微生物驱油技术的研究进展与应用前景

微生物驱采油技术主要分为两种类型——第一类是把细菌代谢物（又称外源微生物）作为驱油剂注入地层;第二类是直接在地层中有目的地培养和发展微生物（又称内源微生物）,形成具有驱油特性的细菌代谢物。叙述了两种技术类型的下艺特点及微生物驱适用的油藏地质条件．同时介绍了国内外微生物驱油技术的研究与应用现状。国内各油田已开展微生物采油先导性试验约2000井次,有些地区已进入推广应用阶段,微生物采油技术成本低、采收率增值高,同时由于其本身所具有的绿色环保优势．必将成为老油田提高采收率的新途径。     

朝阳沟油田微生物驱油实践与认识

朝阳沟油田在2002～2006年开展了微生物驱油试验研究,取得了较好的增油效果。通过对微生物驱油试验研究结果的分析,指出微生物注入与发生作用的区域以中高含水区域为主;微生物在油层中大量繁殖是实现增油的根本保障;微生物可改善原油物性,使原油在地层中的流动性变好。微生物驱油取得较好效果与微生物在油层中的停留时间及反应时间、油层内部原油的转化程度、微生物的营养物供应等条件有关。     

中原油田提高采收率优化技术

中原油田相继开展了CO2吞吐、N2驱、空气驱、合成聚合物驱、交联聚合物驱、微生物采油等项现场试验。鉴于中原油田地层温度高、地层水矿化度高,常规三次采油技术难以适应。对中原油田提高采收率的技术进行优化分析,对油田地质特点、开采特点和不同类型油藏采收率现状进行归纳,并对各技术潜力进行分析,得出结论:从储层条件和原油性质来看,适用中原油田的三次采油方法是CO2混相驱、天然气非混相驱,其次是化学驱。研究预测显示,通过水驱综合调整和气驱,可提高采收率11.1个百分点,达到40.5%,其中水驱综合调整增加可采储量3841×104t,提高采收率7.4个百分点,三次采油提高采收率3.7个百分点。总结出中原油田提高采收率的方向和思路:水驱提高采收率仍是油田当前开发的重点,重组开发层系、强化差层开采、提高油藏水驱采收率,大力发展堵水调剖等配套工艺技术、提高水驱控制程度,气驱仍是今后的主要发展方向。     

Efficacy of Bacillus subtilis for the biodegradation and viscosity reduction of waxy crude oil for enhanced oil recovery from mature reservoirs

Increasing maturity of the crude oil reservoirs across the world have led to the production of waxy crude oil which need economical and efficient methods for enhanced oil recovery (EOR). The studies on the performance of bacteria in the presence of waxy crude oil is rare. In this study, experiments were performed to understand the efficacy of thermophillic microorganism Bacillus subtilis on the biodegradation of waxy crude oil for EOR applications. Bacterial growth, changes in crude oil composition, viscosity reduction, and surface and emulsification activity have been monitored to evaluate the oil degradation capabilities of the bacteria. This study also presents the effect of temperature, salinity, pH, and pressure on the stability of the produced biosurfactant for EOR applications. The biosurfactant produced by bacteria in the presence of crude oil was found to be stable up to 120°C, 10 MPa, 15% salinity, and wide range of pH, and thus favorable for reservoir environment. The crude oil composition before and after degradation at 75°C was determined using gas chromatography-mass spectroscopy and observed to be 60% in one day, while the maximum viscosity reduction was found to be 60% from initial values. Experimental results showed that the bacteria used in this work are capable of surviving at reservoir conditions, and are easy to grow on the waxy crude oil for enhanced oil recovery operations.     

川中油区侏罗系特低渗油藏中后期采油工艺技术对策

川中油区侏罗系油藏属于非均质特低孔渗、低丰度、低采收率非常规油藏。在历年开采中,先后采用了抽汲、柱塞采油、超声波解堵、低频脉冲解堵、微生物采油、振荡洗井、挤轻质油、热油洗井、机抽、螺杆泵等采油工艺技术,部分工艺取得较好效果。目前,大部分油田进入开采中后期,呈现出油藏压力低、单井产量低、井筒液面低、结蜡较为严重等特点。对川中油藏的开发现状进行梳理分析,对历年采油工艺应用进行总结,归纳了当前采油工艺存在的三个技术难点,并结合目前采油工艺技术发展水平．着重从间歇井提高单井产量、清防蜡采油配套工艺研究和水平井采油工艺及配套技术研究等方面,提出适合于侏罗系特低渗油藏现状的采油工艺技术思路：重视井筒和近井地带的处理技术;继续研究并发展小泵深抽技术,特别是研究如何提高泵效和机抽井系统效率问题;开展采油工艺技术试验,特别是螺杆泵采油和柱塞采油工艺试验：同时,针对清蜡频繁且存在蜡堵、影响生产的井,优选电磁防蜡工艺等。     

提高采收率技术矿场应用进展与发展方向

通过对不同国家提高采收率技术(EOR)应用情况进行分析、统计,了解提高采收率技术的应用状况和发展趋势。2014年,世界EOR产量约为46.1×104m3/d,约占世界产油量的3.3%。稠油热采、气驱和化学驱技术是世界工业化应用的三大提高采收率技术。其中,稠油热采技术相对成熟,应用规模最大,其产量接近世界EOR产量的一半;气驱和化学驱技术发展较快,应用规模不断扩大,其产量约占世界EOR产量的四分之一。在高油价下,提高采收率技术得到更为广泛的关注,多个国家都重视新技术、新方法的研究与试验。美国、中国、加拿大、委内瑞拉和俄罗斯是提高采收率技术应用规模较大的5个国家,中国的化学驱和稠油热采技术及应用规模居世界前列,已成为提高采收率技术应用大国。适应苛刻油藏条件的驱油剂、驱油体系和流度控制技术,是制约提高采收率技术工业化应用的瓶颈;不同成熟技术的组合应用将是提高采收率技术的发展方向。     

Sensitivity analysis and optimization on effective parameters during chemical enhanced oil recovery (CEOR) using experimental design and numerical simulation

Several factors effect on choosing the best enhanced oil recovery process in a hydrocarbon reservoir. In the present study, effective factors on chemical enhanced oil recovery involved in polymer flooding, surfactant flooding, surfactant–polymer flooding, and alkaline–surfactant–polymer flooding are discussed in numerical simulation. The numbers of the simulation runs are estimated based on the number of factors and their maximum and minimum values using experimental design software. Oil recovery factor from reservoir simulation is considered as comparison factor in all of the run cases. The results from one parameter and two interaction factors during each flooding case were analyzed by Tornado and Parto plot. The oil recovery factor also was estimated using statistical analysis using Minitab. The results show that there is a strong correlation between simulation and statistical analysis. Furthermore, the results show that each selected factor has a different effect on oil recovery in each case of chemical flooding. The case study results on two Iranian oil fields at the end of the present study clarified that results of this study can be useful for selecting the best chemical process for oil reservoir based on reservoir properties.     

微生物提高采收率技术的回顾与展望

调研了国内外有关微生物提高采收率的文献，对其理论研究及技术应用、进展作了综述，并对其发展前景进行展望。     

中深层稠油蒸汽驱注采剖面调整工艺技术研究

从1997年开始,辽河油田进行了中深层稠油蒸汽驱先导试验,目前已进入蒸汽驱先导试验的后期调整阶段,先导试验区的稠油采出程度由试验前的24%提高到57%,基本达到方案设计指标,先导试验获得成功。然而,在蒸汽驱先导试验及随后的扩大试验中,存在着纵向动用程度不均、平面动用程度差等问题,影响蒸汽驱先导试验效果。为此,从2004年开始,辽河油田钻采工艺研究院开展了中深层稠油蒸汽驱注采剖面调整工艺技术研究工作,形成了中深层稠油蒸汽驱注采剖面调整系列技术,主要包括耐高温化学调堵技术与机械封堵技术,并应用于现场,有效解决了蒸汽驱层间、层内动用不均的问题,提高了中深层稠油的采收率。下一步仍需加大高温调剖剂的深入研究,研制高效、经济的高温调剖剂;对生产井机械封堵工艺技术的研究重点,是加快对耐高温胶筒的选优,满足现场生产需求。     

Effects of pretreatment method of natural bacteria source on microbial community and bio-hydrogen production by dark fermentation

The effects of pretreatment method of cow dung compost, which was employed as natural hydrogen bacteria source, on the microbial community, population distribution of microbes and hydrogen production potential were investigated in the batch tests. The maximum hydrogen yield of 290.8 mL/L-culture appeared in the pretreated method A (infrared drying) by dark fermentation. The pretreated method of compost significantly affected microbial succession, population distribution of microbes. Both Clostridium sp. and Enterobacter sp. were found to be two species of preponderant hydrogen-producing bacteria, the next best was Bacteroides sp. and Veillonella sp., the last was Lactobacillus sp. and Streptococcus sp., which were also essential. The results showed that the mutualism and symbiosis relations of the mixed bacteria played a critical role in hydrogen fermentation process.     

Stimulated-based characterization recovery enhancement feedback of oil-rim reservoirs

Oil-rim reservoirs are a kind of such unconventional reservoirs which the oil layer was occupied by the gas cap and aquifer layer. Regarding the economic prosperity of drilling this reservoir types, petroleum engineers would always try to find novelistic enhanced oil recovery techniques to produce more oil volume which economically profitable owing to the vast experiences of drilling and production operations are. However, oil-rim reservoirs production would be a particular challenge due to its unique characterization for several decades, in this comprehensive study, we try to simulate six different scenarios with drilling new wells horizontally or vertically on the oil recovery enhancement and choose the optimum technique which has more compatibility with the reservoir characteristics. Moreover, another objective of this study is to investigate the dominant influence of simulation procedures in each scenario on the critical parameters of gas oil ratio, water cut and, pressure drop. Consequently, scenario six regarding the drilling of a horizontal well and its potential contact with the reservoir has been the best scenario among other scenarios and scenario four and five due to the drilling new vertical wells have witnessed an excellent economical choice for commencing the production operation.     

固定化微生物技术降解石油废水研究进展

介绍了固定化微生物的起源、发展过程、制备材料、制备方法以及特点和优点。重点介绍了固定化微生物技术处理油田采油废水、石油加工废水和含石油成分废水的应用研究。对固定化微生物技术的优缺点进行了总结,其优点是可大幅提高微生物浓度、减少反应器体积、提高代谢活性和抗毒性、抗负荷冲击能力强、反应启动快、处理效率高、运行稳定、产污泥量少等;不足之处是可供固定的微生物种类较少,载体的费用较高。高效降解有机物的机理是载体有空穴结构,利于微生物的固定化,为微生物的生长和繁殖提供了良好的环境;载体可减轻水力负荷的冲击,受氧扩散的限制,载体内部产生缺氧区域,为厌氧、兼性和好氧处理的同步进行创造了条件;厌氧和好氧混合菌可加速生物转化,载体能在单位容积内提供巨大比表面积利于生物膜的生长。分析认为固定化微生物是极具发展前景的生物处理技术,提出了未来重要研究方向应为固定化材料的优化与组合、优势菌种的筛选和驯化、与其他处理技术联用等。     

胜利油区河50丛式井组调整井钻井技术

河50断块丛式井组为全国最大的陆基平台井组,1989年投入开发,共有油水井45口,其中斜井43口,最大井斜角在19°～63°之间,现已进入高含水期,产能建设亟需进行调整开发。该断块探明含油面积2.6km2,地质储量1052×104t,可采储量242×104t,呈扇状分布,属稀油低渗、低饱和高压岩性构造油藏,具有天然能量充足、产量递减快的特点。由于老区采油地层压力亏空,调整井钻井过程中易出现井漏、井涌、坍塌等复杂情况,加之老区井网密集、斜井众多,井身轨迹控制困难,防碰难度大,对钻井技术、油气层保护和固井质量提出了更高的要求。对此,制定了井身轨迹控制与防碰技术措施;优选了适宜不同地层的钻井液体系;形成了井壁稳定与承压堵漏技术、固井技术和油气层保护技术。实钻效果表明:河50丛式井组调整井钻井技术有效解决了该区块井漏、井塌、缩径及固井时水泥浆漏失等井下复杂情况,井身质量和固井质量合格率均为100%。     

Numerical experiments in the simulation of enhanced oil recovery from a porous formation

A numerical reservoir simulation model for the study of enhanced oil recovery (EOR) from a porous formation has been presented. The resistance to oil movement arises from viscous forces in the fluid phase as well as surface tension. Viscous forces can be lowered by hot water injection into the formation or by raising the formation temperature. These methods have been numerically analyzed in the present study. The role of the operating parameters such as the injection pressure and temperature on oil recovery has been reported. Displacement of oil by water is clearly brought out by the saturation and the temperature profiles.The numerical solution of the EOR problem experiences growth of errors during long time integration, particularly on large regions. Possible reasons are scatter in the constitutive relationship data, inexact outflow boundary condition and round-off errors in the calculation of the matrix inverse. The nature of these errors has been addressed in the present work. To solve the computationally intensive field-scale problems, two domain decomposition algorithms namely, Schwarz's and Uzawa's algorithms have been evaluated.Results show that oil recovery can be improved when the formation temperature is higher, or the injection temperature and pressure are raised. Adverse results can however be obtained when the injection temperature exceeds a critical value. Optimum conditions prevail when the speed of the oil–water interface is matched with that of the thermal front. As a computational tool, the domain decomposition algorithms are conditionally seen to improve the numerical performance of the oil recovery codes.     

周43断块底水油藏高含水期提高采收率技术研究

宋家垛油田周43断块K2t1为一天然能量充足的疏松砂岩底水油藏,因底水锥进和储层出砂双重影响,高含水开发期剩余油分布相对复杂。该断块自1996年投入开发以来,经历过2次加密调整,但由于储层出砂、底水锥进等因素影响,油井无水采油期短、见水后含水上升快。截至2010年4月,区块采油速度下降到0．58％,含水上升到90．9％,阶段采出程度仅为13．49％。针对周43断块高含水期采油速度低、出砂严重、含水上升率快等问题,通过剩余油定量化描述研究．应用短水平段水平井整体开发调整、化学堵水,以及优化避水厚度和临界产量参数等防砂控水技术,采取防治结合的思路,日产油水平从调整前的40．7t／d最高上升到132t／d,综合含水由90．7％下降到80．3％,目前日产油水平为117t／d,综合含水为83.8％,采收率从调整前的24％提高到29．7％,采收率提高5．7％。     

应用水平井挖掘杜84块兴Ⅱ组单砂体稠油油藏潜力

辽河油田杜84块兴隆台油藏纵向划分为兴Ⅵ组、兴Ⅲ组、兴Ⅱ组、兴Ⅰ组四套油层组。其中,兴Ⅵ组采用直平组合SAGD(蒸汽辅助重力泄油技术),兴Ⅰ组采用双水平井SAGD,兴Ⅱ、Ⅲ组互层状油藏水平井吞吐挖潜,实现杜84块多元化立体高效开发。通过开发方式转换,杜84块实现了油田纵向储量的均匀动用,很多区域达到或超过油田标定采收率(29.2%)。通过深化地质研究,发现兴Ⅱ组还存在未得到有效动用的单砂体油藏。结合部署界限和油藏发育情况,在兴Ⅱ组隔夹层发育稳定区域部署规划两口水平井杜84兴H2111井、杜84兴H2112井,控制地质储量11.5×104t,部署区域基本未动用。两口水平井目的层厚度在7m左右,水平段长度为240m以上,单井储量在5×104t左右。应用近钻头地质导向、随钻地质跟踪以及水平井同注同采技术,挖潜单砂体油藏潜力。     

Energy balance and greenhouse gas emissions of biodiesel production from oil derived from wastewater and wastewater sludge

It has been recognized that oils derived from microorganism and wastewater sludge are comparable replacements of traditional biodiesel production feedstock, which is energy intensive and costly. Energy balance and greenhouse gas (GHG) emissions are essential factors to assess the feasibility of the production. This study evaluated the energy balance and GHG emissions of biodiesel production from microbial and wastewater sludge oil. The results show that energy balance and GHG emissions of biodiesel produced from microbial oil are significantly impacted by the cultivation methods and carbon source. For phototrophic microorganism (microalgae), open pond system gives 3.6 GJ higher energy gain than photo bioreactor system in per tonne biodiesel produced. For heterotrophic microorganisms, the energy balance depends on the type of carbon source. Three carbon sources including starch, cellulose, and starch industry wastewater (SIW) used in this study showed that utilization of SIW as carbon source provided the most favorable energy balance. When oil extracted from municipal sludge is used for biodiesel production, the energy gain is up to 29.7 GJ per tonne biodiesel produced, which is higher than the energy gain per tonne of biodiesel produced from SIW cultivated microbes. GHG emissions study shows that biodiesel production from microbes or sludge oil is a net carbon dioxide capture process except when starch is used as raw material for microbial oil production, and the highest capture is around 40 tonnes carbon dioxide per tonne of biodiesel produced.     

超稠油蒸汽驱先导试验效果分析

杜229块兴隆台油藏为中厚互层状超稠油油藏,单层厚度薄、储层物性好、原油黏度高,已进入蒸汽吞吐末期,综合含水率快速上升,产量递减严重,亟需实施开发方式转换。针对该区块蒸汽吞吐后期的特点,运用开发机理研究、数值模拟研究等方法,论证了超稠油蒸汽驱的可行性,并于2007年规划了7个70m井距"反九点"井组,开展蒸汽驱先导试验。经过8年的探索与实践,先导试验取得成功,井组年产油由转驱前的4.1×104t上升至5×104t左右,油汽比为0.17,采注比为1.09,采出程度达到53.8%,各项指标达到国际先进水平。通过对历史生产资料及监测资料分析研究,初步形成了超稠油蒸汽驱"先连通、再驱替"的驱油机理,掌握了影响生产效果的各项主要因素,总结了汽驱阶段的动态调控理念及方法。该试验的成功实施,突破了超稠油不能实施蒸汽驱的认识禁区。     

草舍油田CO2驱采油井注缓蚀剂高效防腐技术

草舍油田泰州组油藏于1981年发现并投入开发,石油地质储量为142×104t,1990年8月转入注水开发阶段,水驱采收率24%,可采储量34.1×104t。该油藏于2005年7月开始气水交替注CO2驱油试验,至2011年12月,采油井日产CO2气量为12000m3,综合含水率为51%,CO2对井下套管、生产管柱及井下工具的腐蚀十分剧烈,必须加以解决。根据该油藏采油井高含CO2气体防腐的要求,复配出4种HS系列高效CO2缓蚀剂,通过室内实验,评价出HS-20型CO2高效缓蚀剂,并在现场CO2驱试验区采油井中添加,其浓度为50～200μL/L。采用油管内、外监测挂环监测油管腐蚀速率,结果表明,井下油管腐蚀速率仅为0.01～0.001mm/a,具有良好的防腐效果,满足CO2驱采油井的防腐要求,保证了采油井的正常生产。相比于其他防CO2腐蚀措施,本方法简便有效,可供国内其他油田CO2驱油时借鉴。