| 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 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...
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