Can We Successfully Cross the “Historic Three Gorges” of the Energy Transition

正Since China’s leaders put forward the "30/60" goals in September 2020(achieving peak carbon dioxide emissions by 2030 and carbon neutrality by 2060),how to achieve the goals on schedule has become a hot topic in the whole of society. At present,from the central government to local governments,from the business community to the academic community,and from think tanks to media networks, the discussion around"Carbon Neutrality and Peak Carbon Dioxide Emissions" is in full swing.     

C-Nanostructures Cluster Models in Organic Solvents： Fullerenes,Tubes, Buds and Graphenes

The existence of nanographene in cluster form is discussed in organic solvents. Theories are developed based on the columnlet, bundlet and droplet models describing the size-distribution functions. Phenomena present a unified explanation in the columnlet model in which free energy of Cgraphene involved in cluster is combined from a volume part proportional to the number of molecules n in cluster and a constant. The columnlet model enables describing distribution function of Cgraphene clusters by size. From purely geometrical considerations the columnlet （Cgraphene）, bundlet （single-wall carbon nanotube）, CNT （carbon nanotube）, SWNT （single-wall C-nanotube）, and carbon nanobud, CNB （carbon nanobud）） and droplet （fullerene） models predict dissimilar behaviours. The interaction-energy parameters of Cgraphene are taken from C60. An CNB behaviour or further is expected. The decay of solubility with rising temperature is smaller for Cgraphene than for SWNT and CNB and, furthermore, than for C60, in agreement with lesser numbers of units in Cgraphene clusters. The discrepancy between the experimental data of the heat of solution of fullerenes, CNTs, CNBs and graphenes is ascribed to the sharp concentration dependence of the heat of solution. The diffusion coefficient drops with temperature result greater for Cgraphene than CNB and SWNT than C60 corresponding to lesser number of units in clusters. The aggregates near （C60）13, SWNT/CNB7 and （Cgraphene）3 could be representative of the droplet, bundlet and columnlet models.     

Energy Transition Strategy of Chinese Oil & Gas Companies and their Green Financial Routes under the Carbon Neutrality Tendency(Ⅰ)

正In 2020, China announced that it will strive to achieve carbon peak by 2030 and carbon neutrality by 2060. The time from carbon peak to carbon neutrality promised by China is far shorter than that of developed countries, which requires hard work. Under the trend of carbon neutrality, Chinese oil and gas enterprises need to accelerate the pace of adjusting to the change in energy consumption structure. It is urgent to formulate energy transformation strategy in line with the trend of "carbon neutrality".     

Geochemcal characteristics of abiogenic alkane gases

Recently abiogenic alkanes have been found in various locations in the world and other celestial bodies.The chemical composition of abiogenic alkane gases varies widely.The content of methane is low and nearly no C2+ is found in the abiogenic alkane gases from fluid inclusions in volcanic rocks or hot springs in China.In the unsedimented submarine hydrothermal vent system C1/C2+ ratios are much greater than those for the thermogenic gases,mostly >800 and in some cases up to 8,000.In the Songliao Basin,China,C1/C2+ of some abiogenic gases are often less than 150.Abiogenic alkane gases which have been found in nature often have carbon isotopic reversal among C1-C4 alkanes(δ13C1>δ13C2>δ13C3>δ13C4),whereas both regular and reversed hydrogen isotope distribution pattern among C1-C4 alkanes have been reported.The δ13C of abiogenic methane is mainly greater than-30‰ though laboratory synthesized methane can have δ13C as low as-57‰,and its δD1 values vary widely and overlap with biogenic gases.High 3He/4He ratios often indicate the addition of mantle-derived helium and are related to abiogenic gases.However,some biogenic gases can also have high 3He/4He ratios up to 8.The CH4/3He end-member is often lower than 106 for abiogenic alkane gases while greater than 1013 for biogenic gases,and the values between these two end-members often reflect the mixing of biogenic and abiogenic gases.     

Sedimentary environment controls on the accumulation of organic matter in the Upper Ordovician Wufeng–Lower Silurian Longmaxi mudstones in the Southeastern Sichuan Basin of China

The Upper Ordovician–Lower Silurian mudstones(including the Wufeng, Guanyinqiao and Longmaxi Formations) in the Sichuan Basin are some of the most important shale gas plays in China. In order to enhance our understanding of the process of formation of organic carbon up to 10%, optical, microscopy and geochemical methods have been used to investigate the petrographic and geochemical characteristics of the formation. Firstly, three mudstone lithofacies were identified based on a wide variety of mudstone laminations. These are:(a) indistinctly laminated mudstone;(b) parallellaminated mudstone; and(c) nonparallel-laminated mudstone. Then, combining with the evidence from depocenter migration, Th/U ratios and total organic carbon, the abundant organo-minerallic fabrics suggest that organic carbon was preferentially deposited and preserved in anoxic, low energy and stagnant water conditions during deposition of the Wufeng and Longmaxi Formations. On the contrary, the Guanyinqiao Formation with poor organic carbon was deposited in oxic and high-energy water conditions.     

Alkaline diagenesis and its genetic mechanism in the Triassic coal measure strata in the Western Sichuan Foreland Basin, China

The reservoir of the upper Triassic Xujiahe Formation(T3x) in the Western Sichuan Foreland Basin is a set of terrigenous clastic rocks in an environment of coal measure sediments.Diagenesis greatly controls the physical properties of the reservoir through different responses of minerals to acidic and alkaline diagenetic environment.The dissolution of unstable components such as feldspar,rock fragments,carbonate cement,and clay minerals is the major source of secondary pores under acidic diagenesis,while the dissolution of quartz increases the reservoir space in the fault-fold zone of Longmen Mountain and Leikoupo paleo-hills.The dissolution of quartz is a result of cross-formation flow of fluid in the Himalaya epoch and the invasion of alkaline formation water from the Triassic Leikoupo and Jialingjiang formations through fault and fracture systems.In the vertical succession,acidic dissolution occurs at a shallow depth of less than 2,180 m,and alkaline dissolution occurs at a greater depth of more than 2,280 m.The reservoir space is formed by the influence of both acidic and alkaline dissolution in the depth interval of 2,180-2,280 m.     

Application of butane geochemistry of natural gas in hydrocarbon exploration

In order to distinguish the source and migration direction of natural gas by geochemical characteristics of butane,the components and carbon isotopes of natural gas from major hydrocarbonbearing basins in China were analyzed.The results showed that:(1) Oil-type gas has i-C 4 /n-C 4 <0.8,δ 13 C butane <-28‰,δ 13 C i-butane <-27‰,δ 13 C n-butane <-28.5‰,whereas coal-type gas has i-C 4 /n-C 4 >0.8,δ 13 C butane >-25.5‰,δ 13 C i-butane >-24‰,δ 13 C n-butane >-26‰.(2) When δ 13 C i-butane-δ 13 C n-butane is greater than 0,the maturity of oil-type gas is generally more than 2.4% and that of coal-type gas is greater than 1.4%,whereas when the difference is less than 0,the maturity of oil-type gas is generally less than 1.1% and that of coal-type gas is less than 0.8%.(3) When natural gas migrates through dense cap rocks,the value of i-C 4 /n-C 4 increases,whereas when it migrates laterally along a reservoir,the value of i-C 4 /n-C 4 decreases.(4) Sapropelic transition zone gas with composition and carbon isotopic signatures similar to those of oil-type gas in the low thermal evolution stage is found to have a relatively high butane content.(5) The values of i-C 4 /n-C 4 and δ 13 C n-butane δ 13 C i-butane of gas which has suffered biological degradation are significantly higher than those obtained from thermogenic and bio-thermocatalytic transition zone gas.Thus,natural gas of different genetic types can be recognized through component analysis and carbon isotopic signatures of butane,the natural gas maturity can be estimated from the difference in carbon isotopic content between isobutane and n-butane,and the migration direction of natural gas can be determined from i-C 4 /n-C 4 ratios and transport conditions,which can also be used to thermogenic and bio-thermocatalytic transition zone gas.     

Geochemical characteristics of Callovian –Oxfordian carbonates in Samandepe gas field,Amu Darya Basin, Turkmenistan

The Callovian-Oxfordian carbonate reservoirs are the most important hydrocarbon reservoir in the Samandepe gas field,Amu Darya basin,Turkmenistan.Based on the analysis of Fe,Mn and Sr trace elements,and carbon,oxygen and strontium isotopes,the genesis and evolutionary characteristics of the carbonate reservoirs were studied,and the conclusions were follows:1) Sustained transgressive-regressive cycles played an important role during Callovian-Oxfordian.The reservoir of reef-bank facies was well developed in the period of transgression,while the regional dense cap rocks developed in the period of regression;2) The 87 Sr/86 Sr ratio measured from rudist shells yields an age of 157.2 Ma according to the global strontium isotope curve;3) As diagenetic intensity increased,δ 13 C changed little,and δ 18 O showed strong negative deviation but was still limited to the range of Late Jurassic seawater.High Fe and Sr contents,and low Mn content,and the evolutionary trend of δ 13 C and δ 18 O all indicate that diagenesis occurred in a relatively confined environment,where the fluids were relatively reducing and contained hot brine.The stage of diagenesis reached is mesodiagenesis,which is very favorable for preservation of primary pores in carbonates;4) Strong dissolution of reef limestones,burial dolomitization and hydrothermal calcite precipitation were all the results of the interaction between the 87 Sr-rich diagenetic fluid and rocks;5) The analysis results of isotopes,fluid inclusions and vitrinite reflectance show that the diagenetic fluid was compaction-released water that originated from the deep,coal-bearing clastic strata.     

Fluid migration paths in the marine strata of typical structures in the western Hubei– eastern Chongqing area, China

The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structure and the Jiannan gas field, were selected to analyze biomarker parameters in marine strata and to examine various types of natural gas and hydrocarbon sources. Fluid inclusions; carbon, oxygen, and strontium isotopic characteristics; organic geochemical analysis and simulation of hydrocarbon generation and expulsion history of source rocks were used for tracing fluid migration paths in marine strata of the study area. The Carboniferous-Triassic reservoirs in three typical structures all experienced at least two stages of fluid accumulation. All marine strata above the early Permian were shown to have fluids originating in the Permian rocks, which differed from the late stage fluids. The fluids accumulated in the late Permian reservoirs of the Xinchang structure were Cambrian fluids, while those in the late Carboniferous reservoirs were sourced from a combination of Silurian and Cambrian fluids. A long-distance and large-scale cross-formational flow of fluids destroyed the preservation conditions of earlier accumulated hydrocarbons. A short-distance cross-formational accumulation of Silurian fluids was shown in the late Permian reservoirs of the Longjuba structure with favorable hydrocarbon preservation conditions. The fluid accumulation in the Carboniferous reservoirs of the Jiannan structure mainly originated from neighboring Silurian strata with a small amount from the Cambrian strata. As a result, the Jiannan structure was determined to have the best preservation conditions of the three. Comparative analysis of fluid migration paths in the three structures revealed that the zone with a weaker late tectonism and no superimposition and modification of the Upper and Lower Paleozoic fluids or the Upper Paleozoic zone with the fluid charging from the Lower Paleozoic in the western Hubei-eastern Chongqing area are important target areas for future exploration.     

Collaborative Analysis of the Development of China's CCUS Industry and Carbon Market

With the global attention to climate ch ange and the national carbon neutrality,CCUS has received increasing attention as the key to achieve the carbon neutrality target.However,Due to poor economics,CCUS is difficult to commercialize in large scale.The carbon market is a relatively economical means to achieve emission reduction goals.Currently the carbon market is an important platform to achieve emission reduction goals and reduce the overall cost of social emission reduction.In the future,the...     

塔里木盆地“多元复合—过程叠加”成藏模式及其应用

阐述了复杂叠合盆地油气地质特征及油气成藏主控因素,提出了多元复合—过程叠加成藏模式及有利勘探区带预测方法。研究表明,中国复杂叠合盆地具有多期次构造变革、多套生储盖组合、多旋回油气成藏、多期次调整与改造的油气地质特点,油气藏形成与分布主要受古隆起、烃源灶、区域盖层以及构造平衡带4个要素的控制。"要素复合、过程叠加、多期成藏、晚期定型"是复杂叠合盆地油气藏形成、演化和分布的基本模式。依据这一模式,在恢复研究区4个主要控藏因素演化历史的基础上,对塔里木盆地各主要成藏期奥陶系目的层有利油气聚集区带及构造调整改造后的有利勘探区带进行了预测和评价。     

要素匹配成藏模式在塔里木盆地的应用

塔里木盆地志留系分布面积广,是主要的油气产层之一。该目的层油气来源多样,油气藏经历多期成藏和调整改造,类型复杂,导致该层系油气藏分布预测十分困难。根据国家973项目"中国典型叠合盆地油气形成富集与分布预测"中提出的叠合盆地多要素匹配成藏模式(T-CDMS),预测塔里木盆地志留系为有利成藏领域。首先建立各主控因素与油气藏之间的数学模型,然后定量评价4大主控因素(区域盖层C,沉积相D,古隆起M,烃源岩S)单独作用时的控藏范围和概率,在此基础上,按照多地质要素匹配模式原理预测了四大要素综合作用下的油气成藏概率和成藏范围。结果表明:志留系最有利区为孔雀河斜坡、英吉苏凹陷西部和满加尔凹陷周缘;有利区主要分布在塔北隆起英买力构造带和塔中隆起部分地区;巴楚隆起部分地区成藏可能性相对较小。     

塔里木多旋回盆地与复式油气系统

长距离漂移的小板块、条块分割的基底结构和相邻板块的复杂作用控制了塔里木盆地多旋回的演化历史。自塔里木运动后,盆地经历了古亚洲洋、古特提斯洋、中特提斯洋、新特提斯洋四大演化阶段,形成了多种原型盆地和统一、分割、又统一的叠加过程以及多变的热体制。多旋回盆地演化形成了复式油气系统。多套烃源、多个生烃坳陷和多期生烃构成了复式烃源;原生、次生孔隙型储层与“改造型”储层构成了复式储集空间;多套盖层与异常压力带构成了复式封盖系统;不整合、断裂、输导层和汇烃脊构成了复杂的输导网络;联合复合变形作用与沉积、成岩作用形成了复式圈闭系统;油气形成后的改造、重建封闭和保存导致了复杂的成藏史,形成了一些复式油气聚集带。基于上述认识,塔里木盆地今后油气勘探应立足于已知油气田,扩大储产规模,形成规模效应;积极向外拓展,争取战略突破;探索新类型、新层位、新深度,拓宽勘探领域;完善一批关键技术,攻克一批特殊目标,实现储、产量的快速增长。     

中国西部叠合盆地深部油气勘探面临的重大挑战及其研究方法与意义

在综合调研和收集了世界深部油气藏大量资料及对中国西部叠合盆地油气地质特征深入研究的基础上,总结提出中国西部叠合盆地深部油气勘探面临着三方面的重大挑战:①油气组成复杂,多期混合、来源不清,致使深部油气勘探方向难以确定;②富集油气的有效储层裂缝和溶蚀孔洞混杂,成因机制不清,导致勘探区带预测困难;③油气相态变异大,油气分布特征受深部高温压环境、低孔渗介质条件和多种运聚动力的影响,使得现有的成藏理论难以有效指导勘探目标的预测。因此认为,加速中国西部叠合盆地深部油气勘探必须解决三个关键科学问题:①多期构造过程叠加与深部油气生成演化;②深部有效储层形成机制与发育模式;③深部油气复合成藏机制与油气富集规律。为此,建议采用油气成藏过程正演模拟和油气成藏过程反演剖析相结合的研究方法和“深部成藏条件-深部成藏机制-深部成藏规律”的技术主线,重点选择深部资源潜力最大的塔里木盆地和准噶尔盆地开展研究,期待形成和发展中国叠合盆地深部油气复合成藏理论,研发深部油气分布预测配套技术,促进中国西部深部油气勘探和储量的快速增长。     

塔里木盆地含油气系统特征与划分

塔里木盆地含油气系统具有多源叠加复合、油气普遍混源、形成含油气系统的关键时刻多、成藏期次多和含油气系统多的特点。根据含油气系统形成的构造背景与烃源岩叠合分布特征及油气源对比结果,将塔里木盆地划分为克拉通型、前陆型和克拉通-前陆叠合型3类10个含油气系统。其中库车、塔西南油气系统为已证实的两个前陆型含油气系统,成气条件十分优越。轮南-草湖、哈拉哈塘、塔中、巴楚-盖麦提油气系统为已证实的海相克拉通型含油气系统,是塔里木盆地海相油气聚集的最有利区。塔东、阿瓦提油气系统则属克拉通-前陆叠合型含油气系统。     

东西伯利亚地台碳酸盐岩成藏条件对我国油气勘探的启示

东西伯利亚地台里菲纪（1 650～800 Ma）和文德纪（670～590 Ma）碳酸盐岩大油气田形成的有利条件为：里菲纪坳拉谷演化阶段形成暗色泥页岩优质烃源岩,克拉通盆地长期发育的古隆起是油气富集的主要区带,稳定分布的膏盐岩盖层是古油藏保存的关键,构造背景上的地层岩性油气藏是主要成藏类型。 对比我国四川、塔里木及鄂尔多斯盆地,均具有碳酸盐岩储层非均质性强、变化快的共性特征,差异性包括我国叠合盆地下组合泥页岩烃源岩生烃指标变化大、中-新生界沉积厚度大及下组合埋藏深度大等。我国碳酸盐岩油气勘探要系统评价震旦系、寒武系暗色泥页岩烃源岩条件以及多期改造作用叠合盆地的盖层条件,突出构造背景上的地层岩性油气藏勘探。 近期勘探要立足大盆地,寻找构造大背景,主攻构造岩性复合大区带。 以四川、塔里木和鄂尔多斯盆地为重点,持续开展大型古隆起复式油气聚集带勘探,加大区域不整合面、古隆起斜坡带、大型地层剥蚀尖灭带、台缘带礁滩体及与蒸发岩共生的台内颗粒滩地层岩性油气藏勘探。     

塔里木盆地与威利斯顿盆地古生界海相碳酸盐岩油气成藏特征对比

塔里木盆地和威利斯顿盆地均以古生界海相碳酸盐岩为主要勘探层系。基于对构造沉积背景和油气成藏条件的对比分析,探讨了两个盆地古生界海相碳酸盐岩油气成藏的异同。威利斯顿盆地所处的北美板块规模较大,构造相对稳定,沉积主要受海平面升降的控制。塔里木盆地所处的塔里木板块规模较小,构造变动强烈,沉积受构造运动影响较大。威利斯顿盆地发育了高丰度的烃源岩、良好的孔隙型储层和蒸发岩盖层。而塔里木盆地古生界发育高-过成熟度烃源岩、岩溶型和白云岩储层及泥岩和蒸发岩主导的盖层。二者均发育有多种类型圈闭的古隆起,可作为盆地油气富集的主要区带。威利斯顿盆地发育的多套蒸发岩盖层使得含油气系统概念在该盆地能够得到有效的应用,而油气成藏体系则可以更有效地指导以塔里木盆地为代表的多源、多灶和多成藏期盆地的油气勘探。白云岩-蒸发岩构成了威利斯顿盆地重要的储-盖组合类型。以此类比,塔里木盆地巴楚和塔中地区的中、下寒武统白云岩-中寒武统膏盐岩储-盖组合是未来勘探的有利目标区。     

塔里木盆地深层海相轻质油/凝析油的成因机制与控制因素

塔里木盆地是中国蕴含丰富海相凝析油的克拉通含油气盆地,目前已在塔北隆起、塔中隆起及其斜坡区的震旦系—三叠系发现6个大型海相凝析油气藏,这些油气藏呈现出轻质油、高含蜡凝析油气、干气—轻质油—挥发性油多种类型油气藏围绕烃源岩有序聚集的特点。基于烷烃损失量计算、凝析油中烃类分子成熟度参数和天然气同位素组成的分析,提出塔北隆起满深—顺北地区轻质油和塔中隆起西部地区凝析油气藏是烃源岩在高成熟度演化阶段的产物,明确轮古东—吉拉克—桑塔木地区和塔中东段凝析油气藏是气洗分馏作用的产物。多套烃源岩差异生烃形成多期油气充注是塔里木盆地海相凝析油气藏的物质基础;晚期天然气对早期油藏的改造,导致液态烃组分与天然气发生溶解-解溶作用;构造抬升或断裂活动导致的地层温度和压力条件改变,决定了油气藏的相态。叠合盆地的多期构造活动、多源灶的多阶段供烃以及盆地在晚期的持续深埋作用,共同控制了塔里木盆地海相轻质油和凝析油气藏的富集和分布。气洗分馏作用机制不仅可为叠合盆地拓展轻质油/凝析油勘探领域提供新思路,也有助于预测盆地深层斜坡区油气的物理性质、评价深层天然气的勘探潜力。     

中国南方海相油气勘探前景

对南方海相构造-层序-油气系统的综合研究表明,南方海相地层发育5套区域性主力烃源岩和多套局域性烃源岩(下寒武统、下志留统、中二叠统、上二叠统、下三叠统),烃源岩热演化程度的不均一性决定了南方下古生界以天然气勘探为主,上古生界为油气勘探兼顾.印支及其以后的改造运动对南方海相及中新生代盆地的含油气性控制起到主要作用,叠合盆地中、晚期形成的油气系统最具勘探潜力.原生及次生油气藏的分布主要受生烃有利相带和古隆起、古斜坡的控制.环扬子陆块叠合盆地群、苏北-南黄海南部盆地以及江南隆起北缘冲断推覆体下海相地层保存区将是南方海相油气勘探的重点.     

中国中西部前陆盆地油气分布控制因素

从中国中西部前陆盆地类型、构造单元和构造带3个层次深入分析控制油气分布的主要因素。中国中西部主要发育叠加型、改造型、早衰型和新生型4种前陆盆地,其油气成藏条件、成藏特征与油气聚集模式决定了不同类型前陆盆地油气分布的差异。前陆盆地发育冲断带、前渊、斜坡带和隆起带等构造单元,不同构造单元在烃源岩发育与演化、圈闭类型及成藏过程、保存条件等方面的差异导致不同构造单元油气分布特征的差异。前陆冲断带是中西部前陆盆地油气富集的主要构造单元,烃源岩与储盖组合、构造特征及保存条件是其油气聚集成藏的主控因素,冲断带断层、盖层的时空配置控制了油气分布的分带、分段特征和富集规律,指示着不同构造段的油气富集部位及有利勘探目标。