轻质原油低温氧化催化技术

注空气采油技术由于气源和成本优势,具有广阔的发展潜力,但是安全问题一直是限制其应用的重要因素。为加快氧气消耗速率,降低生成烟道气中氧气的含量,提高注空气的安全性,进行了原油低温氧化催化技术研究。通过评价过渡金属元素对低温氧化反应的催化效果,筛选了催化剂及其用量;研究了温度、压力、含水率和岩石矿物等对催化性能的影响,并采用多管平行实验研究了不同反应阶段低温氧化反应的特征;在动力学参数计算和红外谱图分析的基础上研究了原油低温氧化催化反应的催化机理。实验结果表明:过渡金属元素Cu对原油低温氧化反应有很好的催化效果,优选的催化剂为CuCl₂,最佳用量为原油质量的0.88%,在油藏条件下可提高反应速率近2倍;温度和压力升高对低温氧化反应有促进作用,在所研究的温度、压力和反应阶段内,催化剂的低温氧化催化效果显著;催化剂对原油低温氧化反应的催化机理为配位催化,可显著降低反应的活化能,加快低温氧化反应速率,提高原油的耗氧能力。     

Influence of ferrous iron on the oxidation of crude oil at a low temperature

Air flooding can be successfully applied in a low-temperature reservoir due to the existence of ferrous ions in formation water. However, few published papers can be found about the mechanism of oxidation of crude oil on condition with Fe²⁺ at a low temperature, by far. Therefore, in order to reveal the mechanism, some static oxidation experiments are carried out at 30°C in this paper. On condition with Fe²⁺, the rate of oxygen consumption is increased by 2.3 times as that on condition without Fe²⁺, and the concentration of O₂ in the air is decreased to 7.5% after oxidation. According to the results of the changes in the compositions of the air and the crude oil, not only can Fe²⁺ accelerate the rate of the oxidation but can also affect the pathway of the oxidation. The experimental results can provide a basis for how to further improve the development effect of air flooding in Ganguyi oilfield and safely make use of air flooding in other low-temperature reservoirs.     

Catalytic effect of in-situ preparation of copper oxide nanoparticles on the heavy oil low-temperature oxidation process in air injection recovery

In situ prepared hydrophobic CuO nanoparticles, about 84.3 nm in mean diameter, was synthesized and used to catalyze heavy oil low-temperature oxidation (LTO) reaction. Experimental results showed the average oxygen consumption rate with CuO nanoparticles addition increased by 1.4 times, and the residue oxygen content in tail gas in autoclave was decreased from 8.76% to 3.9% compared to the blank experiment (without CuO nanoparticles). In addition, the CuO nanoparticles could facilitate the cleavage reaction during LTO. This study can provide guidelines to improve effectively the safety of air flooding technology in the heavy oil.     

Accelerated oxidation during air flooding in a low temperature reservoir

To ensure the safety of application of air flooding in a low temperature reservoir, the accelerated oxidization of oxygen and the crude oil is studied at low temperature. The stabilized chlorine dioxide solution can be used as a type of catalyst, which can accelerate the reaction rate of oxygen and the crude oil to decrease the concentration of remaining oxygen when the gas reaches the production well. The experimental results of oxidization show that O₂ concentration is greatly reduced and CO₂ concentration is greatly increased on condition with catalyst. In addition, the amount of heavy components can be further reduced and the amount of light components can be further increased. These can ensure the safety of application of air flooding in low temperature reservoir. The experimental results of adaptability of the accelerated oxidation under different water saturation show air flooding can be better used in the low-temperature reservoir with low water saturation on condition with catalyst but cannot be used in the low-temperature reservoir with high water saturation. The experimental results can provide theoretical basis for the application of air flooding in a low-temperature reservoir.     

Catalytic effect of zinc naphthenate on the heavy oil low-temperature oxidation in an air injection process

Air-assisted steam flooding is a new effective technique for enhanced oil recovery in heavy oil reservoirs. The authors prepared zinc naphthenate as the catalyst in the laboratory and the investigated effects on low-temperature oxidation of heavy oil through the isothermal reactor. The results indicated that zinc naphthenate could accelerate the oxygen consumption rate and facilitate the cleavage reaction in the low-temperature oxidation process. The data shed more light on the mechanisms of low-temperature oxidation reactions of heavy oil and can provide a new way to enhance the recovery of heavy oil reservoir.     

稠油油田空气辅助蒸汽驱现场试验

为考察稠油油田空气辅助蒸汽驱的开采效果,开展了稠油油田空气辅助蒸汽驱现场试验研究工作。在齐40块蒸汽驱试验区选择原油濒临枯竭的、油藏已经发生严重蒸汽窜流和超覆的、亟待改变开发方式的5个井组进行现场试验,结果表明:5个试验井组平均单井组日产油由14.8 t/d升至16.1 t/d,油汽比由0.14升至0.17;油层纵向动用程度明显提高,分析认为是注入的空气在纵向和平面上首先向蒸汽驱优势方向波及,与残余原油发生低温氧化反应使孔隙中沥青质沉积增加,降低油层渗透率,迫使蒸汽转向,扩大蒸汽波及范围。研究认为:空气辅助蒸汽驱宜采用连续式空气/蒸汽注入方式;汽气比接近1: 40可取得较高采收率;70 m井距注入的空气与地下原油发生低温氧化反应,油藏温度有所提高,产出氧气含量可降到安全范围内。现场试验取得成功,利用空气辅助蒸汽驱改善稠油油田蒸汽驱开发效果具有可行性。所选试验井组存在的问题在普通稠油蒸汽驱井组生产后期具有普遍性,因此本文试验方法和相关技术参数可为类似井组开展空气辅助蒸汽驱试验提供参考。     

“三低”油藏空气泡沫驱低温氧化可行性研究——以甘谷驿油田唐80区块为例

甘谷驿油田＂三低＂油藏具有非均质性强、水源匮乏和单井产能低等特点,而低成本、高调驱能力的空气泡沫驱技术在该区具有广阔的应用前景。为了进一步验证空气泡沫驱低温氧化的可行性,并确保注空气的安全性,通过调研该技术的应用现状、室内动静态低温氧化模拟实验研究及实际矿场试验检测,研究了不同压力、不同温度下原油与空气的氧化反应以及实际矿场试验含氧量监测分析。结果表明：在该类＂三低＂油藏条件下同样可发生低温氧化反应,且反应速度随着压力的增加而加快。     

空气-泡沫驱提高采收率技术的安全性分析

空气-泡沫驱提高采收率技术的安全性问题一直是学术界关注的焦点,它关系到这项技术的应用。从气体爆炸极限和氧气的消耗两个角度对该问题进行分析。在气体爆炸理论的基础上,推导出天然气与空气混合爆炸工程估算的方法,并对一种实际天然气进行估算,得出该天然气的爆炸上限为3.210%,下限为10.320%;随着天然气甲烷含量的增加,估算出来的爆炸界限与甲烷单组分的爆炸极限值相接近。通过低温氧化反应及其动力学机理分析得出,由干低温氧化及用,空气中的氧气与原油中的烃类物质发生反应而被消耗,生成二氧化碳和一氧化碳等“烟道气”,从而增加了安全可靠性。现场测试的结果也证明只要注意控制注入压力和注入量,监测油管内气体含量,该技术就具有安全性。     

低渗透油藏空气驱原油氧化机理实验

为深入探究低渗透油藏空气驱开发过程中原油的氧化特征及其影响因素,评价其驱油效果,以新疆油田低渗透油藏为研究对象,开展原油组分分析、原油氧化特征、空气驱及空气泡沫驱等实验,系统研究了不同条件下原油氧化特征及规律。实验结果表明:相同条件下,油砂比纯油样静态氧化反应速率大,反应充分,且反应速率与反应压力、温度、作用时间呈正相关;油藏温度下,原油经历氧化反应后轻重比减小,主峰碳增加;反应温度对空气驱原油动态氧化特征有较大影响,温度越高耗氧量越大,反应越充分;空气驱具有较好驱油效果,但易发生气窜;泡沫驱可有效封堵气窜通道,扩大空气波及体积,改善空气驱效果。研究成果对空气驱理论研究及应用具有借鉴意义。     

冷1块稠油低温空气氧化物模研究

为了进一步发展注气提高采收率技术,提高超稠油油藏的开发效果,采用低温空气氧化驱油物理模型实验,研究建立了二组线型物理模型,开展了冷1块稠油注空气驱油实验。实验研究了冷1块稠油与空气发生低温氧化的温度、产出含氧量,并对其原油低温氧化采油的可行性进行了分析。实验结果表明：随着温度的升高,冷1块稠油低温氧化的采出程度增大;将空气中的氧消耗到安全值以内,浸泡的时间随温度升高不断减少;冷1块进行注空气吞吐可以采出6．86％-10．24％的原油,技术上是可行的。     

延长油田典型“三低”油藏空气泡沫驱试验与认识

为了提高延长油田“三低”油藏开发效果,探索空气泡沫驱在该类油藏的可行性,在室内研究的基础上,分别选取东、西部具有代表性的唐80井区和旗35井区开展了空气泡沫驱矿场试验。结果表明:空气泡沫驱最终驱油效率可以达到80%以上。相比先水驱再空气泡沫驱,直接空气泡沫驱的驱动方式更有效,获得相同的较高驱油效率需要的总注入量更小。同时,据2个井区的矿场试验结果,单井月增油幅度最高达215%,单井累积增油幅度最高达近40%,单井含水率最高下降40个百分点以上;唐80井区综合含水率下降约16个百分点,自然递减率较注水区低13个百分点以上,降水增油效果非常明显。另据耗氧安全分析和矿场试验监测结果,套管气氧含量基本都在5%以内,且随时间的延长,氧含量均越来越低。通过上述研究和试验认为:空气泡沫驱在延长油田“三低”油藏具有经济和安全的双重可行性,打破了低温低压油藏不适合空气泡沫驱的常规理念,对同类油藏的实施具有借鉴和向导意义。建议矿场试验中采取有效措施减缓气窜的发生,加强油藏动态和产出气的监测与分析,保证在安全的前提下取得良好的驱油效果。     

空气泡沫驱数学模型与数值模拟方法

为了描述空气泡沫驱过程中空气与泡沫的运移规律和复杂的驱油机理,通过相与组分关系的相关假设,借鉴火烧油层数学模型方法,结合空气低温氧化动力学方程、泡沫驱经验数学模型与物化参数的处理,建立了空气泡沫驱数学模型,分析了该模型的封闭性,并提出了相应数值模型的求解方法。建立了概念模型,通过空气泡沫驱室内实验拟合修正了氧化动力学模型,并模拟评价了空气泡沫低温氧化驱油机理影响因素的敏感性。结果表明,室内实验各阶段驱替效果与见水时间的拟合都比较好;空气泡沫驱效果更好、成本更低,适合于非均质油藏（变异系数0.7~0.8）或注水开发后期正韵律油藏;采用高温高压、高注低采、水驱至含水率96%左右时转泡沫驱以及反七点井网等方式,都有利于增强空气泡沫的驱油效果;当气液比为1∶1 ~ 2∶1、空气注入速度0.1~0.2 PV/a,以及采用空气泡沫/空气交注注入方式时,驱油效果最佳。     

Effect of low-temperature oxidation of light oil on oil recovery during high pressure air injection

In this research, the low-temperature oxidation (LTO) behavior of light oil was evaluated via isothermal oxidation tube experiments. Also, the core model together with nuclear magnetic resonance (NMR) analyzer was implemented to explore the effect of LTO of light oil on oil recovery during high pressure air injection (HPAI). The results indicated that the polycondensation reaction of light components (C₅-C₆) and intermediate ones (C₇-C₁₇) for light oil was the preferred reaction path during LTO process. The oxygen addition was the primary oxidation reaction in LTO, but the LTO reaction presented a more favorable trend for the bond scission with the oxidation degree. Because of the gas flow steering resulting from property variation of light oil and heat release determined by LTO, the total oil recovery yielded by air flooding was 8.82% higher than nitrogen flooding.     

Mechanism of action of additives improving jet fuel thermal-oxidative stability

Summary Oxygen consumption kinetics have been followed by gas chromatography when T-1 fuel is heated (in a TSRT-2 instrument) in the presence of various additives that improve the thermal-oxidative stability of jet fuels.It has been established that the antioxidant additive AO22-46, at concentrations that eliminate sediment formation, very nearly eliminates oxygen consumption.The addition of IPODA or copolymeric methacrylate-vinylpyridine additive to the fuel at concentrations eliminating sediment formation does not eliminate oxygen consumption or gum formation, both of which are still significant; this indicates that the use of these additives does not influence the oxidation process.The comparative data on oxygen consumption kinetics, together with the data on gum and sediment formation that have been obtained for the various additives, indicate that the use of this gas chromatographic method has made it possible to establish the antioxidant or dispersant action of the test additives.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 8, pp. 23–26, August, 1974.     

渤海 Ｋ油田空气驱对原油低温氧化影响研究

以渤海K油田为研究对象,利用氧化实验仪,模拟油藏温度(110℃)和压力(24MPa),系统研究了不 同氧含量(3%~12%)减氧空气对该油田原油的氧化可行性;并利用气相及液相色谱仪检测减氧空气及原油氧化 前、后组份构成与含量。实验结果表明,实验前、后原油和减氧空气组份含量明显不同,如原油中较高烃组成(≥ C14)含量下降、较低烃组成(C8~C10)含量增加;减氧空气中氧含量下降、二氧化碳有定量(<0.6%)增加;说明K油田原油在油藏温度压力下可与减氧空气发生低温氧化反应。反应过程中,原油以氧化降解为主,完全氧化生成 二氧化碳为辅;该氧化反应进行程度随减氧空气中含氧量增加而增大,表现为对应氧耗量增大、原油被氧化的“临 界碳数”下降(由 C22下降至 C14)、二氧化碳含量由 0.075%增加至 0.6%。实验减氧空气与K油田原油氧化 120 h后残余氧含量均低于 10%,表明渤海Ｋ油田实施减氧空气驱具有良好的安全可行性。     

The effect of low-temperature oxidation in air-assisted steam flooding process for enhancing oil recovery

Air-assisted steam flooding is a new promoting technique for enhanced oil recovery compared to the other traditional thermal recovery methods. In this study, five experiments, including one steam flooding experiment, three combined steam–air flooding experiments, and one combined steam–N₂ flooding experiment were studied, under the conditions of 180 °C and back-pressure valve of 8 MPa, with sand-packed model. The volume fraction of mixed gas in these four combined steam–air (or N₂) flooding experiments were 80% steam+20% air, 60% steam+40% air, 40% steam+60% air, and 60% steam+40% N₂, respectively. The experimental results showed that air-assisted steam flooding could enhance the oil displacement efficiency when the volume fraction of air and steam was in a certain number, and the optimal condition is 60% steam+40% air. Furthermore, water cut curves and saturate, aromatic, resin, and asphaltene (SARA) analysis results also demonstrate that the low-temperature oxidation reaction in air-assisted steam flooding process advantageous to profile control of generating high viscosity “PLUG” to seal high-permeability channel in reservoir.     

中高渗油藏空气泡沫调驱技术

研究了泡沫驱油机理,高温、高矿化度条件下泡沫体系,胡12块原油低温氧化性能,甲烷在空气中的爆炸极限,现场集输流程,安全控制系统.通过胡状油田12块沙三中86-8层系矿场试验,分析了空气泡沫调驱技术对储层的调剖能力、封堵能力.试验结果表明,空气中的氧气在地层中得到了充分氧化,产出氧气浓度<3%,阶段提高采收率幅度为3.94%,无安全事故.     

微生物驱配气工艺参数优化试验研究——以孤岛中一区Ng_3区块为例

在空气辅助微生物驱油技术中,氧气的配注量直接影响油藏好氧微生物生长代谢的情况,进而影响驱油效率.在模拟胜利油田孤岛中一区Ng_3区块油藏条件下,通过物理模拟试验研究考查产出液表面张力、微生物浓度变化和代谢产物中的低分子有机酸、醇、酚和脂,分析确定了氧气的最佳注入量,研究结果表明,在中一区Ng_3区块油藏条件下空气辅助微生物驱最佳配气量为气液比20:1(常压),该结论为空气辅助微生物驱现场试验提供了理论依据.     

甲烷催化部分氧化制合成气反应器的改进

在带空气分布器的固定床反应器中,以空气为氧源,采用NiO-La2O3/MgAl2O4-α-Al2O3催化剂,进行了甲烷催化部分氧化制合成气的研究。考察了空气流量分配比(D)对催化性能、催化剂床层轴向温度分布、催化剂床层轴向原料组成和产物分布的影响。实验结果表明,D不影响催化剂床层出口处的气体组成;当D为80%时,沿催化剂床层轴向n(O2):n(甲烷)可保持在0.10～0.22,催化剂床层入口处的温升明显下降,整个催化剂床层轴向温度分布均匀,表明采用空气分布器有利于提高甲烷部分氧化反应的选择性,抑制了甲烷的完全氧化。     

注空气开发中地层原油氧化反应特征

通过分析中国不同类型油藏注空气开发的技术优势,依据室内实验和现场试验的研究成果,阐述了轻质油和稠油不同氧化阶段的氧化反应特征。研究认为,不同氧化阶段地层原油的氧化反应特征存在明显差异：在中低温氧化阶段,氧气直接与原油接触,温度越高氧化反应越强;无论轻质油还是稠油,高温氧化阶段氧化反应的主要对象是焦碳而不是原油。进一步提出了划分轻质油和稠油氧化反应4个阶段的温度区间,轻质油比稠油中温氧化反应的起始温度低,放热量大,轻质油比稠油更容易诱发氧化反应;轻质油高温放热峰值（8.06 mW/mg）略高于中温放热峰值（6.42 mW/mg）,而稠油高温放热峰值却是中温放热峰值的5倍,稠油注空气火驱开发应该以实现高温氧化为主要目标。因此,根据油藏温度和油品性质等关键指标可选择空气驱或火驱等注空气开发方式：当油藏温度小于120℃时,由于氧化放热不明显,为了避免注空气开发的爆炸风险,应以减氧空气驱有效补充地层能量的开发方式为主;当油藏温度大于120℃时,在油藏条件下原油就可发生明显的氧化反应,此时可实施不减氧空气驱,充分利用原油氧化反应放热提高采收率;对于油藏温度小于120℃的稠油油藏,可通过电加热器等人工手段实现高温点火,进行高温火驱开发。