热/化学驱提高稠油采收率研究现状及进展

对稠油热/化学驱的研究现状及进展进行了综述.详细论述了各种开采技术的机理和特点,认为热/有机碱/表面活性剂复合驱与稠油井下改质技术是稠油开采的主要发展趋势.     

热-化学技术提高稠油采收率研究进展

在稠油开采过程中,热力采油法一直是提高稠油采收率的主要方式。针对稠油油藏水驱采收率低及部分油层(如部分薄层、深层、热敏层等)不适宜于热采的特点,在稀油化学驱技术的基础上发展了稠油化学驱技术。近年来研究发现,将稠油热采和稠油化学驱技术相结合使用,可大大提高稠油采收率。在调研大量相关文献的基础上,综述了稠油化学驱以及稠油热(蒸汽)-化学复合采油技术的研究进展,分析了其提高稠油采收率的作用机理和存在的问题,认为热-化学水平井复合采油技术是今后稠油开采的一项重要技术。     

提高采收率技术的应用状况及发展趋势

通过对世界提高采收率（EOR）技术应用状况的统计分析,了解了不同国家提高采收率技术应用现状及发展趋势。热采、气驱、化学驱是目前规模化应用的三大提高采收率技术,大规模应用的热采技术主要为蒸汽吞吐、蒸汽驱和SAGD,主要在美国、加拿大、中国、委内瑞拉和印度尼西亚应用,规模化应用的气驱技术主要为CO2混相驱和烃混相/非混相驱,主要在美国、委内瑞拉和加拿大应用,化学驱技术主要在中国应用,聚合物驱已进入工业化应用。世界提高采收率项目主要集中在美国、中国、加拿大、委内瑞拉和印度尼西亚,这5个国家的EOR产量约占世界EOR产量的98.3%。中国已成为世界提高采收率技术应用大国,蒸汽吞吐、聚合物驱和复合驱技术应用规模均居世界前列。为适应温室气体减排的要求,CO2-EOR技术应用规模将不断扩大。     

稠油化学降粘复合驱提高采收率实验研究

受地层压力高、储层厚度薄、边底水活跃等油藏条件影响,部分稠油油藏热采时的热损失大、成本高、采收率低,难以得到有效开发。通过室内驱油实验,研究稠油降粘剂驱、聚合物驱以及化学降粘复合驱提高采收率机理,对比分析不同驱油体系对于稠油提高采收率效果的影响。实验结果表明:利用水溶性降粘剂和聚合物组成稠油化学降粘复合驱驱油体系,可以提高采收率16.04%,优于仅使用降粘剂或聚合物作为驱油剂。对于稠油化学降粘复合驱效果,从换油效率角度考虑,优化复合驱段塞中聚合物和水溶性降粘剂的质量分数分别为0.3%和1.0%;从提高采收率角度对比,优化采用前置聚合物段塞后置水溶性降粘剂段塞的注入方式,相比于前置水溶性降粘剂段塞后置聚合物段塞的注入方式,可提高采收率7.2%~10.7%;在此基础上,优化得到水溶性降粘剂与聚合物段塞的最佳体积比为3∶2。在非均质模型和微观可视化模型中,化学降粘复合驱不仅兼具聚合物和降粘剂的驱油机理,而且还产生了协同增效作用,对于稠油较单一化学剂驱可大幅度提高波及范围和洗油效率。     

前苏联提高采收率技术的应用情况

该文介绍了前苏联应用提高采收率技术的主要情况，前苏联原油产量八十年代后期开始下降，提高采收率和完善水驱技术已成为抑制产量递减的主要手段，１９９１年，依靠各种提高采收率方法的增油量达２．７８×１０＾４ｍ＾３／ｄ，依靠完善水驱方法的增油量达９．５４×１０＾４ｍ＾３／ｄ。文中介绍了前苏联石油工业面临的形势，提高采收率技术的应用现状和各种技术的矿场应用效果，并对２０００年及２０１０年的形势进行了展望。     

提高胜利油区稠油热采收率技术研究

对胜利油区的稠油资源进行了分类评价,指出胜利油区稠油油藏类型的复杂多样性;在分析该区稠油注蒸汽热采开发形热的基础上,认为稠油热采所暴露的主要矛盾是：已开发区块基本进入高轮次吞吐阶段,面临如何确定下步开发方式及提高采收率问题;而尚未开发的新区大多属于超稠油,低渗,薄层或深层等开采难度较大的低品位油藏。     

提高采收率技术的应用及其发展趋势

随着油气储量发现难度的加大,油气采收率已备受世界各国的关注,提高采收率技术发展迅速。本文介绍了世界范围内热采、气驱、化学驱和微生物驱等提高采收率技术的应用情况,分析总结了提高采收率技术的发展趋势：提高采收率技术将向集成化和高科技方向发展;化学辅助提高采收率技术将成为今后一个时期的主流技术;现代科学技术和工艺技术的进步将继续引领提高采收率技术的变革与发展。     

微生物提高稠油采收率室内研究

利用辽河稠油区块和江汉油田油水样中分离的4株本源微生物,对江汉王新斜3稠油样的微生物作用进行了详细测定和分析。比较微生物作用前后的原油组成,发现4种菌种均能不同程度地作用长链烷烃、芳烃,且混合菌较单一菌效果好,并同时生成大量具有生物表面活性的羧酸、酯、酮和醇类物质。粘度测定结果表明,混合菌能使江汉、南阳等地原油粘度明显降低。模拟试验表明,4种微生物及混合菌种均能不同程度地提高原油采收率。     

提高稠油油藏原油采收率的直流电场强化驱油技术

Electro-Petroleum公司(EPI)证实了直流电场对提高圣玛丽亚(加利福尼亚)盆地和阿尔伯塔平原东部稠油油藏原油采收率的有效性(这项技术被称为"Electro-Enhanced Oil Recovery",简称EEOR).利用大尺度岩样(体积为1 m3)进行了室内实验以评估现场试验中未预料到的结果.最近的研究表明,EEOR技术能够在地层中冷裂稠油,从而降低产出油密度,并增加油藏压力.在井深2 500 ft以下,蒸汽驱操作有实际难度,而EEOR技术能在10 000 ft的深度发挥作用.观察到产出流体的以下性质发生了变化:采油速度增加;产出原油黏度减小,API重度增加;含水率降低;硫化氢产量降低;天然气产量增加;产出天然气中重质气的含量增加;多环芳香族化合物的产量降低.产出流体的所有化学变化都能利用直流电场的作用给予解释.     

化学驱提高普通稠油采收率的研究进展

针对普通稠油油藏水驱采收率低,而且经济上不适合于热采的特点,介绍了国内外化学驱提高普通稠油采收率技术的一些研究进展,主要包括聚合物驱,碱驱,碱/表面活性剂驱.综述了各种方法提高普通稠油采收率的研究现状和机理研究进展,并指出了不同方法存在的问题和当前的研究热点.     

Improvement of heavy oil recovery and role of nanoparticles of clay in the surfactant flooding process

Increasing demand and dwindling supply of crude oil have spurred efforts toward enhancing heavy oil recovery. Recently, applications of nanoparticles (NPs) for heavy oil recovery have been reported. In this study, the use of clay NPs is investigated for enhanced oil recovery. Surfactant solutions and newly developed nanosurfactant solutions with 1600–2000 ppm SDS were tested. The crude oil had a viscosity of 1320 mPa.sec at test conditions. In this study, the role of NPs in the adsorption of surfactant onto solid surfaces of reservoir core is studied. The core flooding experiments showed high potential of using nanoclay for enhancing heavy oil recovery, where 52% of surfactant flooded heavy oil was recovered after injecting the NPs solvent. Moreover, nanoclay has generally better performance in enhancing the oil recovery at surfactant solution, near CMC conditions. The nanoclay surfactant solutions improved oil recovery. The nanoclay, however, showed improved performance in comparison with clay.     

辽河油区稠油采油工艺技术发展方向

分析了辽河油区稠油开发中存在的问题和目前的技术水平,论述了提高蒸汽吞吐效果、开发方式转换、特殊工艺井相结合的常规热力采油技术,采用添加剂(催化剂)的热化学采油技术以及稠油井下改质技术机理及应用情况,指出今后可能具有发展前景的采油工艺技术.     

Optimum effective viscosity of polymer solution for improving heavy oil recovery

Severe viscous fingering during waterflooding of heavy oil leaves a large amount of oil untouched in the reservoir. Improving sweep efficiency is vital for increasing heavy oil recovery. Polymer flooding, a widely recognized mobility control enhanced oil recovery (EOR) technology for conventional oil, is generally not recommended for oils with viscosities higher than 200 mPa s according to the traditional EOR screening criteria. However, polymer flooding of heavy oil reservoirs is becoming increasingly feasible with the wide use of horizontal wells and because of relatively high oil price.This study investigated the relationship between the tertiary oil recovery by polymer flooding and the effective viscosity of polymer solution. Twenty-eight sandpack flood tests were conducted using oils with viscosities ranging from 430 mPa s to 5500 mPa s. Results showed that there existed a minimum value and an optimum value of effective viscosity for the injected polymer solution. Rapid increase in oil recovery was observed when the effective viscosity of the polymer solution was increased between these two values. Outside of this range, the increase in the effective viscosity of polymer solution resulted in only small incremental oil recovery. It was also found that both the minimum and optimum effective viscosities of polymer solution increased with increasing oil viscosity.     

中国稠油热采开发技术与发展方向

稠油是重要的石油资源类型,实现稠油资源持续、高效开发,对保障国家能源安全具有重要的现实意义。针对中国热采稠油的主要特征进行了分析和总结:在地质和油藏特征方面,中国稠油油藏类型多、埋藏深、油层薄、储层非均质严重、油水系统复杂;在组成特征方面,胶质和沥青质分子之间相互作用形成空间网状结构导致稠油黏度大;在流变特性方面,稠油存在临界温度,当温度大于临界温度时,稠油流变行为呈现牛顿流体流变特性,当温度小于临界温度时,稠油流变行为呈现具有屈服值的宾汉流体特征;在渗流特征方面,稠油在地下渗流呈现非达西渗流特征,存在启动压力梯度,其受温度、储层渗透率、地层原油黏度及沥青质含量影响。综述了国内外稠油开发技术现状,详细阐述了蒸汽吞吐、蒸汽驱、蒸汽辅助重力泄油(SAGD)、火烧油层、热复合开发等技术的主要机理、适用条件、应用实例、存在问题和发展方向,蒸汽吞吐仍是稠油热采的主要方式,蒸汽驱是蒸汽吞吐后有效接替技术之一,SAGD技术在引进吸收中取得重要进展,火烧油层成为大幅度提高采收率的重要技术,热复合开发技术实现难采稠油高效开发。研究结果表明,未来稠油开发需要发展高质高效的热力开发技术,协同采收率和油汽比"双目标"最大化,持续加强油藏描述、动态监测和注采调控,积极探索产热方式转变,从而实现稠油效益开发和绿色低碳发展。     

大港油区稠油井开采工艺现状及发展趋向

大港油区立足于稠油冷采，形成了稠油井开采系列配套工艺技术，其中地层处理配套技术主要包括单井化学吞吐、微生物采油、有机溶剂清洗等，举升工艺主体技术包括常规有杆泵、电热杆、螺杆泵、电潜泵等，同时广泛配套环空掺水加药降粘工艺。目前的工艺配套技术能够满足大港油田稠油尤其是普通稠油的开采需要，但在今后的稠油开采中，应该对各项工艺技术进行更深入的研究、优化、配套，提高特稠油和稠油井的开采工艺配套水平，降低稠油井开采成本。     

Application of nano-fumed silica in heavy oil recovery

The resources of heavy oil in the world are more than twice those of conventional light crude oil and the technology utilized for the recovery of heavy oil has steadily increased recovery rates. Polymer flooding is the most commonly applied chemical enhanced heavy oil recovery technique. However, still there is a need for a large amount of polymer, leading to high operational costs, presenting a big challenge in technologies. This challenge can be addressed by considering the newly emerging nanomaterials especially those made from silica. In this work, the author focuses on roles of silica nanoparticles on polymer viscosity and improvement of recovery in heavy oil recovery. The author presents the results obtained from a coreflood experiment with polymer injection in heavy oil at 1320 mPa.sec viscosity. The results indicate that polymer flooding with higher viscosity can significantly improve oil recovery. These laboratory results will be helpful for the planning of nano silica polymer flooding for heavy oil reservoirs. Also flooding test showed a 8.3% increase in oil recovery for nanosilica polymer solution in comparison with polymer solution after one pore volume fluid injection.     

普通稠油化学驱油技术现状及发展趋势

对于普通稠油,一次采油后常采用注水开发和热采方法。据中石化2007年底统计,采用注水开发动用的普通稠油储量占稠油总储量的30.1%,但由于水油流度比高,使得普通稠油油藏水驱采收率低。当油层太薄或埋藏太深时,热量损失严重,经济上不适合采用热采方法。化学驱方法是一个重要的接替手段。因此,文中重点综述了聚合物驱、碱驱、碱/表面活性剂驱、碱/聚合物驱技术在普通稠油油藏中应用的国内外研究现状和机理研究进展,指出了稠油化学驱中出现的问题和未来的发展趋势。     

Microemulsion flooding for enhanced oil recovery

Petroleum recovery methods basically consist of fluid injection aiming to displace the oil out of the rock pores. Among the methods used in enhanced oil recovery, chemical methods, which may involve microemulsion flooding, are cited. In this work, injection assays have been carried out with two types of microemulsion: one was prepared with a commercial surfactant (MCS) and another contained a surfactant synthesized in laboratory (MLS). The experiments basically consisted of the injection of fluids into cylindrical plug samples from the Assu Formation (RN, Brazil). During the microemulsion flooding, samples were collected as a function of time and the mass of oil recovered by the microemulsion was determined. From the results obtained, one could conclude that the use of microemulsion prepared with the commercial MCS allowed for recovery indices as high as 87.5%, whilst the use of the MLS microemulsion permitted recovery indices as high as 78.7%. This was mainly due to the difference in viscosity between the two microemulsions used.     

聚合物驱阶段提高采收率预测模型的建立与应用

为了预测聚合物驱开发指标,根据实际生产数据,综合应用驱替特征曲线和经验回归方法,建立了聚合物用量与提高采收率变化规律的预测模型。并对A油田39个一类油层和二类油层聚合物驱区块进行拟合和预测,计算结果表明:在半对数坐标系下,聚合物用量与提高采收率成线性关系;在聚合物驱的含水稳定阶段与含水回升阶段,该方法预测精确度较高,提高采收率绝对误差为0.01 % ~0.58 % ,相对误差为0.09 % ~6.24 % 。该预测模型能够应用于聚合物驱的长远规划与年度规划,也可用于聚合物驱开发调整措施效果评价和确定单井组转后续水驱时机。