Rapid CO2 Evolution Method for Determining Shelf Life of Refrigerated Catfish

The feasibility of a CO₂ evolution method using an IR analyzer to evaluate the shelf life of refrigerated (4deg;C) catfish was investigated. Aerobic plate count (APC), and isoelectric focusing (IEF) of samples were compared with the CO₂ evolution rate (CER) determinations. The increase in CER (25.78 to 195.63 Lg^?1h^?1) for farm raised catfish stored from 0 to 10 days correlated highly with APCs (4.32 to 10.24 log CFU g^?1). The IEF data also confirmed the APC and CER results. Catfish spoilage was evident after 6 days at 4°C. Direct measurement of CER is a rapid and effective method to determine the microbial quality of catfish.     

渤海湾盆地东营凹陷中央背斜带构造特征和演化机理

渤海湾盆地东营凹陷沙四段盐膏层和沙三段超压泥岩层等塑性物质的存在,为弹性基础悬臂梁理论在该区的应用提供了必要的物质基础.自沙四段沉积晚期开始,东营凹陷东段的受力以及变形状态就类似于以下伏盐膏层为弹性基础,以南部广饶凸起为固定端,以北部陈南断层为自由端的弹性基础悬臂梁,在自身重力以及上覆沉积物载荷不断增大的情况下,自由端的沉降幅度逐渐增大,使得盆地整体呈箕状产出,在这个沉降过程中,塑性物质不断流动聚集,对上覆地层造成拱升,从而形成中央背斜带.此后悬臂梁又一分为二,单独作用,继续推动着整个凹陷的演化进程.     

油藏类型与属性的动力学涵义

油藏的各种属性是成藏动力学环境的体现,具有明确的单一或多重动力学含义.通过分析油柱高度、油藏压力、含油饱和度、油藏类型等油藏属性与不同动力形式的关系,明确了不同油藏属性与成藏动力的内在联系.结果表明:油柱高度、油藏压力与不同的动力形式及聚集过程有关;含油饱和度也与动力形式密切相关,是不同动力学形式的统一反映;油藏类型可随成藏动力而发生变化,表现出不同于圈闭类型的存在样式.不同油藏属性的量化特征可以准确反映成藏动力的类型和量化特征.油藏属性的变化形式在盆地中与不同的区带和油藏类型的演变形式具有明显的关联性,从宏观上反映了盆地成藏动力系统的特征和演变.以不同类型油藏属性及其演变为基础,对成藏动力、油藏属性及成藏机制的深入分析,形成了基于盆地成藏动力学环境及圈闭类型分布特征的油藏预测模式.     

全尺寸射孔完井水平井筒流动压降实验

采用外径139.7 mm的壁面打孔套管模拟射孔完井水平井筒,通过模拟实验研究射孔参数及壁面注入比对各种压降的影响规律。实验结果表明:①随着射孔密度、射孔孔径、射孔相位的增大,壁面摩擦压降和总压降均增大,混合压降减小。②射孔套管出口主流雷诺数相同时,随着壁面注入比的增大,总压降和混合压降均增大。壁面注入比小于临界值(本研究条件下为0.05%～0.10%)时,混合压降小于零;壁面注入比大于临界值时,混合压降大于零。壁面注入比小于0.10%时,加速度压降可以忽略;壁面注入比大于0.10%时,加速度压降随壁面注入比的增大而显著增加。③随着壁面注入比的增大,壁面摩擦压降占总压降的比例逐渐减小,加速度压降占总压降的比例逐渐增大。壁面注入比小于1.00%时,混合压降占总压降的比例随壁面注入比的增大而增大;壁面注入比大于1.00%时,混合压降占总压降的比例基本保持不变。     

苏里格气田苏14 井区盒8 段河流相砂体展布与演化规律研究

河流相砂体横向相变快,连续性和连通性差,储层非均质性强,严重影响了河流相储层的开发效果。依据储层沉积学的研究方法,对苏里格气田苏 14 井区盒 8 段河流相砂体展布与演化规律进行了研究。结果表明：苏 14 井区盒 8 段属于早期辫状河沉积向晚期曲流河沉积逐渐转化的沉积背景,其主要沉积微相包括河道滞留沉积、心滩、边滩、决口扇、天然堤、河漫砂及泛滥泥。 受基准面升降与沉积物供应的共同作用,该区河流相砂体演化呈阶段性变化,大致经历了辫状河繁盛发育期、辫-曲共存转化发育期及曲流河繁盛发育期 3 个阶段,其中辫状河繁盛发育期的心滩砂体与辫-曲共存转化发育期的心滩及边滩砂体是主力含气储层。 研究区优质储集砂体的发育受沉积微相展布与基准面旋回的控制。     

巴西Solimoes盆地构造演化及油气成藏特征

巴西陆上Solimoes盆地属克拉通盆地,其沉积组合和油气成藏非常特殊。文中重点研究盆地的形成演化及构造特征、沉积地层特征、石油地质特征,分析盆地成藏特征及成藏模式,确定成藏主控因素。盆地经历了多期构造运动,古生代经历了多次沉降,中生代抬升,新生代以挠曲沉降为主,构造样式以先正后逆的反转构造为特点。沉积地层以古生界为主,岩性组合复杂,包含了碎屑岩、碳酸盐岩、蒸发岩、冰碛岩及火山岩等多种岩石类型,层系之间均为不整合接触。主要烃源岩为上泥盆统页岩,总有机碳含量高,热演化程度高;主要储层为石炭系Jurua组砂岩;主要盖层为石炭系-二叠系蒸发岩,封盖能力强,生储盖配置好。盆地内构造圈闭发育,以背斜、断背斜为主。盆地成藏模式特殊,尽管烃源岩埋深较浅,却在火山岩侵入的烘烤作用下快速成熟并进入高成熟演化阶段--生气阶段;风成砂具有良好的储集性能,储层孔隙由于埋藏深度小而保留,不整合面和复活的基底断裂是油气运移的良好通道。断层相关的构造圈闭控制油气的聚集。     

Tectonic evolution and its control over deposition in fault basins: A case study of the Western Sag of the Cenozoic Liaohe Depression, eastern China

The main petroliferous basins in eastern China are Cenozoic fault basins, most of which have experienced two-stage tectonic evolution, i.e., rifting subsidence in the Paleogene and post-rifting thermal subsidence in the Neogene-Quaternary. The episodic tectonic evolution and syndepositional faulting had significant influence on the fault basins in terms of accommodation space, deposition rate, and depositional facies zones. In this study, the tectonic deformation characteristics and the tectonic-depositional evolution of the Western Sag of the Cenozoic Liaohe Depression were investigated by comprehensive analysis of the available geological and geophysical data using the modern theory of tectonic geology and the balanced section technique. The tectonic deformation of the Cenozoic fault basin was characterized by superimposed faults and depression. In addition, there existed relatively independent but still related extensional tectonic systems and strike-slip tectonic systems. The tectonic evolution of the fault basin involved five stages, i.e., initial rifting stage (E2s4), intense faulting stage (E2s3), fault-depression transition stage (E3s1-2 ), differential uplifting stage (E3d), and depression stage (N-Q). According to the characteristics of tectonic development and evolution of the Western Sag, the depositional evolution in the Cenozoic fault basin was divided into two stages, i.e., multi-episodic rifting filling in the Paleogene and post-rifting filling in the Neogene-Quaternary. The former rifting stage was further subdivided into four episodes with different characteristics of depositional development. The episodic faulting controlled the filling process and filling pattern of the Cenozoic Western Sag as well as the development and spatial distribution of associated depositional systems, whereas the syndepositional faults that developed in multiple stages in various tectonic positions controlled the development of depositional systems and sand bodies in the Western Sag. That is, the fault terraces on steep slopes controlled the development of sand bodies, the fault terraces on gentle slopes controlled the development of low-stand fan bodies, and the fault terraces or fault troughs in the central basin controlled the development of fluxoturbidite bodies.     

北京地面沉降与地下水开采时空演变对比

区域地面沉降是世界上很多城市都要面对的一种"城市病"。地下水过量开采是这一问题最普遍的原因,北京也因此出现了严重的地面沉降问题。为了全面认识地下水开采格局变化下的地面沉降发育分布的新特点,推动实现《北京地面沉降防治规划(2013-2020年)》中的"控沉目标",对北京市从解放初期至今60多年间的地下水开采和地面沉降演变进行了时间和空间上的定性定量对比分析。结果表明:地面沉降的形成发展阶段与地下水开发利用阶段高度吻合;地面沉降中心区与地下水位降落漏斗区的时空变化高度相关;随着地下水开采深度整体上向地表以下更深层发展,主沉降层逐渐向深部(100m以下)地层转移,为地面沉降防控决策制定提供了依据。     

Application of the Stream Evolution Model to a Volcanically Disturbed River: The North Fork Toutle River,Washington State,USA

In this study, a recently revised version of the channel evolution model, named the Stream Evolution Model (SEM), was applied to the upper North Fork Toutle River disrupted by the deposition of a 2.5‐km³ debris avalanche during the catastrophic eruption of Mount St. Helens in 1980. The results show that, in the first few years following the eruption, upstream channel reaches generally incised, evolving in SEM Stage 4 (i.e. degradation and widening), while downstream reaches aggraded, evolving in Stage 5 (i.e. aggradation and widening). However, starting in the late‐1980s, this simple pattern was disrupted by incision in the downstream reaches, which seemed to propagate upstream. Since the 1990s, lateral channel adjustments have become predominant as rates of vertical adjustment have slowed and river valley top widths relaxed to asymptotic values. Spatial and temporal sequences of channel evolution have tended to follow the sequences of stages expected according to the SEM, although these sequences have been frequently disrupted by renewed incision, secondary cycles of adjustment and the impacts of local geologic, geomorphic and hydraulic conditions. Within the quasi‐full SEM cycles, stages 4 and 5 were sometimes repeated, while stage 6 (quasi‐equilibrium) was sometimes omitted, and stage 8 (anabranching) only occurred in the downstream braided/anabranching reaches. According to the SEM, degradation, widening and lateral activity (stages 4 and 7) are forecast to continue until transverse valley profiles and channel planforms stabilize and floodplain and terrace surfaces are fully colonized by vegetation. Copyright © 2017 John Wiley & Sons, Ltd.     

城市雨洪放大效应驱动因子时空演变规律分析

城市雨洪具有复杂的放大效应,引起该现象较直接的原因包括大暴雨的频繁出现、可渗透地表面积的骤减以及排蓄水能力的改变和排水管网的扩张等。以武汉市为例,选择降雨强度、不透水面积比例、排水管道密度作为洪水放大效应的驱动因子进行趋势分析和演变规律分析,计算表明:从20世纪80年代开始,暴雨雨量和历时明显增加;不透水面在20世纪90年代初增加较快;排水管道在1990~2006年间缓慢增长,2007年跳跃式增长。降雨量和历时的增加使城市洪量增大,排水压力随之上升,在一定程度上增加了内涝几率;不透水面积的逐年增多以及水体等天然蓄水区的减少,不但增加了产流量,也使汇流时间更短,且雨水管渠的建设缩短了天然汇流路径,导致城市洪水呈现峰高量大,洪峰提前的放大效应。研究成果可用于城市雨洪放大效应对其驱动因子的定量响应研究,为进一步量化城市内涝风险与驱动因子间的关系提供依据,从而为内涝风险调控措施提供技术支撑。