Effect of acid number of crude oil on oil recovery of smart water coupled with silica nanoparticles

Spontaneous imbibition (SI) is one of the most important mechanisms in reservoir engineering. In order to activate of this mechanism completely in carbonate reservoirs, wettability of these oil wet rocks should be altered to water-wet. Multi-step spontaneous imbibition tests were designed and conducted in this study. Results indicated that mixture of smart water and nano silica could increase oil recovery up to 5 percent. Effect of acid number of crude oil on oil recovery of this mixture was investigated by using three samples of crude oil during SI tests: A (0.38 mg KOH/g), B (0.25 mg KOH/g) and C (0.18 mg KOH/g). Maximum oil recovery of SI tests was recorded for oil sample C which had lowest acid number. Ion analysis of imbibing fluids indicated sharp reductions in concentration of sulfate ion in each step of SI tests which confirmed occurrence of ion exchange mechanism in the rock surface of core samples.     

高酸值原油的成因与分布

原油酸值是表示原油中酸性物质总含量的参数,即中和1g原油所需要的KOH的数量。对世界大量原油酸值进行了调研,并根据酸值的大小将原油划分为正常原油、含酸原油、高酸值原油和特高酸值原油。其中将酸值高于1mg/g的原油称为高酸值原油。根据高酸值原油的成因,进一步划分出原生高酸值原油、次生生物降解型高酸值原油和混合型高酸值原油。研究发现,海相和湖相环境生成的原油,其酸值随生物降解程度的增加而增加的速率不同,湖相远高于海相。全球高酸值原油主要由生物降解作用形成,主要储量分布在前陆盆地的前缘地带,以大型地层圈闭油藏为主;其次分布在裂谷盆地、被动大陆边缘盆地和克拉通盆地含油气系统的边缘和浅层的各种背斜、断块和地层圈闭中。     

超高酸原油中环烷酸类型及分布规律研究

通过对国内某原油进行实沸点切割和环烷酸分离,采用电位滴定仪、红外光谱仪及质谱仪等研究原油、馏分油中环烷酸分布及类型.研究结果表明:原油酸值为13.18 mg(KOH)/g,属于超高酸原油,其环烷酸主要集中为400～425℃,425～450℃和>450℃馏分,分别占原油总酸质量的4.68％,5.34％和54.44％;超高...     

苏丹Melut盆地Palogue油田高酸值原油成因

苏丹Melut盆地Palogue油田原油主要为中质油(20API°34),其次为重质油(API°20),但普遍高含酸,酸值最高可达10 mg/g。高酸值原油主要产于古近系砂岩储集层,上白垩统产层原油酸值相对较低,一般低于1 mg/g。地球化学分析认为:下白垩统Alrenk组烃源岩于晚白垩世末期开始生烃,并在上白垩统和古近系储集层中聚集成藏;由于渐新统末期构造运动造成地层抬升和剥蚀,烃源岩生、排烃停止,地表淡水注入古近系,形成重碳酸钠型地层水,使古近系油藏遭受生物降解,形成高酸值重油,深大断裂活动造成地壳深部CO2气体侵入,加速了高酸值油藏的形成;新近纪盆地发生拗陷作用,使烃源岩继续深埋,重新开始生、排烃,新生成的正常原油不断充注到古近系油藏,形成早期降解油与后期正常油混合的混合油藏,由此形成了酸值不等的高酸值油藏。图4表3参11     

The Removal of Naphthenic Acids from Beijiang Crude Oil With a Sodium Hydroxide Solution of Ethanol

Abstract

A new method is introduced in this article to separate naphthenic acids from Beijiang highly acidic crude oil with a sodium hydroxide solution of ethanol. The sodium hydroxide solution of ethanol was used as the acid removal reagent by mixing with the crude oil and then allowing the two phases to separate, with the naphthenic acids being extracted from the crude oil. Data indicated that the optimal content of sodium hydroxide in crude oil was 3,000 μg/g and the optimal extraction time was 5 min with the reagent/oil ratio being 0.4:1 (wt/wt). The suitable reaction temperature could be room temperature. The total acid number of the crude oil was lowered from 3.92 to 0.31 mg KOH/g and the acid removal could reach up to 92.1%.     

无机碱非水溶液脱除高酸原油中的环烷酸

以NaOH无水乙醇溶液为萃取剂,与高酸原油中的环烷酸进行一级萃取反应。通过界面张力分析和显微镜观察油相水滴分布情况表明,该脱酸方法不会引起油水乳化现象,要求醇的含水质量分数控制在4%以下。结果表明,小型混合澄清槽连续化操作的优化工艺条件为:NaOH用量3 200μg/g,反应温度55℃,反应时间5 min,溶剂/原料油(质量比)0.4,搅拌速率350 r/min。原油经脱酸反应后,酸值(KOH)可降低到0.28 mg/g,脱酸率达到94.2%。     

电位滴定法测定原油酸值

从测定酸值用的滴定溶剂中筛选出能够快速溶解原油(特别是稠油)的溶剂,考察了原油中的水与无机盐对电位滴定法测定原油酸值的影响。结果表明,甲苯/异丙醇/四氢呋喃/水混合溶剂(体积比=50.0:24.5:25.0:0.5)能快速溶解稠油,在电位滴定法中用该滴定溶剂测定原油酸值准确、快速。对滴定曲线有明显突跃的原油。原油中水与无机盐对原油酸值测定结果没有影响。对滴定曲线没有明显突跃的原油,当水含量≤5％或无机盐含量≤100μg/g时,对测定结果影响很小;但水含量>5％或无机盐含量>100μg/g时,原油酸值随水含量或无机盐含量的增加而增加。     

减二线馏分油微波辐射脱酸新方法的研究

以NaOH与去离子水为复合溶剂用微波辐射法对江苏减二线馏分油进行了脱酸精制研究。得到的最佳精制条件为 :V(复合溶剂 )∶V(油 ) =0 .2 2∶1、压力 0 .0 9MPa、恒压辐射时间 4min、微波功率 375W、静置时间 2 5min。馏分油的酸值 (KOH)由 0 .5 7mg/ g降至 0 .0 4 81mg/ g ,馏分油回收率为 99.3%。     

Variations in wetting behavior of mixed-wet cores resulting from probe oil solvency and exposure to synthetic oil-based mud emulsifiers

Mixed wettability (MXW) results from adsorption from crude oil on rock surface which is not overlain by bulk water. Crude oil/brine/rock interactions and their effect on oil recovery are often investigated after replacing the crude oil with a mineral oil. If crude oil is displaced directly by mineral oil, extreme wettability alteration, referred to as MXW-DF (direct flood), is observed. Less change is observed if an intermediate solvent, such as decalin, is used to avoid destabilization of asphaltenes contained in the crude oil; wettability conditions attained by this treatment are referred to as MXW-F (film). The oil used in a displacement test is referred to as the probe oil, the most common choice being either crude oil or mineral oil. There is strong practical interest in developing MXW-F cores that have wetting properties that are comparable to wettability at reservoir conditions. The main objective of this work is to compare the effect of probe oil solvency, characterized by refractive index, on wetting behavior, characterized by spontaneous imbibition, with MXW wettability given by the parent crude oil. The tested probe oils included mineral oils, alkanes, decalin, toluene, alpha-methylnaphthalene (AMN), crude oils and modified crude oils with both increased and reduced solvency, and base oils and solutions of emulsifiers used in synthetic oil-based mud (SBM) formulations. Wettability established by direct displacement of crude oil with an alkane (MXW-DF) showed systematic increase in water wetness with increase in solvency of the probe oil. Other approaches to tuning MXW-F wettability states by choice of probe oil are also presented. Base oils used in the formulation of SBM had essentially no effect on the imbibition behavior of MXW-F, whereas exposure of MXW-F cores to two kinds of emulsifier resulted in persistently suppressed imbibition for a wide range of probe oils.     

油溶性优良的环保型异硬脂酸钙清净剂的合成及评价

本文使用异硬脂酸及氢氧化钙为主要原料,合成了一种油溶性优良的异硬脂酸钙清净剂。其反应工艺条件包括氢氧化钙与异硬脂酸的摩尔比、甲醇和氢氧化钙的摩尔比、水与氢氧化钙的摩尔比、碳酸化反应温度、二氧化碳的通入速率及通入量均被优化。在最佳工艺条件下,可以分别得到碱值为358mgKOH/g的高碱值异硬脂酸钙清净剂产品及碱值为406mgKOH/g的超高碱值异硬脂酸钙清净剂产品。最终,异硬脂酸钙清净剂的性能通过粒度分析、热重分析及成焦倾向测试进行了评价。     

加工高酸高钙原油延迟焦化装置工艺设备选材及腐蚀情况分析

介绍了加工环烷酸含量(KOH)高这13．82mg/g原油的延迟焦化装置工艺设备的选材情况,并提供了该装置投产一年后的挂片腐蚀试验数据。为同类装置的设计选材提供了借鉴。     

聚羧酸螯合剂的制备及原油酸性氧化脱有机钙的实验研究

实验以丙烯酸、马来酸酐、丙烯酰胺为单体,过硫酸钾为引发剂,于70～90℃反应4～6 h,合成一种多酰胺基多羧基聚羧酸螯合剂,并用EDTA标准溶液测定了其钙螯合性能,傅里叶红外光谱仪进行了结构表征。在SH-Ⅱ型电脱盐仪上考察了该螯合剂在弱酸性氧化条件下,对4种原油有机钙脱除效果。实验结果表明,当丙烯酸、马来酸酐、丙烯酰胺单体摩尔比为4:7:2时,对钙的螯合力达99.38 mg/g;经弱酸性氧化剂H_2O_2抽提后,原油中有机钙含量降低16%～20%;在剂钙摩尔比为2.5、温度为125～130℃时,该螯合剂对三种实验原油有机钙的脱除率达75%,同时对Mg、Fe、Ni也可部分脱除。     

Effects of Process Conditions on Desalting and Demetalization of Crude Oil

The efficiency of desalting for six crude oils was studied with a SY-1 dynamic simulation experimental installation. The demulsifier DC2 was examined for 1#, 2#, and 4# crude oil and DC4 was used for 3#, 5#, and 6# crude oil. The effects of temperature, electric field gradient, dosage of demulsifier, and washing water on the desalting efficiency of six crude oils were investigated. The results showed that at the optimization process condition after desalting, the desalting efficiency and the salt content of 1# crude oil reached 89.17% and 1.92 mg/L; that of 2# crude oil reached 85.08% and 1.04 mg/L; that of 3# crude oil reached 91.06% and 1.35 mg/L; that of 4# crude oil reached 81.67% and 1.51 mg/L; that of 5# crude oil reached 81.03% and 2.32 mg/L; and that of 6# crude oil reached 86.64% and 2.67 mg/L. Different crude oils have different metal contents. Three assistants, ammonium nitrate (TJ1), nitric acid (TJ3), and polyamine carboxylate (TJ4), were used to improve the efficiencies of desalting and demetalization of six crude oils. TJ4 was more efficient in removing calcium and iron for 1# and 2# crude oil. TJ1 was more efficient in desalting and demetalizing 5# crude oil. The efficiencies for removal of calcium, iron, nickel, and vanadium respectively reached 99.89%, 98.33%, 20.58%, and 43.02%. TJ3 has better efficiency desalting and demetalizing for 6# crude oil. With the concentration of TJ3 increasing from 0 to 80 mg/L, the desalting efficiency increases from 31.22% to 73.54%, and the iron removal efficiency increases from 56.0% to 74.05%.     

Effects of Process Conditions on Desalting and Demetalization of Crude Oil

Abstract

The efficiency of desalting for six crude oils was studied with a SY-1 dynamic simulation experimental installation. The demulsifier DC2 was examined for 1#, 2#, and 4# crude oil and DC4 was used for 3#, 5#, and 6# crude oil. The effects of temperature, electric field gradient, dosage of demulsifier, and washing water on the desalting efficiency of six crude oils were investigated. The results showed that at the optimization process condition after desalting, the desalting efficiency and the salt content of 1# crude oil reached 89.17% and 1.92 mg/L; that of 2# crude oil reached 85.08% and 1.04 mg/L; that of 3# crude oil reached 91.06% and 1.35 mg/L; that of 4# crude oil reached 81.67% and 1.51 mg/L; that of 5# crude oil reached 81.03% and 2.32 mg/L; and that of 6# crude oil reached 86.64% and 2.67 mg/L. Different crude oils have different metal contents. Three assistants, ammonium nitrate (TJ1), nitric acid (TJ3), and polyamine carboxylate (TJ4), were used to improve the efficiencies of desalting and demetalization of six crude oils. TJ4 was more efficient in removing calcium and iron for 1# and 2# crude oil. TJ1 was more efficient in desalting and demetalizing 5# crude oil. The efficiencies for removal of calcium, iron, nickel, and vanadium respectively reached 99.89%, 98.33%, 20.58%, and 43.02%. TJ3 has better efficiency desalting and demetalizing for 6# crude oil. With the concentration of TJ3 increasing from 0 to 80 mg/L, the desalting efficiency increases from 31.22% to 73.54%, and the iron removal efficiency increases from 56.0% to 74.05%.     

OCCURRENCE AND DISTRIBUTION OF n-ALKANESAND n-FATTY ACIDS IN SAUDI ARABIAN CRUDE OILS

Ten crude oil samples, covering wide range of maturity (API gravity = 18·5-36·1), were assembled from Safaniya, Abqiq, Ain Dar, Wafra. Marjan and Zuluf oil fields in the area of Arabian Gulf. n-Alkanes of were separated from the petroleum distillate ((150°C-450°C) of the crude oils by urea adduction. n-Fatty acids were separated from the fraction of n-alkanes by treatment with aqueous solution of KOH. Distribution of n-alkanes and n-fatty acids has been investigated by means of gas chromatography. The studied crude oils showed symmetrical distribution curves of n-paraffins and fatty acids of low molecular weight were abundant as compared with n-paraffins. The n-paraffins distribution curve of Wafra/Iucene biodegraded immature crude oil showed three maxima at C₁₇, C₁₉, and C₃₁ whereas the maxima of n-fatty acids are located at C₁₄,C₂₂and C₂₄. The results were interpreted in terms of origin, maturation and depositional environments of the crude oils.     

快速蒸馏法及其在原油酸值分布规律研究中的应用

原油和馏分的酸值(TAN)是反映其加工过程中腐蚀性的重要指标。传统的实沸点蒸馏(TBP)方法未考虑石油酸在原油蒸馏过程中的分解,得到的馏分酸值严重偏低,影响了对馏分腐蚀性的判断以及相应防腐措施的制订。为此开发了一种原油快速蒸馏(RD)仪,采用短分馏柱、高真空度、高蒸馏速率对原油进行分段蒸馏切割,有效避免了原油中石油酸的分解,使各馏分酸值的加权值达到了原油酸值的90%以上。在此基础上,研究了几种典型高酸原油酸值的分布规律,发现原油可馏出部分的酸值基本上都是随着沸点的升高而增高。另外,通过傅里叶变换离子回旋共振质谱(FT-ICR MS)分析表明,实沸点蒸馏过程中酸值降低的主要原因是大分子石油酸的分解,而与石油酸的类型相关性较小。     

实沸点蒸馏对2种高酸原油腐蚀性的影响及表征

高酸原油经实沸点蒸馏后酸值会发生较大程度的损失,哪些类型的石油酸发生了损失及高酸原油腐蚀性是否同等降低却不得而知。针对这一问题,对2种典型高酸原油实沸点蒸馏前后的酸值和腐蚀性进行了考察,并对蒸馏前后高酸原油中的石油酸进行了质谱表征。结果表明：2种高酸原油实沸点蒸馏后液相腐蚀速率减小,而气相腐蚀速率明显增大,说明大分子石油酸分解成了沸点较低的小分子石油酸;2种高酸原油的气、液总腐蚀速率降低都远小于酸值的损失,说明分解生成的小分子石油酸的腐蚀性更强;2种高酸原油实沸点蒸馏前后石油酸的类型变化不大,但碳数分布变化明显,碳数越高的大分子石油酸分解越多。高酸原油的腐蚀性与酸值并非线性关系,石油酸的类型即脂肪酸和一环环烷酸含量可能是影响高酸原油腐蚀性的重要因素。     

原油／碱－聚合物水溶液乳状液流变性研究

测定了不同含油率的大港羊三木原油／碱－聚合物水溶波乳状液的流变性，用七个流变方程对实测结果进行了曲线拟合，发现此乳状液服从Ｃａｓｓｏｎ方程，结合显微观察结果讨论并解释了乳状液粘度和ＣＡｓｓｏｎ方程参数随含油率和剪切速率变化的规律。     

于离子液体的高酸原油脱酸效果研究

利用咪唑和环烷酸反应生成与原油极性差异大、易于分离的离子液体，脱除原油中的环烷酸。考察了咪唑含量、剂油比、反应时间、反应温度和搅拌速率对高酸原油一级脱酸效果的影响，并在所选的一级脱酸反应条件下，进一步考察了三级逆流萃取的脱酸效果。结果表明，在咪唑质量分数为30%、剂油质量比为0.4、反应时间5 min、反应温度30 ℃、搅拌速率300 r/min的条件下，北疆原油的一级脱酸率可达61.5%，酸值较低的蓬莱原油的一级脱酸率可达68.6%，酸值更低的1号和2号调和油一级脱酸率分别达到了70.6%和72.2%。试验所用的四种原油在剂油质量比为0.4时，三级逆流萃取的脱酸率可以提高到75%左右；当剂油质量比增大到0.6时，三级逆流萃取的脱酸率可达到84%以上。     

催化酯化地沟油的裂解油制备燃料油

以地沟油为原料,通过高温热裂解得到高酸值85mg（KOH）／g的裂解油,进而通过催化酯化反应降低热裂解油的酸值。讨论了催化剂种类、甲醇用量等因素对酯化率的影响。结果表明,以自制的S2O8^2-／ZrO2固体超强酸作催化剂,甲醇用量（以裂解油质量计）为30％时,酯化效果最好,可以使裂解油酸值降至2mg（KOH）／g。还考察了催化剂的使用寿命,结果表明,催化剂使用到第3次时,酯化率仍可达到84．8％。酯化后裂解油的燃料油性能有所改善。