Several series of cracking tests in a comprehensive study were conducted on separate occasions involving all or parts of ten Canadian vacuum gas oils (VGOs) and two catalysts with bottoms-cracking or octane-barrel ca...Several series of cracking tests in a comprehensive study were conducted on separate occasions involving all or parts of ten Canadian vacuum gas oils (VGOs) and two catalysts with bottoms-cracking or octane-barrel capability. VGOs were cracked in fixed- and/or fluid-bed microactivity test (MAT) units, in an Advanced Cracking Evaluation (ACE) unit, and in a modified ARCO riser reactor. Individual yields of gas, liquid, and coke from the MATs at 55, 65, 70, and 81 wt% conversion levels were compared with their respective pilot plant data. Good linear correlations could be established between MAT and riser yields except for liquefied petroleum gas (LPG) and light cycle oil (LCO). At a given conversion, correlations existed among the fixed- and fluid-bed MAT units and the ACE for each product yield. Liquid products from the fixed or fluid-bed MAT were analyzed for hydrocarbon types, sulfur, nitrogen and density, most of which showed good agreement with those obtained from the riser study. When cracking Canadian oil-sands-derived VGOs, the bottoms-cracking catalyst containing a large-pore active matrix was found to be more suitable than the octane-barrel catalyst with smaller pores to produce higher yields of valuable distillates, but with less superior qualities (in terms of sulfur and nitrogen contents). The advantages of hydrotreating some poor feeds to improve product yields and qualities were demonstrated and discussed.展开更多
It is well known that gas oils from oilsands bitumen are difficult to hydrotreat. In order to develop the most appropriate flow sheet and operating conditions, a thorough knowledge of the molecular structure and beha...It is well known that gas oils from oilsands bitumen are difficult to hydrotreat. In order to develop the most appropriate flow sheet and operating conditions, a thorough knowledge of the molecular structure and behaviour of bitumen and its gas oil products is needed. In this work, the gas oil samples are fractionated in an attempt to isolate and identify the problematic molecular species for hydrotreating. It is found that the major nitrogen sources in coker gas oils are associated with relatively small pentane insoluble species and an even smaller, highly polar, hexane insoluble species. Structural information obtained for these fractions indicates that they are formed during the cracking of resin molecules. Nitrogen speciation shows that the pyrroles are the primary nitrogen type, with pyridines also being an important species. Both nitrogen species are undesirable in the hydrotreating process. Pyrroles in particular are subject to polymerisation, producing gums and sediments that foul filters and other equipment while pyridines can directly deactivate the hydrotreating catalyst.展开更多
Accurate prediction of chemical composition of vacuum gas oil (VGO) is essential for the routine operation of refineries. In this work, a new approach for auto-design of artificial neural networks (ANN) based on a...Accurate prediction of chemical composition of vacuum gas oil (VGO) is essential for the routine operation of refineries. In this work, a new approach for auto-design of artificial neural networks (ANN) based on a genetic algorithm (GA) is developed for predicting VGO saturates. The number of neurons in the hidden layer, the momentum and the learning rates are determined by using the genetic algorithm. The inputs for the artificial neural networks model are five physical properties, namely, average boiling point, density, molecular weight, viscosity and refractive index. It is verified that the genetic algorithm could find the optimal structural parameters and training parameters of ANN. In addition, an artificial neural networks model based on a genetic algorithm was tested and the results indicated that the VGO saturates can be efficiently predicted. Compared with conventional artificial neural networks models, this approach can improve the prediction accuracy.展开更多
The kinetic model of vacuum gas oil (VGO) hydrocracking based on discrete lumped approach was investigated, and some improvement was put forward at the same time in this article. A parallel reaction scheme to descri...The kinetic model of vacuum gas oil (VGO) hydrocracking based on discrete lumped approach was investigated, and some improvement was put forward at the same time in this article. A parallel reaction scheme to describe the conver- sion of VGO into products (gases, gasoline, and diesel) proposed by Orochko was used. The different experimental data were analyzed statistically and then the product distribution and kinetic parameters were simulated by available data. Fur- thermore, the kinetic parameters were correlated based on the feed property, reaction temperature, and catalyst activity. An optimization code in Matlab 2011b was written to fine-me these parameters. The model had a favorable ability to predict the product distribution and there was a good agreement between the model predictions and experiment data. Hence, the ki- netic parameters indeed had something to do with feed properties, reaction temperature and catalyst activity.展开更多
The catalytic activity of CoMoS /CNT towards the Egyptian heavy vacuum gas oil hydrotreating was studied. The delivered CNT was functionalized with 6 mol /L HNO_3. The CNT were loaded with 12% MoO_3( by weight) and 0....The catalytic activity of CoMoS /CNT towards the Egyptian heavy vacuum gas oil hydrotreating was studied. The delivered CNT was functionalized with 6 mol /L HNO_3. The CNT were loaded with 12% MoO_3( by weight) and 0.7 Co /Mo atomic ratio with impregnation methods. The γ-Al_2O_3 catalyst was also prepared by impregnation method to compare both catalysts activities.The analysis tools such XRD,Raman spectroscopy,TEM,and BET were used to characterize the catalysts. The autoclave reactor was used to operate the hydrotreating experiments. The hydrotreating reactions were tested at various operating conditions of temperature 325-375 ℃,pressure 2-6 MPa,time 2-6 h,and catalyst /oil ratio( by weight) of 1 ∶75,1 ∶33 and 1 ∶10. The results revealed that the CoMoS /CNT was highly efficient for the hydrotreating more than the CoMoS /γ-Al_2O_3. Also, the hydrodesulfurization( HDS) increased with increasing catalyst /oil ratio. Additionally,results showed that the optimum condition was temperature 350℃,pressure 4 MPa,catalyst /oil ratio of 1 ∶75 for 2 h. Furthermore,even at low CoMoS /CNT catalyst /oil ratio of 1 ∶75,an acceptable HDS of 77.1% was achieved.展开更多
Vacuum gas oil(VGO)is the most important feedstock for hydrocracking processes in refineries,but its molecular composition cannot be fully acquired by current analysis techniques owing to its complexity.In order to bu...Vacuum gas oil(VGO)is the most important feedstock for hydrocracking processes in refineries,but its molecular composition cannot be fully acquired by current analysis techniques owing to its complexity.In order to build an accurate and reliable molecular-level kinetic model for reactor design and process optimization,the molecular composition of VGO has to be reconstructed based on limited measurements.In this study,a modified stochastic reconstruction-entropy maximization(SR-REM)algorithm was applied to reconstruct VGOs,with generation of a general molecule library once and for all via the SR method at the first step and adjustment of the molecular abundance of various VGOs via the REM method at the second step.The universality of the molecule library and the effectiveness of the modified SR-REM method were validated by fifteen VGOs(three from the literature)from different geographic regions of the world and with different properties.The simulated properties(density,elemental composition,paraffin-naphthene-aromatics distribution,boiling point distribution,detailed composition of naphthenes and aromatics in terms of ring number as well as composition of S-heterocycles)are in good agreement with the measured counterparts,showing average absolute relative errors of below 10%for each property.展开更多
Toluene insoluble matter (TIM) in coker heavy gas oil (CHGO) from oil sands bitumen is harmful to the downstream hydrotreating, and it may be difficult to be removed by conventional filtration. In order to determine i...Toluene insoluble matter (TIM) in coker heavy gas oil (CHGO) from oil sands bitumen is harmful to the downstream hydrotreating, and it may be difficult to be removed by conventional filtration. In order to determine its origin, the TIM must first be separated from CHGO for characterization. Two techniques are described to accomplish this goal. In the ultra-centrifugation approach used in this work, CHGO is blended with a miscible liquid and centrifuged under 366000 G (gravity) force. Through this procedure toluene and hexane diluents yielded TIM contents of 24μg·g-1 and 88μg·g-1 respectively. In an alternative simplified procedure, the initial ultra-centrifugation step is omitted. Several different solvents are evaluated for use as diluents but, in each case, toluene is still used in the subsequent washing steps. TIM contents determined by this method range from 23 to about 200μg·g-1. The amount of TIM separated by means of this method depends primarily on the initial diluent used. Other conditions, such as diluent-oil ratio, water-oil ratio, mixing time, temperature and water pH value, are also studied.展开更多
This work was mainly concentrated on the removal of naphthenic acids(NAs) from dewaxed vacuum gas oil(VGO) by adsorption using a commercial grade activated clay(AC) adsorption during lube base oil refining. The NAs in...This work was mainly concentrated on the removal of naphthenic acids(NAs) from dewaxed vacuum gas oil(VGO) by adsorption using a commercial grade activated clay(AC) adsorption during lube base oil refining. The NAs in dewaxed VGO cut-4 were identified by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS). The AC sample from a refinery was characterized by XRD, BET, TG/DTA, and SEM. A series of experiments were carried out to investigate the performance of NAs adsorption by AC using a batch adsorption technique, in which some key experimental parameters such as temperature, contact time, initial concentration of NA in oil sample as well as the dosage of adsorbent were investigated. Equilibrium isotherms were analyzed using the Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich(D-R) adsorption models. The pseudo-first order, the pseudo-second order, and intraparticle diffusion models were employed to describe the kinetics data. The results revealed that the D-R isotherm provided a better fit to the experimental data than other isotherms, and the adsorption kinetics followed the pseudo-first order kinetic equation. The thermodynamic data indicated that the adsorption process was feasible and spontaneous as an endothermic process. The results could provide a clear understanding of the NAs adsorption by AC during lube base oil processing at refineries.展开更多
This study set out to gain a deeper understanding of a fluid catalytic cracking(FCC)coprocessing approach using canola oil mixed with bitumen-derived heavy gas oil(HGO),for the production of partially-renewable gasoli...This study set out to gain a deeper understanding of a fluid catalytic cracking(FCC)coprocessing approach using canola oil mixed with bitumen-derived heavy gas oil(HGO),for the production of partially-renewable gasoline,with respect to its composition and quality.The FCC coprocessing approach may provide an alternative solution to reducing the carbon footprint and to meet government regulatory demands for renewable transportation fuels.In this study,a mixture of 15 v%canola oil in HGO was catalytically cracked with a commercial equilibrium catalyst under typical FCC conditions.Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation(ACE)unit at a fixed weight hourly space velocity of 8 h^(à1),490–530C,and catalyst/oil ratios of 4–12 g/g.The total liquid product samples were injected via an automatic sampler and a prefractionator(to removet254C)into a gas chromatographic system containing a series of columns,traps,and valves designed to separate each of the hydrocarbon types.The analyzer gives detailed hydrocarbon types of à200C gasoline,classified into paraffins,iso-paraffins,olefins,naphthenes,and aromatics by carbon number up to C_(11)(C_(10)for aromatics).For a feed cracked at a given temperature,the gasoline aromatics show the highest selectivity in terms of weight percent conversion,followed by saturated iso-paraffins,saturated naphthenes,unsaturated iso-paraffins,unsaturated naphthenes,unsaturated normal paraffins,and saturated normal paraffins.As conversion increases,both aromatics and saturated iso-paraffins increase monotonically at the expense of other components.Hydrocarbon type analysis and octane numbers with variation in feed type,process severity(temperature and catalyst/oil ratio),and conversion are also presented and discussed.展开更多
In this research, the affect of storage time and different metals concentration of copper and iron on gum formation in gas oil is investigated. A study of the affect of gum content on properties of sample is performed...In this research, the affect of storage time and different metals concentration of copper and iron on gum formation in gas oil is investigated. A study of the affect of gum content on properties of sample is performed, where the gas oil derived from (Kirkuk crude oil) have boiling point range (266-420)℃. For this purpose, a gas oil sample has been doped with these two metals ions at concentration levels of 0.5, 1.5, 2.5 and 3.5 μg mL-1. Washed gum content tests have been carried out using ASTM D-381 on samples stored for 8, 16, 24 and 32 days. The experimental results show that an increase in storage time and metal concentration strongly increases the rate of gum formation for all metal investigations and this increase in gum concentration affects the viscosity of samples towards increasing of viscosity.展开更多
This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields ...This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields and selectivities of ethylene and propylene in cocracking. The difference in coking tendencies betWeen the cocracking and the separate cracking is compared as well.展开更多
The Well Tashen 5(TS5),drilled and completed at a vertical depth of 9017 m in the Tabei Uplift of the Tarim Basin,NW China,is the deepest well in Asia.It has been producing both oil and gas from the Sinian at a depth ...The Well Tashen 5(TS5),drilled and completed at a vertical depth of 9017 m in the Tabei Uplift of the Tarim Basin,NW China,is the deepest well in Asia.It has been producing both oil and gas from the Sinian at a depth of 8780e8840 m,also the deepest in Asia in terms of oil discovery.In this paper,the geochemical characteristics of Sinian oil and gas from the well were investigated and compared with those of Cambrian oil and gas discovered in the same basin.The oil samples,with Pr/Ph ratio of 0.78 and a whole oil carbon isotopic value of31.6‰,have geochemical characteristics similar to those of Ordovician oils from the No.1 fault in the North Shuntuoguole area(also named Shunbei area)and the Middle Cambrian oil from wells Zhongshen 1(ZS1)and Zhongshen 5(ZS5)of Tazhong Uplift.The maturity of light hydrocarbons,diamondoids and aromatic fractions all suggest an approximate maturity of 1.5%e1.7%Ro for the samples.The(4-+3-)methyldiamantane concentration of the samples is 113.5 mg/g,indicating intense cracking with a cracking degree of about 80%,which is consistent with the high bottom hole temperature(179℃).The Sinian gas samples are dry with a dryness coefficient of 0.97.The gas is a mixture of kerogen-cracking gas and oil-cracking gas and has Ro values ranging between 1.5%and 1.7%,and methane carbon isotopic values of41.6‰.Based on the equivalent vitrinite reflectance(R_(eqv)=1.51%e1.61%)and the thermal evolution of source rocks from the Cambrian Yu'ertusi Formation of the same well,it is proposed that the Sinian oil and gas be mainly sourced from the Cambrian Yu'ertusi Formation during the Himalayan period but probably also be joined by hydrocarbon of higher maturity that migrated from other source rocks in deeper formations.The discovery of Sinian oil and gas from Well TS5 suggests that the ancient ultra-deep strata in the northern Tarim Basin have the potential for finding volatile oil or condensate reservoirs.展开更多
Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Ba...Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Based on system and control theories,System-Theoretic Accident Model and Processes(STAMP)is a widely recognized approach for accident analysis.In this paper,we propose a STAMP-Game model to analyze accidents in oil and gas storage and transportation systems.Stakeholders in accident analysis by STAMP can be regarded as players of a game.Game theory can,thus,be adopted in accident analysis to depict the competition and cooperation between stakeholders.Subsequently,we established a game model to study the strategies of both supervisory and supervised entities.The obtained results demonstrate that the proposed game model allows for identifying the effectiveness deficiency of the supervisory entity,and the safety and protection altitudes of the supervised entity.The STAMP-Game model can generate quantitative parameters for supporting the behavior and strategy selections of the supervisory and supervised entities.The quantitative data obtained can be used to guide the safety improvement,to reduce the costs of safety regulation violation and accident risk.展开更多
This study predicts favorable oil and gas source-rock formation conditions in the Aryskum Depression of the South Turgay Basin,Kazakhstan.This study assesses the thermal maturity and characteristics of organic matter ...This study predicts favorable oil and gas source-rock formation conditions in the Aryskum Depression of the South Turgay Basin,Kazakhstan.This study assesses the thermal maturity and characteristics of organic matter by determining its environmental conditions using data from geochemical analysis of core(pyrolysis)and oil(biomarkers and carbon isotopic compositions)samples.According to the geochemical parameters obtained by pyrolysis,the oil generation potential of the original rocks of most studied samples varies from poor to rich.The facies–genetic organic matter is predominantly humic and less frequently humus–sapropel,indicating organic matter accumulation in the studied samples were under moderately reducing conditions(kerogenⅢand Ⅱ types)and coastal–marine environments(kerogen typeⅠ).The carbon isotopic compositions of oils derived from the Jurassic deposits of the Aryskum Depression also indicate the sapropelic and mixed humic–sapropelic type of organic matter(kerogenⅡandⅠ).Biomarker analysis of oils indicates original organic matter formation in an anoxic environment.展开更多
With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of inv...With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.展开更多
In the pursuit of global net zero carbon emissions and climate change mitigation,ongoing research into sustainable energy sources and emission control is paramount.This review examines methane leakage from abandoned o...In the pursuit of global net zero carbon emissions and climate change mitigation,ongoing research into sustainable energy sources and emission control is paramount.This review examines methane leakage from abandoned oil and gas(AOG)wells,focusing particularly on Lubbock,a geographic area situated within the larger region known as the Permian Basin in West Texas,United States.The objective is to assess the extent and environmental implications of methane leakage from these wells.The analysis integrates pertinent literature,governmental and industry data,and prior Lubbock reports.Factors affecting methane leakage,including well integrity,geological characteristics,and human activities,are explored.Our research estimates 1781 drilled wells in Lubbock,forming a foundation for targeted assessments and monitoring due to historical drilling trends.The hierarchy of well statuses in Lubbock highlights the prevalence of“active oil wells,”trailed by“plugged and abandoned oil wells”and“inactive oil wells.”Methane leakage potential aligns with these well types,underscoring the importance of strategic monitoring and mitigation.The analysis notes a zenith in“drilled and completed”wells during 1980-1990.While our study's case analysis and literature review reiterate the critical significance of assessing and mitigating methane emissions from AOG wells,it's important to clarify that the research does not directly provide methane leakage data.Instead,it contextualizes the issue's magnitude and emphasizes the well type and status analysis's role in targeted mitigation efforts.In summary,our research deepens our understanding of methane leakage,aiding informed decision-making and policy formulation for environmental preservation.By clarifying well type implications and historical drilling patterns,we aim to contribute to effective strategies in mitigating methane emissions from AOG wells.展开更多
Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and ...Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and minerals were characterized microscopically,the measured trap sealing indexes were compared,the biomarker compounds of crude oil were extracted,the genesis of condensate gas was identified,and the reservoir-forming conditions were examined.On this basis,the Paleogene Enping Formation in the Huizhou 26 subsag was systematically analyzed for the potential of oil and gas resources,the development characteristics of large-scale high-quality conglomerate reservoirs,the trapping effectiveness of faults,the hydrocarbon migration and accumulation model,and the formation conditions and exploration targets of large-and medium-sized glutenite-rich oil and gas fields.The research results were obtained in four aspects.First,the Paleogene Wenchang Formation in the Huizhou 26 subsag develops extensive and thick high-quality source rocks of semi-deep to deep lacustrine subfacies,which have typical hydrocarbon expulsion characteristics of"great oil generation in the early stage and huge gas expulsion in the late stage",providing a sufficient material basis for hydrocarbon accumulation in the Enping Formation.Second,under the joint control of the steep slope zone and transition zone of the fault within the sag,the large-scale near-source glutenite reservoirs are highly heterogeneous,with the development scale dominated hierarchically by three factors(favorable facies zone,particle component,and microfracture).The(subaqueous)distributary channels near the fault system,with equal grains,a low mud content(<5%),and a high content of feldspar composition,are conducive to the development of sweet spot reservoirs.Third,the strike-slip pressurization trap covered by stable lake flooding mudstone is a necessary condition for oil and gas preservation,and the NE and nearly EW faults obliquely to the principal stress have the best control on traps.Fourth,the spatiotemporal configuration of high-quality source rocks,fault transport/sealing,and glutenite reservoirs controls the degree of hydrocarbon enrichment.From top to bottom,three hydrocarbon accumulation units,i.e.low-fill zone,transition zone,and high-fill zone,are recognized.The main area of the channel in the nearly pressurized source-connecting fault zone is favorable for large-scale hydrocarbon enrichment.The research results suggest a new direction for the exploration of large-scale glutenite-rich reservoirs in the Enping Formation of the Pearl River Mouth Basin,and present a major breakthrough in oil and gas exploration.展开更多
Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability...Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.展开更多
Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential en...Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.展开更多
Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil env...Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil environment. The SCC behavior of X80 pipeline steel under the magnetic field and sulfate-reducing bacteria(SRB) environment was investigated by immersion tests, electrochemical tests, and slow strain rate tensile(SSRT) tests. The results showed that the corrosion and SCC sensitivity of X80 steel decreased with increasing the magnetic field strength in the sterile environment. The SCC sensitivity was higher in the biotic environment inoculated with SRB, but it also decreased with increasing magnetic field strength, which was due to the magnetic field reduces microbial activity and promotes the formation of dense film layer. This work provided theoretical guidance on the prevention of SCC in pipeline steel under magnetic field and SRB coexistence.展开更多
文摘Several series of cracking tests in a comprehensive study were conducted on separate occasions involving all or parts of ten Canadian vacuum gas oils (VGOs) and two catalysts with bottoms-cracking or octane-barrel capability. VGOs were cracked in fixed- and/or fluid-bed microactivity test (MAT) units, in an Advanced Cracking Evaluation (ACE) unit, and in a modified ARCO riser reactor. Individual yields of gas, liquid, and coke from the MATs at 55, 65, 70, and 81 wt% conversion levels were compared with their respective pilot plant data. Good linear correlations could be established between MAT and riser yields except for liquefied petroleum gas (LPG) and light cycle oil (LCO). At a given conversion, correlations existed among the fixed- and fluid-bed MAT units and the ACE for each product yield. Liquid products from the fixed or fluid-bed MAT were analyzed for hydrocarbon types, sulfur, nitrogen and density, most of which showed good agreement with those obtained from the riser study. When cracking Canadian oil-sands-derived VGOs, the bottoms-cracking catalyst containing a large-pore active matrix was found to be more suitable than the octane-barrel catalyst with smaller pores to produce higher yields of valuable distillates, but with less superior qualities (in terms of sulfur and nitrogen contents). The advantages of hydrotreating some poor feeds to improve product yields and qualities were demonstrated and discussed.
文摘It is well known that gas oils from oilsands bitumen are difficult to hydrotreat. In order to develop the most appropriate flow sheet and operating conditions, a thorough knowledge of the molecular structure and behaviour of bitumen and its gas oil products is needed. In this work, the gas oil samples are fractionated in an attempt to isolate and identify the problematic molecular species for hydrotreating. It is found that the major nitrogen sources in coker gas oils are associated with relatively small pentane insoluble species and an even smaller, highly polar, hexane insoluble species. Structural information obtained for these fractions indicates that they are formed during the cracking of resin molecules. Nitrogen speciation shows that the pyrroles are the primary nitrogen type, with pyridines also being an important species. Both nitrogen species are undesirable in the hydrotreating process. Pyrroles in particular are subject to polymerisation, producing gums and sediments that foul filters and other equipment while pyridines can directly deactivate the hydrotreating catalyst.
文摘Accurate prediction of chemical composition of vacuum gas oil (VGO) is essential for the routine operation of refineries. In this work, a new approach for auto-design of artificial neural networks (ANN) based on a genetic algorithm (GA) is developed for predicting VGO saturates. The number of neurons in the hidden layer, the momentum and the learning rates are determined by using the genetic algorithm. The inputs for the artificial neural networks model are five physical properties, namely, average boiling point, density, molecular weight, viscosity and refractive index. It is verified that the genetic algorithm could find the optimal structural parameters and training parameters of ANN. In addition, an artificial neural networks model based on a genetic algorithm was tested and the results indicated that the VGO saturates can be efficiently predicted. Compared with conventional artificial neural networks models, this approach can improve the prediction accuracy.
基金the fund of"National‘Twelfth Five-Year’Plan for Science&Technology Support"(No.2012BAE05B04)"Research on Hydrocracking Catalysts Grading Technology"undertaken by Fushun Research Institute of Petroleum and Petrochemicals(FRIPP)supported by SINOPEC(No.101102)
文摘The kinetic model of vacuum gas oil (VGO) hydrocracking based on discrete lumped approach was investigated, and some improvement was put forward at the same time in this article. A parallel reaction scheme to describe the conver- sion of VGO into products (gases, gasoline, and diesel) proposed by Orochko was used. The different experimental data were analyzed statistically and then the product distribution and kinetic parameters were simulated by available data. Fur- thermore, the kinetic parameters were correlated based on the feed property, reaction temperature, and catalyst activity. An optimization code in Matlab 2011b was written to fine-me these parameters. The model had a favorable ability to predict the product distribution and there was a good agreement between the model predictions and experiment data. Hence, the ki- netic parameters indeed had something to do with feed properties, reaction temperature and catalyst activity.
文摘The catalytic activity of CoMoS /CNT towards the Egyptian heavy vacuum gas oil hydrotreating was studied. The delivered CNT was functionalized with 6 mol /L HNO_3. The CNT were loaded with 12% MoO_3( by weight) and 0.7 Co /Mo atomic ratio with impregnation methods. The γ-Al_2O_3 catalyst was also prepared by impregnation method to compare both catalysts activities.The analysis tools such XRD,Raman spectroscopy,TEM,and BET were used to characterize the catalysts. The autoclave reactor was used to operate the hydrotreating experiments. The hydrotreating reactions were tested at various operating conditions of temperature 325-375 ℃,pressure 2-6 MPa,time 2-6 h,and catalyst /oil ratio( by weight) of 1 ∶75,1 ∶33 and 1 ∶10. The results revealed that the CoMoS /CNT was highly efficient for the hydrotreating more than the CoMoS /γ-Al_2O_3. Also, the hydrodesulfurization( HDS) increased with increasing catalyst /oil ratio. Additionally,results showed that the optimum condition was temperature 350℃,pressure 4 MPa,catalyst /oil ratio of 1 ∶75 for 2 h. Furthermore,even at low CoMoS /CNT catalyst /oil ratio of 1 ∶75,an acceptable HDS of 77.1% was achieved.
基金supported by the National Natural Science Foundation of China(21978093)。
文摘Vacuum gas oil(VGO)is the most important feedstock for hydrocracking processes in refineries,but its molecular composition cannot be fully acquired by current analysis techniques owing to its complexity.In order to build an accurate and reliable molecular-level kinetic model for reactor design and process optimization,the molecular composition of VGO has to be reconstructed based on limited measurements.In this study,a modified stochastic reconstruction-entropy maximization(SR-REM)algorithm was applied to reconstruct VGOs,with generation of a general molecule library once and for all via the SR method at the first step and adjustment of the molecular abundance of various VGOs via the REM method at the second step.The universality of the molecule library and the effectiveness of the modified SR-REM method were validated by fifteen VGOs(three from the literature)from different geographic regions of the world and with different properties.The simulated properties(density,elemental composition,paraffin-naphthene-aromatics distribution,boiling point distribution,detailed composition of naphthenes and aromatics in terms of ring number as well as composition of S-heterocycles)are in good agreement with the measured counterparts,showing average absolute relative errors of below 10%for each property.
基金CHGO sample was provided by Synrude Canada Ltd.Plant.
文摘Toluene insoluble matter (TIM) in coker heavy gas oil (CHGO) from oil sands bitumen is harmful to the downstream hydrotreating, and it may be difficult to be removed by conventional filtration. In order to determine its origin, the TIM must first be separated from CHGO for characterization. Two techniques are described to accomplish this goal. In the ultra-centrifugation approach used in this work, CHGO is blended with a miscible liquid and centrifuged under 366000 G (gravity) force. Through this procedure toluene and hexane diluents yielded TIM contents of 24μg·g-1 and 88μg·g-1 respectively. In an alternative simplified procedure, the initial ultra-centrifugation step is omitted. Several different solvents are evaluated for use as diluents but, in each case, toluene is still used in the subsequent washing steps. TIM contents determined by this method range from 23 to about 200μg·g-1. The amount of TIM separated by means of this method depends primarily on the initial diluent used. Other conditions, such as diluent-oil ratio, water-oil ratio, mixing time, temperature and water pH value, are also studied.
基金supported by the Young Talent Fund of University Association for Science and Technology in Shaanxi, China (No. 20160222)
文摘This work was mainly concentrated on the removal of naphthenic acids(NAs) from dewaxed vacuum gas oil(VGO) by adsorption using a commercial grade activated clay(AC) adsorption during lube base oil refining. The NAs in dewaxed VGO cut-4 were identified by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS). The AC sample from a refinery was characterized by XRD, BET, TG/DTA, and SEM. A series of experiments were carried out to investigate the performance of NAs adsorption by AC using a batch adsorption technique, in which some key experimental parameters such as temperature, contact time, initial concentration of NA in oil sample as well as the dosage of adsorbent were investigated. Equilibrium isotherms were analyzed using the Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich(D-R) adsorption models. The pseudo-first order, the pseudo-second order, and intraparticle diffusion models were employed to describe the kinetics data. The results revealed that the D-R isotherm provided a better fit to the experimental data than other isotherms, and the adsorption kinetics followed the pseudo-first order kinetic equation. The thermodynamic data indicated that the adsorption process was feasible and spontaneous as an endothermic process. The results could provide a clear understanding of the NAs adsorption by AC during lube base oil processing at refineries.
基金Natural Resources Canada and government of Canada's interdepartmental Program of Energy Research and Development (PERD)
文摘This study set out to gain a deeper understanding of a fluid catalytic cracking(FCC)coprocessing approach using canola oil mixed with bitumen-derived heavy gas oil(HGO),for the production of partially-renewable gasoline,with respect to its composition and quality.The FCC coprocessing approach may provide an alternative solution to reducing the carbon footprint and to meet government regulatory demands for renewable transportation fuels.In this study,a mixture of 15 v%canola oil in HGO was catalytically cracked with a commercial equilibrium catalyst under typical FCC conditions.Cracking experiments were performed using a bench-scale Advanced Cracking Evaluation(ACE)unit at a fixed weight hourly space velocity of 8 h^(à1),490–530C,and catalyst/oil ratios of 4–12 g/g.The total liquid product samples were injected via an automatic sampler and a prefractionator(to removet254C)into a gas chromatographic system containing a series of columns,traps,and valves designed to separate each of the hydrocarbon types.The analyzer gives detailed hydrocarbon types of à200C gasoline,classified into paraffins,iso-paraffins,olefins,naphthenes,and aromatics by carbon number up to C_(11)(C_(10)for aromatics).For a feed cracked at a given temperature,the gasoline aromatics show the highest selectivity in terms of weight percent conversion,followed by saturated iso-paraffins,saturated naphthenes,unsaturated iso-paraffins,unsaturated naphthenes,unsaturated normal paraffins,and saturated normal paraffins.As conversion increases,both aromatics and saturated iso-paraffins increase monotonically at the expense of other components.Hydrocarbon type analysis and octane numbers with variation in feed type,process severity(temperature and catalyst/oil ratio),and conversion are also presented and discussed.
文摘In this research, the affect of storage time and different metals concentration of copper and iron on gum formation in gas oil is investigated. A study of the affect of gum content on properties of sample is performed, where the gas oil derived from (Kirkuk crude oil) have boiling point range (266-420)℃. For this purpose, a gas oil sample has been doped with these two metals ions at concentration levels of 0.5, 1.5, 2.5 and 3.5 μg mL-1. Washed gum content tests have been carried out using ASTM D-381 on samples stored for 8, 16, 24 and 32 days. The experimental results show that an increase in storage time and metal concentration strongly increases the rate of gum formation for all metal investigations and this increase in gum concentration affects the viscosity of samples towards increasing of viscosity.
文摘This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields and selectivities of ethylene and propylene in cocracking. The difference in coking tendencies betWeen the cocracking and the separate cracking is compared as well.
基金funded by projects of the National Natural Science Foundation of China(Nos.:42272167,U19B6003 and 41772153)projects of the Science&Technology Department of Sinopec(Nos.:P22121,P21058-8 and P23167).
文摘The Well Tashen 5(TS5),drilled and completed at a vertical depth of 9017 m in the Tabei Uplift of the Tarim Basin,NW China,is the deepest well in Asia.It has been producing both oil and gas from the Sinian at a depth of 8780e8840 m,also the deepest in Asia in terms of oil discovery.In this paper,the geochemical characteristics of Sinian oil and gas from the well were investigated and compared with those of Cambrian oil and gas discovered in the same basin.The oil samples,with Pr/Ph ratio of 0.78 and a whole oil carbon isotopic value of31.6‰,have geochemical characteristics similar to those of Ordovician oils from the No.1 fault in the North Shuntuoguole area(also named Shunbei area)and the Middle Cambrian oil from wells Zhongshen 1(ZS1)and Zhongshen 5(ZS5)of Tazhong Uplift.The maturity of light hydrocarbons,diamondoids and aromatic fractions all suggest an approximate maturity of 1.5%e1.7%Ro for the samples.The(4-+3-)methyldiamantane concentration of the samples is 113.5 mg/g,indicating intense cracking with a cracking degree of about 80%,which is consistent with the high bottom hole temperature(179℃).The Sinian gas samples are dry with a dryness coefficient of 0.97.The gas is a mixture of kerogen-cracking gas and oil-cracking gas and has Ro values ranging between 1.5%and 1.7%,and methane carbon isotopic values of41.6‰.Based on the equivalent vitrinite reflectance(R_(eqv)=1.51%e1.61%)and the thermal evolution of source rocks from the Cambrian Yu'ertusi Formation of the same well,it is proposed that the Sinian oil and gas be mainly sourced from the Cambrian Yu'ertusi Formation during the Himalayan period but probably also be joined by hydrocarbon of higher maturity that migrated from other source rocks in deeper formations.The discovery of Sinian oil and gas from Well TS5 suggests that the ancient ultra-deep strata in the northern Tarim Basin have the potential for finding volatile oil or condensate reservoirs.
基金supported by the National Natural Science Foundation of China(Grant No.52004030)the R&D Program of Beijing Municipal Education Commission(Grant No.KM202310016003)the Exchange Program of High-end Foreign Experts of Ministry of Science and Technology,China(Grant No.G2022178013L)。
文摘Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Based on system and control theories,System-Theoretic Accident Model and Processes(STAMP)is a widely recognized approach for accident analysis.In this paper,we propose a STAMP-Game model to analyze accidents in oil and gas storage and transportation systems.Stakeholders in accident analysis by STAMP can be regarded as players of a game.Game theory can,thus,be adopted in accident analysis to depict the competition and cooperation between stakeholders.Subsequently,we established a game model to study the strategies of both supervisory and supervised entities.The obtained results demonstrate that the proposed game model allows for identifying the effectiveness deficiency of the supervisory entity,and the safety and protection altitudes of the supervised entity.The STAMP-Game model can generate quantitative parameters for supporting the behavior and strategy selections of the supervisory and supervised entities.The quantitative data obtained can be used to guide the safety improvement,to reduce the costs of safety regulation violation and accident risk.
基金Funding from the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan under Grant Agreement No.AP13268843.
文摘This study predicts favorable oil and gas source-rock formation conditions in the Aryskum Depression of the South Turgay Basin,Kazakhstan.This study assesses the thermal maturity and characteristics of organic matter by determining its environmental conditions using data from geochemical analysis of core(pyrolysis)and oil(biomarkers and carbon isotopic compositions)samples.According to the geochemical parameters obtained by pyrolysis,the oil generation potential of the original rocks of most studied samples varies from poor to rich.The facies–genetic organic matter is predominantly humic and less frequently humus–sapropel,indicating organic matter accumulation in the studied samples were under moderately reducing conditions(kerogenⅢand Ⅱ types)and coastal–marine environments(kerogen typeⅠ).The carbon isotopic compositions of oils derived from the Jurassic deposits of the Aryskum Depression also indicate the sapropelic and mixed humic–sapropelic type of organic matter(kerogenⅡandⅠ).Biomarker analysis of oils indicates original organic matter formation in an anoxic environment.
基金the financial support from the National Natural Science Foundation of China(71934004)Key Projects of the National Social Science Foundation(23AZD065)the Project of the CNOOC Energy Economics Institute(EEI-2022-IESA0009)。
文摘With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.
文摘In the pursuit of global net zero carbon emissions and climate change mitigation,ongoing research into sustainable energy sources and emission control is paramount.This review examines methane leakage from abandoned oil and gas(AOG)wells,focusing particularly on Lubbock,a geographic area situated within the larger region known as the Permian Basin in West Texas,United States.The objective is to assess the extent and environmental implications of methane leakage from these wells.The analysis integrates pertinent literature,governmental and industry data,and prior Lubbock reports.Factors affecting methane leakage,including well integrity,geological characteristics,and human activities,are explored.Our research estimates 1781 drilled wells in Lubbock,forming a foundation for targeted assessments and monitoring due to historical drilling trends.The hierarchy of well statuses in Lubbock highlights the prevalence of“active oil wells,”trailed by“plugged and abandoned oil wells”and“inactive oil wells.”Methane leakage potential aligns with these well types,underscoring the importance of strategic monitoring and mitigation.The analysis notes a zenith in“drilled and completed”wells during 1980-1990.While our study's case analysis and literature review reiterate the critical significance of assessing and mitigating methane emissions from AOG wells,it's important to clarify that the research does not directly provide methane leakage data.Instead,it contextualizes the issue's magnitude and emphasizes the well type and status analysis's role in targeted mitigation efforts.In summary,our research deepens our understanding of methane leakage,aiding informed decision-making and policy formulation for environmental preservation.By clarifying well type implications and historical drilling patterns,we aim to contribute to effective strategies in mitigating methane emissions from AOG wells.
基金Supported by the CNOOC Major Technology Project During the 14th FIVE-YEAR PLAN PERIOD(KJGG2022-0403)CNOOC Major Technology Project(KJZH-2021-0003-00).
文摘Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and minerals were characterized microscopically,the measured trap sealing indexes were compared,the biomarker compounds of crude oil were extracted,the genesis of condensate gas was identified,and the reservoir-forming conditions were examined.On this basis,the Paleogene Enping Formation in the Huizhou 26 subsag was systematically analyzed for the potential of oil and gas resources,the development characteristics of large-scale high-quality conglomerate reservoirs,the trapping effectiveness of faults,the hydrocarbon migration and accumulation model,and the formation conditions and exploration targets of large-and medium-sized glutenite-rich oil and gas fields.The research results were obtained in four aspects.First,the Paleogene Wenchang Formation in the Huizhou 26 subsag develops extensive and thick high-quality source rocks of semi-deep to deep lacustrine subfacies,which have typical hydrocarbon expulsion characteristics of"great oil generation in the early stage and huge gas expulsion in the late stage",providing a sufficient material basis for hydrocarbon accumulation in the Enping Formation.Second,under the joint control of the steep slope zone and transition zone of the fault within the sag,the large-scale near-source glutenite reservoirs are highly heterogeneous,with the development scale dominated hierarchically by three factors(favorable facies zone,particle component,and microfracture).The(subaqueous)distributary channels near the fault system,with equal grains,a low mud content(<5%),and a high content of feldspar composition,are conducive to the development of sweet spot reservoirs.Third,the strike-slip pressurization trap covered by stable lake flooding mudstone is a necessary condition for oil and gas preservation,and the NE and nearly EW faults obliquely to the principal stress have the best control on traps.Fourth,the spatiotemporal configuration of high-quality source rocks,fault transport/sealing,and glutenite reservoirs controls the degree of hydrocarbon enrichment.From top to bottom,three hydrocarbon accumulation units,i.e.low-fill zone,transition zone,and high-fill zone,are recognized.The main area of the channel in the nearly pressurized source-connecting fault zone is favorable for large-scale hydrocarbon enrichment.The research results suggest a new direction for the exploration of large-scale glutenite-rich reservoirs in the Enping Formation of the Pearl River Mouth Basin,and present a major breakthrough in oil and gas exploration.
基金supported by the Sichuan Science and Technology Program (Grant Nos.2023NSFSC0004,2023NSFSC0790)the National Natural Science Foundation of China (Grant Nos.51827901,52304033)the Sichuan University Postdoctoral Fund (Grant No.2024SCU12093)。
文摘Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.
基金supported by the projects of the China Geological Survey(DD20230043,DD20240048)the project of the National Natural Science Foundation of China(42102123)。
文摘Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.
基金supported by the National Science Foundation of China(Grant numbers 52274062)Natural Science Foundation of Liaoning Province(Grant numbers 2022-MS-362)。
文摘Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil environment. The SCC behavior of X80 pipeline steel under the magnetic field and sulfate-reducing bacteria(SRB) environment was investigated by immersion tests, electrochemical tests, and slow strain rate tensile(SSRT) tests. The results showed that the corrosion and SCC sensitivity of X80 steel decreased with increasing the magnetic field strength in the sterile environment. The SCC sensitivity was higher in the biotic environment inoculated with SRB, but it also decreased with increasing magnetic field strength, which was due to the magnetic field reduces microbial activity and promotes the formation of dense film layer. This work provided theoretical guidance on the prevention of SCC in pipeline steel under magnetic field and SRB coexistence.