The AVO Effect of Formation Pressure on Time-Lapse Seismic Monitoring in Marine Carbon Dioxide Storage

The phase change of CO_(2) has a significant bearing on the siting, injection, and monitoring of storage. The phase state of CO_(2) is closely related to pressure. In the process of seismic exploration, the information of formation pressure can be response in the seismic data. Therefore, it is possible to monitor the formation pressure using time-lapse seismic method. Apart from formation pressure, the information of porosity and CO_(2) saturation can be reflected in the seismic data. Here, based on the actual situation of the work area, a rockphysical model is proposed to address the feasibility of time-lapse seismic monitoring during CO_(2) storage in the anisotropic formation. The model takes into account the formation pressure, variety minerals composition, fracture, fluid inhomogeneous distribution, and anisotropy caused by horizontal layering of rock layers(or oriented alignment of minerals). From the proposed rockphysical model and the well-logging, cores and geological data at the target layer, the variation of P-wave and S-wave velocity with formation pressure after CO_(2) injection is calculated. And so are the effects of porosity and CO_(2) saturation. Finally, from anisotropic exact reflection coefficient equation, the reflection coefficients under different formation pressures are calculated. It is proved that the reflection coefficient varies with pressure. Compared with CO_(2) saturation, the pressure has a greater effect on the reflection coefficient. Through the convolution model, the seismic record is calculated. The seismic record shows the difference with different formation pressure. At present, in the marine CO_(2) sequestration monitoring domain, there is no study involving the effect of formation pressure changes on seismic records in seafloor anisotropic formation. This study can provide a basis for the inversion of reservoir parameters in anisotropic seafloor CO_(2) reservoirs.

Characteristics and discovery significance of the Upper Triassic–Lower Jurassic marine shale oil in Qiangtang Basin,China

Mesozoic marine shale oil was found in the Qiangtang Basin by a large number of hydrocarbon geological surveys and shallow drilling sampling.Based on systematic observation and experimental analysis of outcrop and core samples,the deposition and development conditions and characteristics of marine shale are revealed,the geochemical and reservoir characteristics of marine shale are evaluated,and the layers of marine shale oil in the Mesozoic are determined.The following geological understandings are obtained.First,there are two sets of marine organic-rich shales,the Lower Jurassic Quse Formation and the Upper Triassic Bagong Formation,in the Qiangtang Basin.They are mainly composed of laminated shale with massive mudstone.The laminated organic-rich shale of the Quse Formation is located in the lower part of the stratum,with a thickness of 50–75 m,and mainly distributed in southern Qiangtang Basin and the central-west of northern Qiangtang Basin.The laminated organic-rich shale of the Bagong Formation is located in the middle of the stratum,with a thickness of 250–350 m,and distributed in both northern and southern Qiangtang Basin.Second,the two sets of laminated organic-rich shales develop foliation,and various types of micropores and microfractures.The average content of brittle minerals is 70%,implying a high fracturability.The average porosity is 5.89%,indicating good reservoir physical properties to the level of moderate–good shale oil reservoirs.Third,the organic-rich shale of the Quse Formation contains organic matters of types II1 and II2,with the average TOC of 8.34%,the average content of chloroform bitumen'A'of 0.66%,the average residual hydrocarbon generation potential(S1+S2)of 29.93 mg/g,and the Ro value of 0.9%–1.3%,meeting the standard of high-quality source rock.The organic-rich shale of the Bagong Formation contains mixed organic matters,with the TOC of 0.65%–3.10%and the Ro value of 1.17%–1.59%,meeting the standard of moderate source rock.Fourth,four shallow wells(depth of 50–250 m)with oil shows have been found in the organic shales at 50–90 m in the lower part of the Bagong Formation and 30–75 m in the middle part of the Quse Formation.The crude oil contains a high content of saturated hydrocarbon.Analysis and testing of outcrop and shallow well samples confirm the presence of marine shale oil in the Bagong Formation and the Quse Formation.Good shale oil intervals in the Bagong Formation are observed in layers 18–20 in the lower part of the section,where the shales with(S0+S1)higher than 1 mg/g are 206.7 m thick,with the maximum and average(S0+S1)of 1.92 mg/g and 1.81 mg/g,respectively.Good shale oil intervals in the Quse Formation are found in layers 4–8 in the lower part of the section,where the shales with(S0+S1)higher than 1 mg/g are 58.8 m thick,with the maximum and average(S0+S1)of 6.46 mg/g and 2.23 mg/g,respectively.

Diagenesis and Restructuring Mechanism of Oil and Gas Reservoir in the Marine Carbonate Formation,Northeastern Sichuan:A Case Study of the Puguang Gas Reservoir

Based on the technology of balanced cross-section and physical simulation experiments associated with natural gas geochemical characteristic analyses, core and thin section observations, it has been proven that the Puguang gas reservoir has experienced two periods of diagenesis and restructuring since the Late Indo-Chinese epoch. One is the fluid transfer controlled by the tectonic movement and the other is geochemical reconstruction controlled by thermochemical sulfate reduction （TSR）. The middle Yanshan epoch was the main period that the Puguang gas reservoir experienced the geochemical reaction of TSR. TSR can recreate the fluid in the gas reservoir, which makes the gas drying index higher and carbon isotope heavier because C2＋ （ethane and heavy hydrocarbon） and 12C （carbon 12 isotope） is first consumed relative to CH4 and 13C （carbon 13 isotope）. However, the reciprocity between fluid regarding TSR （hydrocarbon, sulfureted hydrogen （H2S）, and water） and reservoir rock results in reservoir rock erosion and anhydrite alteration, which increases porosity in reservoir, thereby improving the petrophysical properties. Superimposed by later tectonic movement, the fluid in Puguang reservoir has twice experienced adjustment, one in the late Yanshan epoch to the early Himalayan epoch and the other time in late Himalayan epoch, after which Puguang gas reservoir is finally developed.

Heterogeneity and influencing factors of marine gravity flow tight sandstone under abnormally high pressure:A case study from the Miocene Huangliu Formation reservoirs in LD10 area,Yinggehai Basin,South China Sea

The characteristics of reservoir heterogeneity of the marine gravity flow tight sandstone from the Miocene Huangliu Formation under abnormally high pressure setting at LD10 area in Yinggehai Basin are studied,and the influencing factors on reservoir heterogeneity are discussed,based on modular formation dynamics test,thin sections,XRD analysis of clay minerals,scanning electron microscopy,measurement of pore throat image,porosity and permeability,and high pressure Hg injection,as well as the stimulation of burial thermal history.The aim is to elucidate characteristics of the heterogeneity and the evolution process of heterogeneity of the reservoir,and predict the favorable reservoirs distribution.(1)The heterogeneity of the reservoir is mainly controlled by the cement heterogeneity,pore throat heterogeneity,quality of the reservoir heterogeneity,and the diagenesis under an abnormally high pressure setting.(2)The differences in pore-throat structure caused by diagenetic evolution affected the intergranular material heterogeneity and the pore throat heterogeneity,and finally controlled the heterogeneity of reservoir quality.(3)Compared with the reservoir under normal pressure,abnormally high pressure restrains strength of the compaction and cementation and enhances the dissolution of the reservoir to some extent,and abnormally high pressure thus weakening the heterogeneity of the reservoir to a certain degree.The favorable reservoirs are mainly distributed in the gravity flow sand body under the strong overpressure zone in the middle and lower part of Huangliu Formation.

3D reservoir characterization of the Mangahewa Formation,Mangahewa Field,Taranaki Basin,New Zealand

The Mangahewa Formation is the primary reservoir target in the Mangahewa Field in the Taranaki Basin,New Zealand.This formation is distinguished by its marginal marine substantial tight-sand reservoir,having thickness exceeding 800 m.The aim of this study is to assess the reservoir properties of the Mangahewa Formation through 3D reservoir modeling,employing 3D seismic data,core data,and well data from the Mangahewa Field.Utilizing variance attributes,the faults and horizons have been identified successfully within the field.The majority of the interpreted faults exhibit dip angles exceeding 60°,with a maximum displacement of 118 m.To detect direct hydrocarbon indicators,root-mean-square amplitude seismic attribute,envelope,and generalized spectral decomposition techniques have been employed.Subsequently,four lithofacies,comprising 78.3%sandstone,9.2%siltstone,9.5%claystone,and 3.0%coal have been established by utilizing the Sequential Indicator Simulation(SIS)algorithm to create a lithofacies model.A property model has been generated using the Sequential Gaussian Simulation(SGS)algorithm.Petrophysical evaluation indicates that the Mangahewa Formation exhibits reservoir qualities ranging from fair to good,with porosity levels between 8%and 11%,permeability averaging up to 10 mD,variable shale volumes,and hydrocarbon saturation in the range of 40%-50%.This study's methodologies and findings can serve as a valuable foundation for similar investigations in other tightsand gas fields located in different regions.

The Drifting History of the China Main Blocks during Specific Periods and their Tectonic Constraints on Marine Potash Formation

1 Introduction Most of the world well know potash mines are deposited in marine environment.Regarding the serious potash shortage,no significant progress has been made in marine potash in China,while the terrestrial potash

The Analysis on Comparison of Forming Condition with Abroad Palaeo-Epicontinental Marine Basin and Possibility of Potash Formation in North China

1 Introduction Currently,all six different continents have discovered potash deposits and potash-bearing salt lake saline water.However,the distribution is extremely uneven,which is mostly concentrated in Canada,Russia,Middle-Asia and

Biostratigraphy of Triassic Marine Reptiles in Southwest Guizhou and Its Adjacent Area

This paper briefly reviews the Triassic marine reptile fossils in Guizhou Province, especially the fossils that have been recently found in the Guanling area. Based on three sections at Guanling and Xingyi, Guizhou Province and Luoping, Yunnan Province, four horizons with vertebrate fossils are recognized in the Middle and Upper Triassic of this area; They are from bottom to top: Member I and Member II of the Guanling Formation, and the Zhuganpo Member and the Wayao Member of the Falang Formation.

Exploration Potential of Marine Source Rocks Oil-Gas Reservoirs in China

So far, more than 150 marine oil-gas fields have been found onshore and offshore about 350. The marine source rocks are mainly Paleozoic and Mesozoic onshore whereas Tertiary offshore. Three genetic categories of oil-gas reservoirs have been defined for the marine reservoirs in China： primary reservoirs, secondary reservoirs and hydrocarbon-regeneration reservoirs. And three exploration prospects have also been suggested： （1） Primary reservoirs prospects, which are chiefly distributed in many Tertiary basins of the South China Sea （SCS）, the Tertiary shelf basins of the East China Sea （ECS） and the Paleozoic of Tarim basin, Sichuan basin and Ordos basin. To explore large-middle-scale even giant oil-gas fields should chiefly be considered in this category reservoirs. These basins are the most hopeful areas to explore marine oil-gas fields in China, among which especially many Tertiary basins of the SCS should be strengthened to explore. （2） Secondary reservoirs prospects, which are mainly distributed in the Paleozoic and Mesozoic of the Tarim basin, Sichuan basin, Qiangtang basin and Chuxiong basin in western China, of which exploration potential is less than that of the primary reservoirs. （3） Hydrocarbon-regeneration reservoirs prospects, which are chiefly distributed in the Bohai Bay basin, North Jiangsu-South Yellow Sea basin, southern North China basin, Jianghan basin, South Poyang basin in eastern China and the Tarim basin in western China, of which source rocks are generally the Paleozoic. And the reservoirs formed by late-stage （always Cenozoic） secondary hydrocarbon generation of the Paleozoic source rocks should mainly be considered to explore, among which middle-small and small oil-gas fields are the chief exploration targets. As a result of higher thermal evolution of Paleozoic and Mesozoic source rocks, the marine reservoirs onshore are mainly gas fields, and so far marine oil fields have only been found in the Tarim basin. No other than establishing corresponding marine oil-gas exploration and development strategy and policy, sufficiently enhancing cognition to the particularity and complexity of China＇s marine petroleum geology, and applying new thoughts, new theories and new technologies, at the same time tackling some key technologies, it is possible to fast and effectually exploit and utilize the potential huge marine oil-gas resources of China.

Lower limit of thermal maturity for the carbonization of organic matter in marine shale and its exploration risk

Based on the drilling data of the Silurian Longmaxi Formation in the Sichuan Basin and periphery, SW China, the Ro lower limits and essential features of the carbonization of organic matter in over-high maturity marine shale were examined using laser Raman, electrical and physical property characterization techniques. Three preliminary conclusions are drawn:(1) The lower limit of Ro for the carbonization of Type I-II1 organic matter in marine shale is 3.5%; when the Ro is less than 3.4%, carbonization of organic matter won't happen in general; when the Ro ranges from 3.4% to 3.5%, non-carbonization and weak carbonization of organic matter may coexist; when the Ro is higher than 3.5%, the carbonization of organic matter is highly likely to take place.(2) Organic-rich shale entering carbonization phase have three basic characteristics: log resistivity curve showing a general "slender neck" with low-ultralow resistance response, Raman spectra showing a higher graphite peak, and poor physical property(with matrix porosity of only less than 1/2 of the normal level).(3) The quality damage of shale reservoir caused by the carbonization of organic matter is almost fatal, which primarily manifests in depletion of hydrocarbon generation capacity, reduction or disappearance of organic pores and intercrystalline pores of clay minerals, and drop of adsorption capacity to natural gas. Therefore, the lower limit of Ro for the carbonization of Type I-II1 organic matter should be regarded as the theoretically impassable red line of shale gas exploration in the ancient marine shale formations. The organic-rich shale with low-ultralow resistance should be evaluated effectively in area selection to exclude the high risk areas caused by the carbonization of organic matter. The target organic-rich shale layers with low-ultralow resistance drilled during exploration and development should be evaluated on carbonization level of organic matter, and the deployment plan should be adjusted according to the evaluation results in time.

Petroleum geology of marl in Triassic Leikoupo Formation and discovery significance of Well Chongtan1 in central Sichuan Basin,SW China

In 2022,the risk exploration well Chongtan1(CT1)in the Sichuan Basin revealed commercial oil and gas flow during test in a new zone–the marl of the second submember of the third member of Leikoupo Formation(Lei-32)of Middle Triassic,recording a significant discovery.However,the hydrocarbon accumulation in marl remains unclear,which restricts the selection and deployment of exploration area.Focusing on Well CT1,the hydrocarbon accumulation characteristics of Lei-32 marl are analyzed to clarify the potential zones for exploration.The following findings are obtained.First,according to the geochemical analysis of petroleum and source rocks,oil and gas in the Lei-32 marl of Well CT1 are originated from the same marl.The marl acts as both source rock and reservoir rock.Second,the Lei-32 marl in central Sichuan Basin is of lagoonal facies,with a thickness of 40–130 m,an area of about 40000 km^(2),a hydrocarbon generation intensity of(4–12)×10^(8) m^(3)/km^(2),and an estimated quantity of generated hydrocarbons of 25×10^(12) m^(3).Third,the lagoonal marl reservoirs are widely distributed in central Sichuan Basin.Typically,in Xichong–Yilong,Ziyang–Jianyang and Moxi South,the reservoirs are 20–60 m thick and cover an area of 7500 km^(2).Fourth,hydrocarbons in the lagoonal marl are generated and stored in the Lei-32 marl,which means that marl serves as both source rock and reservoir rock.They represent a new type of unconventional resource,which is worthy of exploring.Fifth,based on the interpretation of 2D and 3D seismic data from central Sichuan Basin,Xichong and Suining are defined as favorable prospects with estimated resources of(2000–3000)×10^(8) m^(3).

论变质重结晶作用对晶质菱镁矿矿床成矿的贡献

晶质菱镁矿矿床赋存于海相碳酸盐岩建造,为富镁碳酸盐经后期变质重结晶的产物,属沉积-变质型矿床。本次研究将中国境内的晶质菱镁矿矿床按变质重结晶程度分为三类(高、中和低),并进行了地质和地球化学研究,获得如下认识:(1)产于古生代海相碳酸盐岩中的菱镁矿矿床经历低程度变质重结晶作用(绿片岩相),矿石结晶度差,品位相对较低(44.98%~47.35%),且保留有海相碳酸盐岩建造的碳同位素地球化学特征(δ^(13)C_(V-PDB):-0.4‰~+0.3‰);(2)大型(>5000万t)优质(MgO>46%)晶质菱镁矿矿床集中分布在华北克拉通东部的古元古代胶-辽-吉活动带海相碳酸盐岩中,矿体后期经历中等程度变质重结晶作用(中—低角闪岩相),矿石发生中等程度的重结晶作用,继承了海相碳同位素地球化学特征(δ^(13)C_(V-PDB):-1.9‰~+1.7‰);(3)经历高角闪岩相(高级)变质作用的菱镁矿矿床矿石结晶程度最优,但强烈的变质作用引发外源含硅热液流体加入而发生蛇纹石化作用,矿石品位低(MgO=44.42%~45.55%),具有较高的TFeO、Mn和Ti含量,整体亦显示较低的碳同位素组成(δ^(13)C_(V-PDB):-4.1‰~-3.5‰)。因此,沉积-变质型菱镁矿矿体的镁质富集可能发生在海相沉积成岩期,后期变质作用引发富镁碳酸盐矿物重结晶作用,镁质碳酸盐和钙质碳酸盐矿物进一步发生近原地分离重结晶作用,形成晶质菱镁矿矿体和富镁白云石夹石,但过高(高角闪岩相及以上)或过低(绿片岩相)的变质作用可能均不利于形成大型优质晶质菱镁矿矿床。

鄂尔多斯盆地东缘奥陶纪马家沟期边界断层的新认识及其对成钾凹陷的控制

鄂尔多斯盆地陕北盐盆奥陶系马家沟组具备良好的成钾潜力,然而,当前仅勘探到薄钾石盐矿层和厚层钾石盐矿化段,大规模钾盐矿尚未发现。通过分析鄂尔多斯盆地东缘地震剖面的构造特征,认为盆地东缘晋西挠褶带西部马五6亚段沉积期存在活动边界正断层。在该断层作用下,形成东断西超的活动同沉积凹陷,富钾卤水大量汇聚于此。在持续干旱的强蒸发环境下,卤水持续浓缩,成钾窗口出现,钾石盐大规模析出,进而形成整装海相优质固体钾石盐矿床。侏罗纪末期,挤压应力导致成钾凹陷抬升,形成古凹今隆的格局,钾盐层抬升至较浅部位,有利于水溶法经济开采。

西准噶尔构造带包古图地层小区上泥盆统红山梁组的建立及地质意义

西准噶尔构造带包古图地层小区白碱滩北红山梁剖面上新发现一套晚泥盆世红色“硅质岩、粉砂质硅质岩、凝灰质硅质岩”海相沉积组合,与上覆包古图组深灰色—灰黑色含碳粉砂岩呈整合接触。经区域对比确认,该套地层显著有别于研究区乃至整个西准噶尔构造带地层分区已发现的全部上泥盆统各组岩石地层,符合“野外可识别、界面可区别、区域可对比、图面可表达”的原则,据此新建红山梁组。本次于红山梁组枕状玄武岩、玄武岩、安山岩中分别获得365.9±5.0Ma、370.6±7.4Ma和374.6±3.6Ma的LA-ICP-MS锆石U-Pb年龄,佐证其时代为晚泥盆世。红山梁组与包古图组连续沉积之确认,消除了包古图组老于希贝库拉斯组这一存疑,建立了完整的下石统地层序列,新增了包古图地层小区泥盆纪的沉积记录,为区域沉积与构造演化研究提供了新资料。

四川盆地涪陵南地区奥陶系五峰组—志留系龙马溪组页岩古构造应力场及裂缝特征

通过岩石力学实验、声发射实验和地震资料综合解释,利用有限元数值模拟方法,对涪陵南地区奥陶系五峰组—志留系龙马溪组海相页岩古构造应力场进行了数值模拟,并结合岩心实测结果,预测了构造裂缝的发育特征。研究结果表明:①涪陵南地区裂缝主要形成期(燕山晚期)构造应力和裂缝的分布受断层、岩石力学性质和构造应力的影响,断层广泛发育的区域容易出现应力集中,并引起较大的应力梯度。②利用库伦-莫尔破裂准则预测了研究区构造裂缝的发育,同时引入剪切破裂指数R定量表征裂缝发育的强度,其值越大反映裂缝发育程度越高。窄陡断背斜和断层附近裂缝发育,以高角度剪切裂缝为主,而在宽缓向斜部位裂缝发育程度最弱,研究区五峰组—龙马溪组底部硅质页岩应力集中,裂缝最发育。③涪陵南地区海相页岩气保存有利区主要为3个区带:远离大断层的凤来向斜内部,主要构造变形期未遭受大的破坏作用,其位于应力低值区,具有良好的保存条件,为Ⅰ类有利区;白马向斜内部小断层发育,应力值位于中等水平,保存条件中等,为Ⅱ类较有利区;石门—金坪断背斜遭受到强烈改造作用,容易产生大规模剪切裂缝,破坏了保存条件,为Ⅲ类不利区。

深层—超深层海相碳酸盐岩地震勘探技术发展与攻关方向

随着塔里木盆地顺北油气区、轮南地区轮探1井在8200 m深度以下获得工业油气流,碳酸盐岩勘探迅速向深层-超深层领域迈进,向地震勘探技术提出了严峻挑战。主要分析了超深层复杂波场地震成像理论研究进展及面临的问题。在超深层储层预测关键技术方面,分析了由地震数据结构表征识别小断裂、基于数字岩心的孔隙结构定量化预测方法等现状;从勘探地质需求的角度,提出深层—超深层碳酸盐岩储层与流体预测技术发展趋势和重点攻关方向,以期为海相碳酸盐岩地震勘探的理论及技术研究提供借鉴。获得以下认识:①针对超深层低信噪比地震数据,Q叠前深度偏移和TTI介质RTM技术在碳酸盐岩储层成像中取得了一定效果,基于波动理论的层间多次波压制、各向异性Q⁃RTM、最小二乘Q⁃RTM及各向异性全方位角度域成像技术是重点攻关方向。②深层—超深层强非均质性碳酸盐岩储层地震预测技术存在欠缺理论依据、预测精度较低等问题,亟待加强理论方法探索和技术攻关。③地震岩石物理实验与储层地质的深度融合以及基于双相介质波动特征(频率、频散与衰减等)的储层敏感属性精细化地震预测技术、人工智能碳酸盐岩储层定量预测及流体检测技术等均是重要发展方向,“可靠的深层地震资料、多学科联合的储层高精度表征和深度学习人工智能”发展趋势十分明显。

川东红星地区二叠系茅口组页岩气勘探突破及富集主控因素

四川盆地二叠系页岩气具有良好的成藏条件和勘探潜力,继二叠系吴家坪组获得勘探突破后,将低勘探程度层系——茅口组“高灰”页岩气作为重要的勘探接替方向。利用HYM-1等井的岩心、测录井和分析化验资料,系统开展茅口组页岩气藏条件与富集特征的研究,认为茅口组四段一亚段页岩具有高碳、高灰、高孔隙度、高含气性、高杨氏模量、薄储层、多夹层的“五高一薄一多”的典型地质特征;与五峰组—龙马溪组等页岩相比,茅四段页岩碳酸盐矿物含量更高、黏土矿物含量更低,储集空间类型以有机质孔为主,无机孔较少,孔隙度平均4.27%,整体表现为高孔隙度;茅四段一亚段平均含气量为4.96m^(3)/t,具备较高的含气量。综合分析认为,富藻高碳页岩的发育、良好的储集能力和保存条件,以及页岩储层的可压裂性,是茅四段页岩气富集高产的主控因素。

渤海湾盆地临清坳陷西部山西组—太原组海陆过渡相泥页岩沉积环境及有机质富集

海陆过渡相页岩气勘探开发处于初级阶段,而渤海湾盆地临清坳陷西部石炭—二叠系山西组—太原组泥页岩具有良好的生烃潜力,也是中国海陆过渡相页岩气开发的重要层位。为研究山西组—太原组泥页岩沉积环境与有机质富集关系,以XJ1井为研究对象,系统开展了岩石矿物、有机地球化学、元素地球化学以及数值分析等工作。研究表明:研究区山西组—太原组泥页岩脆性矿物含量低、黏土矿物含量高,压裂难度大,TOC含量平均值为4.03%,属于优质烃源岩,具备页岩气勘探开发潜力;太原组泥页岩沉积时期处于温暖湿润的气候条件,具有频繁变化的陆源碎屑输入、较低的沉积速率以及低—中等古生产力水平,沉积水体为海水沉积,处于缺氧还原和中等滞留环境;山西组泥页岩沉积时期,古气候条件复杂多变,具有稳定且较高的陆源碎屑输入、中等的沉积速率以及中—高等古生产力水平,沉积水体为微咸水—海水沉积,处于缺氧还原和中等—强滞留环境。根据古环境条件与TOC含量的线性相关性、灰色关联度以及稳健回归分析,认为太原组泥页岩有机质富集主要受控于古气候、古氧化还原以及古水体盐度条件,而山西组泥页岩有机质富集主要受控于古气候以及陆源碎屑输入条件。

面向FEM快速建模的船体模型数据处理算法

[目的]为提高船体有限元几何建模效率,解决船舶设计软件导出的船体模型无法直接应用于有限元几何建模的问题,提出一种基于XML文件数据的几何模型处理方法。[方法]以AVEVA Marine(AM)软件导出的船体XML文件为研究对象,通过对文件的数据结构解析,明确几何模型的数据表达规则,依据船体有限元几何建模规范,通过修改模型数据实现对船体模型的几何修正,包括对角隅、开孔等构件的删除、简化处理,对球扁钢和肘板的转化处理,对型材和板缝的移动处理。[结果]实际运用结果表明,处理后的船体几何模型可直接导入有限元软件HyperMesh中,符合有限元实体几何建模规范,保留了原模型材料、板架厚度等相关属性。[结论]与人工建模相比,测试分段实体几何建模效率显著提高,所提方法有助于船体设计模型复用、提高有限元几何建模效率。