The Description of Oil Displacement Mechanism in Steam Injection of Multi-Field Synergy with Exergy Transfer

Steam injection is a most effective way for improving heavy oil recovery efficiency, and it has academic and practical significance for the mechanism of multi-field synergy oil displacement. Mechanism of “diversified” oil displacement which is obtained by traditional study methods in the exploitation territory of oil and gas fields has both respective roles and mutual cross shortages. To describe and analyze the displacement process of multi-field coupling with exergy transfer can simplify this kind of problem by introducing a unified goal-driving exergy. It needs to use the method of theoretical modeling, numerical simulation and experimental validation to study the basic law of exergy transfer in the oil displacement process of multi-field synergy, make a thorough research for the flooding process of steam injection with exergy transfer theory and reveal the oil displacement mechanism in steam injection of multi-field synergy. Thus the theory instruction and technical support can be provided to improve reservoirs producing degree and extraction ratio.

Analysis and Calculation of the Flow Pressure in the Multipoint Steam Injection String of a Horizontal Well

The multipoint steam injection string of the horizontal well is a commonly used downhole component for high efficiency steam injection of the thermal recovery horizontal well. A reasonable layout of the valves to ensure an even steam output of each point is still not well designed. At present, a general design method which is urgently necessary isn＇ t applied by each factory. According to the balance relationship of the momentum, the energy and the mass of the fluid flowing in the string, the pressure distribution equation of the fluid flowing in the multipoint steam injection string is built. On the basis of this equation, the design calculation method of the multipoint steam injection string is come up with. A specific example is given in the paper. Study shows that, with the equation built in this paper, the string can be designed with each axial valve having the same output, so that the technical demand of an even steam injection of the horizontal well section can be met.

Experimental study on absorption of blade vibration of honeycomb seal and shunt injection

Honeycomb seals and shunt injection have been proposed to weaken the blade vibration.Honeycombseals,as well as,smooth seals were tested with different seals' clearances and shrouded blades.Theshunt injection was sprayed to the blade tip clearance in the reverse direction of the main flow.Experi-mental results showed that both honeycomb seals and shunt injection had the damping effect for blade vi-bration,and the blade vibration magnitude could be reduced by more than 25 % and 17 %,respectively.When the two methods were adopted synchronously,more than 1/3 of the blade vibration could be re-duced.Consequently,adopting honeycomb seal and superinducing proper shunt injection are two usefulways to minimize vibration of the blade from the viewpoints of avoiding blade rupture and improving therotor stability.

Injection-production parameters optimization research SAGD production stage

Steam assisted gravity drainage （SAGD） technology has been industrialized popularization and application in our country, according to the characteristics of Xing group I SAGD experimental zone in liaohe oilfield, SAGD production stage injection-production parameters such as the operating pressure, Sub - Cool control, steam injection rate, steam dryness, production factor are studied and selected.

Effect of water injection on hydrogen generation during severe accident in PWR

Effect of water injection on hydrogen generation during severe accident in a 1000 MWe pressurized water reactor was studied. The analyses were carried out with different water injection rates at different core damage stages. The core can be quenched and accident progression can be terminated by water injection at the time before cohesive core debris is formed at lower core region. Hydrogen generation rate decreases with water injection into the core at the peak core temperature of 1700 K, because the core is quenched and reflooded quickly. The water injection at the peak core temperature of 1900 K, the hydrogen generation rate increases at low injection rates of the water, as the core is quenched slowly and the core remains in uncovered condition at high temperatures for a longer time than the situation of high injection rate. At peak core temperature of 2100–2300 K, the Hydrogen generation rate increases by water injection because of the steam serving to the high temperature steam-starved core. Hydrogen generation rate increases significantly after water injection into the core at peak core temperature of 2500 K because of the steam serving to the relocating Zr-U-O mixture. Almost no hydrogen generation can be seen in base case after formation of the molten pool at the lower core region. However, hydrogen is generated if water is injected into the molten pool, because steam serves to the crust supporting the molten pool. Reactor coolant system (RCS) depressurization by opening power operated relief valves has important effect on hydrogen generation. Special attention should be paid to hydrogen generation enhancement caused by RCS depressurization.

页岩油藏提高采收率技术现状、瓶颈及对策

介绍了页岩油的储量分布、成因及赋存机理,详细概述了页岩油早期勘探、储层改造及后期提采等不同阶段的开发现状。在此基础上,着重综述了当前国内外页岩油藏提高采收率主体技术的应用现状及进展,深入分析了不同页岩油提采技术的优势与不足,同时给出了针对理论认识、技术及经济壁垒的相应策略,最后从不同角度入手,展望了今后页岩EOR的发展前景。

高机动车载注汽锅炉集成化设计及其相关技术

油田热采注汽锅炉作为稠油开采的专用注汽设备,在稠油热采生产中得到了广泛的应用。传统注汽锅炉结构型式和运输车辆相对落后的设计理念,限制了较大蒸发量注汽锅炉的应用,已经很难适应油田稠油开采的需要。开发具有能够实现快速移动和较大蒸发量的注汽锅炉,将会成为注汽锅炉机组的研究与创新方向之一。以燃油燃气车载注汽锅炉为研究对象,回顾国内油田注汽锅炉的应用现状和存在的问题,从注汽锅炉本体结构型式、运载车辆优化设计、车载化集成技术及大型运输车辆的安全性等方面出发,探讨高机动集成化车载注汽锅炉的相关技术问题。根据实例分析注汽锅炉的结构型式及其集成设计是实现车载化的基础,运输车辆与锅炉辅助系统的融合与优化是实现集成化的关键,运输车辆悬挂机构与隔振机构的稳定性是实现高机动集成化的基本保证,以上结果对车载注汽锅炉研制具有一定的指导意义。

稠油开采注汽锅炉在线综合预警关键技术

为了对工作在高温高压下注汽锅炉的各项运行参数进行在线准确监测和异常预警,本文在对稠油开采注汽锅炉工况参数进行采集、处理、分析的基础上,提出对注汽锅炉显性故障和隐性故障进行检测的方案。采用长期短期记忆神经网络,利用锅炉的时序数据对系统进行分析和建模,完成锅炉显性故障检测和预警,并通过预测数据的方式缓解锅炉大时滞的特性;利用深度异常检测技术,将无故障判别标准的数据进行隐性故障分析和预警。本文提出的综合预警方案对克拉玛依油田注汽锅炉进行了实验验证,预测误差仅有0.08%,同时异常检测范围也在设定值范围内。

油田注汽锅炉产汽单耗的计算方法与影响因素分析

为有效降低油田注汽锅炉产汽单耗,通过系统分析油田注汽锅炉生产工艺、生产设备、能耗水平及产汽单耗的计算方法,确定影响产汽单耗水平的关键因素包括温度、压力、干度、过热度、运行管理水平、锅炉热效率等,对各项因素的影响效果进行了分析验证。采用实际测试结果与理论计算数据对比的方法,得出了常见工况下油田注汽锅炉产汽单耗的变化规律,在此基础上明确了注汽锅炉节能提效的重点方向和技术措施,分析各项措施提效降耗的基本效果,对油田注汽锅炉的节能提效、降低产汽单耗和企业生产成本提供了良好借鉴。

海上特超稠油油藏小井距蒸汽吞吐汽窜堵调工艺

渤海某大规模热采开发的特超稠油油藏在一轮次注热期间井间汽窜率超70%,严重影响油田产能。针对该情况,基于探井、测井认识,先后开展药剂性能评价、单/双管驱替实验及现场堵调应用,对高含水层物性得到了进一步认识,随后开展泡沫调剖、井组同注数值模拟及现场试验,井间汽窜得到有效控制。研究结果表明,局部高含水低渗储层经蒸汽冲刷后平均渗透率或高于探井阶段测量值,对于已汽窜井开展井组同注措施,对于未汽窜井及井组边部井采用强化泡沫调剖,该措施不仅可以有效控制和预防汽窜,同时可均匀动用储层,优势层段吸汽剖面级差降低46.8%。泡沫调剖辅助井组同注的工艺策略实施后单井产能提高12%~33%,对海上特超稠油高效开发具有指导意义。

水/蒸汽喷射时刻对汽油机燃烧和排放影响研究

通过由试验验证的型号为LJ465Q汽油发动机热力学模型,研究了缸内水和蒸汽喷射时刻对发动机性能和排放的影响规律。结果表明,在发动机2000r/min及全负荷下,喷射质量为9mg,喷射压力为10bar,喷射时刻为(-110~-60)°CA时,水喷射工况输出功率随着喷射时刻滞后逐渐减小,功率最大可提高0.71%,燃油消耗率可降低0.74%,喷水后减少了局部高温和局部过浓区域,有助于明显降低NOx排放,其最大降低了66.3%,HC排放有所增加;过热蒸汽喷射工况输出功率随着喷射时刻滞后逐渐增大,功率最大可提高1.7%,燃油消耗率可降低1.8%,NOx排放量随喷射时刻增大而减少,最大降低了55.2%,HC排放降低了15.4%。综上,缸内蒸汽喷射相比于水对发动机性能和排放的影响效果具有一定优势。

海上稠油热采井临界配注工具研究及应用

随着海上稠油热采规模化推进,长水平段热采井普遍存在储层吸汽不均、动用程度差等问题。临界配注工具在一定适用条件下可实现蒸汽恒流配注,有效解决长水平段油藏动用不均问题。通过临界配注机理研究及模拟分析,揭示了临界流动的物性条件、流道几何尺寸要求;研制了采用系列化拉瓦尔喷嘴结构的临界配注工具,室内试验验证具有恒流注汽功能,整体耐温350℃、耐压21 MPa,恒流测试误差小于2%;现场试验表明临界配注工具在高温工况下结构可靠,水平段注汽剖面均匀,有效改善了注汽质量,适合在海上稠油热采井均衡注汽中推广使用。

Application of steam injection in iron ore sintering:fuel combustion efficiency and CO emissions

Improving the combustion efficiency of fuels is essential to reducing pollutant emissions in the iron ore sintering process.The sintering bed surface steam-injection technology has attracted significant research interest for its potential advantages in low-energy consumption and low emission.The effect of steam injection on fuel combustion efficiency and CO emission was studied by comparing the thermodynamic response from the sintering process before and after steam injection.The mechanism of improving combustion efficiency was also revealed.The results indicated that the sintering gas medium of H_(2)O-H_(2)-N_(2)-O_(2) with the blown steam improved the heat transfer conditions of fuel combustion and promoted the water gas reaction.The optimum state of steam injection was achieved at 15 min after ignition with 0.02 m^(3) min^(-1).The CO emission reduction is 10.91% compared with the base case.The combustion efficiency was 88.83%,6.15% higher than conventional sintering,and the solid fuel consumption was reduced by 1.15 kg t^(-1).It was indicated that steam injection would improve combustion efficiency and reduce solid fuel consumption.Meanwhile,the steam injection could improve the combustion kinetic conditions in the zone of unburned fuel and low oxygen partial pressure.It was conducive to the reaction of H_(2)O with C and CO to convert the CO of reducing atmosphere to CO_(2),which in turn realized the complete combustion of fuel and CO and improved the efficiency of fuel combustion.

In-situ synthesis of high thermal stability and salt resistance carbon dots for injection pressure reduction and enhanced oil recovery

Carbon dots(CDs)show great potential as a new type of oil-displacing agent for unconventional oil and gas development.However,the instability and easy aggregation epitomize the challenges that accompany the application of CDs in high temperature and high salinity(HT/HS)reservoirs.In this research,novel benzene sulfonate-modified carbon dots(BS-CDs)with remarkable thermal stability and salt resistance were fabricated through an in-situ electrochemical exfoliation method.Molecular simulation verifies that the introduction of benzene sulfonate groups substantially strengthens the electrostatic repulsion between BS-CDs,leading to outstanding dispersibility and stability even at a temperature of 100℃ and salinity of 14×10^(4) mg/L.Core flooding tests show that 0.05 wt.%BS-CDs nanofluid can significantly reduce the water injection pressure by 50.00%and enhanced oil recovery(EOR)to 68.39%under HT/HS conditions.According to the atomic force microscopy(AFM)scanning results,the adhesion force between the core(after BS-CDs treatment)and oil decreased by 11.94 times,indicating that the hydrophilicity of the core surface was increased.In addition,the distribution of the adhesion force curve is more concentrated,which means that the micro-scale wettability of the core changes from oil-wet to more homogeneous water-wet.This study provides a feasible way for the development and application of good thermal stability and salt resistance CDs in unconventional reservoir development.

油田注汽站运行中安全隐患分析及防范措施

燃气注汽站由于其特殊性,存在着各种安全隐患,如气体泄漏、火灾爆炸、设备故障等。这些隐患可能对人员安全和环境造成严重威胁,因此需要进行定期的安全检查和培训,加强监测和应急准备,以确保燃气注汽站的安全运行和环境保护。本文就油田燃气注汽站运行中存在的安全隐患进行了分析,并提出了相应的防范措施。通过加强注汽站的安全管理,定期检查和维护设备,加强员工培训,建立应急预案等措施,可以有效预防事故的发生,确保注汽站的安全运行。

注汽锅炉过热及提效改造技术的研究

随着油田开采深度的增加,被广泛使用的湿饱和蒸汽和高干度蒸汽注采方法将受到限制,由于管线和井筒输送损失,到达井底的干度较低,降低了加热效果,因此需提高锅炉出口蒸汽干度,以改善开发效果。辽河油田注汽锅炉平均热效率约89%,距离国家标准规范热效率(92%以上)有一定的差距,还有提效空间。目前热注站汽水分离器产生的25%高温分离水与给水换热后直接外排至联合站,不仅造成了约15%热量的浪费,而且还增加联合站的污水处理费用。为了解决上述问题,采用注汽锅炉过热及提效改造技术,主要包括新增过热段,改造对流段、过渡段保温改造、汽水流程调整以及自控系统升级,其节能降耗效果显著,具有一定的推广价值。

海上稠油热采插入密封工具研制与试验

为了解决海上稠油热采作业注汽不均匀、油藏局部吸热、开采效率低的问题,通过工艺分析,研制了海上稠油热采插入密封工具。该工具采用导热油吸热膨胀作为坐封动力源,可有效简化工具结构和作业流程。通过对比试验对热膨胀试验油进行了优选,采用专业软件对工具关键部件进行有限元分析,验证了工具结构及选材的合理性,并在室内对工具的性能进行验证。现场测试结果表明:该插入密封工具在经过3个轮次、350和50℃高低温密封测试后,仍可承受2.1×10^(7)Pa压差,在高低温条件下均保持较小的解封力,试验后高温密封组合未发生明显损坏。该工具结构简单,性能可靠,与常规的注汽阀配套使用,可满足海上油田稠油热采分段注汽的要求,具有良好的应用前景。研究成果可为海上油田高效开发提供良好的技术储备。

稠油注汽系统清洁替代储热系统设计

在大力推行新能源的背景下,太阳能光热是稠油注汽清洁替代的重要选择之一。针对油田稠油开采实现低碳转型的需求,分析稠油开采清洁替代的特点,以油田稠油注汽项目为例,简要分析包括熔融盐储罐、熔盐泵等在内的熔融盐储热系统的主要设备计算选型,测算熔融盐储热系统形成的蒸汽综合成本。研究表明,通过设计优化可以进一步控制系统投资。

基于水环泵与蒸汽喷射泵组合技术下的RH真空系统节能实践

针对某炼钢厂RH蒸汽喷射泵蒸汽耗量大、供汽不稳定的问题,提出一种改造方案,该方案应用水环泵与蒸汽喷射泵组合技术,以新设蒸汽专线优先供应RH精炼设备。改造后,RH精炼外部蒸汽用量降低约25%,在现有条件下可以满足RH正常生产需要,达到了节能降耗的目标。

烟道气回收CO_(2)与蒸汽伴注对井下工具腐蚀防护研究

注入烟道气回收CO_(2)可以有效提高采收率,并且有降低碳排放的环保意义,但有严重的腐蚀风险,针对渤海某油井采用的烟道气回收CO_(2)与蒸汽伴注方案,开展井下工具20Cr13、42CrMo、25CrMnMo、ZG35四种材质的腐蚀实验,进而开展缓蚀剂实验与材质升级实验,提出了针对烟道气回收CO_(2)与蒸汽伴注工况的防腐手段。