流体性质变化对双河油田储集层的损害

在双河油田近２０年的高效开发过程中，流体性质发生了变化，对油层造成不同程度的损害。主要表现在：①注入水的长期冲刷，加大了储集层物性和孔隙结构变化速度，使得后期储集层各类溶孔非常发育，孔隙和喉道在三维空间上的分布、组合及配置关系更加复杂，它与注入水的水质及与地层水的配伍性和储集层敏感性有关，是油层损害的主要原因。②地层水中离子的变化，特别是某些阳离子（Ｃａ２＋、Ｍｇ２＋、Ｋ＋、Ｎａ＋等）易与岩石颗粒进行离子交换，造成矿物的转化、溶解和沉淀，形成更多的地层微粒和细小喉道，增大油层渗透率非均质性。③原油在地层中含盐量、含硫量、含蜡量的变化等也可使油层渗透性能变差。④外来液体对地层的水锁效应，降低了油相渗透率；润湿性反转造成地层损害；细菌繁殖造成注水井地层堵塞，固体颗粒堵塞孔隙、喉道等。流体性质的变化与油层物性变化关系密切，是当前储集层损害及评价研究的重要组成部分。照片６图２表３参３（郭海莉摘）     

智能水矿化度及离子组成对碳酸盐岩储集层矿物结垢的影响

利用碳酸盐岩岩心开展岩心驱替实验,研究了在智能水驱过程中由于矿物结垢沉淀而引起的储集层伤害风险以及注入水矿化度和离子组成对矿物结垢沉淀的影响。设计了一种新的室内岩心驱替实验程序以模拟注入水和地层水在储集层中的流动条件,考虑了注入水和地层水的原位接触时间对矿物结垢沉淀的影响。在确定了最佳接触时间之后,通过改变注入海水的矿化度和离子浓度来研究渗透率下降程度的变化。利用扫描电镜对结垢后的岩心样品进行目测分析,以研究结垢晶体形态。实验结果表明,在设定的实验条件下,CaSO_4和CaCO_3复合结垢沉淀导致的渗透率下降幅度为初始渗透率的61.0%～79.1%,注入智能水的矿化度、离子组成以及注入水与地层水的接触时间对CaSO_4和CaCO_3结垢沉淀有显著影响。扫描电镜图像显示,岩心渗透率的损失主要是由结垢晶体积聚并垂直于孔隙壁面生长造成的。图11表5参33     

A油田注入水水质变化原因分析及稳定对策

海上A油田注入水经过精细过滤后,水质变浑浊,且对岩心的堵塞比较严重,不能满足回注要求。因此,室内通过测定离子组成、浊度值、溶解氧质量浓度、细菌数量等水质指标以及浑浊物成分,分析注入水水质变化的原因。结果表明:注入水中溶解氧质量浓度的增大导致细菌大量繁殖是造成水质变浑浊的主要原因。通过除氧剂以及杀菌剂的优选实验,研究了适合该油田注入水的水质稳定措施,在注入水中加入1000 mg/L的除氧剂CYJ-10和30 mg/L的杀菌剂SJJ-3能使水样浊度值不发生明显变化,岩心驱替100 PV后的渗透率保持率大于85%。现场应用结果表明,采用水质稳定措施后,注入水水质未发生明显改变,M井的注入量能够保持较长时间的稳定,增注效果良好。     

双河油田注入水适应性及注水井酸化解堵研究

考察了双河油田双河联、江河联注入水堵塞地层的因素;膨胀性黏土，悬浮固体颗粒。细菌及悬浮污油。含膨胀性黏土的双河南、双河北及不含膨胀性黏土的双江岩心粉，在注入水中相对于地层水中的体积膨胀度分别为14．5％、11．1％及0．02％；注入100PV不含悬浮颗粒的等体积比地层水、注入水混合水使双河、双江岩心渗透率分别下降7％和4％、9％和7％。注入水中悬浮颗粒引起岩心渗透率下降，粒径越大、颗粒浓度越大、注入量越大，则渗透率越低。在粒径2．1μm或颗粒浓度3mg／L前后下降幅度变化较大。注入水中硫酸盐还原菌引起岩心渗透率下降，含菌量越大则渗透率开始下降时的注水量越小，注入含菌50个／L的水100PV使岩心渗透率下降7％。岩心对注水合油量敏感，注入含油量20mg／L的水50PV使岩心渗透率下降20％。在岩心注水实验中渗透率下降最严重的是双河南岩心，其次是双河北岩心．江河岩心较轻，注入精细过滤水的双河北岩心渗透率下降大大减少．说明悬浮固体是造成注水堵塞的主要因素。为了解除双河油田注水井的堵塞，研制了含黏土稳定剂、缓蚀剂、铁离子稳定剂、互溶剂的土酸液，与南阳油田使用的低伤害酸液一起，用于1口注水井的解堵，效果良好。图7表4参5。     

微生物驱油的参数敏感性分析

用反映细菌、营养液在油藏中的传输及细菌繁殖的一维三相微生物采油数学模型进行微生物驱油过程中的参数敏感性分析，结果表明，在微生物驱油过程中，存在驱油效果最好的细菌注入速率最佳值；细菌初始浓度越大，注入井井底细菌浓度增长就越快，细菌沉积量相应就越大，营养液初始浓度越大，细菌生长率就越大。     

辽河油田XH27断块储集层岩石特征分析

XH27断块含油目的层为东营组一段．，属三角洲沉积环境。为进一步研究该断块岩石沉积环境，了解储集层岩石矿物成分、黏土矿物含量及其敏感性，通过岩心扫描、储集层物性数据检测、岩心微观结构研究、地层损害实验获取大量数据，进行储集层岩石特征综合分析评价，加深了对储集层主要岩石的组成矿物、结构及储集层内地层流体情况的认识，对引起油层损害的因素进行系统研究。认为该断块具有水下分流河道和分流河道间沉积特征，含油砂岩的矿物成分以石英和长石为主，岩性疏松．胶结物以泥质为主，胶结较差；储集层中黏土矿物含量较高，以伊利石为主，次为伊／蒙混层黏土；储集层敏感性评价水敏性较强，盐酸酸敏性中等。提出应调整注入流体的性质，采取防范措施，避免发生水敏性伤害；在采用酸化作业改造油层时．筛选合适酸化液，也可加入适量防膨剂提高酸化效果；针对储集层碱敏性较强的特点，尽量不用强碱调节工作液pH值。为提高油层保护的研究水平，制定科学的油藏开发方案提供了依据。     

油基钻井液对注水井吸水能力影响的室内评价

针对现场油基钻井液所钻井出油少，注水困难等问题，评价了油基钻井液滤液，完井液、水泥浆，注入水、地层水间的配伍性，以及油基钻井液滤液，原油对岩心动静污染后吸水能力的影响，实验结果表明：油基钻井液滤液与水泥浆、完井液、注入水，地层水存在一定的乳化作用；水泥浆与完井液、注入水、地层水不配伍，有沉淀生成；油基钻井液、原油动静污染后岩心注水能力下降，性注水水能有效提高油基钻井液静污染后岩心吸水能力。     

阿拉伯地区过去十年来的MEOR研究

从沙特阿拉伯和埃及的原油和地层水中分离出了10种以上细菌。进行了实验研究以辨别细菌的隔离种群，确定适当营养物的成分，完成地面征侯测量。在所获得结果的基础上，发现细菌的存在影响溶液的相体积、油水间界面张力、岩石润湿性和相对渗透率特性。这些影响取决于细菌类型、营养物类型以及浓度、盐度、温度和原油组分。在均质填砂模型和Berea砂岩岩心中用不同类型的细菌溶液(营养物为葡萄糖、蔗糖和糖蜜)进行了一些列微生物驱替实验室试验。研究了营养物类型及其浓度、细菌类型、盐度、API重度和渗透率对原油采收率的影响。结果显示，最高原油采收率来自1％糖蜜浓度的本源细菌的话化。发现有些种类的细菌产生了沼气、生物表面活性剂和生物聚合物，这些均能提高原油采收率。填砂模型渗透率的变化或API重度对原油采收率没有影响。     

油层水淹地球化学响应机理及评价方法研究

随着油田开发技术的不断发展，注水采油已广泛应用到油田开发中来，由于各种液体的注入改变了原有储集层的特性，也使得储集层的评价产生了困难，该文通过岩心模拟真实地层条件下驱替实验，在注入水和化合物情况下，储集层流体性质在驱替过程中的变化，利用岩石热解、气相色谱等方法进行分析，建立水淹层的地球化学评价方法。为解决水淹层的评价开创了新的思路，并见到了实际效果。此外，通过水驱油、化合物驱油实验还表明，由于注水对储集层内的烃组成有一定影响，在地化分析参数上产生一定变化，水驱油实验的结论证实了地球化学技术评价水淹层的正确性，针对不同储集层可以采用注入驱替试剂，达到既提高产量又保护储集层、延长开采周期的目的。     

纯化油田注入水中细菌堵塞岩心实验研究

岩心流动实验装置全系统灭菌;地层水和注入水过滤、灭菌;储层岩心洗油、饱和地层水;用注入水接种培养,制备低、中、高含菌量的驱替用水,其中TGB、SRB、IB菌总菌数分别为1.06×102、1.49×103、1.29×104个/mL。用低、中、高含菌量的3种含菌水驱替岩心,注入量分别为70、70、64PV,岩心对地层水的渗透率分别由9.06×10-3、15.93×10-3、11.84×10-3μm2变为10.16×10-3、1.45×10-3、0.72×10-3μm2,对岩心渗透率的伤害分别为-12.1%、90.9%、93.9%,岩心流出液中总菌数分别为0、4.0×100、4.1×101个/mL。讨论了注水过程中细菌在岩心孔隙中的截留和岩心堵塞。认为纯化油田砂岩油藏注入水中各种细菌的总数应控制在1×102个/mL以下。图3表4参2。     

微生物菌液的界面特性

借助界面扩张流变测量方法,研究了2种微生物菌液体系与油相形成的界面特性.结果表明,微生物细胞及其代谢产物具有良好的表面活性,能够有效地降低油水界面张力.菌液与油相形成界面后,菌液内活性物质在界面上吸附和富集,界面张力迅速降低并达到较低的平衡值.微生物细胞的表面活性存在一个最佳温度范围,可能与微生物的最佳生长代谢温度相关.微生物细胞具有降低粘弹模量的作用,并改变了扩张粘度模量和扩张弹性模量对粘弹模量的贡献比例.     

Bioremediation process of oil spill using fatty-lignocellulose sawdust and its enhancement effect

The present paper deals with the treatment of oil spills using weights of modified lignocellulose sawdust. The crude oil sorption on the surface of sawdust was discussed. Nineteen crude oil-degrading bacterial isolates were separated from an oil-polluted area in Saryaqos, Al-kanakah and Mustorud area, Egypt. Four bacterial species showed the predominated growth rate on crude oil hydrocarbons. The effect of the different weight of sawdust (0.1–0.5 w/v) on the bacterial degradation of the crude oil sample was investigated. Biodegradation potential was evaluated after 5 days. The total oil was removed from the microcosms after the biological treatment ranging from 65 to 80% after 5 days. Gas Chromatographic (GC) analysis of the crude oil remaining in the culture medium, showed that the higher biodegradation of isoparaffins than n-paraffins in microcosms containing biosurfactant, the higher weight of fatty sawdust (FSD) at 0.5 g and BI1, BI4 and a bacterial consortium of four bacterial isolates separately. The result shows that these bacterial strains can be used for the bioremediation using modified sawdust in oil-polluted area.     

Estimating probability distributions of bacterial concentrations in food based on data generated using the most probable number (MPN) method for use in risk assessment

Estimating probability distributions that describe bacterial concentrations in food products is a key element of quantitative microbial risk assessments. Standard bacteriological protocols for bacterial enumeration first apply a detection test to a set of samples. For samples that test positive, bacterial concentrations are quantified using a serial dilution assay such as the most probable number (MPN) method. Estimation of bacterial concentration distributions based on a set of such data, however, represents a considerable statistical challenge. A maximum likelihood approach has been published to estimate bacterial concentrations from this type of data while accounting for the censored nature of the data. In this study, we derived an alternative method, based on complete likelihood maximization from observed MPN pattern data. Both methods were first evaluated in simulation studies, which showed that the latter method generated unbiased estimates of the parameters of the bacterial concentration distribution, while the former method generated biased results. The bias was particularly pronounced when bacterial concentrations were low. Both methods fail to predict accurately low contamination levels at low prevalence (e.g. mean of ?7 log₁₀ for contaminated products and prevalence of 0.2). The methods were then applied to bacteriological data from a food survey of Listeria monocytogenes in the United States. The former method led to approximately 1 log₁₀ cfu higher estimated mean bacterial concentration compared to estimates generated using the alternative method. The alternative method is preferable, in particular if bacterial concentrations are low.     

Assessment of bacterial profiles in aged,home-made Sichuan paocai brine with varying titratable acidity by PacBio SMRT sequencing technology

Sichuan paocai, a traditional Chinese fermented vegetable, is rife with lactic acid bacteria (LAB). However, the precise bacterial profiles of home-made Sichuan paocai brine (HSPB) remain unclear. In this study, the bacterial compositions of 38 aged HSPB samples with varying titratable acidity (TA) were determined by SMRT sequencing of the full-length 16S rRNA gene. The lactic and acetic acids of HSPBs were also measured to determine any relevance with the bacterial profiles. The SMRT sequencing results reveal that the HSPB bacterial communities were comprised of numerous phylogenetic taxa, including 35 phyla, 371 genera, and 593 species; the bacterial diversity decreased as HSPB acidity increased. Lactobacillus acetotolerans, which was positively correlated to HSPB acidity, was the most dominant species followed by Lactobacillus brevis, which was positively related to acetic acid in the samples. A few opportunistic pathogens (e.g. Serratia marcescens and Stenotrophomonas maltophilia) were also detected. Sample groups with lower acidity had higher bacterial diversity and more Lactobacillus species with relative abundance >1% and opportunistics than higher-acidity samples. The results presented here report the comprehensive bacterial profiles of home-made Sichuan paocai for the first time via SMRT sequencing technology and the correlation between TA and bacterial compositions. It is necessary to further investigate the opportunistics detected in this work as they relate to the safety and quality of paocai.     

微生物对胶态分散凝胶体系成胶性能的影响

研究分析了多种微生物对胶态分布凝胶（CDG）体系的作用，结果表明，多种微生物（如腐生菌，硫酸盐还原菌，铁细菌，已酸菌等）都会对CDG体系成胶过程中及成胶后的粘度产生影响，使体系粘度迅速下降。在此基础上，对杀菌剂与CDG体系之间的关系做出了初步评价。认为在DCG体系中加入适当浓度的杀菌剂，能够保证CDG体系在地层厌氧条件下的稳定性，该研究结果为矿场试验中应用CDG体系进行调剖驱油提供了实验依据。     

抗菌腈纶纤维性能研究

介绍了抗菌无机添加剂、抗菌腈纶纤维的生产过程及其性能。纤维中添加0.5％～1％的抗菌添加剂,基本不影响其物理机械性能,纤维的抗菌率可达90％以上。     

油田注入水中的细菌类型及危害

文章论述了细菌的类型及其特征 ,讨论了注入水中细菌对油层、管线的危害 ,并以垦利油田垦 -95断块为例 ,重点讨论了细菌堵塞油层引起油层渗透率下降、吸水能力下降后如何解除堵塞的问题 ,对油田生产具有一定的指导意义。     

A new insight into the adsorption mechanism of patulin by the heat-inactive lactic acid bacteria cells

The primary objective of this study was to identify the characteristics of the heat-inactived lactic acid bacteria (LAB) cells involved in the adsorption of patulin. The bacterial cells were characterized by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Transmission Electron Microscopy (TEM) and Brunauer–Emmett–Teller (BET) technique. The patulin-exposed bacterial cells and patulin-unexposed bacterial cells were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Zeta Potential and Contact Angle Method. It was found that Lactobacillus brevis 20023 (LB-20023), which has the highest specific surface area and cell wall volume, showed the highest capacity to adsorb patulin from the aqueous solution. Five major elements (C, N, O, P, and S) were detected by SEM-EDS, and LB-20023 displayed the highest nitrogen-to-carbon (N/C) ratio (0.2938). LB-20023 exhibited the highest hydrophobicity, but the zeta potential was not prominent compared to other bacterial cells. The main functional groups involved in adsorbing patulin were C–O, OH and/or NH groups, suggesting that polysaccharides and/or protein were important functional components. Above all, the adsorption capacity of bacterial cells had close relationships with physical and chemical properties of cell surface, including specific surface area, cell wall volume, nitrogen-to-carbon (N/C) ratio, hydrophobicity and functional groups. Further study will be needed to find other additional functional factors.     

威远页岩气区块某平台配液用水与采出水细菌群落演替规律

目的探究在页岩气生产过程中的关键腐蚀细菌,解析其中细菌潜在的演替规律。 方法利用16S rRNA高通量测序分析技术对威远地区页岩气某平台配液用水和采出水菌群进行检测。 结果清水配液的细菌结构与采出水、回用返排液完全不同,压裂后细菌的丰富度及多样性降低;关键腐蚀细菌包括弓形杆菌属(Arcobacter)、海细菌属(Marinobacterium)、假单胞菌属(Pseudomonas)等;清水配液中细菌群落是由嗜温、好氧、硫酸盐还原和产酸等功能较弱的细菌为主,而回用返排液中存在大量具有硫代谢、产酸和产生物膜功能的细菌,经压裂后,采出水中以兼性厌氧、厌氧或严格厌氧,即具有硫酸盐还原、硫还原、硫氧化、产酸、产生物膜、铁还原等功能的细菌为主,并鉴定出部分嗜热细菌。 结论可为进一步研究集输管道细菌腐蚀及管道防护提供理论与技术支持。      

The Enhanced Biodegradation of Petroleum Lubricant by Bacterial Strains Harvested From Oil Contaminated Soil

Up to now, little information has been available on biodegradation of petroleum lubricant oils by microbial inoculation. Understanding the abilities of microorganisms in biodegrading petroleum lubricants is imperative for optimum use of bacteria in bioremediation of lubricant-contaminated environments. In the study, three bacterial strains of genera Pseudomonas sp., Ochrobactrum tritici, and Bordetella petrii, which were previously isolated from oil-contaminated soils, were inoculated into a lubricating oil culture medium. The abilities for the three bacterial strains to biodegrade a petroleum lubricating oil were evaluated by determining the chemical oxygen demand (COD) of the inoculated oil culture mediums. Effect of pH on degrading abilities of the bacterial isolates and impact of temperature on microbial growth were also explored. Results showed that the CODs of the inoculated lubricating oil culture mediums were much lower than that of the oil medium without bacterial inoculum, indicating that the three bacterial strains effectively enhanced biodegradation of the mineral lubricating oil, of which the member of genus Ochrobactrum was the most excellent enhancer. Furthermore, the abilities for the strains to biodegrade lubricating oil were different at different pH values. They provided excellent oil-degrading ability in the pH range from 6.0 to 7.8. On the other hand, the microbial populations of the bacterial strains markedly increased with increasing incubation durations in an exponential phase at the temperatures ranging from 28°C to 35°C.