克拉玛依油田空气辅助微生物驱油室内研究

针对克拉玛依油田油藏地质条件,室内进行了兼性采油菌的好氧、厌氧培养和代谢原油性能测定及空气辅助物理模拟驱油试验。结果表明,在好氧条件下,兼性采油菌的生长繁殖能力和代谢原油的性能都优于厌氧条件;空气辅助微生物驱比单一微生物驱提高最终采收率3.75个百分点,能进一步提高微生物驱油效果。     

胜利油田沾3块内源微生物驱物理模拟试验研究

物理模拟试验是内源微生物驱现场试验的重要组成部分.试验采用单管填砂模型,模拟胜利油田沾3块油藏条件(油藏温度60℃、压力10MPa、渗透率900×10-3μm2和矿化度8055mg/L),利用筛选出的激活剂配方,开展了不同激活剂注入量、注入方式和空气配注量下的物理模拟驱油试验.通过对产出液中的微生物群落结构和代谢产物低...     

微生物驱配气工艺参数优化试验研究——以孤岛中一区Ng_3区块为例

在空气辅助微生物驱油技术中,氧气的配注量直接影响油藏好氧微生物生长代谢的情况,进而影响驱油效率.在模拟胜利油田孤岛中一区Ng_3区块油藏条件下,通过物理模拟试验研究考查产出液表面张力、微生物浓度变化和代谢产物中的低分子有机酸、醇、酚和脂,分析确定了氧气的最佳注入量,研究结果表明,在中一区Ng_3区块油藏条件下空气辅助微生物驱最佳配气量为气液比20:1(常压),该结论为空气辅助微生物驱现场试验提供了理论依据.     

本源微生物驱油技术

1．筛选油藏条件及实施过程本源微生物驱油机理是激活并使细菌快速生长和繁殖,一般需要注入磷源、氮源矿物质和氧气。增油机理分两个阶段:第一阶段近井带好氧区,存在好氧菌和兼性菌。第二阶段油层深部厌氧区,存在厌氧菌。经研究及现场应用,总结出符合以下条件的油藏开展本源微生物驱油试验(见表1)。     

孤岛油田中一区馆3 区块聚合物驱后微生物驱油先导试验

为了探索微生物驱油技术在聚合物驱后油藏的适应性和驱油效果,在孤岛油田中一区馆3区块开展了先导试验。在室内筛选了激活剂配方,有效激活了试验区块的内源微生物群落;同时筛选了4株在油藏环境下能大量生长繁殖的外源高效驱油菌种,对试验区原油具有良好的乳化作用。室内物理模拟驱油实验结果表明,聚合物驱后微生物驱可提高驱油效率7.8%～8.3%。在室内实验基础上开展了现场试验,油井产出液跟踪检测结果表明,油藏微生物得到了有效激活,且具有良好的代谢活性,代谢产物乙酸根质量浓度最高可达105 mg/L;生产动态分析表明,试验后油藏的生产动态得到了显著改善,提高采收率为1.27%,试验期间试验区采出程度提高了4.7%,达57.8%。     

罗801区块油藏环境厌氧微生物链的形成及其对微生物驱采收率的影响

概述了油藏厌氧生境中的厌氧微生物链并给出图解式。根据胜利罗家油田罗 80 1区块微生物驱油试验中的监测数据 ,注入驱油菌BS、FM及营养物质后 ,试验区产出水中水解菌、产氢产乙酸菌、反硝化菌、产甲烷菌、同型产甲烷菌的总菌数由 10 0 ～ 10 7个 /mL增加到 10 3 ～ 10 4个 /mL ,乙酸根浓度由 2 1.8mg/L增加到 4 0 0mg/L以上。由此推断 ,注入的水解类菌BS和FM及营养物质激发了油藏中各类厌氧菌的活性 ,通过各类菌群的繁殖代谢 ,形成了新的厌氧微生物链。该微生物链的首端为注入油藏的和油藏中原有的水解菌 ,以产氢产乙酸菌、反硝化菌、同型产乙酸菌为中间阶段 ,末端为产甲烷菌 ,给出了该厌氧微生物链的图解式 ,讨论了链中一些微生物的生长代谢、相互作用及驱油作用。介绍了罗 80 1区块微生物驱油试验的结果 :产油量递减率控制在 5 %以内 ,年产油量稳定在4 .4× 10 4t以上 ,平均年增产油量 1.2 7× 10 4t ,采收率已提高 2 .11% ,预计最终可提高采收率 5 .6 6 %。图 7表 1参5。     

微生物与空气协同驱油的耗氧规律

微生物与空气协同驱油是一种新的驱油方法,其主要机理为利用空气中的氧气提高微生物生长代谢速率,同时微生物耗氧使空气驱变得更为安全。通过实验研究不同初始溶氧浓度下实验菌种的生长规律和耗氧规律,及溶氧浓度对微生物脱油效率的影响。结果表明:在增氧与未增氧的条件下,实验菌种生长均存在停滞期、对数生长期、稳定期和衰退期,初始溶氧浓度为4.5和5.5 mg/L时,微生物生长的最大浓度是未增氧时的3倍以上;对数生长期溶氧浓度呈对数降低趋势,稳定期和衰退期溶氧浓度呈线性降低趋势,油藏内耗氧主要为补偿微生物衰退时数量减少的生长耗氧;微生物脱油效率随初始溶氧浓度的增大而增大。在微生物耗氧规律和油藏渗流规律的基础上,建立了仅考虑微生物耗氧时油藏内氧浓度计算数学模型,计算了不同注入参数下氧浓度分布。结果显示,耗氧后,油藏内氧浓度随油藏半径的增加指数下降,油藏内有足够的氧供微生物生长;微生物耗氧可将空气中的氧浓度降到安全浓度,微生物耗氧到氧安全浓度的最小油藏半径约为145 m。     

以烃类为碳源的微生物驱油探索研究

针对大庆油田油层的物化环境,从数百个含油污水中分离、筛选了8株以烃类为碳源的兼性厌氧菌,并进行了系统的性能评价和长管填充油砂模型物理模拟实验驱油效果评价,实验结果表明,所筛选的8株菌种,在厌氧条件下,能以原油为唯一碳源生长、繁殖,并具有降解原油,降低原油粘度,产生活性物质,降低界面张力的作用,岩心驱替实验表明,微生物驱比水驱提高采收率10%左右。     

S12区块内源微生物驱油技术现场试验

为了利用微生物技术进一步提高原油采收率,针对S12区块开发现状和地质条件,通过对油藏内部的微生物群落结构组成、地层流体的性质进行分析,确定了实施内源微生物驱油技术的可行性。通过大量室内试验筛选了可以激活油藏中利于采油细菌的营养配方,并通过物理模拟试验确定了激活剂的注入浓度,物理模拟试验结果表明,在进行水驱之后,实施内源微生物驱油技术可提高采收率9个百分点以上,在室内试验的基础上进行了现场注入试验。现场跟踪测试结果表明,注入筛选的营养剂配方以后,油藏中的细菌被激活,并代谢产生了有利于提高原油采收率的物质,起到了一定的增油效果。     

微生物驱油技术在文明寨油田的应用

为了进一步提高油藏采收率,针对文明寨复杂小断块油田的开发现状和地质条件,选卫7块明159井组对微生物驱油的可行性进行了研究。用中原油田高温高盐油藏筛选出的耐温耐盐菌种,开展了注入水和地层水的微生物学特征分析、试验菌液的微生物适应性评价和微生物驱物理模拟试验研究,确定了微生物菌液的注入量及浓度,制定了施工方案。微生物驱现场试验已增产原油1695t。表明微生物驱油能够起到强化采油、提高原油采收率的效果。     

施工因素对微生物驱油效果影响的物理模拟研究

为了提高微生物驱油效果,开展了施工因素对微生物强化采油效果影响的物理模拟试验。利用"四因素三水平"正交试验设计方法,将注入方式、注入量、关井时间及重新开井时的微生物驱替速度分3个水平进行微生物驱替试验。驱替试验按在水驱之后注入微生物关井一段时间、再利用微生物发酵液驱替的顺序进行。评价各因素在不同水平组合下的采收率,从而优选出各因素最佳水平。利用正交试验设计方法设计的驱替试验结果优化,采用无机培养基和接种活化的菌液按照1:1的段塞注入方式,注入量为0.6倍孔隙体积,关井2 d,重新开井时的驱替速度为3倍孔隙体积/h时微生物强化采油效果最佳,这一最优组合方式在水驱产水率达到95%的基础上,采收率可以进一步提高近32百分点。这表明微生物注入方式等施工参数对微生物强化采油效果有较大影响,在实际施工中应先进行参数优化,以取得最佳强化采油效果。      

An Evaluation for Two Bacillus Strains in Improving Oil Recovery in Carbonate Reservoirs

Many successful field cases of microbial enhanced oil recovery (MEOR) method have been reported for sandstone reservoirs. The objective of this study is to investigate the potential of MEOR method in UAE carbonate reservoirs. Two Bacillus strains were incubated at temperatures from 35 to 55°C, and their effects on crude oil properties and recovery were examined. It was discovered the strain could effectively reduce interfacial tension. Bacteria solutions were subsequently injected into a glass Hele-Shaw model to simulate microbial flooding in a fracture. It was observed that both strains grown under 45°C achieved maximum enhanced recovery of over 13%. Core flooding tests were conducted at elevated temperature of 70°C with limestone core. The two strains achieved enhanced oil recovery of more than 4.5%. The observation on core flooding test indicated selective plugging as the dominant recovery mechanism.     

The Application of Microbial Enhanced Oil Recovery Technology in Shengli Oilfield

For the last 20 years Shengli oilfield has done research into the application of microbial enhanced oil recovery (MEOR). The authors summarize and analyze MEOR progress in mechanism research and field application in Shengli oilfield. The results indicate MEOR could improve oil recovery after water flooding and polymer flooding with multiple mechanisms. Cumulative oil increment of MEOR application on seven blocks was 212,366 t. The research and application of MEOR should concentrate on air assisted microbial flooding and indigenous microbial flooding in the future.     

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.     

空气辅助微生物改变地层岩石与流体性质的能力研究

为了提高微生物采油的应用效果,研究了空气辅助对微生物改变地层岩石与流体性质作用机理。通过实验研究空气辅助微生物改变岩石表面润湿性、油水界面张力及微生物降解原油机理,以岩石润湿性和油水界面张力改变为基础,探讨了空气中氧对微生物改变岩石表面和黏附功的影响。实验结果表明,空气中氧可提高微生物菌液改变石英表面润湿角速度,溶氧4.5～5.5mg/L菌液中润湿角降低50.14%～56.94%。4.5 mg/L溶氧条件下,菌液作用后原油界面张力下降80%。与含溶氧5.5mg/L培养的微生物作用后,油质组分增加8.414%,蜡质组分降低7.728%,胶质组分降低5.538%。实验表明,空气辅助可增强微生物改变地层岩石与流体性质的能力,进一步提高原油采收率。     

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.     

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...     

新疆油田稠油微生物开采矿场试验研究

为了提高稠油油藏开发效益,与新疆油田合作,优选了混源采油菌组合,采用单井吞吐的生产方式,分2批对21口稠油开发井进行了微生物开采矿场试验。结果表明,所选用的采油菌组合对胶质、沥青质含量高的稠油作用效果显著,经采油菌作用,作业区的稠油粘度大幅度降低,在停止注蒸汽的情况下,大多数试验井都能达到经济产能,试验得到了较高的投资回报率。认为稠油微生物开采技术值得在新疆油田的稠油开发中加以推广。