen isotopes of…
The marine crude oil in Tarim Basin is considered to be mainly originated from two sets of source rocks, i.e., Cambrian-Lower Ordovician and Middle-Upper Ordovician, but which is a dominant contributor has been in dispute for a long term. Based on…
Although Pb, U, and Th may be fractionated between crude oil and formation waters, Pb isotopes are not. This unique property makes Pb isotopes a particularly useful marker of hydrocarbon generation and migration. Here we show that Pb isotopes offer a…
Thallium (Tl) isotope ratios are an emerging tool that can be used to trace crustal recycling processes in arc lavas and ocean island basalts (OIBs). Thallium is a highly volatile metal that is enriched in volcanic fumaroles, but it is unknown…
To understand the isotope fractionation of methane (CH4) during thermochemical sulfate reduction (TSR), isothermal pyrolysis of CH4/N2 gas involving gypsum + MgCl2 and MgSO4 solutions were conducted in a gold-tube system. CH4 was oxidized to generate…
Here we discuss the current state of knowledge on how atmospheric escape processes can fractionate noble gas isotopes and moderately volatile rock-forming elements that populate primordial atmospheres, magma ocean related environments, and…
Abstract.: Noble gases, and the way they fractionate, is a promising approach to better constrain origin, migration and initial state distributions of fluids in gas and oil reservoirs. Thermodiffusion, is one of the phenomena that may lead to isotope…
The gas in-place (GIP) content and the ratio of adsorbed/free gas are two key parameters for the assessment of shale gas resources and have thus received extensive attention. A variety of methods have been proposed to solve these issues, however none…
Sulfur isotope ratios are among the most commonly studied isotope systems in geochemistry. While sulfur isotope ratio analyses of materials such as bulk rock samples, gases, and sulfide grains are routinely carried out, in-situ analyses of silicate…
Reactive transport modeling was employed to investigate the relative importance of fractionations associated with gas solubility, sorption and diffusive transport on dissolved methane, ethane and propane concentrations and the isotopic composition of…
Strandings of semi-solid to solid asphaltic bitumen along the coastline of South Australia have been reported as far back as the late 1800s. Hitherto only a single variety, now referred to as asphaltite, has been attributed to seepage from the nearby…
Carbon isotope composition (13C) has been used as a standard geochemical tool to explore the genetic and post-genetic information of natural gas systems. However, little attention has been paid to the influence of the diffusion loss on the real 13C…
Methane carbon isotope fractionation (CIF) during shale gas desorption provides a new method to evaluating in-situ gas content and the ratios of adsorbed and free gas as well as predicting the production status of shale gas wells. Considering…
The Ordos Basin is abundant in natural gas resources, and the Shanxi Formation with the transitional facies is considered as a potential stratum for shale gas reservoir. However, the origin and geochemical characteristics of the Shanxi Formation…
Gas-in-place (GIP) content and gas-adsorbed ratio are crucial parameters for resource potential assessment, sweet spot prediction, and production strategy optimization. Various methods have been proposed from different perspectives to evaluate these…
The deep coal-measure gas, including coalbed methane (CBM), tight gas (TG) and shale gas (SG), has attracted widely attention because of its great potential for natural gas development and multiple benefits. To determine the gas origin, migration and…
This study reports a comprehensive approach for analysis of increasing hydrogen sulfide (H2S) concentration after 10 years of sweet gas production from Kangan and Dalan formations (Khuff) in a gas field. Increasing H2S concentration as a toxic and…
The origin and potential source of the presalt natural gas in the Lower Paleozoic Ordovician carbonates within the Ordos Basin, China, is heavily debated, and the causes of carbon isotope reversal are currently unclear. This study analyzes the source…
Position-specific isotope analysis (PSIA) of propane can provide novel and valuable information to constrain the origin and history of natural gases. We conducted a systematic experimental study to determine the kinetics of propane pyrolysis,…
In recent years, great breakthroughs have been achieved in the exploration of Shaximiao Formation tight gas in Jinqiu Gas Field in central Sichuan-western Sichuan transition zone, and multi-stage gas rich sandstone formations have been discovered…
Following the large increase in unconventional hydrocarbon production in North America and elsewhere in the last 15 years, many jurisdictions have implemented groundwater monitoring programs to verify whether these subsurface industrial activities…
Oil spill events in the marine environment can have a deleterious impact on the affected ecosystems, such as coral reefs, with direct consequences for their socioeconomic value. The mutualistic relationship between tropical corals and their…
Gas-in-place (GIP) and gas-adsorbed ratio are crucial parameters for resource potential assessment and production strategy optimization. Although various methods have been proposed to evaluate these two parameters, none have been widely recognized…
In this study, frontal chromatography experiments have been conducted with hydrocarbon gases (methane and ethane) on selected stationary phases (quartz, 3 Å, 5 Å and 13X molecular sieves, activated carbon, coal and shale) to study compositional and…
Gas content is a key parameter for the determination of the gas resources in unconventional reservoirs. In this study, we propose a novel method to evaluate the gas content of shale through a new perspective: fractionation of carbon isotopes of…
The energy and material carried by deep fluids (C, H, and catalytic substances) can facilitate the hydrocarbon generation by activation and hydrogenation in high-mature hydrocarbon sources. However, As H2 in natural gas is generally at trace level,…
Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects. Based on the geological theory and method of natural gas reservoir formation,…
The terrestrial carbon to nitrogen ratio is a key geochemical parameter that can provide information on the nature of Earth's precursors, accretion/differentiation processes of our planet, as well as on the volatile budget of Earth. In principle,…
The Risha field is one of the Jordan's most important gas fields, but little has been known about the origins and the underlying formation mechanism(s) of its gases. Hence, we carried out studies to determine the origin and formation mechanism of the…
This paper studied the origin and the maturity of the Jurassic subsalt condensate in the northeastern margin of the Amu Darya Basin and analyzed its formation condition and mechanism through conducting geochemical analysis of biomarkers, carbon…