提高采收率技术研究

通过对油田内提高采收率技术的研究现状进行总结和描述,重点研究了水驱、化学驱、稠油热采以及气驱四类技术在油田开发中的应用,这四种方法较为成熟,因此在油田中得以大规模应用。目前,主要依靠细分重组层系和立体优化井网井型这两种手段来提高水驱技术,从而建立规范和卓有成效的注采系统。稠油热采技术则是利用复杂结构井、各类助剂和蒸汽,进而提高稠油油藏的开发效率。在气驱技术中,二氧化碳驱油是个研究热点。化学驱技术表现在高温高盐油藏和聚合物驱后油藏等方面。     

热采井抗高温长效水泥固井技术研究与现场应用

稠油油藏大多采用热力降粘的方式开采,主要是采用蒸汽热采的方法。注蒸汽热采一般为蒸汽吞吐,后期转为蒸汽驱,因此热采稠油井的固井必须适合和满足蒸汽吞吐和蒸汽驱开采方式。后期注蒸汽开采时,由于地层的保温效果很差,高温蒸汽在注入过程中能量通过水泥环很快耗散到地层中,导致稠油油藏达不到注蒸汽热采的效果,严重影响稠油油藏的开发效果。在注蒸汽开采过程中,水泥石在高温蒸汽环境中强度衰减严重,导致水泥环破裂损坏,使原本封固好的环空失效,引发油气水窜,严重缩短油井寿命。针对稠油油藏固井存在的问题,须研究开发一种适用于封固稠油热采井的长效固井技术,使该固井技术具有水泥浆热容高、保温效果好,可延缓蒸汽注入过程中能量损失;水泥浆具有良好的强胶结性能,大大改善固井第二界面胶结强度,有效防止油气水窜的发生,提高浅层水泥封固段长期封固效果;水泥石强度高,抗高温性能好,其强度在高温下衰减缓慢,可经受稠油热采高温蒸汽的侵蚀的优点。有效解决稠油热采井在高温驱替环境下固井质量差、油井寿命短的问题,为稠油油藏勘探开发提供有力的技术支撑。     

蒸汽吞吐主要参数对开发效果影响研究

在普通稠油油藏开发过程中,蒸汽吞吐通过注蒸汽、焖井、开井生产三个阶段可以降低原油粘度,改善流度比,从而降低残余油饱和度,提高驱替效率,是一项有效的开采稠油的方式。蒸汽吞吐的开发效果是热采参数综合作用的结果。本文通过数值模拟的方式,系统的研究了注汽强度、注汽速度、焖井时间、排液时间对开发效果的影响,对普通稠油油藏开发具有提供相应的参考     

氮气泡沫辅助蒸汽吞吐提高采收率机理研究

边底水稠油油藏注蒸汽热采开发中，水体和蒸汽容易沿大孔道发生窜流，引起含水上升，热采开发效果变差。通过开展注蒸汽后氮气泡沫封堵实验，研究泡沫封堵机理，分析氮气泡沫的增产效果。结果表明：注入氮气泡沫后，改变了底水水侵流动方向，促使底水向水平段两端运移，扩大了水驱波及范围，有效抑制了水淹。注入氮气泡沫能够实现增压、降水、增油的效果，实验生产压差从350 kPa增至390 kPa，含水率从90%降至80%，产油量从0.02mL·min^-1增至0.05mL·min^-1，最终采出程度接近60.0%，比单纯蒸汽驱提高11.5%。此研究成果对于边底水热采稠油油藏水平井开发过程中实现抑水增油，具有参考价值和指导意义。     

蒸汽-泡沫复合驱提高稠油采收率机理研究

目前开采稠油的主要方法为蒸汽驱和蒸汽吞吐,但在开采过程中存在波及系数小和洗油效率低的问题。蒸汽-泡沫复合驱是在向油层注蒸汽的同时添加非凝析气体和耐高温起泡剂的一种驱油方式。文章分析了蒸汽-泡沫复合驱提高稠油采收率的机理,认为泡沫能够封堵蒸汽窜流通道,抑止蒸汽超覆,改善油藏的温度分布,提高波及系数和洗油效率,具有比较好的效果     

稠油热采技术及开发效果影响因素分析

总结了多种稠油热采技术的特点,如蒸汽吞吐、蒸汽驱、多元热流体吞吐、热水驱、火烧油层、蒸汽辅助重力泄油。然后对稠油热采开发效果的影响因素(油藏参数和注入参数)进行了详细分析与研究,希望可以为相关从业者提供一定的参考,从而促进我国石油工业的发展。     

内蒙达14块稠油活化能测定及数值模拟研究

目前,国内外大部分稠油油藏使用蒸汽热采方式开采,成本高、采收率低。与蒸汽热采相比,火烧油层技术具有采收率高、改善剩余油性质、适用条件更广泛等特点。内蒙达14块属于薄互层稠油油藏,位于达尔其油田西构造,属于薄互层油藏。本文针对达14块稠油样开展火驱开发室内相关研究。通过室内实验深入认识各个阶段的氧化特征,采用数值模拟方法模拟火驱过程中油藏燃烧过程,为提高油藏采收率奠定理论基础。     

蒸汽吞吐泡沫调剖体系室内实验研究

针对稠油油田蒸汽吞吐过程中蒸汽超覆推进、沿高渗透层突进而影响油田开发效果的问题,筛选出适用于稠油油藏蒸汽吞吐的泡沫调剖体系QP-3,并采用高温高压泡沫扫描仪与岩心驱替装置考察了泡沫的稳定时间、泡沫半衰期、阻力因子、耐温性、封堵性能和驱油效率。结果表明,QP-3在300℃恒温24 h后稳泡时间为149.51 s、泡沫半衰期为225.62 s、阻力因子为80.77、最佳使用浓度为1.2%。泡沫阻力因子随着渗透率的增大先增加后减小,在渗透率为11 800 m D时达到最大,但注泡沫后岩心两端的压差随着渗透率的增大而不断减小。泡沫调剖对渗透率极差小于5.24的岩心提高驱油效率明显,对渗透率极差为9.10的岩心调剖作用较小。随着渗透率极差的增大,泡沫驱油效率变小。段塞注入泡沫的方式驱油效率最高。     

薄互层稠油油藏火驱开发研究与应用

火驱技术是稠油油藏蒸汽吞吐后大幅度提高采收率技术之一。国外已经开展了浅层单层火驱的工业化应用,并取得了很好的开发效果。对于薄互层状稠油油藏,采用单层火驱单井产量低、采油速度低,开发效果差。针对此问题,本文应用数模、油藏工程计算等方法开展了薄互层稠油油藏火驱技术研究,对井网形式、燃烧方式、注采参数进行了优化设计,并评价了先导试验效果,认识火线推进规律,该研究对同类油藏的火驱开发具有一定的借鉴作用。     

乐安油田草20块蒸汽吞吐开发后期注汽参数优选

乐安油田草20块特稠油油藏自90年起转入注蒸汽开发，目前已进入开发后期。区块开发初期，研究制定了一整套适合薄层砂砾岩特稠油油藏热采开发的注采工艺，成为区块前十年的稳产奠定了基础。其中，合理的注汽参数是开采取得成功的技术关键。但在目前阶段，周期产量下降，周期油汽比降低，原有的注汽参数不再适应目前的生产现状，因此依据目前生产动态重新进行分析、优选。     

CO_2辅助蒸汽驱驱油效率实验研究

稠油开发是世界性的大难题。在中国能源紧缺的今天,稠油资源无疑是中国不可忽视的能源之一。传统的稠油开采方法采用的是单一注蒸汽的热力开采方式,但单一的注蒸汽会带来很多的问题,如汽窜、产量递减过快等问题。随着稠油开采技术的进步,发现在蒸汽中加入CO_2会改善注汽效果。本文进行了CO_2辅助蒸汽驱驱油进行了室内研究,通过改变CO_2与蒸汽的注入比、注入段塞的大小、注入速度来确定最优的注入参数。     

潭口稠油热采技术探讨

潭口稠油为浅层特稠油油藏,通过对潭口注汽吞吐采油认识,结合现有工艺技术,优化吞吐参数,合理的注汽方式,达到高效注汽吞吐采油;通过注氮辅助配套及汽窜的治理,探索潭口稠油油田合理的注汽采油模式,提高蒸汽吞吐的有效性,提高其开发效果。     

SIMULTANEOUS HEAT AND FLUID FLOW IN POROUS MEDIA: CASE STUDY: STEAM INJECTION FOR TERTIARY OIL RECOVERY

Heat transfer and fluid flow in porous media occur simultaneously in thermal enhanced oil recovery and significantly increase the rate of energy transfer. The purpose of this investigation was to take advantage of such contemporary transfers and to study heavy oil recovery efficiency using hot-water flooding, cold-water flooding, and steam injection into porous media. A set of multistage laboratory tests was performed to find the temperature profile during steam injection as a means of tertiary oil recovery. Sand-packed models were utilized to investigate the oil recovery efficiency during cold and hot water injection as well as steam flooding for both secondary and tertiary oil production stages. An oil bank was formed in steam injection during the tertiary oil recovery from a vertical standing sand-packed model, resulting in very high oil recovery efficiency. Steam injection was found to be very effective, compared to cold- and hot-water flooding, for the recovery of heavy oil. Based on the principles of transport phenomena in porous media, a mathematical model was developed to predict the temperature profile during the steam injection process. Satisfactory agreement is achieved between the temperature profile predicted from the model and the experimental results.     

SIMULTANEOUS HEAT AND FLUID FLOW IN POROUS MEDIA: CASE STUDY: STEAM INJECTION FOR TERTIARY OIL RECOVERY

Heat transfer and fluid flow in porous media occur simultaneously in thermal enhanced oil recovery and significantly increase the rate of energy transfer. The purpose of this investigation was to take advantage of such contemporary transfers and to study heavy oil recovery efficiency using hot-water flooding, cold-water flooding, and steam injection into porous media. A set of multistage laboratory tests was performed to find the temperature profile during steam injection as a means of tertiary oil recovery. Sand-packed models were utilized to investigate the oil recovery efficiency during cold and hot water injection as well as steam flooding for both secondary and tertiary oil production stages. An oil bank was formed in steam injection during the tertiary oil recovery from a vertical standing sand-packed model, resulting in very high oil recovery efficiency. Steam injection was found to be very effective, compared to cold- and hot-water flooding, for the recovery of heavy oil. Based on the principles of transport phenomena in porous media, a mathematical model was developed to predict the temperature profile during the steam injection process. Satisfactory agreement is achieved between the temperature profile predicted from the model and the experimental results.     

稠油热采废水回用电站锅炉补给水工艺

常规稠油热采废水处理采用除油软化工艺,出水水质较低,仅能用于直流小注汽锅炉补水。由于小注汽锅炉参数低,排污量大,能耗高,造成采油蒸汽成本高。针对该问题,开发了预处理-蒸发-生物处理-膜处理-混床工艺处理稠油热采废水,并通过实验对工艺各子系统运行性能进行研究以提高处理效果,使系统处理出水可用于电站高参数锅炉补给水,达到以热电联产机组取代小注汽锅炉,降低采油蒸汽费用的目的。研究结果表明,采用该工艺对稠油热采废水进行处理,各子系统运行稳定;废水经除硅软化预处理及蒸发后,产水TOC平均约22mg/L;曝气生物滤池产水TOC平均约6mg/L;再经超滤-反渗透处理后产水TOC含量小于0.15mg/L;继续经混床处理,最终出水电导率≤0.15μS/cm、二氧化硅≤10μg/L、TOC≤200μg/L,满足电站高参数锅炉补水水质要求,每吨水直接运行费用为8.05元。     

Reducing heavy oil carbon footprint and enhancing production through CO2 injection

The world's dependence on heavy oil production is on the rise as the existing conventional oil reservoirs mature and their production decline. Compared to conventional oil, heavy oil is much more viscous and hence its production is much more difficult. Various thermal methods and particularly steam injection are applied in the field to heat up the oil and to help with its flow and production. However, the thermal recovery methods are very energy intensive with significant negative environmental impact including the production of large quantities of CO₂. Alternative non-thermal recovery methods are therefore needed to allow heavy oil production by more environmentally acceptable methods. Injection of CO₂ in heavy oil reservoirs increases oil recovery while eliminating negative impacts of thermal methods.In this paper we present the results of a series of micromodel and coreflood experiments carried out to investigate the performance of CO₂ injection in an extra-heavy crude oil as a method for enhancing heavy oil recovery and at the same time storing CO₂. We reveal the pore-scale interactions of CO₂-heavy oil-water and quantify the volume of CO₂ which can be stored in these reservoirs.The results demonstrate that CO₂ injection can provide an effective and environmentally friendly alternative method for heavy oil recovery. CO₂ injection can be used independently or in conjunction with thermal recovery methods to reduce their carbon footprint by injecting the CO₂ generated during steam generation in the reservoirs rather than releasing it in the atmosphere.     

稠油油藏蒸汽吞吐开发技术研究

自从20世纪50年代末注蒸汽技术首次投入工业应用以来,世界上的稠油产量迅速增长,在整个原油生产中占有重要的位置。热采方法是稠油油藏最主要的开采方法,而蒸汽吞吐为最常用的热采方法。通过阐述蒸汽吞吐的热采技术机理,了解和掌握基本的稠油油藏蒸汽吞吐开发技术。     

稠油井分层稳恒注汽技术

注蒸汽吸汽不均问题是稠油非均质油藏蒸汽吞吐开发主要矛盾之一,多年来工艺技术人员研究应用选配注技术,通过分隔纵向油层,实施配汽,取得了较好的效。但是不能同时给两个油层注汽,只能先注下层,然后投球配注上层,蒸汽的热损失大,而且存在人为误差和蒸汽的浪费,同时在热采井口投球存在不安全隐患。针对这类问题,研制应用了分层稳恒注汽技术,将分层稳恒注汽管柱下入指定位置。注汽时,蒸汽通过稳恒注汽阀按设计注汽量进入油层,达到调整和改善油层的吸汽剖面,使油井各层位产能达到均衡动用,提高热采效果和采收率。     

风城油田重18井区超稠油油藏注气方式优化选择研究

水平井热采模式一直是改善特、超稠油油藏开发效果的有效手段。在热采中后期,常规同采同注的注气方式存在着蒸汽热利用率低、蒸汽波及范围小和剩余油量大等问题。研究不同注气方式对该类油藏开发效果和经济效益的影响,研究表明,水平井组一注多采和直平井组合吞吐方式均能很大程度提高蒸汽利用率,有效驱替井间的剩余油。