聚合物溶液配注过程中的粘度损失

聚合物驱油是大庆油田高含水开发后期原油稳产的主要技术措施。注聚合物的目的是为了增加注入水的粘度。要达到较好的驱油效果,在聚合物溶液配注过程中就要注重对粘度损失的研究。大庆萨北油田３年多的聚合物驱油生产实践表明：聚合物溶液配制成分的质量和配注系统中的机械、化学和生物降解因素对溶液的粘度均有影响。通过对粘度损失规律的认识,有利于采取各种技术措施降低粘度损失,提高溶液配注质量,确保聚合物的驱油效果。     

注聚合物速度对提高原油采收率的影响

通过对孤岛油田注聚合物先导区,孤岛油田注聚合物扩大区,孤东油田注聚合物扩大区注聚合物驱油效果的研究,认为聚合物溶液粘度受剪 切速度的影响,在地层中的滞留情况与现场注入速度有关,年平均注聚速度高的区块见效早,早期采收率提高幅度高,但最终采收率低于年平均注入速度低的区块,因此,应根据各区块地质特点适当控制注入速度,以减少由于剪切,滞留待地聚合物粘度造成的影响,达到提高原渍采收率的目的,该三个区块注聚驱获得的成功经验为胜利油区其它同类油田开展聚合物驱油提供了重要依据。     

提高聚合物驱开发效果的主要做法--以下二门油田H2Ⅱ油组为例

下二门油田H2Ⅱ油组是河南油田第一个工业化推广应用区块,该区块注聚开发取得了明显的降水增油效果,日产油由注聚前的105t增至187t,含水降低了16.1个百分点,目前已累积增油14.1×104t,提高采收率9.14个百分点。本文总结了该区块为提高聚合物驱效果采取的主要作法,分析了聚合物驱开发效果,对其它同类油田开展聚合物驱应用有借鉴意义。     

提高二类储量高温聚合物驱开发效果对策研究——以双河油田V上层系为例

双河油田V上层系是河南油田第一个二类储量高温聚合物驱先导试验区块,通过采取优化聚驱井网,提高井网控制程度;利用油藏数值模拟方法优化聚合物注入参数;注入聚合物前调剖封堵大孔道;见效油井及时提液等对策,使该区块日产油由注聚前125t增至182t,综合含水降低了3.3个百分点,阶段累积增油2.35×10^4t,聚合物驱阶段开发取得了明显的降水增油效果,形成了一套提高二类储量高温聚合物驱效果的作法,对二类储量聚合物驱推广应用有借鉴意义。     

H201区Y8油藏聚合物驱实验研究及应用

长庆油田H201区Y8油层是中低渗透油藏,非均质强,开发中后期平面和剖面矛盾突出,含水上升快,产量递减严重,水驱进一步提高采收率难度较大,为此对该区块进行了聚合物驱研究应用。室内进行了对聚合物的抗盐性、热稳定性等性能评价及岩心驱油实验研究;在H201区开展了聚合物驱现场试验,累积注入0.196PV聚合物溶液后,试验区注入压力上升,综合含水下降,含水最低时下降了7.4%,累积增油9237t。     

渤海油田中高含水期聚合物驱实践——以锦州X油田西区为例

以渤海锦州X油田西区为例,开展了海上油田中高含水期聚合物驱实践,通过提高注聚粘度、增加注水井、实施酸化、调整产液结构等措施有效保证了聚合物开发及增油效果,同时在实践中形成了较为完善的动态跟踪调整及效果评价体系。锦州X油田中高含水期聚合物驱实践为海上类似油田高速高效开发提供了参考依据。     

锦州9-3油田高含水期开发效果评价研究

针对目前锦州9-3油田高含水期开发现状,应用油藏工程方法,从开发效果评价指标体系入手,对注入倍数增长率、水驱指数、存水率、综合含水等指标进行了客观分析,适时监测油田开发动态,及时发现油田存在主要问题,为全面了解油田开发状况,进行下步调整挖潜提供理论依据。评价结果表明,该油田注水开发过程中,在提液稳油、追求上产的同时,控水措施没有及时跟上,导致含水上升较快。但2004年以后的历次开发调整措施发挥了较好的作用,起到了稳油控水的效果。在今后开展稳油措施的同时,建议进一步加强找、堵水等控水工作,以保证开发效果向好的方向发展。     

飞雁滩油田聚合物驱油藏动态特征分析

聚合物驱是以聚合物水溶液为驱油剂的一种三次采油技术.主要针对特高含水期飞雁滩油田开展了含水较低时(转注聚前综合含水86.1%)的聚合物驱矿场试验.设计注入总量470 PV·mg/L,主段塞浓度1 800mg/L,年注入速度0.07 PV.聚合物驱后地层流动系数大幅度降低,吸水剖面改善,波及体积扩大,综合含水降低14.5%,日产油增加255 t,累积增油46×104t,提高采收率3.9%.飞雁滩油田在高含水后期实施聚合物驱取得了很好的降水增油效果.     

压力指数决策技术在青海油田调驱中的应用

随着油田的开发,注水油田进入高含水开发期,在非均质油层中形成高渗透条带,使注入水单层突进,严重影响注水开发效率,导致注水井吸水剖面很不均匀。深部调驱工艺技术作为改善区块和井组开发效果的一项重要工艺,可以将调剖和驱油有机地结合在一起,最大限度地提高油田的注入水波及系数和采收率,挖掘中高含水油田的开发潜力,实现控水增油的目的。在深部调驱决策技术方面,利用压力指数决策技术对区块综合治理进行选井和设计优化,在油田调驱中发挥了很好的作用。     

油田采出水HPAM水溶液粘度稳定剂的研制

针对油田三次采油开发过程中不同的水质使部分水解聚丙烯酰胺(HPAM)水溶液的粘度降低的现象,研究其主要影响因素,分析粘度降低规律,确定了HPAM粘度稳定剂的主要研制方向,并且通过研制HPAM粘度稳定剂提高聚合物溶液粘度,使粘度保留率达到80%以上,降低了聚合物驱油成本.     

The Evaluation of a Technological Trend in Polymer Flooding for Heavy Oil Recovery

This work evaluated an emerging technological trend in polymer flooding for heavy oil recovery in the near future (i.e., the injection of polymer solution with higher viscosity [concentration] and larger slug size). The rheological properties and flow behavior in porous media of two typical enhanced oil recovery (EOR) polymers (a partially hydrolyzed polyacrylamide and a xanthan gum) and a novel hydrophobic polymer were first investigated to identify their potential functionality in displacing heavy oil. Tertiary oil recovery was then conducted by polymer flooding using a heavy oil of 1000 mPa·s. The results indicate that polymer flooding with higher viscosity and larger slug size can significantly improve oil recovery and produced water/oil ratio, which proves the technical and economic feasibility of this trend in oil fields. Xanthan gum exhibits an outstanding flow behavior and EOR performance in sandpack displacement tests compared to other polymers, making it a promising candidate for this trend.     

影响聚合物驱采收率因素的研究

通过室内物理模拟驱油实验,考察了水油黏度比、地层渗透率、聚合物注入量对聚合物驱效果的影响.结果表明,当岩心渗透率为1.5μm2,地下原油黏度为50.7 mPa·s时,聚合物驱的合理水油黏度比为0.06 ～0.6;聚合物驱提高采收率的最佳地层渗透率为2.0 μm2;水驱后转注浓度为3 000 mg/L的聚合物溶液,提高采...     

Effect of Nanoclay on Heavy Oil Recovery During Polymer Flooding

Polymer flooding for improving sweep efficiency has been studied extensively in laboratory and tested in fields for conventional oils. A novel nanofluid based on polyacrylamide clay has been developed and its properties have been experimentally tested as a suitable candidate in polymer flooding for oil field projects. This authors review the polymer flood fundamentals as they are applied to heavy oil recovery. In this study, they focus on roles of clay nanoparticles on polymer viscosity and improve recovery in heavy oil recovery. The theory is supported with coreflood and physical model results for several oils ranging in viscosity from 200 to 4200 mPa.sec. For some of these coreflood tests the nanopolymer flood was able to increase the oil recovery in comparison to a baseline polymer flood. These laboratory results will be helpful for the planning of nanoclay polymer flooding for heavy oil reservoirs. Also flooding test showed a 5% increase in oil recovery for nanoclay polymer solution in comparison with polymer solution after one pore volume fluid injection.     

Research into polymer injection timing for Bohai heavy oil reservoirs

Polymer flooding has been proven to effectively improve oil recovery in the Bohai Oil Field. However, due to high oil viscosity and significant formation heterogeneity, it is necessary to further improve the displacement effectiveness of polymer flooding in heavy oil reservoirs in the service life of offshore platforms. In this paper, the effects of the water/oil mobility ratio in heavy oil reservoirs and the dimensionless oil productivity index on polymer flooding effectiveness were studied utilizing relative permeability curves. The results showed that when the water saturation was less than the value, where the water/oil mobility ratio was equal to 1, polymer flooding could effectively control the increase of fractional water flow, which meant that the upper limit of water/oil ratio suitable for polymer flooding should be the value when the water/oil mobility ratio was equal to 1. Mean while, by injecting a certain volume of water to create water channels in the reservoir, the polymer flooding would be the most effective in improving sweep efficiency, and lower the fractional flow of water to the value corresponding to D Jmax. Considering the service life of the platform and the polymer mobility control capacity, the best polymer injection timing for heavy oil reservoirs was optimized. It has been tested for reservoirs with crude oil viscosity of 123 and 70 mPa s, the optimum polymer flooding effectiveness could be obtained when the polymer floods were initiated at the time when the fractional flow of water were 10 % and 25 %, respectively. The injection timing range for polymer flooding was also theoretically analyzed for the Bohai Oil Field utilizing relative permeability curves, which provided methods for improving polymer flooding effectiveness.     

Network modeling of residual oil displacement after polymer flooding

Research on microscopic flow mechanisms can aid in improving oil recovery after polymer flooding. Based on a two-phase water–oil network model, a simulation model for polymer flooding is proposed that considers various percolation mechanisms of the polymer solution, such as thickening, diffusion, adsorption, entrapment and shear degradation. Thus, the pore structure and the rheological fluid properties can be integrated. This network model can provide an effective tool for the study of residual oil displacement after polymer flooding. The distribution laws for residual oil after polymer flooding were studied using this microscopic simulation. Results show that compared to water flooding, polymer flooding can greatly improve oil recovery. Moreover, the residual oil distribution after polymer flooding tends to be more disperse, complex and variable. At the same time, displacement methods and parameters of the residual oil were investigated. Methods such as increasing the viscosity of the injection fluid can be applied, but the viscosity must be very high. Injection of a slug of displacing liquid with low interfacial tension after polymer flooding can decrease irreducible oil saturation and improve the displacement efficiency, but the interfacial tension needs to be extremely low.     

下二门油田核二段Ⅱ油组普通稠油油藏二次聚合物驱实践与认识

下二门油田核二段Ⅱ油组属于普通稠油油藏,油层厚度薄、非均质严重、地下原油粘度大。经过20多年的水驱、聚合物驱及后续水驱开发后,油藏采收率低、采油速度低、采出程度低、综合含水高,开发效果逐年变差。二次聚合物驱采用井网调整技术、注采参数优化技术、全过程调剖技术、动态调整技术等关键技术,取得了较好的矿场应用效果。实践表明二次聚合物驱能较好地改善该油藏的开发效果,是进一步提高采收率的有效途径。下二门油田核二段Ⅱ油组普通稠油油藏二次聚合物驱是国内第一个开展二次聚合物驱的单元,其成功经验为类似油藏的开发提供了借鉴。     

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.     

交联聚合物技术在胜利油田的应用

交联聚合物技术是一项调驱结合、能大幅度提高原油采收率的工艺技术,与聚合物驱相比不仅大幅度提高了溶液粘度、阻力系数和残余阻力系数,同时也能改善油藏的非均质状况。该技术既可用于交联聚合物驱油,也可用于注聚区低压井添加交联剂改善聚合物驱效果,另外,增大溶液浓度和强度可用于交联聚合物深部堵水调剖。孤岛油田渤19断块交联聚合物驱试验和胜利油区注聚低压井添加交联剂矿场试验结果表明:与聚合物驱相比,交联聚合物在油藏中更容易吸附和滞留,可抑制聚合物窜流,改善油藏的非均质性,提高原油采收率。     

稠油油藏污水活性碱/聚二元复合驱室内试验研究

羊三木油田碱/ 聚驱先导试验存在现场污水配制碱/ 聚二元复合驱体系时出现结垢堵塞地面管线、聚合物严重降解等问题，为此开展了污水配制新型碱/ 聚合物二元复合驱体系研究。采用抗钙镁结垢能力强、降低界面张力幅度大的活性碱与污水聚合物匹配，分析在污水配制条件下，不同碱型与聚合物匹配的驱油能力，以及在原油黏度高达530 mPa·s 时能否继续开展二元复合驱的问题。研究结果表明 :原油黏度为530 mPa·s，污水配制活性碱/ 聚合物二元复合体系溶液黏度为45 mPa·s 时，油水界面张力达到10－3 数量级，活性碱/ 聚合物二元复合驱比纯水驱提高采收率17% 以上；在原油黏度确定及油水界面张力已降至超低值时，超过碱/ 聚二元体系溶液浓度技术临界点后，即使继续增加溶液黏度，采收率也不会大幅度增加。该研究为普通稠油油藏注水开发后期化学驱提高采收率提供了新型有效的技术手段。     

Effect of nano titanium dioxide on heavy oil recovery during polymer flooding

In recent years, polymer flood of heavy oil has been extensively studied in laboratories and successfully applied in several fields. Polymer flooding is the most successful chemical enhanced oil recovery method. However, still, the need for a large amount of polymer, leading to high operational costs, presents a big challenge in technologies. This challenge can be addressed by considering the newly emerging nanomaterials. In this work, the author focuses on roles of TiO₂ nanoparticles on polymer viscosity and improve recovery in heavy oil recovery. He present the results obtained from a coreflood experiment with polymer injection in heavy oil at 1320 mPa.sec viscosity. Nanopolymer exhibits an outstanding flow behavior and enhanced oil recovery performance in coreflood displacement tests compared to base polymers. The results indicate that polymer flooding with higher viscosity can significantly improve oil recovery. Flooding test showed about 4% increase in oil recovery for nanopolymer solution in comparison with polymer solution after one pore volume fluid injection.