泡沫驱提高油田采收率的研究进展

随着我国各大油田陆续进入开发后期,可供开采的常规油气藏资源越来越少,提高采收率的研究越来越受到重视。气体泡沫驱作为一种有效提高采收率的方式,广泛应用于我国各大油田,在现场应用中发挥了堵塞缝隙、降低出水率、提高采收率的作用。介绍了氮气泡沫驱、二氧化碳泡沫驱、空气泡沫驱在国内外的最新研究进展和现场应用情况,对3种泡沫驱进行了比较;讨论了表面活性剂作为发泡剂对提高油藏采收率的作用和影响。分析了3种泡沫驱油方式的优缺点和适应性,并对未来发展提出建议,认为我国的泡沫驱油技术还未成熟,要针对气体-泡沫注入方式以及注入时机等进行更深层次的研究,同时还要研发发泡剂和稳泡剂的配方,降低成本。     

低渗透油藏泡沫驱油机理及应用现状研究

低渗透油气藏在世界范围内分布范围广,储量大,在新探明储量中占得比例越来越大,是全球油气资源增产的主要来源,合理高效的开发低渗透油藏中的油气资源,是未来面临的主要问题。泡沫驱油作为继水驱、气驱之后新的驱油方式,结合了气体和泡沫的优点,以独特的优势越来越得到人们的重视,是低渗透油藏提高采收率的又一个重要途径。分析了泡沫驱相对于其他驱油方式的优势,概述了泡沫驱油的驱油机理,简要分析了空气泡沫驱、氮气泡沫驱各自特点,对泡沫驱油在国内外油田的应用现状做了介绍。对泡沫驱油存在的问题做了阐述,并提出了泡沫驱油的发展方向。     

空气泡沫驱技术的研究现状及展望

介绍了空气泡沫驱技术的起源、国内外研究现状,空气泡沫驱驱油机理以及目前空气泡沫驱技术的不足和发展趋势,指出空气泡沫驱技术研究体系的形成、驱油机理的进一步研究、腐蚀问题、产出气体处理以及注气过程中安全风险问题分析是今后研究方向。空气泡沫驱技术可望成为油田挖潜剩余储量最经济有效的方法之一。     

基于低渗透油田的空气泡沫驱提高采收率二次采油新途径研究

空气泡沫驱油综合了泡沫驱油和空气驱油的双重优势,是一项十分具有创造性的提高采收率的新方法,它不仅具有调剖和驱油的双重功能,而目’还克服了空气驱气窜的缺点。通过理论和实验研究,对空气和泡沫的驱油机理进行了阐述。通过室内实验,主要对原油静态氧化、空气泡沫封堵能力及影响因素、空气泡沫驱油效果及影响因素和孤东七区中、七区西两个区块是否能实施空气泡沫驱提高采收率技术的可行性进行了研究。实验结果表明：通过原油静态氧化反应速率实验,发现所用油样有较好的氧化性能。温度、压力越高,原油氧化速率越快,消耗的氧气和产生的二氧化碳越多;空气泡沫体系封堵能力与气液比、岩心渗透率、泡沫注入方式、残余聚合物等因素有关。     

一种耐高温泡沫体系的驱油效率影响因素分析

对一种耐高温泡沫体系(COL-3)的驱油效率及影响因素进行了实验研究。结果表明,随着起泡剂浓度的增加,泡沫驱油效率逐渐增大,最后趋向平稳,且起泡剂最经济、有效的使用浓度为0.3%;起泡剂采用段塞注入,泡沫的驱油效率最大;随着渗透率极差的增大,泡沫驱油效率变小。     

空气泡沫驱驱油机理与实验研究

针对传统聚合物驱、三元复合驱等驱油体系在中后期油田开采中采油效率不高的问题,提出一种高效空气泡沫驱驱油技术。为验证高效泡沫驱的驱油效果,以延长油田1#地质条件为背景,探讨不同起泡剂浓度、矿化度下对空气泡沫驱的性能影响,从而筛选出空气泡沫驱的最优综合性能,通过驱替实验,对高效泡沫驱驱油机理进行观察。最后通过封堵能力评价验证了空气泡沫驱的性能与驱油机理。     

泡沫驱油机理研究综述

开发进入中后期的中高含水油藏,由于各种化学驱油方式存在着一些因素的制约,使得泡沫驱油这种实施成本相对较低,施工工艺相对简单,提高采收率比较明显的驱油方式成为一种主要的三次采油方式。泡沫驱油方式的不断发展,到目前为止已经发展有氮气泡沫驱油、空气泡沫驱油、CO_2泡沫驱油等多种方式。本文主要从宏观和微观方面介绍泡沫在多孔介质中的渗流以及改善吸水剖面、增加驱油效率、提高采收率等方面的机理和规律。     

复杂气体泡沫体系性能评价及驱油试验研究

胜利油田胜利电厂烟道气CO2捕集纯化后,还有大量复杂气体(组成为91%的N2、5%的O2、3.3%的CO2及其他成分气体),利用成本低廉的复杂气体应用于高温高盐油藏及聚合物驱后进一步提高采收率研究具有重要意义。本文研究了复杂气体不同含量时DP-4泡沫剂的起泡体积和半衰期变化情况,确定了以CNS:B4=6:4进行复配为最终复杂气体泡沫体系,并对该泡沫剂体系性能进行了评价,模拟研究了复杂气体泡沫体系在油藏条件下的驱油效率。     

原油粘度对高温泡沫封堵效果影响研究

本文针对胜利油田三种不同粘度的原油(中二北普通稠油、孤南四特稠油、单56超稠油),研究在高温蒸汽驱下泡沫的封堵压差、阻力因子、驱油效率,从而进一步确定稠油粘度对高温泡沫封堵调剖和驱油性能的影响。     

聚驱后泡沫驱配方优选与评价

针对聚合物驱后油层在纵向上和横向上动用不均匀,剩余油挖潜进一步加大的问题,通过室内实验的方法对聚驱后泡沫驱的可行性进行了研究。结合大庆油田聚合物驱区块实际情况,通过评价泡沫高度、泡沫的半衰期和泡沫综合值方法,对泡沫驱起泡剂种类、起泡剂浓度和稳泡剂浓度进行了优选,考察了不同渗透率岩心、不同气液比和不同注入速度条件下泡沫的封堵能力,确定了泡沫驱的气液比和注入速度,进行了聚驱后泡沫驱的驱油实验,驱油实验结果表明,在聚驱达到含水98%后注入0.4PV泡沫驱能够在聚驱的基础上提高采收率8%左右。     

泡沫复合驱配方ZS-23的研究

泡沫驱作为一项重要的三次采油技术,在降低气油比、增加原油产量、提高波及效率等诸多方面具有很大的发展潜力。对ZS系列泡沫复合驱配方进行了探索性研究,使用Waring Blender法对泡沫复合驱配方的发泡能力和稳定性进行了检测,通过实验筛选出发泡性能好、稳定性强的泡沫复合驱配方。在矿化度NaCl>5 000 mg/L、CaCl2>3 000 mg/L条件下,表现最为优异的配方为ZS-23,在常温(20℃)时,发泡体积达到880 mL,析液半衰期5.3 h以上,加盐后发泡体积达到820 mL,析液半衰期3.5 h以上,均远远好于一般常见的发泡剂。     

The development of heat-resistant and salt-tolerant foam with betaine surfactants

A modified instrument was designed to evaluate foam properties under high temperature and pressure. The type and molar ratio of betaine surfactants were screened to develop the heat-resistant and salt-tolerant foam for Tahe oilfield (130°C, 220 g/L), and the effects of temperature and pressure on foam properties were also investigated. The synergism between surfactants and the enhanced oil recovery (EOR) mechanism of foam flooding in fractured-vuggy reservoirs were studied. Experimental results showed the developed foam had excellent foaming ability and foam stability when the lauramidopropyl hydroxyl sulfobetaine (LHSB): erucic amide propyl betaine (EAB) molar ratio ranged from 1:1 to 1:2 (initial foam volume was 392 ml when the molar ratio was 1:1, drainage half-time was 5.75 min and foam half-time was 72 min when the molar ratio was 1:2 at 130°C and 2 MPa). The synergistic effect was found to reach its maximum when the LHSB:EAB molar ratio ranged from 1:1 to 1:2 according to interaction parameters, which agreed with the results of foam properties. Foam stability was found to considerably increase with increasing pressure, but decrease with increasing temperature. However, temperature and pressure were found to have consistent effects on foaming ability, that is, the foaming ability increased with increasing temperature and pressure. The flooding test showed foam flooding exhibited better sweep efficiency and higher recovery ratio in the fractured-vuggy model than gas flooding and water flooding. This could be because injected foam did not channel through the top (or bottom) path due to its high viscosity and moderate density.     

原油对水相泡沫稳定作用机理研究进展

为了评述原油对水相泡沫稳定性的影响机理,分别介绍了原油在水相泡沫中的存在状态,原油对泡沫的稳定或破坏机理。原油对泡沫的稳定性有着显著影响,稳泡或消泡也极大程度上决定了石油与天然气开采作业中,诸如泡沫驱油、泡沫堵水、堵气、泡沫排液、泡沫压裂等作业效率。重点阐述了假乳液膜对泡沫稳定性的影响机理,总结出原油在水相泡沫体系中以溶解油或乳化油两种状态存在。原油溶解于水相胶束中(溶解油)可降低泡沫的稳定性。大多原油在水相泡沫中以乳化油滴形式存在,油滴与气泡之间被假乳液膜隔开,假乳液膜决定了泡沫体系的稳定性。假乳液膜稳定性好能促进三相泡沫的稳定性;而假乳液膜稳定性差就加剧了三相泡沫地破裂。通过评述指出了原油与水相泡沫相互作用研究领域今后的研究方向。     

泡沫驱提高采收率的研究进展

本文介绍了国内外泡沫驱提高采收率技术的一些研究进展,主要包括氮气泡沫驱、二氧化碳泡沫驱和空气泡沫驱。综述了各种泡沫驱提高采收率的矿场应用现状和机理研究进展,并指出了泡沫驱的当前研究热点和未来发展方向。     

Experimental investigation and modelling of CO2-foam flow in heavy oil systems

In this work, the C_14-16 alpha olefin sulphonate (AOS) surfactant, octylphenol ethoxylate (TX-100), and methyl bis[Ethyl(Tallowate)]-2-hydroxyethyl ammonium methyl sulphate (VT-90) surfactant were selected as representatives of anionic, nonionic, and cationic surfactant to stabilize foam. The effects of surfactant concentration and gas/liquid injection rates on foam performance were examined by performing a series of oil-free foam flow tests by injecting CO₂ and a foaming surfactant simultaneously into sandpacks. Foam flooding was conducted as a tertiary enhanced oil recovery (EOR) method after conventional water flooding and surfactant flooding. Furthermore, a new method was proposed to determine the residual oil saturation. The foam stability in the presence and absence of heavy oil was studied by a comparative evaluation of the mobility reduction factor (F_MR) in both cases. The foam fractional flow modelling by Dholkawala and Sarma^[36] was modified based on experimental results obtained in this study. The range of the ratio of two important model parameters (C_g/C_c) at various foam qualities was determined and could be used for large-scale predictions. The results showed that during the oil-free foam displacement experiments higher foam apparent viscosities () were attained at lower gas flow rates and the maximum was attained at a total gas and liquid injection rate of 0.25 cm³/min with a gas fractional flow ratio of 0.8 for the foam in the absence of oil. The presence of oil reduced the foam mobility reduction factors (F_MR) to different degrees with F_MR-_{without oil} / F_MR-_{with oil} ranging from 4.25–13.69, indicating that the oil had a detrimental effect on the foam texture. The foam flooding successfully produced an additional 8.1–21.52 % of OOIP, which can be attributed to the combined effect of increasing the pressure gradient and oil transporting mechanisms.     

国内轻质油藏注空气、空气泡沫提高采收率效果分析

在重点调研国内油田空气、空气泡沫驱的基础上,论述了注空气、空气泡沫低温氧化技术的原理,对我国油田开展注空气、空气泡沫驱技术的实际效果以及潜力进行了的分析,认为注空气低温氧化工艺技术安全可控,不但可以解决我国储量丰富的低渗透油藏所面临的开发难题,而且可以进一步提高水驱、聚合物驱后油藏的采收率。随着技术进步,注空气低温氧化技术是我国乃至全世界注气提高采收率技术发展的必然趋势。并通过对现场应用情况分析,给出了对轻质油藏注空气、空气泡沫提高采收率的一些建议。     

自生CO2泡沫驱油可行性研究

针对低矿化度,中低温的稠油油藏,开展自生CO<,2>泡沫驱油的可行性研究.通过大量的实验,筛选出了稳定高效、经济可行的生气体系以及性能优越的起泡剂和稳泡剂,得到了优良的自生泡沫体系配方.考察了温度对自生泡沫体系起泡性和稳泡性的影响,并对自生CO<,2>泡沫体系的粘度的长期稳定性和油水界面张力性质进行了测定.实验结果表明...