复合型井组蒸汽辅助重力泄油开发三维势分布规律

采用单水平生产井与多直井复合型井组蒸汽辅助重力泄油开发的稠油渗流规律与传统井型开发的渗流规律不同,水平生产井使原来直井间的注采关系由平行层面转换为立体区域。立体开发三维渗流数学模型的研究以势原理为基础,将水平生产井渗流过程视为三维线汇,建立以水平生产井水平射孔段两端为焦点的椭球形等势面方程;将直井视为多个纵向叠加的平面点源,建立以直井为中心线的圆柱形等势面方程;利用势叠加原理将二者耦合,推导得到复合型井组驱替过程中的渗流压力场和压力梯度场的数学模型。分析了立体开发的动用范围和重力发生泄流时的作用界限,揭示了重力对蒸汽辅助重力泄油开发效果的影响以及重力对油层内压力场和压力梯度场的作用效果,明确了重力会增大压力梯度场在油层内的作用范围和数值大小,特别是在远井地带或由源汇产生的压力梯度较小的地方,重力与驱替压力耦合后的压力梯度促使油层中被加热的流体向水平生产井发生泄流。     

厚层块状稠油油藏火驱调控技术

针对高3618块厚层块状稠油油藏火驱开发中暴露出的井间干扰严重、火线推进不均、增油效果明显变差等问题,在细化监测资料录取基础上,利用数模技术,深化火驱“三场一前缘”及驱油机理研究。研究结果表明：火驱开发中,重力泄油是主要驱动,地层提压是关键,前缘均衡扩展是基础,合理注采井段配置及注气强度是保障。在此认识基础上,按照“高点转驱、线性井排、重力泄油”的思路,重新规划火驱井网,同步提高点火井注气量,适时开展吞吐引效。现场实施后,新增7口受效井,14口井受效明显改善,合计日增油56t/d,火驱开发效果明显改善。该研究可为其他厚层块状稠油油藏火驱开发提供一定借鉴。     

火驱重力泄油技术助力风城超稠油开发

正针对风城油田重18井区侏罗系超稠油储量难动用、原油黏度变化范围大、普通蒸汽开发效果随原油黏度变高而变差的特点,新疆油田公司工程技术研究院科研人员开展了项目综合性研究,在新疆油田首次实现火驱与重力泄油相结合的火驱开发,取得了一定的效果,初步形成了火驱开发的配套技术,达到了提升稠油开发水平、引领火驱发展方向的目的。国内外矿场试验表明,火驱开发技术与常规稠油开发技术、SAGD开发技术相比,具有低能耗、低成本、低污     

超常规稠油油藏改进的蒸汽辅助重力泄油方式应用研究

结合辽河超常规稠油油田的生产实际 ,对蒸汽辅助重力泄油及其改进方式 (蒸汽和气体联合泄油、单井蒸汽辅助重力泄油以及强化蒸汽辅助重力泄油 )的开采机理进行了研究 ,并对以上几种开发方式进行了模拟 ,将模拟结果与蒸汽吞吐和蒸汽驱开发方式的模拟结果进行了比较和方式优选。优选结果认为 :蒸汽辅助重力泄油及强化蒸汽辅助重力泄油是开采超常规稠油油藏较为有效的开发方式 ;在超常规稠油开发早期 ,应采用蒸汽辅助重力泄油 ,后期应转为强化蒸汽辅助重力泄油。在此基础上 ,根据现场调研及数值模拟方法研究 ,确定了采用蒸汽辅助重力泄油和强化蒸汽辅助重力泄油进行超常规稠油开发的技术指标并进行了参数优化 ,分析了蒸汽辅助重力泄油的适应性。研究结果对超常规稠油油藏开发具有一定的指导意义     

超常规稠油油藏改进的蒸汽辅助重力泄油方式应用研究

结合辽河超常规稠油油田的生产实际，对蒸汽辅助重力泄油及其改进方式(蒸汽和气体联合泄油、单井蒸汽辅助重力泄油以及强化蒸汽辅助重力泄油)的开采机理进行了研究，并对以上几种开发方式进行了模拟，将模拟结果与蒸汽吞吐和蒸汽驱开发方式的模拟结果进行了比较和方式优选。优选结果认为：蒸汽辅助重力泄油及强化蒸汽辅助重力泄油是开采超常规稠油油藏较为有效的开发方式；在超常规稠油开发早期，应采用蒸汽辅助重力泄油，后期应转为强化蒸汽辅助重力泄油。在此基础上，根据现场调研及数值模拟方法研究，确定了采用蒸汽辅助重力泄油和强化蒸汽辅助重力泄油进行超常规稠油开发的技术指标并进行了参数优化，分析了蒸汽辅助重力泄油的适应性。研究结果对超常规稠油油藏开发具有一定的指导意义。     

风城油田稠油开发地面集输与处理工艺技术

新疆风城油田稠油资源丰富,稠油种类涵盖普通稠油、特稠油、超稠油,开发方式有蒸汽吞吐、汽驱、SAGD(蒸汽辅助重力泄油)开采、火驱开采工艺等.目前,风城地区稠油主要采用蒸汽吞吐的方法进行热采,同时,开展了蒸汽辅助重力泄油先导试验,并取得了阶段性成果.针对不同开发方式,新疆风城油田开展了稠油集输及处理地面配套工程技术研究,形成了具有新疆油田特色的稠油地面技术.对风城油田稠油吞吐开发集输及处理工艺技术进行了论述,总结了风城油田在稠油SAGD开发集输及处理配套地面工艺技术中取得的经验,并对风城油田稠油开发地面工艺技术的发展趋势进行了展望.     

超稠油油藏火驱辅助重力泄油技术实验研究

火驱辅助重力泄油技术是一种能把火驱的高热效、重力对燃烧前缘的稳定特性、油藏热油运移距离短综合在一起的火驱开发前沿技术。以Ｓ１－３８－３２ 块超稠油油藏为研究对象,利用自主研制的火烧油层比例模拟实验装置,分析了实施火驱辅助重力泄油技术的可行性。根据火线形成与拓展特征,认为点火之前初始热通道的建立、维持泄油斜面的稳定是实现稳定泄油、避免气窜导致火线烧毁水平生产井的重要条件。探索了火线沿水平井段完整推进的３ 种调控方法。该研究可为试验方案设计、现场实施提供有效的技术指导。     

攻坚破壁 硕果仅存 风城水平井火驱运行平稳

<正>水平井火驱辅助重力泄油技术是一项新的稠油开发技术,对生产及调控要求很高。新疆油田风城水平井火驱先导试验区FHWW005井组于2015年11月注气点火,截至2016年底该井组累计产油1 557t,产出气组分含量符合高温燃烧特征,处于逐级提气、稳定燃烧阶段,是国内外目前唯一正常生产的水平井火驱井组。     

吉木萨尔区稠油油藏整体开发方案优化

根据吉木萨尔地区稠油油藏特点,通过三维地质建模对三种开发方式即全直井井网蒸汽吞吐转汽驱、直井+水平井井网吞吐转蒸汽辅助重力泄油技术、全水平井井网蒸汽吞吐转汽驱的开发方式进行了开发效果数值模拟研究,结果表明,直井+水平井蒸汽吞吐转SAGD的开发方案最适合本区块的开发。     

油藏立体开发探讨

为有效开发辽河油田潜山稀油油藏、隔夹层发育的中深层块状稠油油藏及特深层块状稠油油藏,建立了多段多层水平井叠置、直井注汽平面驱替加水平井垂向重力泄油、叠置双水平井注汽排液加直井采油3种立体开发模型,采用现场测试、物理模拟、数值模拟等技术研究了3种立体开发方式的开发机理。潜山稀油油藏立体开发机理为分段均压作用、垂向重力作用及立体联供作用;隔夹层发育的中深层块状稠油油藏立体开发机理为重力泄油和蒸汽驱作用;特深层块状稠油油藏立体开发机理为重力泄水作用、减少热损失作用和提高采注比作用。辽河油田兴古潜山稀油油藏、杜84块兴Ⅵ油层组中深层块状超稠油油藏、洼59块特深层块状稠油油藏现场试验表明,3种立体开发方式可大幅度增加原油产量、实现油田高效开发。     

水平井火驱辅助重力泄油燃烧状态及燃烧前缘预测

为预测超稠油水平井火驱辅助重力泄油燃烧状态和燃烧前缘,采用自主研发的火驱物理模拟实验装置,利用物质平衡法,结合生产动态数据,计算得到燃烧腔体积,预测水平井火驱辅助重力泄油的燃烧前缘;利用生产过程中的气体组分、温度和压力等参数,表征油层燃烧状态。结果表明,温度是最能直观反映燃烧状态的参数,稳定燃烧状态下的燃烧腔与水平井水平段延伸方向存在30°左右的夹角,呈超覆燃烧特征,在水平井上端形成结焦带和油墙,可防止火线进入水平井筒。水平井火驱辅助重力泄油的稳定燃烧期,产出气中CO₂含量高于10%,O₂含量低于3%,水平井段温度低于300 ℃,且油墙压差低于生产压差的一半,若以上特征参数不能满足,水平井则可能出现气窜。     

油砂SAGD开发后期转火驱数值模拟

当蒸汽辅助重力泄油(SAGD)开发进入平台期末时,日产油量降低,汽油比急剧升高,在蒸汽腔发育的楔形区域存在大量剩余油,造成热量的损失,并降低了开发的经济性。文中提出了SAGD开发后期转火驱的接替方式,基于加拿大某油砂区块储层、流体特征建立数值模拟机理模型,将蒸汽腔波及至油层顶部边缘位置时作为转火驱的开发时机,利用在SAGD井两侧添加的垂直注气井排与原水平生产井分别作为火驱开发的注、采井,对转驱开发进行油藏数值模拟研究。结果表明:转驱开发分为4个阶段,即气驱次生水期、火驱见效期、火驱稳产期以及产量递减期;转驱采出程度达到20.9%,平均空气油比仅为788 m~3/m~3,最终采收率达到82.1%。该研究对于油砂高效开发具有积极的推动作用。     

SAGD 重油、油砂开采技术的创新进展及思考

蒸汽辅助重力驱油技术（SAGD）是目前重油、油砂开采中最常用的热采技术之一，相比传统注蒸汽、原位燃烧等技术具有置换稳定、地层接触面积大、驱油效果好、采收率高等优势，同时也存在成本高、蒸汽短循环等问题，为了更好地指导重油、油砂技术创新，开展了基于SAGD 技术的新进展研究。详细阐述了基于SAGD 的技术创新，即单井SAGD、膨胀溶剂SAGD、泡沫溶剂SAGD、燃烧辅助重力驱及氧添加蒸汽辅助重力驱等5 项新技术的原理、创新及优缺点。总结得出，创新一方面是体现在通过井型变化、蒸汽溶剂相结合扩大了蒸汽腔，提高了能量利用率和采收率，另一方面是通过注蒸汽与燃烧法相结合最大限度开采有效能源。基于SAGD 技术的创新发展为重油、油砂开发后续技术储备及创新提供了技术借鉴。     

Effect of drainage height and permeability on SAGD performance

Steam assisted gravity drainage (SAGD) is now considered a commercially successful technique for the recovery of heavy oil and bitumen in Canada. However, our theoretical understanding of the process is based on greatly simplified analytical models which do not always provide accurate assessment of the influence of various process variables. Hence there remains a need for improved analytical models. This paper presents a new semi-analytical model to predict the oil production rate in SAGD. This model was used to study the effects of drainage height and reservoir permeability on production performance.In this model heat conduction problem ahead of the interface is solved by heat integration method (HIM) in an arbitrary orthogonal coordinate system under unsteady-state condition. Several dimensionless numbers are introduced and their relationships are investigated for better understanding of the combination of heat conduction and gravity drainage mechanisms.     

A NUMERICAL ANALYSIS OF THE SINGLE-WELL STEAM ASSISTED GRAVITY DRAINAGE PROCESS (SW-SAGD)

Steam assisted gravity drainage (SAGD) is an effective method to produce heavy oil and bitumen which are important energy resources. In a typical SAGD approach, steam is injected into a horizontal well located directly above a horizontal producer helping to displace heated oil. Single-well (SW) SAGD attempts to create a similar process using only one horizontal well. To improve early-time response of SW-SAGD, it is necessary to heat the near-wellbore area to reduce oil viscosity and allow gravity drainage to begin. Ideally heating should occur with minimal circulation or bypassing of steam. We have investigated early-time processes to improve reservoir heating. A numerical simulation study was performed to gauge combinations of cyclic steam injection and steam circulation prior to SAGD in an effort to better understand and improve early-time performance. Results from this study, include cumulative recoveries, temperature distributions, and production rates. It is found that cyclic steaming of the reservoir offers the most favorable option for heating the near-wellbore area to create conditions that improve initial SAGD response. More favorable reservoir conditions such as low viscosity, thick oil zones, and solution gas, improved reservoir response. Under unfavorable conditions, response was limited.     

The Applicability of Expanding Solvent Steam-Assisted Gravity Drainage (ES-SAGD) in Fractured Systems

Abstract

The aim of this contribution is to evaluate the performance of an expanding solvent steam assisted gravity drainage (ES-SAGD) process in naturally fractured systems. Steam-assisted gravity drainage (SAGD) and ES-SAGD processes have been investigated in both conventional and fractured reservoir models and the effect of networked fractures on the recovery mechanism and performance of ES-SAGD has been investigated. Operational parameters such as steam quality, vertical distances between wells, and steam injection temperature have been also evaluated. Finally, to study the effect of a well's horizontal offset, a staggered ES-SAGD well configuration has been compared to a stacked ES-SAGD.     

A NUMERICAL ANALYSIS OF THE SINGLE-WELL STEAM ASSISTED GRAVITY DRAINAGE PROCESS (SW-SAGD)

Steam assisted gravity drainage (SAGD) is an effective method to produce heavy oil and bitumen which are important energy resources. In a typical SAGD approach, steam is injected into a horizontal well located directly above a horizontal producer helping to displace heated oil. Single-well (SW) SAGD attempts to create a similar process using only one horizontal well. To improve early-time response of SW-SAGD, it is necessary to heat the near-wellbore area to reduce oil viscosity and allow gravity drainage to begin. Ideally heating should occur with minimal circulation or bypassing of steam. We have investigated early-time processes to improve reservoir heating. A numerical simulation study was performed to gauge combinations of cyclic steam injection and steam circulation prior to SAGD in an effort to better understand and improve early-time performance. Results from this study, include cumulative recoveries, temperature distributions, and production rates. It is found that cyclic steaming of the reservoir offers the most favorable option for heating the near-wellbore area to create conditions that improve initial SAGD response. More favorable reservoir conditions such as low viscosity, thick oil zones, and solution gas, improved reservoir response. Under unfavorable conditions, response was limited.     

Molecular composition of in-situ combustion and steam assisted gravity drainage crude oils

This study investigated the property and composition of crude oils from in-situ combustion (ISC) and steam assisted gravity drainage (SAGD). We made comparison of the elemental composition and molecular weight distribution of the two crude oils. It was overserved that ISC crude oil has significant higher oxygen content. The ultra-high resolution mass spectrometry was applied to investigate the molecular composition of acidic compounds in two crude oils. The acidic compounds in ISC crude oil have higher carbon numbers than that of SAGD crude oils.     

Feasibility study on application of the recent enhanced heavy oil recovery methods (VAPEX,SAGD, CAGD and THAI) in an Iranian heavy oil reservoir

Enhanced oil recovery (EOR) methods assisted by gravity drainage mechanism and application of sophisticated horizontal wells bring new hope for heavy oil extraction. Variety of thermal and non-thermal EOR techniques inject an external source of energy and materials such as steam, solvent vapor, or gas through a horizontal well at the top of the reservoir to reduce in-situ heavy oil viscosity. So, the diluted oil becomes mobile and flows downwards by gravity drainage to a horizontal producer located at the bottom of the reservoir.

In this paper, a sector model of an Iranian fractured carbonate heavy oil reservoir was provided to simulate and evaluate capability of some EOR techniques such as Vapor Extraction (VAPEX), Steam Assisted Gravity Drainage (SAGD), Combustion Assisted Gravity Drainage (CAGD), and Toe to Heel Air Injection (THAI) at its reservoir conditions and fluid properties. The simulation results demonstrated that wet CAGD in comparison with other nominated methods could improve heavy oil recovery factor to around 19% much more than each of SAGD, THAI, and VAPEX techniques. It could also reduce the total energy to produced oil ratio index up to 82% with respect to SAGD process in a year.

Although lower oil recovery has been gained by VAPEX process, but using a proper vaporized solvent could produce a kind of de-asphalted and upgraded oil with increased API gravity up to 29°API with no considerable solvent loss.     

辽河油田杜84块超稠油油藏水平井开采数值模拟

针对辽河油田直井注蒸汽开采超稠油油藏效果差的实际情况，利用最新研制的水平井热采数值模拟软件———ＮＵＭＳＩＰ－４软件，研究了杜８４块不同水平井布井方式和开采方式的开发效果。结果表明，该块最佳开采方式为蒸汽辅助重力驱，并采用成对水平井组合，上注下采，水平段长３００ｍ，注采井距１５ｍ的布井方式。该项研究成果可以为类似超稠油油藏的开发所借鉴。