【作者】 张家瑞；

【导师】 王宗贤；

【作者基本信息】 中国石油大学 ， 化学工程与技术， 2010， 硕士

【摘要】 为考察深部地层原油在高温高压下的热解性能,采用高压封闭体系,在不同温度、压力下进行了不同类型原油及其组分、原油加水、加碳酸盐矿物的热模拟实验,并对热解气态烃产量进行了比较,探讨了原油热解机理。研究结果表明:在一定温度范围内,压力成为影响热解较重要的因素,温度越高,压力的影响作用越明显;当压力小于22MPa时,压力对原油的热解有促进作用,超过此压力,表现为抑制作用。油样越重(沥青质含量越多),热解气体产物中C3H8以上烃相对含量越少,CH4和C2H6相对含量越多。温度低于390℃,油样生气量较小。轻质油样Y2大量生烃温度约为390℃,而重质油样Y1,Y3大量生烃温度约为420℃,450℃为油样生烃高峰期,在此高峰期热解转化率均小于60%。沥青质热解最大生气量对应的温度比原油的高,因此,含沥青质较多的原油在地质条件下的保存温度更高。通过Y3油样四组分热解实验可知:总生气量的大小关系为:饱和分﹥胶质﹥沥青质﹥芳香分。热解生成甲烷量的大小关系为:沥青质>饱和分>胶质>芳香分,沥青质是热解气体中甲烷的最大贡献者。水对较重油样的热解影响不大,可以促进轻质油样的热解。碳酸盐矿物可以促进轻质油样的热解,抑制重质油样的热解。通过11级动力学模拟得出:油样Y1与Y3反应的活化能主要分布于57Kcal ? mol-1-63Kcal ? mol-1之间,油样Y2反应的活化能主要分布于49Kcal?mol-1-55Kcal?mol-1之间。油样Y2热解的活化能最小,最易热解;Y1与Y3热解难易程度相当。原油的常压DSC分析表明,油样热解明显吸热的起始温度小于高压热模拟曲线中生气量显著增加的温度。常压下,原油越重,开始发生热解的温度越高,吸热峰顶温度及放热峰顶温度也越高。更多还原

【Abstract】 The thermal simulation of Tarim Basin crude oil and its fractions were carried out in closed and confined system in the temperatures range 350℃to 480℃and pressure range 10MPa to 50MPa, with and without water and carbonate mineral. The generated gas components were analyzed by gas chromatograph (GC). The differences or similarities of gas generation mechanism and pyrolysis behavior of crude oil were discussed on the basis of total gas yield and gas components yield.Pressure effected oil cracking in certain temperature range. High temperature made pressure’s effect more obvious. The increase in total gas yield was observed under 22MPa, and decrease was observed above 22MPa. The more asphaltene content in crude oil, the less relative content of hydrocarbons heavier than propane and more methane and ethane in total gas generation.Gas generation yield was small under 390℃. The temperature of obvious gas generation was 390℃for light oil-Y2, and 420℃for heavy oil-Y2 and Y3. Gas generation yield increased with temperature increasing, the maximum gas generation yield appeared at 450℃for the three oil samples, and then gas generation yield steady decreased with temperature increasing. However, oil to gas conversion rate at this temperature was less than 60%. The temperature at which generates maximum gas yield of asphaltene obtained was higher than that of crude oil. Thus, conclusion was made: crude oil which is rich in asphaltene was kept at higher temperature in geological condition. Total gas generation sequence of Y3’s four components was: saturate>resin>asphaltene>aromatics. Saturate was the first contributor to total gas generation, and then comes resin. Methane yield sequence generated from Y3’s four components was: asphaltene>saturate> resin >aromatics.Water had no obvious effect on heavy oil cracking; however, it propelled light oil cracking. Carbonate mineral promoted light crude oil cracking, while inhibit heavy oil cracking.Kinetic parameters were calculated by using first order parallel reaction: activation energy of Y2 and Y3 oil to gas activated energy was about 57Kcal?mol-1-63Kcal?mol-1, and 49Kcal?mol-1-55Kcal?mol-1 for light oil sample Y2.The conclusion from DSC experiments at normal pressure were obtained: dramatic endothermic temperature at normal pressure was lower than that of crude oil pyrolysis at high pressure. Moreover, the heavier the oil, the easier its pyrolysis at normal pressure. Thus, the maximum endothermal and exothermic temperatures were also high.更多还原