The influence factors analysis of the light crude oil oxidation reaction process

During the high pressure air injection process, there are different types of oxidation reactions, which do not exist, and the predominant reaction type of is dependent on the specific conditions. In this study the influences of formation temperature, pressure, and oxidation time on light crude oxidation have been studied via oxidation experiments. And it is shown that the reaction types could be effectively improved by the temperature increment, which decreases the oil viscosity. As well, the pressure and oxidation time have obvious effects that were mainly present in oxygen addition reactions and the viscosity increase.     

Thermal kinetics investigation on light oil oxidation during high-pressure hypoxic air injection process

In this work, the effects of oxygen concentration and reservoir cutting on thermokinetic characteristics of light oil were analyzed using thermogravimetry (TG/DTG). Results show that three consecutive oxidation reactions of distinct chemical mechanism (low-temperature oxidation [LTO], fuel deposition [FD], and high-temperature oxidation) are detected for all tested samples. Hypoxic air weakens the LTO and FD process and causes a poor FD performance, while reservoir cutting positively influences the thermal characteristics of oil. Kinetic parameters comparison exhibits that the positive effect of reservoir cutting on oil oxidation is significantly stronger than the negative impact caused by hypoxic air. The existence of reservoir cutting greatly reduces the activation energy of oil oxidation in hypoxic air environment, which is a positive signal for the implementation of high-pressure hypoxic air injection process.     

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。     

Oxidation kinetics of Wolfcamp light oil

Air injection has been used for decades as an enhanced oil recovery method. An oxidation kinetics study is important for the application of air injection. Low-temperature oxidation is more feasible in light oil reservoirs. Although an experiment using a small batch reactor has been conducted before, the reaction order with respect to the oxygen partial pressure was not well studied. The authors use a small batch reactor to study the effect of temperature and pressure on the oxygen consumption rate of the Wolfcamp light oil. The reaction order, the activation energy, and Arrhenius constant are calculated.     

轻质油藏注空气低温高压氧化实验研究

空气驱是颇具发展前景的清洁、高效的提高采收率新技术。针对某轻质油藏流体特性开展了轻质原油与空气低温高压氧化实验研究。研究结果表明,氧化反应能大幅度降低空气中的氧气含量,使含氧量下降到安全范围内;氧化反应中有CO2和醛类等新物质生成,同时发生中间烃裂解现象。在实验条件下,裂解轻烃、自生CO2和空气中的N2对原油表现出较强的抽提能力。     

压力对轻质原油氧化动力学参数的影响

利用高压差示扫描量热仪(PDSC)研究了不同压力下轻质原油的氧化放热特性,并结合Friedman方法计算了反应体系的活化能,分析了不同反应阶段压力对氧化动力学参数的影响。结果表明:随着压力升高,放热起始温度、峰值温度和反应结束温度均趋向低温,放热量也随之增大,尤其低温氧化放热速度大幅提高,氧化反应明显加强,说明压力增大导致原油在低温下更容易发生氧化反应;活化能在低温氧化前期迅速上升再下降,进入低温氧化后期趋于稳定,到高温氧化阶段再次上升,活化能随反应进程的波动,说明原油反应行为或反应速度发生了变化;对比不同压力下各反应阶段的活化能发现,活化能均随压力升高而降低,说明压力对氧化反应有促进作用,压力越大,反应越容易进行。     

Influence of clay minerals on oxidation reaction of light crude oil

By means of the static oxidation test of crude oil, the influence of clay minerals on the light crude oil oxidation reaction under reservoir temperature and pressure was investigated by means of orthogonality analysis method. Based on the thermogravimetric analysis, the oxidation characteristics of clay minerals on crude oil during heating were analyzed. The results show that the clay minerals have different catalytic effects on light crude oil, of which montmorillonite has the best catalytic effect and kaolinite has the worst. And they have the positive effect to light crude oil on air injection, which could enhance oil recovery.     

利用高压注空气技术开发低渗透轻质油油藏

本文主要介绍了利用高压注空气技术提高低渗透轻质油油藏采收率的原理，及其与稠油火烧油层工艺的主要区别，综合国外现场及实验室的研究资料，指出：油藏在空气过程中自燃、烟道气与轻质油油藏条件下发生混相，是低渗透轻质油油藏注空气成功开发的2个主要条件。并列举了国外注空气开发低渗透轻质油油藏的几个成功实例。     

稀油火烧油层物理模拟

注空气开发主要分为稀油注空气低温氧化以及稠油火烧油层2种技术。针对轻质原油火烧油层技术开展研究,采用热重/差示扫描量热同步热分析仪研究稀油高温氧化放热特性和反应动力学参数;在实验压力为5 MPa条件下采用高压燃烧管研究稀油高温火烧前缘传播稳定性以及稀油火烧油层基础参数。研究结果表明:测试稀油高温氧化活化能为148 kJ/mol,与文献中稠油高温燃烧反应活化能相近;人工点火后,稀油可以形成稳定的高温氧化前缘,实现稳定的高温燃烧驱替,前缘温度高达500℃;出口CO₂浓度和燃料的视H/C原子比进一步证明,燃烧前缘处的反应类型为高温氧化反应;稀油火烧油层驱油效率达92%,空气/油比为858 m³/t,具有较高的驱油效率和较低空气/油比。     

倾油性有机质生成轻质油的评价方法及其应用

将有机质成烃的过程分解为有机质生成C₁₄⁺油、C₆—C₁₃轻质油及C₅^-天然气3组平行过程,进行了求取各组成烃反应化学动力学参数所需的模拟实验,建立并标定了3组化学动力学模型。运用该模型评价了松辽盆地齐家—古龙凹陷3类油气组分的生成量、排出量及凝析油气的资源量。结果表明,区内凝析油的资源量约为(150~870)×10⁴m³,对应的凝析气的量为(750~4350)×10⁷m³,总体资源潜力不大,但轻质油的总资源量可高达22.3×10⁸t。     

吐哈盆地鄯善油田轻质油藏注空气开发机理研究

为了探讨轻质油藏注空气提高采收率的机理,在注空气室内实验研究的基础上,运用热采数值模拟技术．研究了鄯善油田不同开发阶段注空气后油藏内原油低温氧化反应过程、相态变化规律及分布特征、油藏能量的变化规律;同时研究了油藏温度、油藏压力和空气注入速度等因素对轻质油藏注空气开发效果的影响,阐明了注空气开发的主要驱油机理,即烟道气驱和附加的热效应,对轻质油藏注空气开发矿场试验具有一定的指导作用。     

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.     

准噶尔盆地车排子地区轻质油运移方向研究

准噶尔盆地车排子地区在新近系沙湾组分布有轻质油油藏,前人研究认为轻质油主要来源于侏罗系八道湾组烃源岩。根据车排子地区轻质油的物性、含氮化合物及生物标志化合物等参数变化特征来综合分析该区油气的运移,指出研究区轻质油具有从西南向东北运移的趋势,轻质油应该主要来源于四棵树凹陷东南部的侏罗系烃源岩,并探讨了油气成藏模式,对该区油气勘探部署具有一定的指导意义。     

常压炉出口温度平稳率对轻质油收率的影响探讨

胜利油田分公司石油化工总厂常减压蒸馏装置常压炉出口温度频繁大幅度波动,平均平稳率仅为59.34％,造成常压塔温度和压力波动,给平稳操作带来困难,影响装置轻质油收率.通过分析影响常压炉出口温度的因素（包括工艺过程、仪表控制、燃料系统及原油性质等）,采取修改初馏塔塔底液位控制方案、调整炉出口温度及初馏塔塔底液位的PID控制参数,补充燃料油以稳定燃料气压力等措施,使炉出口温度的平稳率提高到90％以上,从而稳定了换热网络的温度,提高了轻质油收率,降低了减压塔的负荷,取得了较好的经济效益及社会效益.     

Numerical simulation of water-alternating-gas (WAG) in a light oil reservoir

In Brazil, the development of giant deepwater fields seems to have reached a new scale in 2006, with the huge Tupi discovery. As the water-alternating-gas (WAG) process can take advantage of the only two somehow abundant resources available (seawater and the produced or imported gas), the authors present a parametric study of the WAG process, applied to a homogeneous and semisynthetic reservoir, with a light oil, being similar to the average properties found in the Brazilian Pre-Salt. At the end, it was verified the need of a more accurate study before implementing a WAG project.     

继注水后向轻质油油藏注空气的探索

对于许多处于二次采油和三次采油阶段的轻质油油藏,注入空气具有多种提高采收率机理和作用,尤其是深部油藏,可获得独特的经济技术效果。本文介绍有关注空气的室内试验、数值模拟及现场应用与先导试验设计,同时探讨这种工艺方法在提高采收率方面的效果。     

Thermal investigation on crude oil oxidation kinetics through TG/DTG and DTA tests

In this nonisothermal research, the thermal behavior and oxidation kinetics of crude oils were investigated through TG/DTG and DTA tests at three heating rates. The resulting curves exhibit three integrated reactions of distinct oxidation mechanisms (LTO, FD, and HTO) sequentially in overlapped temperature intervals as reaction progresses, the behaviors of that are affected greatly by heating rate. Because of the larger amounts of heavy components and higher availability of deposited fuel, heavy oil exhibits more excellent heat release capability but higher kinetic parameters than light oil, especially in HTO region. Due to the insufficient parameters calculation based on a single kinetic method, other formulated models would be introduced for comparative analysis in the next work to upgrade kinetic research.     

低渗透复杂小断块轻油油藏CO_2吞吐研究

主要分析了江苏富民油田（以下简称ＦＭ油田）富４６（以下简称Ｆ４６）断块生产井Ｆ４８进行ＣＯ２吞吐的室内研究和矿场试验结果。室内长岩心吞吐试验结果表明：ＣＯ２吞吐最佳注入量为０．２～０．３ＰＶ，可增加水驱残余油采收率１０％以上；数值模拟结果表明：控制ＣＯ２注入量（＜１２１．３×１０３ｍ３）、浸泡期（７天）、返排速度（＜５０ｍ３／ｄ）及提高注入速度可获得最佳的吞吐效果，但第二周期吞吐效果远不如第一周期吞吐效果好，这可以用增加采油量和换油率（ＣＯ２利用率的倒数）来评价。现场试验采用管线输送和液态注入工艺方法，实施后，Ｆ４８井初期日增油８ｔ，有效期１４个月，累积净增油１５００ｔ，投入产出比为１∶５．８２，内部收益率８９％。证明ＣＯ２吞吐技术在低渗透复杂小断块轻油油藏运用是可行的。     

聚合物驱油过程中形成油墙的动力学机理研究

目前关于聚合物驱油过程是否形成油墙可以根据产出液含水率曲线的变化特征进行推断,也可以通过在物理模拟模型上直接动态监测含油饱和度的方法判断,这些方法没有从理论上系统说明油墙形成的原因和过程.为了从理论上系统研究油墙的形成,利用分流理论,在分流方程的基础上,建立了聚合物驱油过程中形成油墙的动力学机理数学模型,根据聚合物驱油的基本规律,利用所建立的形成油墙动力学机理数学模型,证明了水驱过程含油饱和度表现出非增的现象,不会形成油墙;而在聚合物驱过程中,含油饱和度表现出增加的现象,有油墙形成.利用所建立的油墙形成动力学机理数学模型可以研究聚合物驱油过程油墙形成的时机,油墙规模大小的影响因素,从而为聚合物驱油过程分子量和注入浓度的选取提供科学的理论依据.