Turbidite Dynamics and Hydrocarbon Reservoir Formation in the Tano Basin: A Coastal West African Perspective

This study examines the turbidite dynamics and hydrocarbon reservoir formation in Ghana’s Tano Basin, which is located in coastal West Africa. Through an exploration of geological processes spanning millions of years, we uncover key factors shaping hydrocarbon accumulation, including source rock richness, temperature, pressure, and geological structures. The research offers valuable insights applicable to exploration, management, and sustainable resource exploitation in coastal West Africa. It facilitates the identification of exploration targets with higher hydrocarbon potential, enables the anticipation of reservoir potential within the Tano Basin, and assists in tailoring exploration and management strategies to specific geological conditions of the Tano Basin. Analysis of fluvial channels sheds light on their impact on landscape formation and hydrocarbon exploration. The investigation into turbidite systems unveils intricate interactions involving tectonics, sea-level fluctuations, and sedimentation patterns, influencing the development of reservoirs. An understanding of sediment transport and depositional settings is essential for efficient reservoir management. Geomorphological features, such as channels, submarine canyons, and distinct channel types, are essential in this situation. A detailed examination of turbidite channel structures, encompassing canyons, channel complexes, convex channels, and U-shaped channels, provides valuable insights and aids in identifying exploration targets like basal lag, channel levees, and lobes. These findings underscore the enduring significance of turbidite systems as conduits for sediment transport, contributing to enhanced reservoir management and efficient hydrocarbon production. The study also highlights how important it is to examine the configuration of sedimentary layers, stacking patterns, and angular laminated facies to identify turbidites, understand reservoir distribution, and improve well design. The dynamic nature of turbidite systems, influenced by basin characteristics such as shape and slope, is highlighted. The research provides valuable insights essential for successful hydrocarbon exploration, reservoir management, and sustainable resource exploitation in coastal West Africa.

Sedimentary architecture models of deepwater turbidite channel systems in the Niger Delta continental slope,West Africa

This paper studied an architecture model of turbidite channel systems based on the shallow- layer high resolution 3D seismic information in the deepwater area in the Niger Delta continental slope, West Africa as a prototype model. Different types of channel systems were identified and the corresponding architecture models were established. The controlling factors, evaluation criteria and spatial distribution of different channel systems were analyzed. This study shows that turbidite channel systems of West Africa could be classified into three types; confined, semi-confined and unconfined, according to the condition of canyon and the levees on both sides. Oil one hand, along the transport direction, channel system evolves from confined to unconfined. Within channel systems, channel complexes, including two types of incised and enveloped, are the most important reservoir bodies. On the other hand, there is a channel complex evolution from incised to enveloped vertically. The geological factors exert impacts of different levels on the architecture of the turbidite channels in different sedimentary systems or even within the same system.

Composite Sand Bodies Architecture of Deep-Water Turbidite Channels in the Niger Delta Basin

Deep-water turbidite channels have attracted much attention as a focused issue in petroleum exploration and development. Extensive studies have been performed on the architecture of turbidite channels, and most researches have focused on their geometric shapes, sedimentary processes and controlling factors. However, little attention has been paid to the distribution patterns, distribution laws and quantitative studies of composite sand bodies of turbidite channels. Taken one slope area of the Niger Delta Basin as an example, this study conducted a semi-quantitative to quantitative analysis on architecture of composite sand bodies of turbidite channels based on cores, well logging and seismic surveys. It is shown that turbidite channel systems can be classified as confined and unconfined channel systems. For confined channel systems, the vertical evolution process involves four stages. The sinuosity of a channel system is controlled by slope, with a negative power function relationship between them. When slope gradient reaches four degrees, the channel system is nearly straight. Based on the migration direction and migration amount of single channels within channel complexes, channel composite patterns can be divided into four classes（the lateral composite, en-echelon composite, swing composite and vertical composite） and several subclasses. Various channel composite patterns show specific distribution laws spatially. For meandering channel complexes at the middle-late evolution stage of confined channel systems, the lateral migration amongst single channels shows the features of integrity and succession. The sinuosity of single channels in the late period is greater than that in the early period, and cut-offs may occur locally when the sinuosity is larger than five degrees. This study provides a better understanding for the geological theory of deep-water sedimentary, and also improves exploitation benefits of this type of reservoirs.

神狐海域高饱和度天然气水合物储层特征及其分布

2017年,中国地质调查局在南海北部神狐海域进行了水合物试验开采,累计产气30.9×10^(4)m^(3),平均日产超5000 m^(3),甲烷含量最高达99.5%,实现了水合物勘察领域的历史性跨越。在水合物试验开采前,精细剖析研究区的测井数据和地震资料,并通过对研究区的区域地质背景和钻井岩芯样品的分析研究,含水合物地层的沉积、断裂、气体成分、碳同位素等特征以及水合物饱和度数据分析,总结研究区高饱和度水合物的储层特征及分布规律。结果表明:①研究区中—高饱和度水合物主要分布在迁移峡谷群的峡谷脊部,而低饱和度水合物站位则主要分布在峡谷群的谷底位置;②海底峡谷水道是陆源物质向深海运移的重要通道,研究区浊积水道和天然堤发育,与水合物富集成藏密切相关;③研究区高饱和度水合物层对应的电阻率和声波速度值显著升高,而中子孔隙度、密度和自然伽马值则有所降低;④高饱和度水合物在地震反射剖面上具有似海底反射(BSR)、穹状反射和模糊杂乱反射特征,BSR之下气烟囱和断裂通道发育,碳氢气体容易运移到温度和压力稳定区域形成高饱和度水合物储集层;⑤研究区水合物聚集和赋存的地层沉积骨架主要为细粒沉积,水合物以均匀颗粒和扩散的形式分布于沉积物中;⑥研究区水合物气源主要为混合成因气,热成因气通过断裂、裂隙、气烟囱构造向浅层运移,降解并与原位生物气混合为水合物形成共同提供气源。

中药复方基于Wnt/β-catenin信号通路调控糖尿病肾病研究进展

糖尿病肾病是糖尿病最常见的微血管并发症之一,也是造成终末期肾病的主要原因。Wnt/β-catenin信号通路与糖尿病肾病肾小管间质纤维化密切相关,主要通过足细胞、肾小球系膜细胞、肾小管上皮细胞等来改善糖尿病肾病。中药复方基于调控Wnt/β-catenin信号通路来改善肾脏病变及纤维化,保护肾脏功能,进而延缓病程进展,在治疗中发挥激活自噬、减少炎症反应及减弱氧化应激等作用。目前,关于中药复方基于Wnt/β-catenin信号通路的研究仍存在以下不足之处:(1)在中药复方的研究中,能够得出中药复方可通过Wnt/β-catenin信号通路发挥作用,但由于中药复方成份复杂多样,大多数仅仅发现相关性,而没有分析其具体的活性成分;(2)Wnt/β-catenin信号通路的相关研究并未深入探索该信号通路在肾纤维化中的作用机制;(3)目前关于中医药的大部分实验为动物体内实验,缺乏体外细胞的相关实验探究。今后,需加强对中药复方活性成分的研究,并开展更多的体外细胞实验,进行深层次的作用机制及靶点研究。

下刚果—刚果扇浊积水道沉积演化与成藏主控因素——以A油田下中新统X砂组为例

下刚果—刚果扇盆地为深水浊积岩油气勘探成功的典型含油气盆地。盆内广泛发育的浊积水道为重要储层类型,蕴含丰富的油气资源。前人从构造和沉积等角度对深水水道沉积模式及控制因素进行了大量研究,取得了长足进展(Henry et al.,2019;陈华等,2021)。然而也有大量实钻资料表明水道体系内部砂体期次的沉积发育和叠置关系非常复杂,储层非均质性很强(张文彪等,2017)。

基于卫气营血-经络系统从三焦论治原发免疫性血小板减少症

张福利教授将叶桂(字天士)核心辨证思想中的卫气营血辨证和络病辨证相融合,得出疾病以卫表阳络—气经—营血阴络的病理机制传变。在此卫气营血—经络系统复合观的纲领下,张福利教授首先创见性地提出以湿热为因、三焦为枢,将内伤杂病中病邪由气经入营血阴络的病进路径具象化,即气经湿热,流连三焦,则三焦气化失司,痰浊内生,滞留于阴络缠绊处,孙络端津血互化受累,痰浊浸淫,血液代谢不出,累及血质;营卫交会受阻,营卫不畅,累及血行,最终血渐瘀积,瘀血生燥化热,内外相合,致使营血阴络瘀热。因此,首先,将杂病病机转趋概括为气经湿热—三焦湿热痰浊—营血阴络瘀热。其次,从微观角度推演出原发免疫性血小板减少症因痰浊积蓄于阴络缠绊处,阻碍营气、津液化生血液,血虚之证渐成等虚损证候病机;因营血阴络瘀热,瘀热之邪迫使血溢脉外,出血之症渐现等出血证候病机。最后,结合复合观层次性和系统性特点,针对气经、营血阴络、三焦不同病层的生理病理特性并且综合卫气营血—经络系统中疾病内侵外透的贯通趋势,构成单层对治、多层同治、逐层透转、顺势祛邪的大方复合法,施用于临床治疗。

从清肝化浊论治痛风性关节炎的临床经验

痛风性关节炎是一种临床常见的代谢性风湿病,可累及身体多个系统。随着人们生活水平的不断提高,痛风性关节炎的患病率呈逐年上升趋势。现代医学对于本病的治疗局限于降尿酸及解热镇痛,疾病复发率较高。临床研究表明,中医治疗除改善患者症状外还可有效减少病情反复。文章总结了朱维平教授治疗痛风性关节炎的学术观点和临床经验。朱教授认为痛风性关节炎是由于先天脾肾不足、后天久病伤脾耗肾导致脾脏的绝对亏虚;或因平素喜食膏粱厚味致使脾胃功能受损,导致脾脏功能的相对不足。二者最终致使脾虚水湿运化无权,进而酿湿成浊生毒,浊毒羁留肝经,流注关节、筋脉从而发为痛风性关节炎。朱教授认为其中脾、肾、肝功能失调,水液代谢异常是痛风性关节炎的主要病机;浊毒羁留肝经为标,肝、脾、肾功能失调为本;病位在足厥阴肝经。治疗上,朱教授主张从肝论治痛风,以清肝化浊法为主,通过对于急性期及缓解期酒大黄用量的把握以达祛邪而不伤正,扶正而不留邪之效。文章分享案例一则,介绍朱教授从清肝化浊论治痛风性关节炎及对于酒大黄这味药的遣药经验,以期为临床提供参考。

Sedimentary characteristics of turbidite fan and its implication for hydrocarbon exploration in Lower Congo Basin

The turbidite is favorable for accumulation of oil and gas and it is the most important reservoir in the deepwater area of West Africa.Currently,some commercial discoveries in such the deepwater area generally belong to turbidite sandstone reservoirs.Based on comprehensive analysis of lithology,lithofacies and configuration of the turbidite,and combined with changes of seismic attributes and sedimentary cycle,the turbidite in the deepwater area of West Africa can be classified into by-pass channel(including the constructive by-pass channel and the erosive by-pass channel),confined channel complex,weakly confined channel complex,and lobe.Different types of turbidite reservoirs have different physical property,so there are differences in hydrocarbon exploration potential;the sandstone in the weakly confined channel complex is the key exploration target in the deepwater area of the Angola Sea.

浊积扇沉积构成及主要单元储层差异:以琼东南盆地梅山组为例

浊积扇沉积构成单元主要包含内扇沟道,中扇沟道、朵叶主体,外扇朵叶、席状砂以及扇缘薄层席状砂等,各单元储层物性差异大,直接影响勘探开发部署,值得开展深入系统研究。本文基于琼东南盆地梅山组20个已钻浊积扇的沉积构成单元储层特征分析,建立了浊积扇主要沉积构成单元的岩—电—震特征及识别标志,详细分析了其主要沉积构成单元的砂体规模、几何形态、厚度变化、粒度分布、储层非均质性等要素。结果表明,中扇沟道—朵叶结合部巨厚层块状砂岩、外扇朵叶厚层砂岩和席状砂岩储层内部均匀,物性较好;内扇沟道砂岩内部非均质严重,储层物性受到影响;扇缘薄层席状砂岩由于层薄、粒度细、高含泥及高含钙而致密。钻探证明多口探井因部署在内扇沟道上未获商业产能;新部署在中扇沟道—朵叶结合部巨厚层砂岩与外扇席状砂的探井均获得了商业成功。

南海东部深水浊积砂岩气藏储层精细描述与连通性研究

南海东部深水区油气资源丰富,深水重力流浊积砂岩展布复杂,砂体构型期次划分、构型单元叠置样式和连通关系直接制约气田的布井开发。以南海东部深水L气田为例开展研究,基于地震沉积学方法,运用沉积模式研究、复合水道体系构型及建模表征方法,开展了基于南海深水重力流复合砂体解剖,建立了本海域深水气田浊积水道复合砂体构型划分方案,开展了单期构型砂体空间演化和展布规律研究。研究成果表明:南海深水L气田浊积水道可划分为复合浊积体、复合水道和单一水道等3个级次,在气田内部平面上发育4条复合水道,纵向上发育2期河道,建立复合水道内部的沉积演化规律,明确了水道间的连通关系,并结合动态生产验证了连通关系的合理性,成功指导相邻B气田部署1口水平井,最高日产达130万方,生产效果较好。研究成果对推动周边气田开发及潜力勘探具有一定借鉴和启示意义。

Different initial density turbidite sediments with coarse grain injection and their corresponding flow pattern: Additional insights from numerical simulation in a study case of South China Sea

The work presents the sedimentology and depositional results of the turbidity flow from Miocene to Pliocene along the North Slope of South China Sea(SCS).The integration of the core-log-seismic data has enabled us to clarify turbidity flow with different density and characterize their corresponding seismic geomorphic sedimentation.Based on the differences between the initial density and the later,we classified the turbidity flow into two types,namely:low-and high-density flow with coarse grain injection.According to the hydrodynamic numerical simulation results,we constructed different subcritical turbidity flow models with various density and rebuilt the depositional pattern along the slope.As to the numerical simulation model,we introduced the erosion rate into the classical full Reynolds-averaged N-S(RANS)equation,which is suitable to the deep-sea slope area.Through comparison of the above simulation models,the results show that the high-density turbidites with coarse-grained injection are mostly developed with lower vertical erosion rates and higher lateral abrasion rates.They are characterized with multi-branched and lobe-shaped sedimentary volumes,while low-density turbidites with coarse-grained injection are characterized with higher vertical erosion rates and lower lateral abrasion rates.And this kind of turbidites can generate single-branched and banding deposits.In addition,the fluctuating sea levels and the varying topographies are important to influence the subcritical turbidity flow models in the deep-water slope.

刚果扇盆地X区块中新统浊积水道类型及沉积演化特征

刚果扇盆地中新统深水沉积领域已发现储量占盆地63%,是该盆地重要的勘探领域。基于井震资料搭建了中新统层序格架,并对浊积砂岩储层发育的主要沉积类型特征进行剖析,指出刚果扇盆地X区块发育侵蚀型、侵蚀-加积型和加积型三种水道类型,并依次剖析了各类水道内部充填结构特征;最后,结合区域构造活动和西非海平面变化,在层序地层格架下总结了浊积水道的沉积演化特征,明确了各三级层序内浊积水道类型、数量及规模,指出研究区主要的勘探层系和水道类型,为刚果扇盆地X区块岩性目标勘探提供了地质依据。

基于SSOM的流动单元划分方法及生产应用——以渤海湾盆地F油田古近系沙三中亚段湖底浊积水道为例

在储层构型级次划分的基础上,归纳总结了渤海湾盆地F油田古近系沙三中亚段湖底浊积水道各级渗流屏障与构型界面的关系,并采用监督模式下的自组织映射神经网络算法开展流动单元定量评价,明确了构型模式控制下的流动单元分布规律。研究结果表明:(1)渤海湾盆地F油田沙三中亚段储层可划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ等4类流动单元。(2)基于SSOM算法的流动单元识别结果表现出较高的预测准确率,其中,256组训练样本的整体回判准确率为82.81%,110组测试样本的识别准确率为80.91%,能够满足地质油藏研究的需求。(3)垂向上,不同类型的单一水道内部发育的流动单元类型不同,造成流动单元垂向分布的差异性。Ⅰ类、Ⅱ类优质流动单元发育在浊积水道体系演化的中期,主要分布在二类单一水道;Ⅲ类、Ⅳ类流动单元发育在浊积水道体系演化的早期和晚期,其中,Ⅲ类流动单元分布广泛,在一类、二类、三类单一水道均有分布,Ⅳ类流动单元发育在一类、三类单一水道。侧向上,受水道体系不同沉积演化阶段的影响,流动单元的侧向分割方式不同。流动单元与非渗透层接触样式发育在浊积水道体系早期沉积旋回中,接触界面明显,属于一类水道沉积砂体;流动单元间的相互接触样式则发育在水道体系中晚期沉积旋回中,属于二类、三类水道沉积砂体。(4)平面上,受单一水道侧向迁移和垂向加积作用的影响,复合水道内部流动单元平面展布差异性明显。Ⅲ类流动单元在单砂体内部广泛发育,井间连续性好,在浊积主水道、浊积水道及水道漫溢沉积砂体处均有发育;渗流能力较好的Ⅰ类、Ⅱ类流动单元分布局限、连续性差,仅在浊积水道主流线方向及主水道砂体处有分布,呈不连续的点状或带状分布;Ⅳ类流动单元呈环带状分布在Ⅲ类流动单元的外缘,在浊积水道漫溢沉积砂体处发育。

工业废水悬浮固体颗粒物污染下河道生态修复研究

悬浮固体颗粒物会导致水体浑浊度提高,降低水质透明度,阻碍水生生物的光合作用和觅食行为,对生态系统造成严重破坏。为了改善水质和恢复河道生态系统的健康状况,故提出工业废水悬浮固体颗粒物污染下河道生态修复方法。首先,介绍了研究区域、样本采集方法和研究方法;其次,设计了由膜分离设备、水生植物浮岛板、曝气复氧、循环泵四部分组成河道生态修复总线路,并通过对照区与生态修复区河道内悬浮固体颗粒物浓度含量对比,和悬浮固体颗粒物去除率、化学需氧量去除率、溶解氧含量三个指标展开河道生态修复效果分析。结果表明,该方法能够有效实现河道生态的修复。最后,提出了面对工业废水悬浮固体颗粒物污染下的河道生态修复建议。

鄂尔多斯盆地南部长6和长7油层浊流事件的沉积特征及发育模式

在鄂尔多斯盆地西南部及南部长6和长7油层组中的半深湖—深湖亚相中发育了典型的浊积岩,构成了该地区的主要储层类型,并成为该地区油气勘探的重要领域。物源分析表明,西部、南部及西南物源是盆地浊积岩的主导物源。浊积岩的类型包括远源、近源浊积岩和厚层块状、薄层、微层浊积岩。盆地浊积岩具有典型的浊流沉积特征,为低Eh值的还原环境产物。该地区浊积岩为低密度流的湖相浊积岩,为盆地西南部辫状河三角洲前缘垮塌成因。对于大型拗陷型陆相湖盆,一旦条件成熟,就有可能形成浊流沉积。建立了该地区浊积岩形成发育模式。

大型坳陷湖盆异重流成因的水道-湖底扇系统--以松辽盆地白垩系嫩江组一段为例

以松辽盆地齐家—古龙地区白垩系嫩江组一段为研究对象,通过地震沉积学、沉积构造和沉积序列等分析,发现异重流成因的大型水道—湖底扇系统,对大型坳陷湖盆深水区分布的异重流及其形成的异重岩进行研究,构建了陆相湖盆异重流成因的水道—湖底扇沉积模式。研究表明,异重流发源于盆地边缘,经北部三角洲后在深水区形成完整的水道—湖底扇系统。自北向南依次发育顺直水道和弯曲水道,直线延伸距离超过80 km,宽度100~900 m;水道末端发育湖底扇,最大面积可达20 km^2。该系统主要以细粒沉积为主,发育块状砂岩和流水成因的沉积构造,内部发育侵蚀接触面,富含陆源有机质碎屑,具底床载荷和悬浮载荷兼有的形成机制。异重岩沉积序列表现为向上变粗和向上变细的旋回成对出现,反映洪水逐渐增强随后又减弱的动力学特点。

浊流沉积研究综述和展望

浊流理论的建立具有划时代的意义。浊流沉积的研究已经进行了半个多世纪 ,从理论到实践都取得了巨大的进展。本文首先讨论了浊流及其相关的几个概念 ,同时概述了浊流沉积的国内外研究历史和进展 ,重点介绍了浊积岩的识别标志及其沉积序列 ,指出下一步研究的重点应放在陆相湖泊浊流沉积及其含矿性上。

水下扇岩相特征及形成机制

２０世纪５０年代初期以来，沉积物重力流研究得到沉积学家们的广泛重视，特别是自６０年代末期，与沉积物重力流密切相关的水下扇研究成为沉积学领域的热点。通过对国内外大量沉积物重力流及水下扇研究成果的总结，结合我国中新生代陆相断陷盆地水下扇发育的特点，将水下扇的组成岩相划分为基质支撑砾岩相、颗粒支撑砾岩相、砾质砂岩相、块状砂岩相、经典浊积岩相。水下扇的形成机制系重力流成因。内扇以杂基支撑、颗粒支撑砾岩组合为特征；中扇以砾质砂岩、块状砂岩组合为特征；外扇以ＣＤＥ序及ＤＥ序经典浊积岩发育为特征。

浊流及相关重力流沉积研究综述

本文首先介绍了浊流及相关重力流的有关概念,并对浊流沉积研究历史进行了简要回顾,概括了当前浊流沉积的研究现状;随后,总结了浊积岩的沉积特征并对其成因进行了扼要解释;最后,对浊流及相关重力流沉积研究中两个有争议的问题——浊积相的划分和浊积相模式的建立进行了探讨。