生物表面活性剂作为牺牲剂在三元复合驱中的应用研究

界面活性研究表明，在一定NaOH浓度下，鼠李糖脂发酵液和表面活性剂按不同比例复配后，可以改善界面活性，界面张力代于表面活性剂为主剂形成的三元复合体系与原油的界面张力。说明生物表面活性剂与表面活性剂复配后存在着明显的协同效应。生物表面活性剂中作为牺牲剂，用其对油砂预吸附后可以降低表面活性剂附损失30％左右。在用生物表面活性剂的三元复合驱矿场试验中，表面活性剂用量减少一半情况下，采出井流出物中表面活性剂相对浓度高于未使用生物表面活性剂的三元复合驱矿场试验中流动出物表面活性剂的相对浓度。化学驱原油采收率平均提高16．64％以上。     

超低界面张力下泡沫驱油试验首次获得成功

通过注碱／表面活性剂／聚合物（ASP）降低原油与驱替液之间的界面张力（IFT），可提高采收率和驱替液的粘度，增加体积扫油效率，将天然气添加到碱／表面活性剂／聚合物液体中会形成一种碱／表面活性剂／聚合物泡沫（ASPF）型驱替液，本文介绍了碱／表面活性剂／聚合物泡沫在实验室和现场试验的结果，目前的采收率为原始原油地质储量的65．5％。     

碱／表面活性剂二元复合驱提高普通稠油采收率室内实验研究

针对辽河油区普通稠油锦45块于Ⅱ油层油藏条件,在室内进行了碱／表面活性剂二元复合驱提高原油采收率实验研究。实验筛选出2种碱剂Na2CO3和NaOH,从6种表面活性剂中优选出分别适合于强碱NaOH和弱碱Na2CO3的2种表面活性剂为QYJ-7和J90;考察了碱与表面活性剂之间的最佳协同效应用量范围,碱／表面活性剂组成的最佳复合驱油体系分别为0．2％J90＋1．1％Na2CO3和0．3％QYJ-7＋0．5％NaOH;筛选出的复合体系使水与原油间的界面张力都达到10^-3mN／m数量级以下,室内驱油试验表明,注入段塞体积0．3PV时,驱油效率皆提高20％以上,地层温度下放置30d,体系与原油间的界面张力在10^-2-10^-3mN／m范围,变化不大,表现出较好的长期热稳定性。     

辽河油田欢50块表面活性剂／碱驱油研究

辽河油田欢５０ 块为低渗透油藏,孔隙度小,岩性致密,地层温度高,原油含蜡量高,凝固点高,导致生产时产量下降快,产能低,采出程度低。针对生产中的问题,进行了碱／ 表面活性剂复合驱提高原油采收率的研究。通过研究复合体系溶液与欢５０ 块原油的界面张力、复合体系溶液的长期热稳定性,从７ 种表面活性剂中筛选出既能降低油水界面张力,又能适应该油藏９９℃高温的表面活性剂,并研究了该表面活性剂和碱形成的复合体系在欢５０ 块油砂上的吸附以及复合体系溶液驱油效率。该体系在９９ ℃时能大幅度降低欢５０块原油的油水界面张力（达０．０１ ｍＮ／ｍ 以下） , 并具有很高的驱替效率,水驱后注入复合体系段塞,平均采收率达６５．２４ ％ ,相对于水驱,提高采收率平均为１８．４％ 。并运用核磁共振成像技术研究复合体系溶液的驱油机理,复合体系注入前后核磁共振成像结果表明,复合驱能提高驱替效率,在复合体系前缘形成富集油带,对进一步采出水驱剩余油明显有效。     

以大庆减压渣油为原料的高效、廉价驱油表面活性剂OCS的制备与性能研究

针对现有三元复合驱油体系化学剂费用投入大，经济效益差的缺点，以廉价的大庆减压渣油为原料在实验室内合成出廉价的驱油用表面活性剂OCS，并初步评价了所得OCS样品的性能。结果表明，OCS表面活性剂制备重复性好，性能稳定。OCS表面活性剂具有优异的降低原油一地层水界面张力的能力，在NaOH存在条件下，能在较宽的碱浓度范围内使大庆四厂原油的油-水界面张力降至10^-3mN／m。在Na2CO3存在条件下，能在较宽的碱浓度范围内使大庆四厂原油、华北油田古一联原油及胜利孤东采油厂原油的油-水界面张力降至10^-3mN／m。在无碱条件下，对于大港油田枣园1256断块原油，当OCS表面活性剂含量达到0．1％时，油-水界面张力即可降至10-3^mN／m。对大庆四厂原油的驱油试验结果表明，OCS表面活性剂、碱和聚合物三元复合体系(ASP)的驱油效率比水驱提高20％以上。     

羧酸盐类表面活性剂用于曙22块化学驱油的适应性研究

针对辽河油田曙22块原油,开展了羧酸盐类表面活性剂的适应性研究。结果表明,羧酸盐类表面活性剂适合曙22块化学驱油用剂,其与回注污水具有较好的配伍性及较好的溶解性和抗盐性。确定了碱／羧酸盐表面活性剂驱油体系最佳配方：1．0％-1．5％Na2CO3＋0．3％-0．5％表面活性剂S—1#,其与原油间界面张力达到10^-3mN／m数量级,具有良好的协同效应。加入聚合物,在地层温度（45℃）下放置30d后,聚合物／碱／羧酸盐表面活性剂三元驱油体系与原油间界面张力仍保持在10^-3数量级,具有良好的热稳定性。     

欢喜岭油田欢50块高温油藏提高采收率方法研究

欢喜岭油田欢５０块高温油藏室内提高原油采收率实验结果证明，欢５０块原油／（碱＋表面活性剂）体系的界面张力随温度的升高而降低。可利用界面张力与温度关系曲线外推，获得不易测定的较高温度下界面张力值，由于欢５０块油藏温度很高，表面活性剂的热稳定性成为化学驱成功与否的关键，试验证明，含盐度是影响表面活性剂热稳定性的主要因素之一，配方１．５％Ｎａ２ＣＯ３＋０．４％ＬＨ可满足高温条件下欢５０块油藏原油低张力驱     

热水和表面活性剂驱室内实验

针对辽河油田海26块油藏原油粘度高、常规水驱开发效果差等现状,通过对表面活性剂进行表面活性、界面张力、耐温性和吸附性等性能的评价,筛选出适用于海26块油藏的表面活性剂。通过一维管式驱油实验,研究了注入温度、表面活性剂溶液质量分数、注入方式对原油采收率的影响。结果表明,随着注入温度的不断升高,最终采收率不断增加,当注入温度超过120℃后,原油的最终采收率增加幅度变缓;随着表面活性剂溶液质量分数的增大,最终采收率不断增加,表面活性剂溶液质量分数达到0.3%后,最终采收率增加幅度变缓;表面活性剂与热水多轮次交替注入比单轮次注入表面活性剂的驱油效果要好。在注入温度为120℃、表面活性剂溶液质量分数为0.3%和4轮次交替注入优化参数下,热水和表面活性剂驱的最终采收率为83.67%。     

驱油用石油磺酸盐界面张力与驱油效果研究

通过对BA表面活性剂复配驱油体系的界面张力和驱油效果的研究表明,单独使用BA体系降低界面张力的能力较低,且达到超低界面张力所需的Na2CO3质量浓度范围较窄;BA/异丙醇/NP表面活性剂复配体系(BF-2)降低原油界面张力的能力最优,对Na2CO3浓度适应范围较宽.模拟驱油实验表明,复配体系(BF-2)可增加原油采收率18%.在此基础上,对复配表面活性剂超低界面张力的作用机理进行了探讨.     

阿拉伯原油与不同溶液问动态界面张力实验研究

研究了不同性质溶液（包括碱、盐、聚合物、表面活性剂）与阿拉伯原油间的界面张力。结果表明，NaOH对界面张力的影响较大，它的浓度变化范围是0．1～5wt％（质量百分数），最佳浓度为0．5％～1％，其相应的最低界面张力值为9×10^-2mN／m和5×10^-2mN／m；NaCl对界面张力的影响也较大，它的最佳浓度是1％，5min后界面张力值为5．78mN／m；醇化物驱聚合物由于物理一化学作用短时间内即可降低界面张力。研究表明，碱和醇化物驱聚合物混合加入可使界面张力值显著降低，并测得了不同种类的表面活性剂，包括非离子表面活性剂三硝基甲苯X—100，阴离子活性剂气雾剂OT，阳离子活性剂季胺盐1622，以及破乳剂烷烃DE-316与原油间的界面张力。结果表明，非离子活性剂降低界面张力的能力最强，最佳浓度范围为0．1～0．5wt％。     

稠油热采添加剂性能的研究

对稠油热采用复合表面活性剂WT进行了性能评价。实验结果表明,随着WT质量分数增加,其与孤岛三区原油间动态界面张力呈下降趋势,在较宽质量分数范围内维持在10-1mN/m数量级;90℃下WT在石英砂上的饱和静态吸附量为2.333 mg/g;在150℃下,WT具有良好耐温性能,200℃下,半衰期在15 d以上;在150,170,200℃条件下,WT商品质量分数为1.6%时,热水(蒸汽)/WT驱采收率比同温度下的热水(蒸汽)驱提高6.5%～12.0%。     

Design of Alkaline/Surfactant/Polymer (ASP) Slug and its use in Enhanced Oil Recovery

Abstract

Studies have been done to design an optimum composition of alkali/surfactant/polymer (ASP) slug and its application in flooding to increase the additional recovery of oil. A very low concentration of alkali and surfactant is used to achieve ultra-low interfacial tension between the trapped oil and the injection water, and polymer is used to increase the viscosity of the injection water for mobility control. Based on the experimental results of physico-chemical properties of polymer, surfactant, and alkali and their mutual interaction in solution, an ASP slug of composition SDS: 0.1 wt%, SDBS: 0.075 wt%, polyacrylamide: 2,000 ppm, and NaOH: 0.7 wt% has been recommended for flooding. Two sets of core-flooding experiments have been conducted using the designed ASP slug in a tri-axial core holder to measure the additional recovery of oil. The average additional oil recovery over conventional water flooding was found to be more than 20% of the original oil in place (OOIP).     

三元复合驱的驱油特征研究

大量室内研究和矿场试验结果表明,在高效的表活剂条件下,三元复合驱是一种非常有效的三次采 油方法,具有良好的应用前景。文中应用数值模拟技术并结合室内研究,给出了三元复合体系不同界面张 力和粘度比条件下,在非均质油层中的驱油特征。分析结果表明,三元复合驱与聚合物驱相比,对油层非 均质性有更大的适用范围;对于非均质油层的三元复合驱,采用增加体系的粘度和降低体系的界面张力的 方式都能获得较好的提高采收率效果,但高粘度是获得好的提高采收率的关键;采取分层注入的方式,或 者在三元复合驱后对高渗透层进行封堵,能更有效地采出中、低渗透层的剩余油,进一步提高采收率。本 项研究对认识三元复合驱的驱油机理和编制调整矿场试验方案提供了重要依据。     

Low gas-liquid ratio foam flooding for conventional heavy oil

The recovery of heavy oil by water flooding is 10% lower than that of conventional crude oil,so enhanced oil recovery (EOR) is of great significance for heavy oil.In this paper,foam flooding with a gas-liquid ratio (GLR) of 0.2:1 for the Zhuangxi heavy oil (325 mPa·s at 55 °C) was performed on cores,sand packs and plate model.In sand pack tests,polymer enhanced foam flooding increased oil recovery by 39.8%,which was 11.4% higher than that for alkali/surfactant/polymer (ASP) flooding under the same conditions.Polymer enhanced foam flooding in plate models shows that the low GLR foam flooding increased oil recovery by about 30%,even when the extended water flooding was finished at 90% water cut.Moreover,it was discovered by microscopy that foam was more stable in heavy oil than in light oil.These results confirm that low GLR foam flooding is a promising technology for displacing conventional heavy oil.     

利用微生物大幅度改善化学驱效果

针对大庆油田原油酸值低、应用三元复合驱难度大等特点,筛选了两株具有良好的产酸、产表面活性剂和改善原油物性的菌种,经鉴定分别为短短芽孢杆菌和蜡状芽孢杆菌。这两株菌可以降解原油中重质成分,尤其是高碳链(C₂₀以上)饱和烃,产生大量的胞外有机酸,可使原油酸值平均升高10倍以上。在发酵液中代谢产生混合酯类生物表面活性剂和低分子量有机酸、醇。微生物作用原油后,产生的有机酸在碱性条件下能与合成表面活性剂产生很好的协同作用,使微生物作用后原油与现有三元复合体系形成更低的界面张力,平均比未作用原油体系界面张力降低一个数量级,达到10^-4mN/m数量级。室内天然岩心驱油实验评价结果表明,微生物-三元复合驱结合可比单独三元复合驱驱油效率增加近10% OOIP。     

Evaluation of Interfacial Tension Between Zahra Oil and ASP Solution

Alkaline-surfactant-polymer (ASP) flooding has been proved to be an effective enhanced oil recovery (EOR) method. Reduction of interfacial tension (IFT) between crude oil and ASP solution is the main mechanism in ASP flooding. Evaluating IFT between crude oil and ASP solution is a key parameter for ASP flooding in laboratory experiments or field projects. In order to obtain good result of ASP flooding in the reservoir in Zahra field, the influence of the concentration of Na₂CO₃ on IFT between Zahra crude oil and ASP solution with three different surfactants, BHJC, SS-231, and SS-233, was researched. IFT was measured with surface tension meter SVT20N, Dataphysics Co. Germany, at 72°C. For the view of IFT result anionic surfactant BHJC is more suitable for the Zahra oil field. This research is helpful for practical application of ASP flooding in Zahra oil field.     

华北油田京11断块三元复合驱配方研究

针对华北油田京11断块油藏原油黏度低、酸值低、水驱采收宰高和储集层黏土含量高等特点，优选得到适合于该油藏的最佳低浓度弱碱三元复合体系：2SY重烷基苯磺酸盐表面活性剂(0．15%)／Na2C03(0．5%)／SY(1．5g／L)。采用实验方法，系统研究京11断块环境因素对该三元复合体系的界面张力性质、流交性以及表面活性剂和碱剂吸附损耗的影响，结果表明：该体系对矿化度、多价金属离子浓度变化以及稀释效应等环境因素影响的耐受性较强。物理模型驱油效率试验结果表明：在水驱至含水98%后，相继注入0．3倍孔隙体积最佳三元复合体系主段塞和0．2倍孔隙体积1．2g／L聚合物溶液保护段塞，可提高采收率21%以上。图3表6参7     

The Demulsification of Crude Emulsion of ASP Flooding by an Organic Silicone Demulsifier

Abstract

In order to enhance crude oil recovery, the dosages of alkali, surfactant, and polymer in the tertiary flooding are becoming increasingly higher, which makes the emulsion more difficult to demulsify. In this article the application of new organic silicone demulsifiers for the demulsification of produced crude emulsion of alkali-surfactant-polymer (ASP) flooding with higher concentrations of alkali, surfactant, and polymer was investigated. The result indicated that organic silicone demulsifiers whose hydrophile–lipophile balance (HLB) number ranged from 10 to 15 had a satisfactory effect on demulsification. The dewatering efficiency can be improved evidently by adding a demulsifier mixed with DC2 and JG31 whose volume ratio was 4:1. The dewatering efficiency for produced crude emulsion from ASP flooding could exceed 80% at 60°C in which the concentrations of alkali, polymer, and surfactant ranged from 1,200 to 9,000 mg/L, 400 to 1,000 mg/L, and 200 to 800 mg/L, respectively. The simulative industrialized experiment of the ASP flooding produced emulsion was made, the dewatering efficiency was 99.6%, and the oil content of the produced water was less than 100 mg/L.     

STUDYING THE INTERACTIONS BETWEEN AN ARABIAN HEAVY CRUDE OIL AND ALKALINE SOLUTIONS

An experimental study to examine the effectiveness of alkaline flooding for the recovery of an Arabian heavy crude oil is presented. The interfacial tension (IFT) behavior of crude oil/alkali systems over a wide range of parameters (pressure, temperature, alkali concentration and time) was studied. These alkaline reagents react with the acidic species in crude oil to form surface-active soaps in-situ. This leads to a lowering of interfacial tension (IFT) and subsequently the mobilization of residual oil. The equilibrium IFTs obtained through alkaline flooding are compared with the IFTs when a synthetic surfactant (dodecyl benzene sulfonic acid sodium salt) is used in EOR recovery. A mathematical model representing the complete chemistry of the transient process is also presented. The model consists of a set of differential equations describing reactions, diffusion, and adsorption at the oil/alkaline solution interface. The kinetic parameters in the model are obtained through a differential algebraic optimization technique. The concentration of the surface active species are related to the measured IFTs through an independent step that is based on isolating the surface active species formed by the reaction between the acids in the crude oil and the alkaline solution. A sensitivity analysis using the model is carried out to study the effect of surface potential and alkaline concentration on the transient interfacial tensions.     

Evaluation of a new alkaline/microbe/polymer flooding system for enhancing heavy oil recovery

The new alkaline/microbe/polymer (AMP) flooding system was first constructed and evaluated for enhancing oil recovery. The system is composed of 0.3?wt% Na₂CO₃, 2?wt% microbial cultures and 0.2?wt% polymer. Compared with the conventional alkaline/surfactant/polymer (ASP) system, the AMP system exhibits identical displacement properties. Chromatography analysis reveals crude oil is not negatively affected by the microbes in AMP system. Further comparative core flooding experiments using the AMP and ASP systems demonstrate that the AMP system possesses greater potential for enhancing heavy oil recovery, which shows the characteristic of two-stage additional oil increment with total additional oil recovery of 17.11%–19.91%.