Grazing rate and feeding selectivity of small and large bodied cladocerans in waters from lakes with different salinity and phytoplankton structure

Cladocera are filter feeders abundant in freshwaters,which consume phytoplankton particles in wide size and taxonomic ranges.The ability of cladocerans to control phytoplankton abundance by grazing is determined by various factors including the characteristics of phytoplankton.Freshwater salinization may reduce the strength of top-down grazing control of phytoplankton because of the detrimental effects of salinity on the grazing intensity of zooplankters.We performed grazing experiments with two species of Cladocera of different body lengths to test their ability to graze on phytoplankton in natural waters differing in salinity and size and taxonomic composition of food particles.Grazing experiments demonstrated that the grazing rate was mostly controlled by the abundance of phytoplankton in the medium.The grazing rate was reduced at salinity ca.above 3 g/L of NaCl in the medium.The lower grazing rate was observed in the medium with larger phytoplankton particles.Both species predominantly consumed phytoplankton particles with a diameter of 6-12μm,which may shift the size distribution of phytoplankton towards a larger average diameter of particles.The taxon-specific feeding was also observed,as both species predominantly consumed diatom algae.Thus,we found that because of grazing,the size and taxonomic characteristics of phytoplankton are shifted towards a less edible community.The detrimental effect of elevated salinity on grazing rate supports growing concern about freshwater salinization negatively affecting water quality,particularly reducing top-down grazing control of phytoplankton.

Development,sand control mechanism and hydrocarbon accumulation of beach-bar sandstone in a saline lake basin:A case from the Neogene of southwestern Qaidam Basin,NW China

Based on the data of field outcrops,drilling cores,casting thin sections,well logging interpretation,oil/gas shows during drilling,and oil/gas testing results,and combined with modern salt-lake sediments in the Qinghai Lake,the Neogene saline lake beach-bars in southwestern Qaidam Basin are studied from the perspective of sedimentary characteristics,development patterns,sand control factors,and hydrocarbon accumulation characteristics.Beach-bar sand bodies are widely developed in the Neogene saline lake basin,and they are lithologically fine sandstone and siltstone,with wavy bedding,low-angle cross bedding,and lenticular-vein bedding.In view of spatial-temporal distribution,the beach-bar sand bodies are stacked in multiple stages vertically,migratory laterally,and extensive and continuous in NW-SE trending pattern in the plane.The stacking area of the Neogene beach-bar sandstone is predicted to be 3000 km^(2).The water salinity affects the sedimentation rate and offshore distance of beach-bar sandstone,and the debris input from the source area affects the scale and enrichment of beach-bar sandstone.The ancient landform controls the morphology and stacking style of beach-bar sandstone,and the northwest monsoon driving effect controls the long-axis extension direction of beach-bar sandstone.The beach-bars have a reservoir-forming feature of“one reservoir in one sand body”,with thick beach-bar sand bodies controlling the effective reservoir distribution and oil-source faults controlling the oil/gas migration and accumulation direction.Three favorable exploration target zones in Zhahaquan,Yingdong-eastern Wunan and Huatugou areas are proposed based on the analysis of reservoir-forming elements.

Potential evaluation of saline aquifers for the geological storage of carbon dioxide: A case study of saline aquifers in the Qian-5 member in northeastern Ordos Basin

The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon neutrality.In this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage project.This study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 member.The results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) t.With the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.

A novel polymer gel with high-temperature and high-salinity resistance for conformance control in carbonate reservoirs

Plugging agents have been widely used to enhance oil recovery in fractured-vuggy carbonate reservoirs.However,the harsh conditions of fractured-vuggy carbonate reservoirs yield a significant challenge in maintaining a long-term stabilization of plugging agents.In this work,we developed an anti-hightemperature and high-salinity polymer gel(APG)with excellent resistance to high temperature(140℃)and ultra-high salinity(240000 mg/L).The rheology and microstructure of APG were characterized before and after gelation.Core plugging tests on fractured cubic cores were conducted to quantify the plugging performance of the gel system.Experimental results showed that the Sclerglucan and Cobalt(Ⅱ)Chloride Hexahydrate filled the three-dimensional(3-D)network with various morphologies,providing extra protection to the cross-linking points of the 3D network structure of APG and thus,leading to a prolongation of the dehydration time.The dehydration rate of APG was only 5%within 30days,and the strength of APG could be maintained at a rigid or near-rigid level over 150 days.Moreover,APG exhibited satisfactory shear and scour resistance.Core plugging tests showed that APG could achieve a plugging rate of 90%and demonstrate ignorable minor damage to the substrate.Our results indicate that APG can serve as a great candidate in channel plugging in fractured-vuggy carbonate reservoirs where fractures are fully developed.

Effect of EM Bokashi application on control of secondary soil salinization

In order to ameliorate saline-alkaline soil, EM Bokashi has been applied to rice production in conjunction with subdrainage in Ningxia Autonomous Region and Zhejiang Province. The preliminary results can be summarized as follows： EM Bokashi can increase soil organic matter content, improve soil porosity and permeability, and raise the soil＇s levels of available nutrients; and EM Bokashi combined with subdrainage treatment is more effective in controlling secondary soil salinization and raising the grain yield and quality than other treatments. The results suggest that EM Bokashi can reduce the necessary amount of chemical fertilizer application, thereby improving the agricultural environment, and that the introduction of EM Bokashi into systems of secondary soil salinization control systems has resulted in significant benefits.

关于西部果区土壤酸化与盐渍化的形成原因及防治措施研究

随着农业现代化进程的不断推进,我国西部地区的果园面积迅速增加。然而,由于长期不合理地施肥和灌溉方式,导致果树生长环境中的土壤质量逐渐恶化,出现了严重的酸性化和盐渍化问题。本文以天水市果区为研究对象,对土壤酸化和盐渍化的形成原因进行了深入分析,并探讨了有效的防治措施。通过对相关文献的梳理和实地调查数据的分析,发现土壤酸化和盐渍化的主要原因是化肥过度使用和农业管理不当引起。针对这些问题,提出了包括合理使用化肥、改善灌溉条件、调整农业结构在内的防治措施。通过这些研究,旨在为改善天水果区的农业生产条件、提高农民的生计和保护土地生态环境提供可行的建议和解决方案。

盐度对正戊烷在水溶液中扩散的影响

以烷烃为代表的有机质对海洋、湖泊及地层水的污染日趋严重。研究有机质在水溶液中的扩散,对分析其在海水、地层水等多电解质溶液中的扩散现象有指导作用,对于海洋污染的治理、油田采出液的脱水有重要意义。本研究采用动态悬滴体积分析技术,分析了正戊烷在不同盐度水溶液中的扩散强度。首先,实验基于正戊烷液滴面积扩张率的变化,评价盐度对扩散的影响。然后,通过Materials Studio软件进行分子动力学模拟,解释盐度对正戊烷扩散强度的影响。实验结果表明:随着盐度的增加,正戊烷在水溶液中扩散强度先增加后降低;存在转折盐度(0.5‰)使得正戊烷扩散最强。分子动力学模拟发现:低盐度时,离子水化使水分子在离子周围定向排布,使非极性分子——正戊烷分子组成的疏水单元周围出现可扩散的空腔,增加非极性分子的扩散强度。盐度增加导致离子间争夺水分子,打乱水分子的定向排布,减弱非极性分子的扩散强度。

一种高温高矿化度复合冻胶的研制与应用

为了解决高温高矿化度油藏深部调驱问题,以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和N,N-二甲基丙烯酰胺(DMAA)为原料合成共聚物PASD,并以酚醛树脂作为交联剂、硫脲作为稳定剂,添加增强剂MZQ制备得到复合冻胶体系。通过红外光谱仪、扫描电镜、岩心流变仪等对冻胶体系进行应用研究,考察了共聚物PASD、交联剂、稳定剂、增强剂加量的影响,确定复合冻胶体系的最佳配方;在150℃、矿化度为25.198×10^(4) mg·L^(-1)下条件下应用,其冻胶强度为Ⅰ级,抗老化脱水性能良好,有效耐温脱水时间超过180d;冻胶封堵能力超过93%,具有良好的封堵性能以及抗盐耐温性能。

Enhancement of a foaming formulation with a zwitterionic surfactant for gas mobility control in harsh reservoir conditions

This work presents the design of a robust foam formulation that tolerates harsh reservoir conditions(high salinity,high divalent ion concentration,high temperature,light oil,and hydrocarbon injection gas)in a sandstone reservoir.For this,we selected anionic Alpha Olefin Sulfonate(AOS)surfactants and studied their synergistic effects in mixtures with zwitterionic betaines to enhance foam performance.The laboratory workflow used to define the best formulation followed a de-risking approach in three consecutive phases.First,(phase 1)the main surfactant(AOS)was selected among a series of commercial candidates in static conditions.Then,(phase 2)the betaine booster to be combined with the previously selected AOS was chosen and their ratio optimized in static conditions.Subsequently,(phase 3)the surfactant/booster ratio was optimized under dynamic conditions in a porous medium in the absence and the presence of oil.As a result of this study,a mixture of an AOS C14-C16 and cocamidopropyl hydroxysultaine(CAPHS)was selected as the one having the best performance.The designed formulation was proven to be robust in a wide range of conditions.It generated a strong and stable foam at reservoir conditions,overcoming variations in salinity and foam quality,and tolerated the presence of oil.

Vietnam’s Future Water Usage Model: A Controlled Living Experiment

The purpose of this study was to explore the water usage profile of future Vietnamese households by carrying out a controlled living experiment with Vietnamese high-income households. By studying showering time, flow rate and toilet-use frequency of these households, the study revealed the water usage believed to be representative of future households in light of continued urbanization. This study also determined that the average time of showering was 9.7 minutes per person per day with an average flow rate of 12 L/minute for the existing shower head and 6.6 L/minute for the water-saving shower head. Toilet usage frequency was 5.25 times per person per day, and there was no difference with the results for an average (middle-income) household.

特高含水油藏剩余油分布特征与提高采收率新技术

渤海湾盆地胜利油区经过60多年开发,整装、断块油藏已处于特高含水开发阶段,含水率超过90%,稠油油藏进入高轮次吞吐开发阶段,整体采出程度不到40%,仍有大幅度提高采收率的潜力,需要攻关进一步提高采收率技术。针对整装油藏特高含水后期高耗水层带发育、低效水循环严重,断块油藏剩余油分布差异大、有效动用难度大,深层、薄层超稠油注汽难、热损失大,有碱复合驱油体系结垢严重,聚合物驱后油藏动态非均质性更强、剩余油更加分散以及特高含水后期套损井多、出砂加剧、精细分层注采要求高等难题,明确地质及剩余油分布特征,深化驱油机制认识,围绕整装油藏经济有效开发、断块油藏高效均衡开发、稠油油藏转方式开发、高温高盐油藏化学驱开发开展技术攻关,形成整装油藏精细流场调控技术、复杂断块油藏立体开发技术、稠油油藏热复合驱提高采收率技术、高温高盐油藏化学驱技术、特高含水期主导采油工程技术等特高含水油田提高采收率技术系列,开辟先导试验区,取得显著开发效果,实现工业化应用,支撑胜利油区持续稳产。

2010—2020年我国实验室海水盐度能力验证结果

2010—2020年期间我国(不包括港澳台地区)开展了5次7组样品的海水盐度能力验证,共有119家实验室参与,历年来获得443个海水盐度检测数据。由于各组数据均明显偏离正态分布,因此迭代算法A比经典统计方法、中位值和标准化四分位距法更适合评定能力验证结果。2010—2020年“不满意”率由20.3%降至4.9%,参与能力验证次数越多的实验室和取得检验检测机构资质认定的实验室,“不满意”结果较少,说明能力验证是提高实验室检测技术能力的有效手段,资质认定质量管理体系对确保检测数据准确性的作用明显。

柴西地区新生界湖相微生物碳酸盐岩岩相组合差异性及控制因素

利用大量露头和岩心薄片及分析化验资料,对柴达木盆地西部地区新生界咸化湖相微生物碳酸盐岩的岩石学特征、微观结构、岩相组合、沉积环境及其控制因素进行了研究。研究结果表明:(1)柴西地区微生物碳酸盐岩岩相组合受古地貌、沉积环境、陆源碎屑供给等因素影响,可分为扇控型和湖控型,扇控型主要发育在湖泊边缘的滨岸环境,分布范围大;湖控型多发育在盆缘斜坡区、断阶带及盆内浅水区,分布范围较小;古近系下干柴沟组上段主要发育扇控型,湖控型发育较局限,上述2类岩相组合在新近系下油砂山组均发育。(2)研究区不同岩相组合中微生物碳酸盐岩的类型与结构特征存在较大差异,扇控型微生物碳酸盐岩形成于湖侵时期,正旋回沉积为主,主要是凝块石,常叠置于厚层块状砂砾岩之上;微观结构以团块(凝块)、球粒及聚合粒为主;矿物成分以亮晶方解石为主。湖控型微生物碳酸盐岩在湖侵、湖退时期均可发育,正、反旋回沉积均发育,凝块石、叠层石及二者共生层均发育,规模相对较小,多与泥晶碳酸盐岩互层;微观结构更复杂,团块(凝块)、球粒及聚合粒和叠层结构均发育;矿物成分以方解石和白云石为主,含丰富的陆源碎屑、黏土矿物等,混积特征明显。(3)研究区扇控型微生物碳酸盐岩的形成主要受控于有机矿化作用和化学沉淀作用;湖控型微生物碳酸盐岩的形成则受控于有机矿化作用、化学沉淀作用以及物理沉积作用。

新疆绿洲土壤次生盐渍化治理研究

地貌学科理论对绿洲学科影响深远。按地貌特征对绿洲进行分类,有助于认识不同绿洲土壤次生盐渍化形成特点,找出治理之道。按照地貌特征,新疆绿洲可分为4种,即山前倾斜平原绿洲、沙漠内大河两岸型平原绿洲、山谷阶地型绿洲和极干旱盆地坎儿井型绿洲。绿洲地貌特征不同,其土壤次生盐渍化治理的关键也有所不同。新时代,现代管水和用水方式为各类绿洲土壤次生盐渍化治理创造了条件。绿洲土壤次生盐渍化研究有助于推进新疆重难点区域土壤次生盐渍化治理。

盐水层CO_(2)稳定埋存效率及储层参数优化

CO_(2)埋存是应对“碳达峰”和“碳中和”最为有效的埋存方式,为了筛选适合CO_(2)长期稳定埋存的盐水层,考虑了CO_(2)在盐水层中的4种埋存方式,建立了评价盐水层CO_(2)稳定埋存效率综合表征指标,并且基于数值模拟与Pearson (皮尔逊)相关系数统计的方法,确定影响盐水层CO_(2)稳定埋存效率的主控因素为储层底层与顶层渗透率的比值、储层中部渗透率和温度,在此基础上进行了盐水层CO_(2)稳定埋存储层参数优化。研究结果表明:反韵律储层有利于盐水层CO_(2)的稳定埋存,且储层底层与顶层渗透率的比值为1/7时,稳定埋存效率综合表征指标较大,盐水层CO_(2)稳定埋存潜力较大;当储层温度为55℃时,稳定埋存效率综合表征指标达到较高水平;随着渗透率的增大,稳定埋存效率综合表征指标先增大后减小,渗透率为0.8μm^(2)时,盐水层CO_(2)稳定埋存潜力较大;因此,确定反韵律储层渗透率级差为7、储层渗透率为0.8μm^(2)、储层温度为55℃时的储层更适合CO_(2)的稳定埋存。研究成果为盐水层CO_(2)稳定埋存储层筛选提供了依据。

中国典型咸化湖盆页岩油富集与流动特征及在“甜点”评价中的意义

咸化湖盆主要发育混积型页岩,长英质、碳酸盐矿物含量高,黏土矿物含量低,有机质形成液态烃时间偏早,但有机质丰度变化较大,且页岩油密度、黏度较高,流动性总体偏差。分析中国典型咸化湖盆页岩岩石组构、页岩油物性与流动性特征,总结提出“甜点”评价关键要素。有机质丰度较高(总有机碳TOC>1.5%或者2.0%)且单层集中段厚度较大(10~15 m或更大)的咸化湖盆页岩,在中低熟阶段(镜质体反射率R_(o)<0.8%)就可形成较多滞留烃,且纵向上具良好的源储组合,有利于页岩油近源微运移,形成富集段;混积型页岩黏土含量较低,对液态烃吸附总量较小,且页岩具有较好脆性,可保证地下可动烃数量较多,人工改造也可形成较好导流效果;页岩油主要赋存于黏土层微纳米孔隙和碳酸质与长英质层超压成因的微裂缝和构造缝中,非均质性极强,但多组分烃和非烃通过混相可改善重质烃和非烃组分的流动性,支撑中低熟液态烃有较高的流动量。此外,良好封闭性是形成异常高压的重要条件;足够高的现今地层温度(最好大于120℃)可提高中低熟页岩油地下流动性,合理的生产制度可保障多组分烃和非烃最佳混相从而形成最大流动量。具备上述条件的咸化湖盆中低熟页岩油称为“甜点”靶体,可用水平井和体积改造等非原位转化技术进行开发,并与需原位转化的淡水湖盆中低熟页岩油并列,构成中国中低熟页岩油两种主要类型,都具有良好的开发潜力,是陆相页岩油革命得于发生的重要资源基础。

膜蒸馏处理炼油化工高含盐废水的膜污染及控制研究进展

膜蒸馏(MD)以其操作温度及操作压力低、可处理高盐度废水、耦合利用低品味热源等优点,在炼油化工高含盐废水脱盐处理方面有着巨大的技术优势,但膜污染问题一直是膜蒸馏走向工业化应用的障碍。介绍了膜蒸馏在处理炼油化工高含盐废水中所遇到的3种膜污染类型,梳理总结了目前控制膜污染的技术方法。

新疆富含有机质油页岩在生态修复中的可行性应用研究

为了把新疆天山北麓准噶尔盆地南缘二叠纪富含有机质油页岩资源综合利用,通过对室内盆栽和大田施用油页岩和半焦对比试验,根据农业、林业、环境、食品相关标准,对油页岩和半焦成分、环境土壤有机碳、果实污染物进行检测,测定试验材料理化、养分、重金属指标,探明油页岩有机质的矿化分解过程,为制备以油页岩为原料的生态修复基质提供科学理论依据。检测指标均符合标准要求,植物长势也明显优于对比组。研究结果表明,新疆油页岩可以作为制备生态修复治理基质材料,可广泛应用于盐碱地改良、沙质荒漠化防治、防护林种植、水土保持、土地复垦、退耕还林、水源地涵养等生态修复工程。

咸化湖盆滩坝砂岩发育特征、控砂机制及油气成藏特征——以柴达木盆地西南地区新近系为例

基于柴达木盆地西南地区野外露头、钻井岩心、铸体薄片、测井解释、钻井油气显示及试油气成果等资料分析,结合青海湖现代盐湖沉积,对柴西南地区新近系咸化湖相滩坝沉积特征、发育规律、控砂因素及油气成藏特征等开展研究。结果表明:新近系咸化湖盆广泛发育滩坝砂体,岩性为细砂岩、粉砂岩,发育波状层理、低角度交错层理、透镜状-脉状层理等;滩坝砂体具有纵向上多期叠置、侧向上迁移、平面上呈北西—南东向广覆式连片的时空分布特征,预测新近系滩坝砂岩叠合面积达3000 km^(2);水体盐度影响滩坝砂岩的沉积速率与滩坝的离岸距离,物源区碎屑输入量影响滩坝砂岩的规模与富集,古地貌控制着滩坝砂体的形态及叠加样式,西北季风驱动效应控制滩坝砂岩的长轴延伸方向;滩坝具有“一砂一藏”的成藏特征,厚层滩坝砂体控制有效储集层分布,油源断裂控制油气运聚主要方向。通过成藏要素分析,提出扎哈泉南、英东—乌南东和花土沟东等3个有利勘探目标区。

An improved ET control method to determine the water-saving potential for farmland in Baiyangdian Watershed, China

Resource-based water-saving potential has been recognized as the reduction of evapotranspiration and water loss of inefficient irrigation systems. In this paper, an improved evapotranspiration control model is applied to calculate resource-based water-saving potential, considering the influences of effective rainfall （uncontrolled evapotranspiration） and irrigated water （controlled evapotranspiration）. Farmland in Baiyangdian Watershed, a highly productive area in northern China, is analyzed to determine the water-saving potential of irrigation processes. The water-saving potential was zero, 163.90 × 10^6m3, and 318.24 × 10^6m3 in wet, normal, and dry years, respectively, and was greater in years with less rainfall. Under the combined effect of rainfall, crop water consumption, and crop water requirements, the water-saving potential showed obvious temporal and spatial variations. July and August comprised almost 98.6% of the annual potential. In the northeast and southwest corner of the study area, potential approached zero. The potential was 1.53 times greater in the north-central than in the south-central area. The model can furnish the appropriate timing and region to water managers for implementing water-saving strategies.