表面活性剂乳化性能对低渗油藏采收率影响研究

为同时解决低渗透油藏面临注入困难和储层非均质性强的问题,基于表面活性剂的降压增注原理和乳化调驱机理,探讨了表面活性剂驱油体系在低渗透油藏的应用可行性。实验选取乳化能力不同,其余性能(降低油水界面张力能力、改变润湿性能力、吸附性能)相同的两种表面活性剂,通过室内洗油实验、岩心注入实验和驱油实验,评价了表面活性剂降压增注性能和低渗透条件下乳状液深部调驱性能,探讨了表面活性剂在低渗透油藏中的提高采收率机理。研究结果表明:乳化能力不同的两种表面活性剂具有相近的洗油能力;乳化能力强的表面活性剂在岩心中驱替原油的过程中会形成稳定的乳状液体系,这会降低表面活性剂的降压增注效果,但却可以起到深部调驱作用,可有效提升驱油剂的波及范围,提升低渗透油藏原油采收率。低渗透油藏表面活性剂驱油体系的筛选,需综合考虑提高采收率效果及降压增注性能,根据油藏实际情况选取性能不同的表面活性剂驱油体系。     

沙7区块聚/表二元体系驱油效果研究

研究了表面活性剂对原油/水界面张力、乳化作用以及对岩石润湿性的影响,开展了表面活性剂和聚合物/表面活性剂二元体系提高低渗透油藏石油采收率的实验研究。结果表明,超低界面张力是影响石油采收率的重要因素,具有良好乳化性能的驱油体系能起到更好的驱油效果,聚合物/表面活性剂二元驱油体系具有更高的提高石油采收率的效能。     

低渗透油藏阴离子/非离子表面活性剂复配机理研究

针对低渗透油藏注水开发采收率低的问题,进行了阴非复配表面活性剂的筛选与评价研究。通过对界面张力及乳化性能的测定,确定十二烷基苯基磺酸盐(SDBS)与脂肪醇聚氧乙烯醚(AEO-9)进行复配,具有良好的表面活性剂性能。通过阴非复配体系的特点、相渗曲线分析以及岩心驱替实验,发现SDBS/AEO-9阴非复配体系具有降低注入压力、提高最终采收率的能力,能够很好的应用于低渗透油藏。确定当表面活性剂浓度为0.5%时,该表面活性剂复配体系能够降低界面张力至10-3m N·m-1,可提高采收率5.41%。     

新型羟基磺基甜菜碱/聚丙烯酰胺二元复合体系性能评价

新型羟基磺基甜菜碱表面活性剂与相对分子质量为2 500万的聚丙烯酰胺进行复合,测定体系的界面张力、黏弹性及乳化性能。结果表明,新型羟基磺基甜菜碱表面活性剂在浓度2.16 mmol/L时,表面张力33.39 m N/m,且乳化性能较好,具有较好的表面活性剂性能。相比于单独的表面活性剂,二元复合体系使溶液的临界胶束浓度增大,且界面张力也升高。当表面活性剂浓度为1.3 g/L,聚合物浓度为0.5 g/L时,体系的界面张力达到最低。聚合物的加入能显著降低体系的粘弹性,且随着聚合物浓度的增加,出现黏度最大值的表面活性剂的浓度越低。当表面活性剂水溶液质量浓度1.3 g/L,聚合物浓度1.5 g/L时,体系乳化性能最佳,实验表明,在低渗透岩心中,可以提高采收率5.78%。     

新型羟基磺基甜菜碱/聚丙烯酰胺二元复合体系性能评价

新型羟基磺基甜菜碱表面活性剂与相对分子质量为2 500万的聚丙烯酰胺进行复合,测定体系的界面张力、黏弹性及乳化性能。结果表明,新型羟基磺基甜菜碱表面活性剂在浓度2.16 mmol/L时,表面张力33.39 m N/m,且乳化性能较好,具有较好的表面活性剂性能。相比于单独的表面活性剂,二元复合体系使溶液的临界胶束浓度增大,且界面张力也升高。当表面活性剂浓度为1.3 g/L,聚合物浓度为0.5 g/L时,体系的界面张力达到最低。聚合物的加入能显著降低体系的粘弹性,且随着聚合物浓度的增加,出现黏度最大值的表面活性剂的浓度越低。当表面活性剂水溶液质量浓度1.3 g/L,聚合物浓度1.5 g/L时,体系乳化性能最佳,实验表明,在低渗透岩心中,可以提高采收率5.78%。     

阴非离子型Gemini表面活性剂驱油体系性能评价

为提高低渗透油藏采收率,开发了一种阴非离子型Gemini表面活性剂ANG7-Ⅳ-7,并测定体系的界面张力、乳化性能和吸附量。结果表明,ANG7-Ⅳ-7表面活性剂浓度在1⁴ g/L范围内,油水界面张力均可达到10-3m N/m的超低数量级,当ANG7-Ⅳ-7浓度为4 g/L时,能使油水界面张力达到最低值6.025×10-3m N/m;在注入浓度为4 g/L时,表面活性剂在油砂上的吸附量为2.035 mg/g。室内岩心驱油试验结果表明,4 g/L的ANG7-Ⅳ-7表面活性剂驱可在水驱后提高采收率11个百分点。     

SB-16/SDS复配微乳液驱油体系性能研究

为提高低渗透油藏采收率,研究了十六烷基磺基甜菜碱(SB-16)和十二烷基硫酸钠(SDS)按不同质量比复配所得表面活性剂体系的临界胶束浓度(cmc)和相应的表面张力(γ_(cmc)),得到该复配体系的最佳复配质量比为7∶3,此时cmc=0.025 g/L,γ_(cmc)=26.7 m N/m,进而以该复配体系为表面活性剂,研究不同质量分数、不同链长的醇类为助表面活性剂时对体系界面张力与乳化率的影响,最终确定质量分数为4%的复配体系+2%的异丁醇为最佳配方,在该条件下可以使油/水界面张力降至超低界面张力数量级(10~(-3)mN/m)。实验结果表明,在低渗透岩心中,复配微乳液驱油体系较水驱可以提高采收率10个百分点,效果较好。     

阴非离子型Gemini表面活性剂驱油体系性能评价

为提高低渗透油藏采收率,开发了一种阴非离子型Gemini表面活性剂ANG7-Ⅳ-7,并测定体系的界面张力、乳化性能和吸附量。结果表明,ANG7-Ⅳ-7表面活性剂浓度在1~4 g/L范围内,油水界面张力均可达到10-3m N/m的超低数量级,当ANG7-Ⅳ-7浓度为4 g/L时,能使油水界面张力达到最低值6.025×10-3m N/m;在注入浓度为4 g/L时,表面活性剂在油砂上的吸附量为2.035 mg/g。室内岩心驱油试验结果表明,4 g/L的ANG7-Ⅳ-7表面活性剂驱可在水驱后提高采收率11个百分点。     

表面活性剂驱油效率的影响因素研究

在83℃下测定了3种表面活性剂DL-S、HL-Y/NNR、GZ-16的油水界面张力、乳化能力以及改变油藏岩石润湿性的能力。利用低渗透岩心驱油实验研究表面活性剂的这3种特性对驱油效率的影响。结果表明,表面活性剂的浓度在1 000 mg/L时,DL-S的油水界面张力达到10-3mN/m超低数量级,HL-Y/NNR表现出较为优越的乳化性能,GZ-16具有较好的润湿性能。在驱油实验中,具有最好乳化性能的HL-Y/NNR提高采收率的幅度最大为12.91%,其次为具有超低界面张力的DL-S,相较而言,改变润湿性的能力对驱油效率的影响最小。     

低渗透粘弹性表面活性剂的研制和评价

针对低渗透油藏注水突破快、无效水循环严重的问题,开展了粘弹性表面活性剂驱油体系的室内研究。通过界面性能和体相流变性能对粘弹性表面活性剂体系进行了评价和优化,得到了具有扩大波及体积和提高驱油效率功能,并具有良好注入性的粘弹性表面活性剂体系。该表面活性剂还具有良好的界面性能,浓度介于0.05%~0.3%时,能够将油水界面张力降低到10-2m N/m数量级,并具有迅速剥离油膜的能力。在0.15%以上,体系的粘度随着浓度的升高而迅速升高,当浓度达到0.3%时,体系的粘度达到20.1 m Pa·s(50℃)。该体系能够通过直径0.2μm的核孔膜,而聚合物则因为堵塞核孔,不能通过0.2μm核孔膜。模拟驱油实验结果表明,该体系可以在水驱基础上提高采收率8%左右。以上研究结果表明,粘弹性表面活性剂体系在低渗透油藏低储层伤害开发中具有很大的潜力。     

Superior enhancement of imbibition recovery by novel surfactant mixtures with a large hydrophobic group combined with nanosilica

Low interfacial tension (IFT) drainage and imbibition are effective methods for improving oil recovery from reservoirs that have low levels of oil or are tight (i.e., exhibit low oil permeability). It is critical to prepare a high efficient imbibition formula. In this work, a novel 2,4,6-tris(1-phenylethyl)phenoxy polyoxyethylene ether hydroxypropyl sodium sulfonate (TPHS) surfactant was synthesized and evaluated for imbibition. Its structure was confirmed by Fourier transform infrared spectroscopy and the interfacial tension (IFT) of the crude oil/0.07% TPHS solution was 0.276 mN/m. When 0.1 wt% TPHS was mixed with 0.2 wt% alpha olefin sulfonate (AOS), the IFT was lowered to 6 × 10⁻² mN/m. The synergy between nanoparticles (NPs) and TPHS/AOS mixed surfactant was studied by IFT, contact angle on sandstone substrates, zeta potential, and spreading dynamics through microscopic methods. The results show that the surfactant likely adsorbs to the NP surface and that NP addition can help the surfactant desorb crude oil from the glass surface. With the addition of 0.05 wt% SiO₂ NPs (SNPs), the imbibition oil recovery rate increased dramatically from 0.32%/h to 0.87%/h. The spontaneous imbibition recovery increased by 4.47% for original oil in place (OOIP). Compared to flooding by TPHS/AOS surfactant solutions, the oil recovery of forced imbibition in the sand-pack increased by 12.7% OOIP, and the water breakthrough time was delayed by 0.13 pore volumes (PV) when 0.05% SNPs were added. This paper paves the way for enhanced oil recovery in low-permeability sandstone reservoirs using novel TPHS/AOS surfactants and SNPs.     

阴-非离子表面活性剂的合成及界面张力研究

以高温高盐油藏为切入点,从提高表面活性剂体系的抗温抗盐性等实际应用出发,介绍了氧乙基数为3、烷基碳数为8,10,12,14,16的五种APES系列表面活性剂的合成方法。同时对该系列表面活性剂与新疆漠北002脱气原油的动态界面张力进行评价;并对该系列表面活性剂的抗盐性进行深入研究。实验表明阴-非离子表面活性剂APES具有较好的耐盐性,十分适合在高盐油藏使用。     

水驱后凝胶与表活剂交替注入驱油效果

针对裂缝性低渗透油藏注入水易沿裂缝突进、含水上升快、水驱效果不理想的情况,开展了水驱后凝胶与表活剂交替注入方式提高采收率室内实验研究。通过室内凝胶体系成胶特性和稳定性评价,筛选出与实际油藏区块注入水配伍的凝胶体系。选择甜菜碱两性表面活性剂用于活性剂驱,开展了双管并联岩心体系驱油效果研究。研究结果表明:凝胶与表活剂交替注入可明显提高注入压力,该体系的采收率平均值为12.03%,低渗岩心的采收率略高于高渗透岩心采收率。与表活剂驱、聚合物与表活剂交替注入相比,驱油效果更好,可以作为裂缝性低渗透油藏水驱后进一步提高采收率的技术。     

表面活性剂对特低渗油藏的适用性及应用

为评价表面活性剂WLW对特低渗油藏的适用性,研究了WLW的渗吸特性、乳化性能和界面张力及其在特低渗油藏物理模拟岩心驱油实验和现场中的应用。室内实验结果表明,WLW对注入水的渗吸效率有促进作用;注入质量分数0.2%的WLW溶液,可在水驱基础上提高驱油效率5%左右;WLW在特低渗岩心中提高驱油效率的幅度明显高于中低渗岩心。2011—2013年在长庆靖安油田A1和A2井组开展注WLW现场试验,累计增油4 781 t,WLW对于特低渗油藏提高采收率效果明显。     

高盐油藏提高采收率的室内研究

高盐油藏在水驱采油之后仍有相当一部分原油滞留在地层中,很难将其采出,因此可选用化学方法动用,但高盐油藏地层水矿化度相对较高,温度相对较高,普通表面活性剂很难满足如此苛刻条件下的油藏环境。因此需要将表面活性剂进行复配,充分发挥各种活性剂的优势,进而达到提高采收率的目的。针对玉门油田鸭儿峡L油藏地层水矿化度的特点,采用阴离子-两性表面活性剂复配,通过测定不同复配比和活性剂浓度下的油水界面张力,最终确定了适用于L油藏的表面活性剂驱油复配体系。实验表明在石油磺酸盐A与C14BE复配比为1:4、1:3,总浓度为0.6%、0.1%时,油水界面张力达到了10-3 m N/m级别。此驱油配方适用于L油藏提高采收率的要求。     

新型两性表面活性剂的驱油体系界面特性变化规律研究

随着三次采油技术的不断发展,复合体系的表面活性性能和含量是在提高采收率技术研究中日趋重要。本文针对新型两性表面活性剂一元及聚合物/表面活性剂二元体系同油的界面特性展开了研究。结果表明：一元体系中表面活性剂质量浓度越高,界面张力达到稳定所需时间越短;随着体系中表面活性剂质量浓度的增加,稳定界面张力值越低。聚合物对两性表面活性剂同模拟油之间的界面张力有影响,且有利于体系同模拟油间的界面张力的降低;但界面张力并不是随着聚合物质量浓度的增加一直单纯降低,当质量浓度为1.0g/L时界面张力最低。     

Research on Oleic Acid Amide Betaine Used in Surfactant-Polymer Compound Flooding for Ordinary Heavy Oil

In view of the low recovery rate associated with water flooding, as well as the scaling problems caused by traditional alkali-surfactant-polymer flooding, the feasibility of using a betaine surfactant with high interfacial activity for chemical flooding of ordinary heavy oil was investigated. Aqueous solutions of oleic acid amide betaine (OAAB) with the mass concentration of 0.01% can reduce the oil–water interfacial tension to the ultralow level (10⁻³ mN m⁻¹), making it suitable for chemical flooding. To solve the problem of high adsorption onto sandstone, static adsorption tests and dynamic adsorption tests were carried out. The results show that the weakly alkaline lignin can significantly reduce the adsorption quantity of OAAB by more than 40%, based on which, a compound-flooding system of 0.1% partially hydrolyzed polyacrylamide (HPAM) + 0.1% OAAB +0.75% lignin was constructed. Compared with water flooding, the ultimate rate was enhanced by 20.4%, resulting in a final recovery rate of 53.9%. The study of oil displacement mechanism shows that the excellent ability to reduce the oil–water interfacial tension of OAAB can emulsify heavy oil to small droplets easily, exhibiting better capacity in oil displacement efficiency. The polymer can increase the viscosity of the aqueous phase, reduce the mobility ratio of water to oil, weaken the fingering effect, and improve the sweep efficiency. Lignin can not only reduce the adsorption quantity of betaine surfactant, but also promote the adsorption of OAAB onto the oil–water interface, leading to enhance the emulsification performance of OAAB and maintain the oil displacement efficiency effectively. Therefore, the surfactant-polymer flooding system based on the betaine surfactant can be developed into an economically and technically feasible flooding technology suitable for ordinary heavy oil reservoirs.     

Preparation and Performance Evaluation of Fatty Amine Polyoxyethylene Ether Diethyl Disulfonate for Enhanced Oil Recovery in High‐Temperature and High‐Salinity Reservoirs

To enhance oil recovery in high‐temperature and high‐salinity reservoirs, a novel fatty amine polyoxyethylene ether diethyl disulfonate (FPDD) surfactant with excellent interfacial properties was synthesized. The interfacial tension (IFT) and contact angle at high temperature and high salinity were systematically investigated using an interface tension meter and a contact angle meter. According to the experimental results, the IFT between crude oil and high‐salinity brine water could reach an ultra‐low value of 10^?3 mN m^?1 without the aid of extra alkali at 90°C after aging. The FPDD surfactant has strong wettability alternation ability that shifts wettability from oil‐wet to water‐wet. The FPDD surfactant with a high concentration also has good emulsion ability under high‐temperature and high‐salinity conditions. Through this research work, we expect to fill the lack of surfactants for high‐temperature and high‐salinity reservoirs and broaden its great potential application area in enhanced oil recovery.     

油田开发中防水锁伤害增产剂的实验研究

在油田钻井、完井、固井、修井及开采等过程中水锁易引起地层损害,分析了产生水锁伤害的机理,研制出了TA-2系列防水锁伤害增产剂,并利用程序界面张力仪、全自动旋转滴界面张力测定仪、岩心流动实验装置等仪器对其进行了综合性能评价.结果表明,与现有配方相比,TA-2系列防水锁伤害剂对储层的伤害程度最小;随着TA-2溶液浓度的增大...