The analysis and forecast for fouling in water pipelines in Daqing oilfield     

Xiaoyan LIU Qianya ZHU Jinlai FENG Gang QI Baosen ZHANG Yingli LI Jingxin SUN 《中国地球化学学报》2006,25(B08):161-161

In order to maintain the reservoir pressure and improve oil recovery efficiency, water flood recovery is used commonly in the middle and last periods of oilfield exploitation. At the same time, in order to avoid environmental pollution, the oilfield sewage should be reinjected. During that manufacture, variations in the conditions of pressure, temperature and unstability and incompatibility of thermodynamics make scale formation in water flood assize, casing, bottom of the wells, surface equipments and gathering lines. Taking the Daqing oil field for example, in which the surface gathering lines the scale forming is comparatively serious. In order to improve crude oil processing effect to warm up wet oil, this measure results in scale formation constant in pipelines and equipments, so inner diameter becomes less, leading to back pressure ascent in pipelines, the loss of efficiency of processing equipment, these all have a strong impact on normal activities in oilfield, increase the frequency of maintenance repairs and replacements for pipelines and equipments, and reduce the completion benefit. So forecasting the scaling tendency of surface gathering pipelines, and judging the degree of the scaling tendency or possibility, preventing and controlling scaling effectively is not a negligible research topic in petroleum production technology and oil-gas-water treatment technology. This paper introduces the fouling process, fouling mechanism and the influence factors of the scale, mainly analyses the formation mechanism of calcium carbonate and calcium sulfate, and some factors, such as temperature, pressure, salinity and some thermodynamics conditions. All these factors lead to changes in ionic equilibrium condition, so they will influence the fouling. This paper analyses the main kinds of scale in the gathered transportation water pipeline in the forth plant in the Daqing Oilfield, adopts the method of saturation exponent and energetic solubility to forecast the trend of fouling, reduces the calcium carbonate showing scaling tendency, calcium sulfate having the possibility of scaling.  相似文献   

黄陵背斜周缘早古生代有机壳化石的光学特性与有机质成熟度     

陈善庆 《地球学报》1995,16(2):211-226

本文主要研究扬子地台西部黄陵背斜周缘早古生代有机壳化石的特征、光学特性和有机质成熟度规律，同时较为详细地研究了有机壳化石反射率随热成熟度变化特点与镜质组反射率之间的关系。提出该区以有机壳化石反射率为主要指标的有机质成熟度划分方案。认为笔石、几丁虫和虫牙等有机壳化石在形态、结构和构造上具有各自的特征，并具有突起、反射色、显微结构构造、非均性、异向光性、反射率和双反射现象等光学特征。有机壳化石反射率与  相似文献   

生物矿物：研究现状与展望     

李忠 《地球科学进展》1993,8(4):49-53

生物矿物是生物成矿作用研究的基础内容。本文总结了生物矿物领域的研究现状,重点评述了生物控制、生物诱导和有机质(分子)与生物矿物形成的相关性以及生物矿物所可能具有的鉴别特征。生物矿物研究是地球科学的前沿课题,无论在思路和方法上都有待突破。  相似文献   

峡东宜昌黄花场下奥陶统生物礁的研究   总被引：12，自引：0，他引：12       下载免费PDF全文

朱忠德 《地质科学》1993,28(1):1-9

首次发现峡东下奥陶统生物礁。造礁生物为攀苔藓虫、托盘藻、古钵海绵、蓝细菌和Pulchrilamina等。按造礁生物形成的格架类型有:粘结粒泥岩,藻粘结岩,攀苔藓虫障积岩,粘结障积岩等4种礁岩微相。这些微相在礁核中有、无和分布差异形成了灰泥岩隆礁,藻岩隆礁,攀苔藓虫障积岩隆礁和藻粘结-古钵海绵障积岩隆礁。各类礁都经历了奠基、发育、衰亡3个阶段。这一演化过程反映了沉积环境和水能量强度对礁发育的制约作用。  相似文献   

Correlation of Filtration Resistance with Microbial Polymeric Substances Extracted from Membranes in a Submerged Membrane Bioreactor          下载免费PDF全文

Necati Kayaalp  Cumali Kinaci  Nadir Dizge  Nizamettin Hamidi 《洁净——土壤、空气、水》2014,42(12):1712-1720

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Fouling acorn barnacles in China—a review     

曹文浩  严涛  黎祖福  李静  程志强 《中国海洋湖沼学报》2013,31(4):699-711

We review the species composition,distribution, and seasonal variation of fouling acorn barnacles in Chinese waters-from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases.0ther environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.  相似文献   

Effect of Different Leachate/Acetate Ratios in a Submerged Anaerobic Membrane Bioreactor (SAnMBR)     

Ergin Taskan  Halil Hasar 《洁净——土壤、空气、水》2012,40(5):487-492

Leachate treatment using a membrane bioreactor is an effective method. This study presents a configuration including an anaerobic bioreactor and a membrane module, called submerged anaerobic membrane bioreactor (SAnMBR), for treating influent with leachate/acetate rations (L/A), that were kept to be 10, 25, 50, 75, and 100% at a constant SRT (100 days). COD removal decreased from 85 to 75% when the L/A ratio increased from 10 to 100. To prevent membrane fouling, a SAnMBR was operated in the case of circulation of mixed liquor under continuous and intermittent suction. The average fluxes were 2.60 and 0.40 L/m² h at the periods of intermittent and continuous suction, respectively. The methane production varied between 0.25 and 0.32 L CH₄/g COD_removed.  相似文献   

Impact of seawater temperature on growth and recruitment of invasive fouling species at the global scale          下载免费PDF全文

Joshua P. Lord 《Marine Ecology》2017,38(2)

Epibenthic fouling communities are dominated by invasive species that are globally distributed and can have substantial ecological and economic impacts in coastal habitats. Little is known about inter‐specific differences in life history strategies that cosmopolitan invasive species employ to acquire space and succeed in invaded habitats. The goal of this study was to examine the impact of seawater temperature on recruitment and growth of several cosmopolitan fouling species including the tunicates Botrylloides violaceus, Botryllus schlosseri and Diplosoma listerianum, as well as the bryozoans Bugula neritina and Watersipora subtorquata. To do this, the iBARGE (Invasive Bryozoan and Ascidian Recruitment and Growth Experiment) program was developed, utilizing a global network of collaborators to examine patterns over a broad geographic scale and a wide range of naturally varying seawater temperatures. This project produced a data set of thousands of photographs from 18 marinas in five countries in summer 2014 and 2015, allowing for recruitment and growth to be tabulated at a variety of temperatures. Thermal growth curves were established for five invasive species, and growth was compared among temperatures across sites, revealing a significant thermal effect. Recruitment was linked to temperature, with generally higher recruitment at warmer seawater temperatures and the highest peak recruitment values for the bryozoan Bugula neritina. Temperature also changed the relative importance of growth and recruitment for several species. These results paint a complex picture of the interactions among invasive fouling species as they relate to seawater temperature.  相似文献   

Non-food-chain transfer of sediment-associated persistent organic pollutants to a marine benthic fish     

Takeo Sakurai  Jun Kobayashi  Yoshitaka Imaizumi  Noriyuki Suzuki 《Marine pollution bulletin》2009,58(7):1072-1077

We investigated the transfer of persistent organic pollutants (POPs) from unspiked bottom sediment to a benthic marine fish, marbled sole (Pleuronectes yokohamae), via non-food-chain pathways, i.e., via sediment particles and water column. One-year-old sole were held for 28 days in an exposure tank with bottom sediment or in a control tank. o,p′-DDE and tri- to penta-chlorobiphenyls were transferred from the sediment to the fish via non-food-chain pathways, as demonstrated by concentrations in the exposed fish at 2.5-30 times the control levels. A model analysis based on first-order kinetic equations indicated that the overall rate constant of transfer of these compounds from sediment to fish was generally lower than that from food (median of ratio, 0.48). It also suggested that relatively high concentrations of the other POPs in the food and the longer times necessary for them to reach a steady state masked any transfer of them from the sediment.  相似文献   

广东长坑金银矿床硅质岩中的放射虫化石及生物化石残迹     

张湖  吴浩若  李统锦  夏萍 《现代地质》2004,18(1):80-88

在广东长坑金银矿床的主要含金岩石碳质硅质岩巾两次找到放射虫化石,其时代可能属于早石炭世。在这些碳质硅质岩中还发现一些生物化石残迹．如石英环、石英圈、石英单晶球、石英多晶球、生物残体和似生物结构。由此认为碳质硅质岩原来含有一定量的微体生物化石．形成于海盆环境,应属沉积成因,这是证明碳质硅质岩属于热水沉积成因而不属于热液蚀变交代成因的有力证据;也表明热水沉积过程有生物物质的加入,热水沉积和生物沉积可以混合发生,说明长坑金银矿床形成手张性、不补偿、水较深的盆地之中。对长坑盒银矿床的矿区含矿地层应泼归属的岩石地层单位提出了疑问。  相似文献