【作者】 王志国；

【导师】 马一太； 张义祥；

【作者基本信息】 天津大学 ， 工程热物理， 2004， 博士

【摘要】 我国稠油开采以注蒸汽热采为主,其产量超过稠油产量的80%。本文以注汽系统为研究对象,以增加注入到井底的蒸汽干度、提高注汽系统能量利用率为目的,开展了基础理论及现场试验研究。本文的主要研究内容包括:1.蒸汽吞吐开采机理及影响因素研究蒸汽吞吐开采包括:注汽、焖井和采油三个阶段,本文对此作了介绍。在此基础上,结合国内外有关研究成果,对蒸汽吞吐开采增产机理、影响因素及提高蒸汽吞吐开采效果的技术措施进行了探讨。2.注汽系统用能评价分析注汽系统由产汽环节、输汽环节、注汽环节和利用环节四个部分组成,各部分均存在能量损失。为了有效地降低系统及各个环节的能量损失,本文根据系统及各个环节组成特点建立了能量转换分析模型,给出了评定准则,并利用测试数据进行了分析计算。在此基础上对注汽系统及各部分的用能状况进行了分析评价,找出了用能薄弱环节及设备,并对形成原因作了分析。本项研究成果,为后续研究工作指明了方向,对同类注汽系统有指导意义。3.提高注汽锅炉运行热效率研究注汽锅炉是注汽系统的关键设备。测算分析结果表明,注汽锅炉运行热效率和火用效率均低于额定工况下的设计值,分别低4.1-8.0个百分点和4.1-6.3个百分点。热效率和火用效率达不到设计值的原因,一是排烟温度超过设计值,二是空气系数偏高。本文从降低注汽锅炉排烟温度和减少空气系数(氧气含量)两个方面开展了攻关研究。该项研究,经历了从现场调研、测试评价分析、确定改造方案、安装调试及现场试验等研究过程。提高注汽锅炉运行热效率研究,从理论分析、试验设计、实际改造运行及节能效益等方面来看,均达到了预期效果。在其它类型注汽锅炉上采取余热回收及配风调节技术,可参照本项研究成果,根据注汽锅炉实际情况进行设计。4.输汽管线保温结构优化设计及试验研究保温效果不良的输汽管线,在注汽系统中的热损率超过10%。通过节能技改研究,可使热损率降低一半以上,节能潜力很大。本项研究通过进行现场调研、测试分析,查清了管线保温存在的问题;然后从影响保温效果和使用寿命的三个主要因素:保温材料性能、保温结构和施工工艺入手, 采用室内模拟试验研究和<WP=4>工程试验相结合的方法, 进行了研究。研究内容包括,筛选优质保温材料、设计最优保温厚度、研制适合于输汽管线的保温结构等。研究过程,按照室内试验、示范试验、改进后的工程试验及扩大试验等的顺序进行。研制的“内层涂料+中间型材+外层涂料”三层复合保温结构,是输汽管线理想的保温结构。5.井筒热损模拟计算及试验对比研究运用传热学、热力学及流体力学等学科知识,对井筒传热过程进行了分析。在此基础上,建立了井筒传热综合计算模型。本文所建的井筒传热综合计算模型,借鉴了国内外已有的研究成果,又有所发展。在该模型中,把蒸汽温度、压力看作变量;考虑了不同隔热管结构;压降按两相流理论计算;模型中的各方程用分段形式来描述,适合用有限差分的计算方法来求解。鉴于模型中的计算,已有公式计算误差较大,本文回归拟合了两个精度比较高的公式。其中ln型WM拟合公式精度更高一些,建议实际计算时选用本文回归的两个公式。根据实际分析计算结果,讨论了井口注汽参数(注汽速度、注汽干度及注汽时间等)变化对注入到井底的蒸汽参数(压力、温度、干度及热损)的影响。实测注入到井底的蒸汽干度小于模拟计算结果,本文通过试验研究,分析了产生这一问题的原因,给出了一些修正办法。根据理论及试验研究结果,提出了一些改进隔热管性能的建议。更多还原

【Abstract】 The main of heavy oil recovery is steam injection of thermal recovery in China and its output is exceeded 80 percents. Based on the research object of steam injection system and the purpose which increasing the steam mass quality injected into bottom hole and improving energy utilization ratio of the system, this paper has launched the basic theory and on-the-spot experimental study. The main research contents of the paper include:1.Study on the mechanism and influence factors of steam stimulation recovery.This paper recommends to the steam stimulation recovery, including three stages of steam injection, soaking time and recovery oil. Based on this and combined domestic and international relevant research results, this paper is discussed on the increasing production mechanism, influence factors and the improving technological and effective measures.2.Exergy assessment and analysis of the steam injection systemThe steam injection system is composed of output, transport, injection and utilizing part, each part has energy losses. For reducing energy lose of system and each part, this paper establishes energy transition and analysis model according to the characteristic of system and each part, provide the criterion of assessment, and utilize the test data to analyze and calculate. Exergy assessment and analysis of the system and each part is processed, weak links and equipments are found out and the reason of producing is analyzed based on the above. This research results pointing out the direction for the follow-up study and have directive significance to the similar steam injection system.3.Study on the operation thermal efficiency of steam injection boiler Steam injection Boiler is the key equipment of the system. Calculation and analysis results indicate that the thermal and exergy efficiency of the boiler are lower than the design value of specified operating mode, which low 4.1～8.0 percentage and 4.1～6.3 percentage, respectively. The low efficiency is caused by the rejection temperature exceeding the design value and the high air coefficient (oxygen content) . This paper studied on the two sides. This research experienced on the process of on-the-spot investigation, testing and assessment analysis, confirming scheme of modification, installing and debugging and on-site experiments. Shown in the theory analysis, test design, actual modification operating and the benefit of energy conservation, the research of thermal operation efficiency improvement of steam injection boiler has reached the anticipated results. Consulted on this research results, other types of steam injection boiler which adopting the technologies of residual heat recovery and air distribution and regulation can be designed, according to the actual conditions of themselves. 4.Insulation structure optimum design and test The thermal loss rate of steam injection system can exceed 10% due to poor insulation of steam pipelines. The study of energy saving technology shows that this system has great energy saving potential by lowering the thermal loss rate to over <WP=6>50%. The study makes the flaws of pipeline insulation clear by field investigation and test analysis. Then starting with three factors of insulation material properties, insulation structure and practical art, which influence insulation effect and lifespan, the investigation is performed by indoor simulation and field test. The study contains the selection of high quality insulation material, the design of optimum insulation thickness, and the development of insulation structure adept to steam pipelines, etc. The study stages are indoor test, paradigm test, improved field test and extend test. An ideal insulation structure is developed, which is a multiple-layer structure with “inner dope+middle shaped-material+outer dope”.5 Comparison of simulation calculation and experimental study of heat loss for wellboreBy using the subject knowledge obtained from heat transfer, thermodynamics and hydromechanics etc., the heat transfer processes in well-bore are analyzed. B更多还原