Organic nutrients for microbial enhanced oil recovery

Abstract

Glass vial tests were conducted to quickly screen nutrient mixtures for microbial enhanced oil recovery (MEOR). Common nutrients, such as food grade milk, were applied to 190 vial cultivation experiments. Five of the nutrient mixtures used in the glass vial tests showed no hydrogen sulfide (H₂S) production. These five were then assessed for oil recovery in a core flooding test. Four of the five nutrient mixtures showed an increased oil recovery of 10%, without H₂S production. Thus, the glass vial test was useful for screening through multiple nutrient mixtures quickly before analysis in the core flooding test.     

Using biosurfactant producing bacteria isolated from an Iranian oil field for application in microbial enhanced oil recovery

Microbial enhanced oil recovery (MEOR) is a useful technique to improve oil recovery from depleted oil reservoirs beyond primary and secondary recovery operations using bacteria and their metabolites. In the present study, the biosurfactant production potential of Bacillus licheniformis microorganisms that were isolated from oil samples of Zilaei reservoir in the southwest of Iran was explored under extreme conditions. Growth media with different temperatures of 40, 50, 60, and 70°C; salinities of 1, 3, 5, and 7 wt%; and yeast extract concentrations of 0.5, 1, 1.5, and 2 g/L were used to find the optimum growth conditions. The results demonstrated that bacteria grown in a mineral salt solution with temperature of 50°C, salinity of 1 wt% and yeast extract concentration of 1 g/L has the highest growth rate and therefore, these conditions are the optimum conditions for growing the introduced bacterium. This isolate was selected as the higher biosurfactant producer. The obtained biosurfactants by bacteria isolated in a medium with these conditions could reduce the interfacial tension of crude oil/water system from 36.8 to 0.93 mN/m and surface tension of water from 72 to 23.8 mN/m. The results of the core flooding tests showed that the tertiary oil recovery efficiency due to the injection of microorganisms was 13.7% of original oil in place and bacteria could reduce the oil viscosity by 41.242% at optimum conditions. Based on these results, the isolated microorganism is a promising candidate for the development of microbial oil recovery processes.     

Microbial community structure of a low sulfate oil producing facility indicate dominance of oil degrading/nitrate reducing bacteria and Methanogens

Analysis of microbial community structure of a low sulfate oil producing facility in Nigeria using 16S rRNA gene sequencing technique revealed dominance of oil degrading and nitrate reducing bacteria and methanogenic archaea in produced waters and oil samples namely, Marinobacter (37%), Azovibrio (21%), Thauera (10–28%), and Methanolobus (22%). On the contrary, the associated oil pipeline samples revealed massive dominance of potentially corrosive Methanolobus (60%) and Methanobacterium (25-27%). Further experimentation shows that the methanogens implicated in oil pipelines are corrosive moderate halophile that utilizes H₂/CO₂ and methanol as substrates. More emphasis should therefore be on methanogenic archaea as opposed to sulfate reducing bacteria (SRBs) during mitigation plans for microbially induced corrosion (MIC) in a low sulfate oil producing facility.     

微生物采油技术研究进展与发展趋势

近十几年来,主要有两方面原因促使微生物采油技术进入快速发展阶段,一是基于16S rRNA的微生物生态分析技术的应用,尤其是高通量测序技术的应用,实现了油藏极端环境微生物群落结构与动态演变规律的快速准确解析;二是以聚合物驱为主导的化学驱油技术的应用已经越过其高峰期,适合化学驱的油藏资源越来越少,对接替技术的迫切需求让微生...     

胜利油田微生物采油技术研究与应用进展

胜利油田微生物采油技术历经二十多年的室内研究和现场试验,机理研究取得深入认识,技术体系日趋完善,已进入工业化应用阶段.微生物界面趋向性、嗜烃乳化、界面润湿改性等主导驱油机理认识更加深入,并实现了量化表征,为菌种(群)改造和调控指明了方向;建立系统的油藏菌群结构分子生物学分析、采油功能菌激活调控、三维物理模拟驱油等微生物...     

Microscopic profile control mechanism and potential application of the biopolymer-producing strain FY-07 for microbial enhanced oil recovery

To promote the application of strain FY-07 in oilfield development, experiments were performed on the mechanism of microscopic profile control using an etched glass micromodel. The physical simulation experiments were applied to evaluate the plugging ability and oil displacement performance. The results showed that the biopolymers were preferentially generated and existed in large pores that can improve the swept volume and oil recovery. The plugging rate of FY-07 for different permeability cores was 67–78%, which indicates FY-07 exhibited good plugging capacity. The EOR value of FY-07 was 10.54%, which demonstrated that FY-07 has great potential to enhance oil recovery.     

微生物局部富集提高原油采收率机理

将主要代谢产物为糖脂类表面活性剂的菌种(同时产少量低分子有机酸)放在载玻片中进行实验,从中可观察到细菌由于具有化学趋向性而在油水界面处富集.在玻璃盒中对其进行了实验,用肉眼可观察到,由于“在位繁殖”效应,油水界面处浑浊程度由低逐渐变高.在距油水界面不同距离处,分别取样定量测定了产物浓度分布梯度.在仿真网络玻璃模型中进行的微生物驱油实验中观察到,菌体优先进入孔隙壁、油、水三相交界处.研究了微生物及其代谢产物乳化启动剩余油、剥离油膜、改变孔道壁润湿性的驱油机理,得到了一些有价值的结论.     

Modelling of microbial enhanced oil recovery application using anaerobic gas-producing bacteria

Microbial enhanced oil recovery （MEOR） methods apply injection of bacteria to depleted oil reservoirs to produce oil, which had remained unrecovered after the conventional methods of production. The ability ofthermophilic anaerobic bacteria to produce gas as the main mechanism in potential MEOR in high salinities of 70-100 g/L was investigated in this study. Maximum gas production of up to 350 mL per 700 mL of salty solution was produced at a salinity of 90 g/L stably during 2-4 days of experiment. The experimental results were upscaled to the Snorre Oilfield, Norway, and simulated using ECLIPSE software for 27 months. The best scenarios showed that the increase in oil recovery on average was at 21% and 17.8% respectively. This study demonstrated that anaerobic bacteria used in biogas plants could be an attractive candidate for MEOR implementation due to their ability to withstand high temperature and salinity, and produce gas in large volumes.     

油田内源硝酸盐还原菌抑制SRB效果评价分析

油田开发进入中高含水期,硫酸盐还原菌(SRB)腐蚀成为影响油田生产的重要原因之一。由于传统化学法和物理法治理存在成本高、二次污染等弊端,利用细菌竞争共生原则进行腐蚀治理的生物法逐渐受到关注。通过对江苏油田筛选的1株内源硝酸盐细菌N411进行抑制SRB的效果评价分析,该菌株在理想的SRB营养条件和最高的活性状态,且抑制体系使用体积浓度2%情况下,3d就可以将SRB产硫化氢活性抑制94%以上,7d抑制率达98%以上。     

Comparison of in-situ and ex-situ microbial enhanced oil recovery by strain Pseudomonas aeruginosa WJ-1 in laboratory sand-pack columns

Microbial enhanced oil recovery (MEOR) applies biotechnology to improve residual crude oil production from substratum reservoir. MEOR includes in-situ MEOR and ex-situ MEOR. The former utilizes microbial growth and metabolism in the reservoir, and the latter directly injects desired active products produced by microbes on the surface. Taking biosurfactant-producing strain Pseudomonas aeruginosa WJ-1 for research objects, in-situ enhanced oil recovery and ex-situ enhanced oil recovery by biosurfactant-producing strain WJ-1 were comparatively investigated in sand-pack columns.The results showed that P.aeruginosa WJ-1 really proliferated in sand-pack columns, produced 2.66 g/L of biosurfactant, altered wettability, reduced oil-water interfacial tension (IFT) and emulsified crude oil under simulated in-situ process. Results also showed that higher biosurfactant concentration, lower IFT, smaller average diameters of emulsified crude oil were obtained in in-situ enhanced oil recovery experiment than those in ex-situ enhance oil recovery experiment. Similar wettability alteration was observed in both in-situ and ex-situ enhanced oil recovery experiment. The flooding experiments in sand-pack columns revealed that the recovery of in-situ was 7.46%/7.32% OOIP (original oil in place), and the recovery of the ex-situ was 4.64%/4.49% OOIP. Therefore, in-situ approach showed greater potential in enhancing oil recovery in contrast with ex-situ approach. It is recommended that the stimulation of indigenous microorganisms rather than injection of microbial produced active products should be applied when MEOR technologies were employed.     

一种新型声波降粘防蜡装置

新型声波降粘防措装置由上、下接头、振动簧片和收缩喷嘴构成。装置安装在抽油泵泵简之下，尾管之上，在压差作用下井下流体以较大速度从装置的喷嘴射出，冲击振动簧片，产生机械振动声波，油水混合液在声波中产生相应的声波力学效应和分散乳化作用等，使混合液在油管内的粘度降低，蜡晶不易聚集长大，从而达到降粘防蜡延长油井热洗周期的目的。室内试验及现场近20口井的应用情况表明，这种装置具有结构简单、成本低廉、应用方便等特点，具有明显的降粘防蜡效果。     

考虑油藏环境因素和微生物因子的微生物采油数学模型

为研究油藏环境耦合作用下微生物驱技术提高采收率机理，建立了能全面反映微生物驱油过程的三维三相六组分数学模型，模型涉及的组分有油、气、水、微生物、营养物以及代谢产物。该模型综合考虑了微生物生长/死亡、营养消耗、产物生成、化学趋向性、对流扩散、油相黏度降低、吸附、解吸附以及油-水界面张力变化等特性。其中，微生物生长动力学方程以Monod模型为基础，考虑油藏环境因素对微生物生长模型的影响且微生物在地上与地下生长速率不一致；同时为了体现菌体对微生物驱油的作用，引入微生物因子到微生物驱油机理中。对微生物生长模型、微生物和营养物的混合溶液注入量、环境抑制系数、最大比生长速率以及微生物因子等进行分析的结果表明，通过完善后的微生物生长方程计算得出的产物浓度要比Monod模型低，但这两种微生物生长方程下的产物浓度的差异对最终采收率的影响较小；随着混合溶液注入量的增长，这两种微生物生长方程下的产物浓度差值和采收率提高幅度将增大；微生物因子对微生物驱油有较大的影响，不同微生物因子下提高原油采收率的绝对误差可高达24.53 %。     

微生物驱油技术在陕北油田实验研究

陕北油田具有低渗低压的特点,因此其采收率普遍较低。进入新世纪以来,石油价格不断攀高。所以,研究微生物采油在陕北油田的应用具有重大意义。主要是在了解微生物采油的基本机理、影响因素、方法以及现状等基本情况的基础上,结合陕北油藏的地质条件,进行室内的微生物驱油实验,从而分析微生物采油方法在陕北地区的可行性。     

大庆油田微生物采油技术研究及应用

大庆油田微生物采油技术始于20世纪60年代,历经50多年的持续攻关,基础研究和现场应用均取得一定进展.研究发现微生物存在主动趋向原油、黏附原油、产表面活性剂乳化原油3种趋向原油方式,确定实验菌株以氧化方式降解烷烃、芳香烃的降解机理.在室内研究的基础上,针对特低渗透油田开展外源微生物现场试验,实施微生物吞吐试验93口井,...     

微生物采油技术及其在延长油田的应用分析

文章介绍了微生物提高石油采收率（MEOR）的发展概况、作用机理与油藏应用条件。根据微生物处理油层的标准,提出延长油田部分油区可以利用微生物驱油来提高采收率,并利用实例证实了它的可行性。     

层内生气提高采收率技术在中原断块油田的应用

介绍了层内生气提高采收率技术机理、室内岩心模拟实验，并对典型区块进行了详细的分析。现场应用21井次，区块平均注水压力下降9．5MPa，单井平均增加注水量5321．9m^3，累积增加注水量111759m^3，油井累积增油15187。49t。矿场试验表明，层内生气提高采收率技术的应用对部分区块和井组控水稳油、控制自然递减起到了积极作用，是一项有应用前景的提高采收率新技术。     

油气田硫酸盐还原菌控制技术应用探讨

在油气田开采、集输和气田水回注系统中,存在着各种微生物群体,包括硫酸盐还原菌、铁细菌以及其他微生物。其中,危害性最大的微生物就是硫酸盐还原菌(SRB)。通过对重庆气矿目前站场SRB分布统计分析,结合站场气田水处理工艺及油套管腐蚀状况,经分析对比现有多种生物腐蚀控制技术,推荐LEMUPZ-H物理法杀菌技术。现场应用表明,该工艺能有效杀灭和抑制气田水中SRB,对站场排污、气田水转输及回注系统均能起到较好的保护作用,是一种经济有效的应对SRB腐蚀的控制保护措施。     

聚合物驱后油藏激活内源微生物驱油现场试验

针对聚合物驱后油藏内源微生物的生长特点,对大庆油田萨南开发区南二区东部聚合物驱后典型油藏开展了激活内源微生物驱油现场试验。通过优选由玉米浆干粉、硝酸钠和磷酸氢二铵构成激活剂,与保护剂聚合物交替注入,并运用分子生态学末端限制性片段长度多态性方法分析了内源微生物激活前后群落结构的变化规律,研究了利用内源微生物驱油技术的可行性。现场试验结果表明：聚合物驱后油藏中有明显的产气增压效果;油藏驱动压力的动态变化及代谢产物气体组分CH₄和CO₂的δ¹³C同位素含量波动,验证了激活剂的加入促使油藏内源微生物微氧和无氧代谢交替进行;产出液的各项生化监测指标均有明显变化,激活后优势菌群为Pseudomonas、Thauera和Arcobacter,且丰度增高;试验区阶段累计增油3 068.13 t,含水率下降2.2% ,驱油增产效果明显。该试验的成功实施证明了聚合物驱后油藏采用激活内源微生物驱油的工艺方法是可行的,并为同类油藏进一步提高采收率提供了可借鉴的方法和途径。     

嗜烃乳化功能菌在多孔介质中的生长规律及驱油机理

嗜热脂肪地芽孢杆菌Geobacillus stearothermophilus SL-1(简称SL-1)菌是从油藏环境中分离获得的一种嗜烃乳化功能菌,烃类乳化能力强,适宜生长温度为65～70℃.利用微观可视模型和岩心填砂模型,对该菌进行了多孔介质中的生长分布规律及驱油机理研究.结果 表明,高温高压油藏环境下,与空白对照...