Deep petroleum occurrences in the Lower Kura Depression, South Caspian Basin, Azerbaijan: an organic geochemical and basin modeling study   总被引：1，自引：0，他引：1  

Sedat Inan  M. Namik Yalin  Ibrahim S. Guliev  Kerem Kuliev  A. Akper Feizullayev 《Marine and Petroleum Geology》1997,14(7-8)

High sedimentation rates (as much as 2500 m/Ma) during Pliocene-Pleistocene, with a resultant undercompacted section as thick as 10,000 m, and lower than normal geothermal gradients are the main characteristics which have created all the means for generation and preservation of oil at deep layers in the Lower Kura Depression.Oils collected from eight different oil fields for analyses seem to have originated from a common source rock which probably is clastic, deposited in relatively subanoxic to suboxic transitional marine environment receiving low to moderate input of terrestrial organic matter.Oils from shallow (< 3000 m) and cold (< 70–80°C) reservoirs have been altered to various extent by bacterial activity.A computer-aided basin modeling study has been carried out to outline the spatial variation of the oil window and thus help in further identification of possible source rocks for the reservoired oil in the Lower Kura Depression. Results suggest that the potential hydrocarbon source horizons of the Miocene and Pliocene Red Bed Series of the so called Productive Succession are, even at depocenter areas, immature with respect to oil generation, and thus, are very unlikely to have been source rocks for the reservoired oils. However, the Oligocene-Lower Miocene Maykop rocks are marginally mature to mature depending on locality and the Eocene and older rocks are mature with respect to oil generation at all representative field locations. Oil generation commenced at the end of Pliocene and continues at present at depths between 6000 and 12,000 m.An unusually deep (> 10,000 m) oil window in the depocenter areas has been caused by the depressed isotherms due to extremely high sedimentation rates (up to 3000 m/Ma) for the last two million years. The main phase of oil generation is taking place at depths greater than what most of the wells in the study are have reached.  相似文献   

Reproductive biology of the mackerel scad Decapterus macarellus from Cabo Verde and the implications for its fishery management     

MPV Costa  DRS Cruz  LS Monteiro  KSM Evora 《African Journal of Marine Science》2020,42(1):35-42

The mackerel scad Decapterus macarellus is of great social and economic importance to Cabo Verde citizens; however, in recent years catches have shown an unexplained decline. The harvest is regulated by way of a minimum legal size and a seasonal closure, with both measures based on the results of reproductive studies that did not consider the microscopic characteristics of the gonads. This study aimed to analyse the gonads microscopically in order to classify the sexual development stage of individuals and to estimate the size at first maturity and the reproductive season. This information was then used to analyse the match between the reproductive parameters and the management measures. The samples comprised 284 females (20–36 cm fork length [FL]) and 85 males (21–35 cm FL). The annual variation in gonadosomatic index and the monthly frequencies of mature phases suggest that the reproductive season occurs from March to October, with two spawning peaks, one in March and another from July to October. The current seasonal closure (from July to September) covers the main reproductive period. However, the species has a long spawning period and the timing of peaks can vary between years; hence, a reassessment of this management measure is recommended. The sizes at first maturity were estimated at 24.1 cm FL for females, and 26.6 cm FL for males. These values are higher than the minimum legal size (20 cm FL) currently established for management of the species at Cabo Verde; thus, we strongly recommend an increase in the minimum legal size in an attempt to reduce catches of immature individuals.  相似文献   

Experimental tests of genetic divergence of farmed from wild Atlantic salmon due to domestication   总被引：6，自引：5，他引：6  

Fleming  I. A.; Einum  S. 《ICES Journal of Marine Science》1997,54(6):1051-1063

  相似文献   

Trends in age-at-maturity and growth parameters of female Northeast Atlantic harp seals, Pagophilus groenlandicus (Erxleben, 1777)     

Kirstine Frie  Anne; Potelov  Vladimir A; Kingsley  Michael C.S; Haug  Tore 《ICES Journal of Marine Science》2003,60(5):1018-1032

  相似文献   

大亚湾丽叶鲹的年龄、生长和个体生殖力     

陈万青  姜国良 《台湾海峡》1990,(3)

本文以耳石作依据对大亚湾丽叶鲹的年龄和生长进行了研究。报道了其年轮特征、年龄组成、体长与体重的分布;给出了丽叶鲹的体长与体重、体长与耳石长的关系和生长方程;采用重量法求得了180尾雌鱼的怀卵量,并计算了其绝对生殖力和相对生殖力及其与体长和体重的关系;分析了卵径分布、性成熟系数的月变化及幼鱼的生长情况。  相似文献   

二次生烃机理在中下扬子高演化烃源岩评价中的应用   总被引：1，自引：0，他引：1  

林小云  刘建 《海洋地质与第四纪地质》2007,27(5):99-104

在野外地质观察、油气地球化学和样品分析的基础上,通过总结二次生烃特征和生烃机理,将其应用到中下扬子区海相高演化烃源岩生烃潜力的评价。模拟实验结果表明,二次生烃具有明显的迟缓现象,也仍具有相对的生烃高峰,二次生烃量与一次生烃量的总和小于连续热演化的生烃量,这些特征都与一次生烃的演化程度密切相关,初始演化程度成为评价高演化烃源岩二次生烃潜力的关键因素。中下扬子区中—古生界发育的6套烃源岩中,下二叠统、下志留统和下寒武统烃源岩具有较强的生烃能力,是主要的烃源层。下古生界烃源岩进入生烃时间较早,在强烈的构造运动背景下,生成的油气难以保存;上古生界烃源岩热演化程度相对较低,燕山—喜山期的再次沉降地区成为二次生烃的供源区。因此,下古生界台地相区和上古生界烃源岩具有一定的二次生烃潜力。  相似文献   

Effect of changes in reproductive potential on perceived productivity of three Northwest Atlantic cod (Gadus morhua) stocks     

Morgan  M. Joanne; Brattey  John 《ICES Journal of Marine Science》2005,62(1):65-74

  相似文献   

准噶尔盆地玛湖凹陷下二叠统风城组烃源岩热演化及沉积古环境评价     

蒋中发  江梦雅  陈海龙  刘龙松  王学勇  卞保力  李娜 《现代地质》2022,36(4):1118-1130

近期准噶尔盆地玛湖凹陷南斜坡地区多口探井钻遇风城组厚层烃源岩,为重新认识玛湖凹陷风城组烃源岩带来了契机,搜集玛湖凹陷南部、北部5口重点探井资料,经分析取得了以下认识:(1)风城组烃源岩在玛湖凹陷内广泛发育,综合玛北、玛南地球化学参数表明其为一套Ⅱ型优质烃源岩;(2)综合现今地温、热解、生物标志物、族组分等参数,认为玛湖凹陷及其周缘地区4 350 m以深的风城组烃源岩处于成熟阶段,4 800 m以深处于高成熟演化阶段,玛湖凹陷风城组烃源岩大范围处于生油高峰期;(3)综合多个生物标志物参数,玛北地区风城组烃源岩为咸化还原沉积,玛南地区风城组二段烃源岩为咸化半还原沉积,风三段烃源岩为半咸化-半还原沉积,陆源有机质输入较多。研究区风城组沉积古环境总体表现出早中期咸化、晚期淡化,北部咸化还原程度高于南部的规律。研究结果对玛湖凹陷风城组后续致密油、页岩油勘探部署提供了理论依据。  相似文献   

渤海湾盆地渤中19- 6凝析气田凝析油成熟度判定及成因意义     

胡安文  于海波  王飞龙  梁舒艺  郭景震 《地质学报》2023,97(7):2354-2362

关于渤海湾盆地渤中19- 6凝析气田凝析油成熟度存在成熟与高成熟两种截然不同观点,尚未达到统一定论。本文综合利用轻烃、饱和烃和芳烃成熟度参数对凝析油成熟度进行了综合判定,并深入分析了凝析油和天然气的成因关系及凝析气藏形成机制。结果表明：异庚烷值与庚烷值、Ts/（Ts+Tm）与C29Ts/（C29Ts+C29H）、甲基单金刚烷指数与甲基双金刚烷指数、甲基菲指数、二苯并噻吩类成熟度参数和TNR2显示渤中19- 6凝析气田凝析油处于成熟阶段。结合天然气成熟度和储层流体包裹体特征,可知渤中19- 6凝析气田的原油成藏期早于天然气,随着晚期大量天然气的充注,油气会发生相控混溶作用形成含液态烃的气流体,当温度和压力达到混溶后烃类体系的露点以上,则形成凝析气藏。  相似文献   

二连盆地乌兰花凹陷烃源灶表征及其对油气分布的控制     

冯伟平  王飞宇  杨雪迪  江涛  高歌  李向阳 《地球学报》2023,44(3):531-542

乌兰花凹陷是近年来在二连盆地南部新发现的富油凹陷,但南北两个洼槽探明的油气资源差异明显。为了准确评价乌兰花凹陷的油气资源潜力,系统地分析了乌兰花凹陷烃源灶特征,讨论了烃源灶与油藏分布的关系。研究表明,乌兰花凹陷阿尔善组至腾一上段发育C、D/E和F相源岩,受构造-层序演化的影响,南北洼槽倾油型(C相)源岩发育层段存在明显差异,南洼槽C相源岩主要发育在阿尔善组,腾一上段和下段以D/E相源岩为主,而北洼槽阿尔善组至腾一上段均发育C相源岩。多口探井热史标定结果表明,乌兰花凹陷烃源岩成熟门限在2000 m左右,南洼槽仅阿尔善组烃源岩进入成熟阶段,阿尔善组C相源岩排油强度为0.5～7.9MMT/km2,为凹陷的主力烃源岩,而北洼槽阿尔善组C相烃源岩主要发育在阿尔善组上段,成熟度较低,最大值仅为0.78%Ro,烃源灶排烃强度小于0.2 MMT/km2,不能形成规模性的油藏。乌兰花凹陷探明的原油均在南洼槽,且集中在烃源灶周围,表现为近源聚集。  相似文献