The conventional biomarkers are limited due to the extremely high thermal stresses in ultra-deep hydrocarbon reservoirs.The diamondoid with cage structure has excellent thermal stability and is an effective tool for c...The conventional biomarkers are limited due to the extremely high thermal stresses in ultra-deep hydrocarbon reservoirs.The diamondoid with cage structure has excellent thermal stability and is an effective tool for characterizing the ultra-deep hydrocarbon and linking its source.We investigated the distribution of diamondoids in ultra-deep reservoirs including black oils,volatile oils,and condensates.The source-related diamondoids indicate that crude oils are mainly sourced from marine siliceous shale.The bulk characteristics(e.g.color,density,Sat/Aro)of crude oils reveal the variations of thermal maturity:low maturity for black oils,moderate maturity for volatile oils,and high maturity for condensates.Based on regular variations in the thermal maturity of crude oils,the thermal evolution of diamondoids is characterized.The abundance of C_(1)-and C_(2)-alkylated diamantanes increases with increasing maturity,and hydrothermal activity may lead to an abnormal increase in the percentage of C_(3)-alkylated adamantanes.Despite the higher thermal stability of 4-methyldiamantane(4-MD),a more sensitive change in relative abundance with maturity for 1-methyldiamantane(1-MD)among all methyldiamantanes(MDs)is observed.Ethyl diamondoids are thermally less stable and their derived indices can effectively indicate the thermal maturity of ultra-deep hydrocarbons.The applications of commonly maturity-related indices should be cautious(e.g.MDI),whereas the novel methyl-ethyl diamantane index(MEDI)is highly recommended.The combination of high MAI values and low MEDI values most likely reflects the influence of late-charged light hydrocarbons.Overall,multiple charging and in-reservoir mixing of light hydrocarbons and oils with various maturities constrained the present phase states of ultra-deep oil reservoirs.This study gives a new perspective to understanding the fate of molecular evolution and phase states of hydrocarbons in the ultra-deep basins.展开更多
The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes...The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes(As)and diamantanes(Ds),are relatively resistant to biodegradation and obvious biodegradation was observed in oils with a Peters-Moldowan(PM)biodegradation rank of 6 or more.Overall,the sensibility of biodegradation on diamondoids is generally similar to hopanes and regular steranes.As biodegradation evolves,the changes in concentration and components of diamondoids show that the biodegradation process is selective and stepwise.The significant increase of MD/MA and DMD/DMA for oils with a PM ranking 6^(+) indicates that diamantanes are generally more resistant to biodegradation than adamantanes.The similar trends of DMA/MA,EA/MA,MD/D,DMD/MD and other relevant indexes,show that higher alkylation homologs are more resistant to biodegradation.The commonly used diamondoid ratios,such as MAI,EAI,MDI and DMID-1,are obviously affected by biodegradation at the stage of high-level biodegradation,which may indicate that these ratios should be used with caution in case of severely degraded oils.展开更多
Oil and gas breakthroughs have been achieved in the Zhongshen 1(ZS1) and 1 C(ZS1 C) wells in Cambrian pre-salt from the Tarim Basin in northwest China. However, Middle and Lower Cambrian reservoirs reveal substantial ...Oil and gas breakthroughs have been achieved in the Zhongshen 1(ZS1) and 1 C(ZS1 C) wells in Cambrian pre-salt from the Tarim Basin in northwest China. However, Middle and Lower Cambrian reservoirs reveal substantial differences in the geochemistry and secondary alteration characteristics between the oils collected from the two wells. High concentrations of thiadiamondoids and diamondoidthiols, including thiatetramantanes, tetramantanethiols, thiapentamantanes, and pentamantanethiols, are detected in the organic sulfur compound fraction of concentrated oil collected from the ZS1 C well, which samples the Lower Cambrian Xiaoerbulake Formation. Higher diamondoids, such as tetramantanes, pentamantanes, hexamantanes, and cyclohexamantane, also occur in the saturate fractions of the concentrated ZS1 C oil. The presence of these compounds is verified by mass spectra analysis and comparison with previous studies. During thermochemical sulfate reduction(TSR), the cage of higher diamondoids is interpreted to open because of sulfur radicals forming open-cage higher diamondoid-like thiols, followed by cyclization that leads to the formation of high thiadiamondoids. Using D_(16)-adamantane as an internal standard, the concentrations of lower diamondoids and thiadiamondoids of non-concentrated Cambrian oil from well ZS1 C are 83874 and8578 μg/g, respectively, which are far higher than Cambrian oil from well ZS1 and most Ordovician oils in the Tarim Basin. The high concentrations of lower thiadiamondoids and occurrence of higher thiadiamondoids and diamondoidthiols support that the oil from well ZS1 C is a product of severe TSR alteration.展开更多
The diamondoid compounds are a large family of important semiconductors,which possess various unique transport properties and had been widely investigated in the fields of photoelectricity and nonlinear optics.For a s...The diamondoid compounds are a large family of important semiconductors,which possess various unique transport properties and had been widely investigated in the fields of photoelectricity and nonlinear optics.For a significantly long period of time,diamondoid materials were not given much attention in the field of thermoelectricity.However,this changed when a series of diamondoid compounds showed a thermoelectric figure of merit(ZT)greater than 1.0.This discovery sparked considerable interest in further exploring the thermoelectric properties of diamondoid materials.This review aims to provide a comprehensive view of our current understanding of thermal and electronic transport in diamondoid materials and stimulate their development in thermoelectric applications.We present a collection of recent discoveries concerning the lattice dynamics and electronic structure of diamondoid materials.We review the underlying physics responsible for their unique electrical and phonon transport behaviors.Moreover,we provide insights into the advancements made in the field of thermoelectricity for diamondoid materials and the corresponding strategies employed to optimize their performance.Lastly,we emphasize the challenges that lie ahead and outline potential avenues for future research in the domain of diamondoid thermoelectric materials.展开更多
On the basis of the results of simulation experiments, now we better understand the contribution of high carbon number hydrocarbons to diamondoid generation during thermal pyrolysis of crude oil and its sub-fractions(...On the basis of the results of simulation experiments, now we better understand the contribution of high carbon number hydrocarbons to diamondoid generation during thermal pyrolysis of crude oil and its sub-fractions(saturated, aromatic, resin, and asphalene fractions). However, little is known about the effect of volatile components in oil on diamondoid generation and diamondoid indices due to the lack of attention to these components in experiments. In this study, the effect of volatile components in oil on diamondoid generation and maturity indices was investigated by the pyrolysis simulation experiments on a normal crude oil from the HD23 well of the Tarim Basin and its residual oil after artificial volatilization, combined with quantitative analysis of diamondoids. The results indicate that the volatile components(≤n C12) in oil have an obvious contribution to the generation of adamantanes, which occurs mainly in the early stage of oil cracking(Easy Ro<1.0%), and influences the variations in maturity indices of adamantanes; but they have no obvious effect on the generation and maturity indices of diamantanes. Therefore, some secondary alterations e.g., migration, gas washing, and biodegradation, which may result in the loss of light hydrocarbons in oil under actual geological conditions, could affect the identification of adamantanes generated during the late-stage cracking of crude oil, and further influence the practical application of adamantane indices.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U20B6001,41472108)。
文摘The conventional biomarkers are limited due to the extremely high thermal stresses in ultra-deep hydrocarbon reservoirs.The diamondoid with cage structure has excellent thermal stability and is an effective tool for characterizing the ultra-deep hydrocarbon and linking its source.We investigated the distribution of diamondoids in ultra-deep reservoirs including black oils,volatile oils,and condensates.The source-related diamondoids indicate that crude oils are mainly sourced from marine siliceous shale.The bulk characteristics(e.g.color,density,Sat/Aro)of crude oils reveal the variations of thermal maturity:low maturity for black oils,moderate maturity for volatile oils,and high maturity for condensates.Based on regular variations in the thermal maturity of crude oils,the thermal evolution of diamondoids is characterized.The abundance of C_(1)-and C_(2)-alkylated diamantanes increases with increasing maturity,and hydrothermal activity may lead to an abnormal increase in the percentage of C_(3)-alkylated adamantanes.Despite the higher thermal stability of 4-methyldiamantane(4-MD),a more sensitive change in relative abundance with maturity for 1-methyldiamantane(1-MD)among all methyldiamantanes(MDs)is observed.Ethyl diamondoids are thermally less stable and their derived indices can effectively indicate the thermal maturity of ultra-deep hydrocarbons.The applications of commonly maturity-related indices should be cautious(e.g.MDI),whereas the novel methyl-ethyl diamantane index(MEDI)is highly recommended.The combination of high MAI values and low MEDI values most likely reflects the influence of late-charged light hydrocarbons.Overall,multiple charging and in-reservoir mixing of light hydrocarbons and oils with various maturities constrained the present phase states of ultra-deep oil reservoirs.This study gives a new perspective to understanding the fate of molecular evolution and phase states of hydrocarbons in the ultra-deep basins.
基金funded by the National Natural Science Foundation of China(No.42272160,No.41502133).
文摘The sensitivity of biodegradation on diamondoids was investigated using a series of biodegraded oil samples from the Ronier tectonic unit of Bongor Basin,Chad.The results suggest that diamondoids,including adamantanes(As)and diamantanes(Ds),are relatively resistant to biodegradation and obvious biodegradation was observed in oils with a Peters-Moldowan(PM)biodegradation rank of 6 or more.Overall,the sensibility of biodegradation on diamondoids is generally similar to hopanes and regular steranes.As biodegradation evolves,the changes in concentration and components of diamondoids show that the biodegradation process is selective and stepwise.The significant increase of MD/MA and DMD/DMA for oils with a PM ranking 6^(+) indicates that diamantanes are generally more resistant to biodegradation than adamantanes.The similar trends of DMA/MA,EA/MA,MD/D,DMD/MD and other relevant indexes,show that higher alkylation homologs are more resistant to biodegradation.The commonly used diamondoid ratios,such as MAI,EAI,MDI and DMID-1,are obviously affected by biodegradation at the stage of high-level biodegradation,which may indicate that these ratios should be used with caution in case of severely degraded oils.
基金supported by the National Natural Science Foundation of China (Grant No. 41772153)State Key Laboratory of Organic Geochemistry, GIGCAS (Grant No. SKLOG2017-02)+1 种基金National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2017ZX05005-002)SINOPEC Ministry of Science and Technology (Grant No. P16090, P17049-1)
文摘Oil and gas breakthroughs have been achieved in the Zhongshen 1(ZS1) and 1 C(ZS1 C) wells in Cambrian pre-salt from the Tarim Basin in northwest China. However, Middle and Lower Cambrian reservoirs reveal substantial differences in the geochemistry and secondary alteration characteristics between the oils collected from the two wells. High concentrations of thiadiamondoids and diamondoidthiols, including thiatetramantanes, tetramantanethiols, thiapentamantanes, and pentamantanethiols, are detected in the organic sulfur compound fraction of concentrated oil collected from the ZS1 C well, which samples the Lower Cambrian Xiaoerbulake Formation. Higher diamondoids, such as tetramantanes, pentamantanes, hexamantanes, and cyclohexamantane, also occur in the saturate fractions of the concentrated ZS1 C oil. The presence of these compounds is verified by mass spectra analysis and comparison with previous studies. During thermochemical sulfate reduction(TSR), the cage of higher diamondoids is interpreted to open because of sulfur radicals forming open-cage higher diamondoid-like thiols, followed by cyclization that leads to the formation of high thiadiamondoids. Using D_(16)-adamantane as an internal standard, the concentrations of lower diamondoids and thiadiamondoids of non-concentrated Cambrian oil from well ZS1 C are 83874 and8578 μg/g, respectively, which are far higher than Cambrian oil from well ZS1 and most Ordovician oils in the Tarim Basin. The high concentrations of lower thiadiamondoids and occurrence of higher thiadiamondoids and diamondoidthiols support that the oil from well ZS1 C is a product of severe TSR alteration.
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:51925101National Natural Science Foundation of China,Grant/Award Numbers:51571007,51772012,52250090,52371208+2 种基金Beijing Natural Science Foundation,Grant/Award Number:JQ18004111 Project,Grant/Award Number:B17002U.S.Department of Energy,Grant/Award Numbers:DE‐SC0014520,DE‐SC0024256。
文摘The diamondoid compounds are a large family of important semiconductors,which possess various unique transport properties and had been widely investigated in the fields of photoelectricity and nonlinear optics.For a significantly long period of time,diamondoid materials were not given much attention in the field of thermoelectricity.However,this changed when a series of diamondoid compounds showed a thermoelectric figure of merit(ZT)greater than 1.0.This discovery sparked considerable interest in further exploring the thermoelectric properties of diamondoid materials.This review aims to provide a comprehensive view of our current understanding of thermal and electronic transport in diamondoid materials and stimulate their development in thermoelectric applications.We present a collection of recent discoveries concerning the lattice dynamics and electronic structure of diamondoid materials.We review the underlying physics responsible for their unique electrical and phonon transport behaviors.Moreover,we provide insights into the advancements made in the field of thermoelectricity for diamondoid materials and the corresponding strategies employed to optimize their performance.Lastly,we emphasize the challenges that lie ahead and outline potential avenues for future research in the domain of diamondoid thermoelectric materials.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41172115&41372138)the National Science&Technology Major Project of the Ministry of Science and Technology of China(Grant No.2011ZX05008-002-32)China Postdoctoral Science Foundation(Grant No.2014M561002)
文摘On the basis of the results of simulation experiments, now we better understand the contribution of high carbon number hydrocarbons to diamondoid generation during thermal pyrolysis of crude oil and its sub-fractions(saturated, aromatic, resin, and asphalene fractions). However, little is known about the effect of volatile components in oil on diamondoid generation and diamondoid indices due to the lack of attention to these components in experiments. In this study, the effect of volatile components in oil on diamondoid generation and maturity indices was investigated by the pyrolysis simulation experiments on a normal crude oil from the HD23 well of the Tarim Basin and its residual oil after artificial volatilization, combined with quantitative analysis of diamondoids. The results indicate that the volatile components(≤n C12) in oil have an obvious contribution to the generation of adamantanes, which occurs mainly in the early stage of oil cracking(Easy Ro<1.0%), and influences the variations in maturity indices of adamantanes; but they have no obvious effect on the generation and maturity indices of diamantanes. Therefore, some secondary alterations e.g., migration, gas washing, and biodegradation, which may result in the loss of light hydrocarbons in oil under actual geological conditions, could affect the identification of adamantanes generated during the late-stage cracking of crude oil, and further influence the practical application of adamantane indices.
