【作者】 李健；

【导师】 陈艳玲；

【作者基本信息】 中国地质大学 ， 油气田开发工程， 2014， 博士

【摘要】 随着常规石油资源的不断减少,为了满足全球日益增长的能源需求,稠油资源的开发在近些年受到了广泛的关注。稠油是全球石油资源的重要组成部分,在全球剩余石油资源中稠油占70%以上,因此具有比常规石油资源高数倍的资源潜力。然而由于稠油具有高粘度和高密度的特性,使得常规开采方法的采收率都极低。目前提高稠油采收率的思路主要是降低稠油粘度、提高油藏渗透率以及增大生产压差。国内外的稠油开采技术大体上可以分为热力开采技术、物理开采技术、化学开采技术以及生物开采技术四大类。其中应用最为广泛的是热力开采技术,未来稠油开采技术的发展趋势基本上都是以热力开采为基础,然后与其他技术相结合,根据各个油田不同的情况进行复合式开采。本文研究的水热裂解催化降粘开采技术就是一项基于热力开采的前沿开采技术。它借鉴了稠油炼化和改质的思路,尝试使稠油可以在井下实现原位改质降粘。它是通过向油层注入高温蒸汽,同时加入水热裂解催化降粘剂,将油层视为一个天然的反应器,利用蒸汽的热量,使稠油在水热条件下实现催化裂解,将稠油中的大分子部分裂解为小分子,部分改变稠油的品质,不可逆的降低稠油的粘度,从而达到易于开采的目的。此项技术的关键是水热裂解催化降粘剂的研制及催化降粘机理的研究。目前报道最多的是过渡金属络合物类型的水热裂解催化降粘剂,国内外学者研究还发现,对某些单独使用水热裂解催化降粘剂降粘效果不佳的稠油,复配加入一些供氢剂(如甲苯、甲酸、四氢萘等),降粘效果会有很大提高,他们认为供氢剂和催化降粘剂对稠油水热裂解反应具有协同作用,但在现场应用时,复配使用供氢剂和催化降粘剂会给施工设备及工艺带来一定的困难,还会增加经济成本,难以适应现场开采的需要。同时,供氢剂的协同作用的机理研究缺乏直接的实验证据,不够系统深入,限制了后续新型催化降粘剂的研制。因此我们尝试设计合成一系列具有供氢体与催化中心双重结构的新型稠油水热裂解催化降粘剂(包括单金属中心类型和双金属中心类型),使其具有更加优异的低温裂解降粘效果,同时又降低成本和方便现场使用。这种新型催化降粘剂的研制以及对其催化作用机理的深入探讨对于特超稠油的开采将具有重要意义。本文针对上述稠油水热裂解催化降粘新方法中的这些关键科学与技术问题,开展了以下研究：首先,受供氢剂对普通两亲结构催化降粘剂(由金属中心和具有两亲结构的有机配体组成,后文统一简称为两亲催化降粘剂)的降粘效果的协同作用的启发,我们成功合成出了铁金属中心的双重结构催化降粘剂B,采用红外分析、有机元素分析和金属元素分析对其结构进行了表征,并对其制备条件进行了优化。同时,选取新疆克拉玛依油田的F10223#超稠油(50°C时,原始粘度为85000mPa-s)为研究对象,对催化降粘剂B的性能进行了室内评价实验,确定了催化降粘剂B的最佳反应条件：反应温度为200℃、油水比为8：2、催化降粘剂用量为0.2wt%以及pH值为7。在最佳反应条件下,对油样的降粘率达到94.7%。此外,我们还发现单独使用催化降粘剂B就具有比复配使用铁金属中心的两亲催化降粘剂A与供氢剂时更显著的降粘效果,而且其具备优异的热稳定性和普适性。随后,我们采用改进后的柱层析分离方法,并利用元素分析仪、核磁共振仪和气相色谱-质谱联用仪对比研究了催化降粘剂A和催化降粘剂B对F10223#超稠油的降粘作用机理。在催化降粘剂A和B的作用下,油样中重质组分含量分别减少了9.39%和10.17%,对应的轻质组分含量均上升。反应后饱和烃中直链烷烃的种类和含量均明显增多,芳香烃中多出了少量的由C13～C15组成的苯系物、醇类及酮类化合物,催化降粘剂B作用下的饱和烃和芳香烃的种类和含量变化更大。经过水热催化反应,胶质和沥青质中的O、N和S杂原子含量均降低,氢碳原子比均增大,催化降粘剂B对重质组分杂原子含量的降低幅度和氢碳原子比的增大幅度均大于催化降粘剂A。反应后重质组分的芳香度均降低,芳香缩合度均增高,胶质分子的支链化指数变大,沥青质分子的支链化指数变小,催化降粘剂B作用下各种平均结构参数的变化幅度最大。反应后更多的气体组分出现在裂解气中,裂解气中除了含有空白实验裂解气中的成分(CO2、直链烷烃、环烷烃、烯烃及苯系物)外,还含有一些含氧化合物如环戊酮和乙酰苯,相比于催化降粘剂A,在催化降粘剂B作用下的反应后裂解气中存在更多的气体组分例如二甲苯和三甲苯等。研究结果表明,稠油重质组分在水热裂解催化降粘的过程中发生了解聚、断桥键、加氢脱杂、开环、异构化、脱羧等作用；裂解后的重质组分含量减少,平均分子结构变小,缔合结构变得更松散,使得分子间内聚力减弱,最终导致稠油粘度大幅度降低。催化降粘剂B因为具有小分子的供氢体结构,使得它更容易进入到重质组分的缔合结构中,从而更容易进攻到特殊位置上的C-R (R=S, N, O)键。这些键在催化金属中心的作用下与周围的高温水分子发生反应,导致杂原子的脱除。同时,催化降粘剂B中的供氢体结构也发挥了部分供氢作用,使得其作用下的重质组分中H元素含量明显高于催化降粘剂A。与催化降粘剂A相比,催化降粘剂B使稠油重质组分发生的各种化学作用均更加显著最终导致其具有更优异的水热裂解催化降粘效果。其次,通过发现对同一种稠油特别是超稠油,铜金属中心的催化降粘剂往往表现出比铁金属中心更好的降粘效果,我们成功制备出了铜金属中心的双重结构催化降粘剂C,并进行了红外表征。对比研究了催化降粘剂B和催化降粘剂C这两种不同金属中心的双重结构催化降粘剂对六种不同地区特超稠油的催化降粘效果。发现铜金属中心催化降粘剂C对所有的稠油样尤其是胜利超稠油(50℃时,原始粘度为180000mPa-s)具有更优异的降粘效果,对沥青质含量越高的稠油,这两种催化降粘剂的降粘率差别越大。随后,我们选取胜利超稠油,采用红外光谱分析、元素分析、核磁共振、凝胶色谱和气相色谱-质谱联用等现代测试手段从反应前后稠油组成和结构上深入系统地研究了这两种双重结构催化降粘剂在稠油水热裂解催化过程中的作用机制的差异。在催化降粘剂C的作用下,油样中的重质组分更多的转化为了轻质组分。反应后重质组分中的S元素的含量均降低,N元素含量均增加,氢碳原子比均减小,催化降粘剂C作用下的重质组分氢碳原子比、N元素含量的升高幅度和O元素含量的降低幅度均大于催化降粘剂B。沥青质的芳香度fA和芳香缩合度HAU/CA在反应后均降低了,而支链化程度BI则相应提高了,与催化降粘剂B相比,催化降粘剂C作用下的沥青质的芳香度、芳香缩合度和支链化程度均更低,相比于沥青质,反应后胶质的结构参数变化很小。在铜金属中心和铁金属中心两种催化降粘剂的作用下,反应后沥青质的数均相对分子质量从原来的7021g/mol分别锐减至1860g/mol和2092g/mol,沥青质平均分子的总碳原子数(CT)、总芳碳原子数(CA)、芳核外周芳碳数(CP)、总环数(RT)、芳环数(RA)、脂环数(RN)、芳核上的取代基数(n)均减少了,相比于催化降粘剂B,催化降粘剂C对沥青质平均分子的结构改变更加显著,在其作用下的反应后裂解气中存在更多的气体组分。研究结果表明,在反应过程中,金属中心主要作用于共轭芳环间的π键和部分桥键,使得稠油重质组分中紧密缔合的大分子稠环结构被解聚成不同大小的片段,一些小分子的片段如直连烷烃、环烷烃、烯烃及苯系物游离进入轻质组分和裂解气中,而残留的大分子片段又重新聚合在一起。两种催化降粘剂均主要作用于稠油中的沥青质,反应后沥青质的含量和结构均发生了明显的变化。在所有的化学作用中,解聚作用和桥键断裂作用对稠油粘度降低的贡献最大。反应后重质组分的减少和轻质组分的增多最终导致稠油粘度的显著降低。相对来讲,对沥青质而言,催化降粘剂C主要作用于大分子稠环体系,引起解聚作用的发生和部分桥键发生断裂,而催化降粘剂B则主要作用于杂环和侧链,导致开环和异构化作用的发生。催化降粘剂C对高沥青质含量的稠油的水热裂解催化降粘效果更好。然后,通过发现不同的金属中心具有不同的催化活性,我们成功制备出了具有铜和钼双金属中心的双重结构催化降粘剂E。选取胜利超稠油,对催化降粘剂E的性能进行了室内评价实验,通过单因子和正交实验确定了其最佳反应条件：反应温度为200°C、油水比为8：2、催化降粘剂用量为0.3wt%以及pH值为7。在最佳反应条件下,对油样的降粘率达到93.9%。同时,我们对比研究了催化降粘剂A(铁金属中心的两亲催化降粘剂)、B(铁金属中心的双重结构催化降粘剂)、C(铜金属中心的双重结构催化降粘剂)、D(钼金属中心的双重结构催化降粘剂)和E(铜和钼双金属中心的双重结构催化降粘剂)的裂解降粘效果。发现不同的催化降粘剂的裂解降粘效果强弱顺序为催化降粘剂E>C>B>D>A；具有双重结构的催化降粘剂的裂解降粘效果要明显强于两亲催化降粘剂；在系列双重结构催化降粘剂中,双金属中心的双重结构催化降粘剂的裂解降粘效果最好,降粘率达到了93.9%,重质组分减少了10.57%。随后,我们将电子自旋共振技术(ESR)引入到了对催化降粘剂的机理研究当中,分析了水热裂解催化降粘反应后稠油及其重质组分自由基的变化。在催化降粘剂E的作用下,反应后稠油自由基浓度随反应温度的升高而增大,当温度大于180°C时,自由基浓度出现显著增长。反应后稠油自由基浓度随加水量、催化降粘剂用量和反应体系pH值的增大均呈先上升后急剧下降的趋势,拐点分别在油水比为6：4、催化降粘剂用量为0.3wt%以及pH值为8时。当催化降粘剂参与稠油水热裂解反应后,稠油及其重质组分自由基的浓度出现了显著增长。从自由基变化角度,各种催化降粘剂对稠油的作用强弱顺序为：催化降粘剂E>C>B>D>A:对胶质的作用强弱顺序为：催化降粘剂E>D>B>C>A:对沥青质的作用强弱顺序为：催化降粘剂E>C>B>D>A。具有双重结构的催化降粘剂的效果要明显强于两亲结构催化降粘剂,催化降粘剂E因为具有双金属中心和供氢体结构而具有最好的作用效果。从重质组分杂原子含量变化角度,具有双重结构的催化降粘剂对杂原子的作用明显要强于两亲结构催化降粘剂A,证实了双重结构催化降粘剂对稠油重质组分分子结构具有更强的破坏能力。所有催化降粘剂中E对S原子的脱除作用最强。最后,新疆风城油田风重023#和FD320037#两口稠油井的现场试验结果表明,铁金属中心的双重结构催化降粘剂具有不错的裂解降粘效果,现场降粘率分别达到52.6%和55.9%,分别有17.33%和6.01%的重质组分转化为了轻质组分。风重023#稠油井的水热裂解催化降粘试验取得了成功,第三轮生产天数缩短,产液量增多,产油量明显增多(高出前两轮一倍多),增油364t,产油率从前两轮的24.38提高到了50.80%。FD320037#稠油井的现场试验没有达到增油的预期。本文的创新点主要体现在两个方面：(1)采用不断深入的方式,设计并合成出了一系列具有双重结构的新型催化降粘剂(包括单金属中心类型和双金属中心类型),将它们应用了到稠油水热裂解催化降粘反应中；并采用多种现代仪器分析测试手段对比研究了不同的催化降粘剂对稠油水热裂解催化反应的区别,利用对比研究系统深入地探讨了双重结构催化降粘剂的催化作用机理。(2)将电子自旋共振技术(ESR)应用到了稠油水热裂解催化降粘机理的研究当中,分析了特超稠油水热裂解催化降粘反应后稠油及其重质组分中自由基的变化规律,尝试从自由基角度研究双重结构催化降粘剂的作用机理,不仅丰富了研究手段,也获得了对催化降粘作用机理的新认识,这两方面的研究工作未见文献报道。更多还原

【Abstract】 With the continuous reduction of conventional crude oil, to meet the world’s growing appetite for energy, heavy oil resource development has aroused much concern these years.Heavy oil accounts for more than70%of the global residual petroleum resources which represent a critically important hydrocarbon reserve for matching the increasing demands for fossil fuels. However, the high viscosity and density of heavy oil prevents it from being exploited by conventional recovery techniques. Reducing the viscosity, improving reservoir permeability and increasing production pressure become the applicable ways to recover the heavy oil. Many methods, such as thermal recovery, physical recovery, chemical recovery, microbial recovery, etc. have been proposed and applied. Among which, thermal recovery techniques are most widely used. The development trend of heavy oil recovery techniques are basically based on thermal recovery, and then combined with other technology under the different conditions in various oilfields.Refer to principle of upgrading of petroleum, catalytic aquathermolysis is one of the most promising technology for exploiting heavy oil on the basis of thermal recovery techniques. In this technology, high-temperature steam is injected into the oil layer with catalysts. The oil layer is regarded as a natural reactor. With the energy provided by the steam, the catalyst can accelerate the aquathermolysis of heavy oil, partially change the quality of heavy oil and irreversible reduce the viscosity of heavy oil. Obviously, the catalyst plays a key role in this technology. To date, many studies have shown that, transition metal ions (serve as catalytic center) with suitable ligands could promote the aquathermolysis reaction. The studies also show that, the viscosity reduction rate of some extra-heavy oil is really poor by using the catalyst alone. But it can be apparently improved when some hydrogen donor such as toluene, methanoic acid and tetralin, etc. is coupled together. Hydrogen donor is regarded to give rise to better pyrolysis performance obeying a concerted mechanism with the catalytic center. Nevertheless, the mixed utilization of catalyst and hydrogen donor brings unnecessary complexity, extra cost and inevitable pollution in field operation, which prevents it from being scaled-up. Meanwhile, the study on the synergy mechanism of hydrogen donor is not systematic and in-depth due to the lack of direct experimental evidence, which limits the development of the novel catalysts. Motivated by the concerted effect brought by hydrogen donor, we attempt to design a series of novel catalysts with catalytic center and hydrogen donor, which are expected to play a dual role of both transition metal and hydrogen donor. Guiding significance is expected for preparing more effective catalysts for field application. In this paper, we carry out the following research in response to the above scientific and technical issues.Firstly, motivated by the concerted effect brought by hydrogen donor, the catalyst B which owns the dual structure of ferrum metal ion and hydrogen donor has been prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EL) and inductively coupled plasma-mass spectrometry (ICP-MS). And then it has been used in catalytic aquathermolysis of Xinjiang F10223#extra-heavy oil (85000mPa·s at50℃). From the orthogonal experiments of catalytic aquathermolysis, we have found the best viscosity reduction of oil sample by94.7%could be obtained using0.2wt%catalyst with the o/w ratio and pH value of8:2and7, respectively at200℃for24h. Moreover, we have also found that the catalyst B shows more signigicant viscosity reduction effectthan the coupling utilization of catalyst A (Ferrum is employed as catalytic center and macromolecular aromatic sulfonic is utilized as ligand.) and hydrogen donor. And it also has excellent thermal stability and universality. Then, the same and different influences on the aquathermolysis of heavy oil catalyzed by catalyst A and B are in-depth studied and compared. The compositions and structure of oil sample before and after reaction were analyzed by element analysis (EL),1H-nuclear magnetic resonance (1H-NMR) and gas chromatography-mass spectrometry (GC-MS). After reaction catalyzed by catalyst A and catalyst B, the heavy components of oil sample has respectively decreased by9.39%and10.17%. The types and levels of alkanes in saturated hydrocarbons (SH) have increased obviously. Meanwhile, a small amount of compounds such as alkylbenzenes, alcohols and ketones appear in the aromatic hydrocarbons (AH). Upon aquathermolysis, the elemental contents of O, N and S are all decreased, with the increasing of the H/C, the changes of the heteroatom components and H/C of resin and asphaltene after reaction with catalyst B are more obvious than catalyst A. after aquathermolysis, both the aromaticity and aromaticity condensation of heavy components have decreased. The structural parameters of the heavy components have changed more obviously upon catalytic aquathermolysis. the aromaticity and aromaticity condensation of resin and asphaltene after reaction with catalyst B are higher than catalyst A. Moreover, after catalytic aquathermolysis, carbon dioxide, alkanes, naphthenes, olefins and benzene series appear in the pyrolytic gas (the compounds are same to the blank sample). Some oxygen-containing compounds such as cyclopentanone and acetophenone exist in the pyrolytic gas after catalytic aquathermolysis. More compositions such as xylene, trimethylbenzene, etc. have been found in the pyrolytic gas after reaction with catalyst B than catalyst A. The results have revealed that, multiple types of actions happened throughout the catalytic aquathermolysis process, such as depolymerization, pyrolysis, hydrogenation, isomerization decarboxylation and ring-opening, etc. The heavy components of oil sample can be pyrolyzed to the light components more easily upon catalytic aquathermolysis. After reaction, the average molecular structure of the heavy oil becomes smaller, the associative structure becomes more loosened and the cohesion between molecules is weakened, eventually leading to the obvious viscosity reduction of heavy oil. Compared to the catalyst A, the above actions are more significant during the catalytic aquathermolysis catalyzed by catalyst B. The outstanding performance of catalyst B may be related to its special structure. Its ligand is rich in the small molecular structure of hydrogen donor. Due to the small ligand size, the diffusion of the catalyst in the heavy components becomes more readily, which allows higher probability for the catalytic center to attack the heteroatoms. The C-R (R=S, N, O) bonds are consequently activated. These bonds can then react with the neighboring water molecules or dissociate directly to form light contents. Meanwhile, the structure of the hydrogen donor in catalyst B also plays some role in making the increasing of H content in heavy component, which is significantly higher than the catalvst A.Secondly, it is found that, with the same ligand type and cation concentration, Cu2+-catalyst has stronger catalytic activity on the viscosity reduction effect for many heavy oils than Fe3+-catalyst, especially for super-heavy oil. Then, the catalyst C which owns the dual structure of copper metal ion and hydrogen donor has been synthesized and characterized by FT-IR. After that, the catalyst B and C are used in catalytic aquathermolysis of six heavy oils for comparative study. Compared to catalyst B, the catalyst C shows better viscosity reduction effect for the heavy oils, especially for the Shengli extra-heavy oil (1.8×105mPa-s at50℃). The higher asphaltene content of heavy oil is, the more difference between the viscosity reduction rates of the two catalysts is. As a result, Shengli extra-heavy oil was selected as the research object to in-depth study the same and different influences on the aquathermolysis of heavy oil catalyzed by the two catalytic ions. The compositions and structure of oil sample before and after reaction were analyzed by EL,’H-NMR, Gel permeation chromatrography (GPC) and GC-MS. Compared to catalyst B, more heavy components have been pyrolyzed to the light components after reaction with catalyst C. Upon aquathermolysis, the amounts of sulfur element and H/C of resin and asphaltene have all decreased, while the nitrogen content of heavy components have increased. By contrast, the decrease of the H/C and oxygen content of resin and asphaltene after catalytic aquathermolysis with catalyst C are more obvious than that of heavy contents after reaction with catalyst B. With the participation of the catalysts, the aromaticity and aromaticity condensation of asphaltene have decreased, while the branching index of that has increased. The aromaticity, aromaticity condensation and branching index of asphaltene after catalytic aquathermolysis with catalyst C are lower than that of asphaltene after reaction with catalyst B. Compared to asphaltene, there is no significant structural change of the resin before and after reaction. The number average molecular weights of asphaltene have respectively decreased from7021to1860and2092g/mol after catalytic aquathermolysis. After reaction, the average structural parameters such as the number of total carbons (CT), aromatic carbons (CA), non-bridgehead aromatic carbons (CP), total rings (RT), aromatic rings (RA), naphthenic rings (RN) and aromatic ring substitution (n) of asphaltene molecule have decreased obviously. Compared to catalyst B, the changes of all these average structural parameters of asphaltene molecule after reaction with catalyst C are more remarkable and more compositions exist in the pyrolytic gas after reaction with catalyst C. The above results have revealed that, during the catalytic aquathermolysis, the catalytic ions chiefly reacted with some conjugated π-bonds and bridge bonds (C-R, R=S, O, N, C), causing the tight macromolecular ring system of heavy components be depolymerized to fragments of different sizes. Some small fragments with high H/C such as alkanes, naphthenes, olefins and benzene series dissociated into light components and pyrolytic gas under the high-temperature catalytic condition, and the remaining macromolecular fragments with low H/C reassociated together after reaction. Moreover, the comparison results show that the two catalytic centers mainly act on the asphaltene of oil sample. The content and structure of the asphaltene have changed evidently after reaction. Among all the actions, the contribution of the pyrolysis and depolymerization to the viscosity reduction of heavy oil are more than the others. The decrease of the heavy contents and the increase of the light contents could eventually cause the significant viscosity reduction of the heavy oil. The catalyst C has stronger catalytic action on the AH and asphaltene than the catalyst B, while it has weaker catalytic action on the SH and resin. In addition, the catalyst C mainly causes the depolymerization and cleavage of some bridge bonds of the macromolecular ring system, whereas the catalyst B primarily leads to the isomerization of side chains and ring-opening. The catalyst C is more suitable to catalyze the aquathermolysis of the heavy oil with high asphaltene for application.Thirdly, it is found that different metal centers have different catalytic activity on the catalytic aquathermolysis of heavy oil. The catalyst E which owns the dual structure with two metal centers has been synthesized and characterized by FT-IR, and then used in catalytic aquathermolysis of Shengli extra-heavy oil. From the single-factor experiments and orthogonal experiments of catalytic aquathermolysis, we have found the optimum conditions are as follows:the temperature is200℃, the o/w ratio is8:2, the percentage of catalyst is0.3wt%, the pH value is7and the reaction time is24hour. And the viscosity could be reduced by93.9%under the optimum reaction conditions. Meanwhile, we have comparatively studied the viscosity reduction effect of the catalyst A, B, C, D (which owns the dual structure of molybdenum metal center and hydrogen donor) and E. We have found that the order of viscosity reduction effect of different catalysts is E> C> B> D> A. The viscosity reduction effect of dual-structure catalysts (B, C, D, E) is better than single-structure catalyst (A). Among the dual-structure catalysts, catalyst E shows the best viscosity reduction effect, the viscosity reduction rate can hit93.9%, with10.57%in conversion of heavy content to light content. After that, electron spin resonance (ESR) has been used to study the mechanism of the dual-structure catalysts for catalytic aquathermolysis of heavy oil. The free radicals of oil sample and heavy components before and after reaction have been analyzed. The radical concentration of oil sample increases with increasing reaction temperature after reaction with catalyst E. The significant growth of radical concentration occurs when the temperature exceeds180℃. With the increasing o/w ratio, percentage of catalyst and pH value, all the radical concentrations of oil sample show a sharp decline after the first rising trend. The inflection points are respectively in the o/w ratio of6:4, percentage of catalyst of0.3%and pH value of8. With the participation of the catalysts, the radical concentrations of oil sample and heavy components arise obviously. From the perspective of free radicals, it is found that the order of activity of different catalysts on the oil sample is E> C B> D> A, the order of activity of different catalysts on the resin is E> D> B> C> A, the order of activity of different catalysts on the asphaltene is E> C> B> D> A. The catalytic activity of dual-structure catalysts is better than single-structure catalyst. Among the dual-structure catalysts, catalyst E shows the best catalytic activity. From the perspective of heteroatom content of heavy components, the hydrodesulfurization of the heavy components is the most significant after reaction with catalyst E.Lastly, the catalyst B has been used in the field tests of FZ023#and FD320037#heavy oil wells. The results indicate that, the viscosity of FZ023#and FD320037#heavy oil could be reduced by52.6%and55.9%, with17.33%and6.01%in conversion of heavy content to light content, which proves the catalyst B shows good viscosity reduction effect in the field test. During the third steam huff and puff periods with the catalyst B, the working days of the FZ023#well have decreased, the liquid and oil production are improved clearly, the oil production has increased by364t. By contrast, the field test of the FD320037#well has not met the expected growth of oil production.There are two innovative points in this paper:(1) A series of dual-structure catalysts for catalytic aquathermolysis of heavy oil have been designed and prepared, which include the types of single metal center and two metal centers. Then, the novel catalysts have been used in the catalytic aquathermolysis of heavy oil. Moreover, a variety of modern instrumental analysis methods have been used to study the mechanism of the dual-structure catalysts comparatively.(2) Electron spin resonance (ESR) has been firstly used to study the mechanism of the dual-structure catalysts for catalytic aquathermolysis of heavy oil. The free radicals of oil sample and heavy components before and after reaction have been analyzed. We have tried to reveal the mechanism of dual-structure catalysts from the perspective of free radicals.更多还原