热采井井筒环形空间温度场分布研究

在稠油热采过程中,必然产生温度场在井筒内传递问题,了解温度场分布等情况对采油周期、出油量、出油质量、套管损坏具有十分重要的价值。以注蒸汽热采井过程中井筒内温度场分布情况作为主要研究内容,利用有限元分析软件ANSYS16.2建立了井筒环形空间温度场分布研究模型,对井筒环形空间进行温度场分析,分析出了不同油管材料下环形空间温度扩散情况。结果显示:油管导热系数对地层-水泥环-套管组合系统的温度有着明显的影响作用。     

碳酸盐岩油藏近井筒区域温度场的模拟

在碳酸盐岩油藏酸化中,近井筒附近的温度场对酸化效果影响很大。通过一种双重尺度模型对这一问题进行了研究,模型考虑了孔隙中的对流传质、传热和液固表面的酸岩反应。结果表明:与实验室常温条件相比,地层高温条件下的酸岩反应速率增快,形成主蚓孔的注酸速度增大(Damköhler数减小),且当注酸速度较大时,突破体积明显下降;当模拟区与外界不发生热交换时(绝热边界),由反应放出的热量使得模拟区的温度上升,造成突破体积比等温边界时的小;若酸液在井筒中不与地层发生热交换,则注酸速度较低时不同地层温度的突破体积几乎没有差别;反之,注酸速度较低时突破体积随着地层温度的上升而增加。     

二氧化碳注入井脉冲中子氧活化解释方法研究

对于二氧化碳注入井,常规的剖面测试技术中仅有脉冲中子氧活化测试技术能够满足现场需求。但脉冲中子氧活化只能测的流体的体积流量,由于二氧化碳流体的特殊性,要把氧活化测得的体积流量转换成质量才能够真实反应地层的吸入情况。利用P-R状态方程法来对二氧化碳气体的偏差因子进行求解,进而求取二氧化碳流体的密度,实现体积流量到质量流量的转换,进而得到二氧化碳流体在井筒中密度曲线,达到充分利用脉冲中子氧活化仪器测得的参数,提高测井解释的精度。     

组合式降粘技术在锦25块的研究与应用

组合式降粘开采是指在蒸汽吞吐开发过程中,根据原油物性及生产情况,通过改变注汽参数、化学降粘、二氧化碳驱油等组合成灵活、经济的降粘技术,以改善沥青质的分子聚集状态,延长油流的加热时间为主要目标,完成从地层到井筒直至进站全程降粘,提高开发效果。     

地层-井筒耦合作用下气体钻开产气层井筒压力变化研究

使用气体钻井钻开产气层可以有效的保护储层,但气层流体高速渗流会引起地层压力的剧烈变化,可能导致严重的安全事故,目前对于气体钻井揭开产气层这一过程尚且缺乏合适的计算模型.本文分别建立了气体钻井井筒流动模型与地层渗流模型,在此基础上求解气体钻井钻开产气层地层-井筒耦合模型,实例计算说明该耦合模型可以准确模拟气体钻开产气层后...     

二氧化碳驱室内试验研究

以中原油田卫334块为研究对象,进行二氧化碳驱室内试验研究。细管试验与压力组分试验研究表明,二氧化碳与目前地层原油可形成混相;注二氧化碳的压力组分试验表明注CO2但可大幅度降低地层原油粘度,使地层原油渗流阻力降低;长岩心驱替试验研究表明,目前地层条件下注CO2可实现混相驱开采,原油采收率高于80％,比注水开采高364个百分点。     

湿蒸汽沿注汽井井筒的压降和传热规律分析

在湿蒸汽热采过程中,精确地预测注蒸汽井井筒内蒸汽压力,温度,和干度等参数的变化,对整个生产过程都相当重要。本文根据传热和两相流动原理,建立了井筒注蒸汽的数学模型,把井筒热传递可合理地分解成井筒内稳态传热和地层内非稳态导热两部分,并选择B—B法求解摩阻压降,用Ramey方法计算井筒内湿蒸汽的传热量。     

泡沫钻井井底压力动态变化分析

泡沫钻井当地层流体侵入时,会使泡沫物性发生变化,直接影响泡沫在井筒的流动状态。基于计算流体力学和多相流的相关理论与研究方法,考虑地层流体的侵入,建立了泡沫在环空中流动的瞬态计算模型,分析了不同注液量、注气量和井口回压下井底压力随时间变化规律。研究结果表明,当注液量、注气量和井口回压不同时,地层流体侵入对井底压力的影响变化非常明显:地层水侵入使得井底压力增大,地层气体侵入使得井底压力降低;在地面可通过合理的设计注液量、注气量和井口回压来实现地层流体侵入时井底压力的控制。     

钻井液完井液侵入半径预测新模型

油气田开发时,需要使用钻井液钻开油气层,形成渗流通道,建立油气井的良好生产条件.然而,外来流体由于所包含的化学剂及本身的流变性和人工操作方面的原因,在进入地层时会造成地层伤害,使岩石结构和表面性质改变,甚至引起储集层润湿性和流体相态的改变,导致井筒附近地层渗透率下降,增加油气流流向井筒的阻力,使产能和注入量下降.因此,本文从地层伤害的基本原理出建立了一种新的钻井液滤失模型.     

井筒温度场、压降及温度-压力耦合模型研究现状

为使油田井筒传热问题的研究结果能更加精准地指导工程实践,须建立高精度井筒传热模型.本文综述了建模中涉及的井筒温度场模型、井筒多相垂直管流压降模型以及井筒温度-压力耦合模型的国内外发展历程和研究现状,其中井筒温度场模型研究方法又分为半瞬态法和全瞬态法.在RAMEY等的原始模型基础上,国内外学者们建立了考虑井液相变、井液与管壁的摩擦和焦耳-汤普森效应等前人忽略掉的众多因素的模型,且模型依然具有计算简便的特点,在指导工程实际问题时可供合理选择并联系实际进行完善.     

Oil well sand consolidation. I. Resins for a three-step process

Oil-bearing formations often consist of loose sandy material. In the production of oil from these formations sand tends to be carried to the well bore along with the oil. The flow of sand can be prevented by consolidating or cementing together the sand particles of the formation around the well bore. The cementing has to be accomplished in such a manner that fluid flow channels between particles remain open. This paper describes a new three-step process that was developed to consolidate oil well sand. The steps in the process involve injection of: (1) resin, (2) inert fluid, and (3) inert fluid containing a catalyst. In the first step of the process, resin in injected into the formation where it fully saturates the interstices between sand grains. Permeability is established in the second step by displacement of the excess resin from the interstices, thereby leaving a thin film of resin on the sand grains. In the third step, polymerization is activated by migration of catalyst from the inert fluid into the thin resin film on the sand. The process has the advantage that resin is placed and permeability is established before the resin is catalyzed. This avoids premature polymerization of the resin which might cause plugging of the formation or the tubing string used to inject resin. Desirable characteristics of a resin for the three-step process are: (1) viscosity of 25–200 cp. at well bore temperature; (2) stability for several days at well bore temperature; (3) high adhesion to sand in the presence of an inert flushing fluid; (4) polymerization by less than 10% catalyst; (5) the polymerized resin binds sand together with a strong bond that is not affected by well fluids. Five different resin types have been tested for use in the three-step sand consolidation process. These are: (1) epoxy–anhydride cured with a tertiary amine; (2) epoxy–epoxy diluent cured with a primary–tertiary amine mixture; (3) furan; (4) unsaturated polyester–vinylpyrrolidone; (5) unsaturated polyester–styrene. The two epoxy resins give strong, permeable consolidated sand which is resistant to well fluids such as brine and crude oil. The furan resin gives a weak consolidation. The unsaturated polyester–vinylpyrrolidone gives good strength and oil resistance but is sensitive to brine. The unsaturated polyester–styrene is difficult to apply. Many oil wells have been successfully treated in the Gulf Coast area and in California with the two epoxy resins. Almost all of these wells are producing free of sand, and, to date, more than five million barrels of oil have been produced from these wells.     

Interfacial tension and density measurement of the system corn germ oil – carbon dioxide at low temperatures

In this article, the physical properties of corn germ oil at high pressures of up to 30 MPa and at low temperatures from ?10 °C to 22 °C are presented. We measured the interfacial tension of the commercially available corn germ oil Mazola® and of unrefined corn germ oil in contact with carbon dioxide, as well as the density of carbon dioxide‐saturated corn germ oil. The interfacial tension of refined and unrefined corn germ oil in contact with gaseous carbon dioxide at temperatures above ?10 °C depends on time, while at higher pressures the equilibrium value of the interfacial tension is reached immediately after the formation of the drops or bubbles. The interfacial tension of unrefined corn germ oil in contact with carbon dioxide is higher than the interfacial tension of refined corn germ oil. This fact is explained in this article. The interfacial tension of refined and of unrefined corn germ oil in contact with carbon dioxide decrease with rising pressure and can be described as a function of the carbon dioxide density for the examined temperature range. The density of carbon dioxide‐saturated corn germ oil is linearly dependent on pressure, with a high slope if carbon dioxide is gaseous and with a low slope if carbon dioxide is liquid.     

固体防垢块的研制

研究了以膦酸盐防垢剂为主要材料的、可悬挂于抽油泵下面使用的固体防垢块。防垢块主要由防垢剂、胶结剂组成。羟基亚乙基二膦酸(HEDP)防垢性能和热稳定性较好,可用作固体块中的防垢剂。固体块中的胶结剂由塑料构成。通过比较塑料的熔点和在柴油中的溶解性能,认为塑料00和DFDA7042可以分别用作低温(70℃以下)、高温(70～90℃)固体防垢块的胶结剂。单纯将塑料00和HEDP粉末制成固体块,由于防垢材料和胶结材料的极性差别较大,造成防垢剂颗粒不能被充分包裹,使固体块中的防垢剂在驱替过程中较快溶于水中,达不到缓释效果。通过加入塑料改性剂YHSL,调节防垢材料和胶结剂材料的极性,可制成具有缓释功能的固体防垢块。     

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。     

HH油田注入水与储层流体配伍性研究

HH油田属于典型的低孔特低渗储层油田。注入水与储层流体的配伍性对注水开发方案设计极为重要。通过开展HH油田注入水与C8、C9储层地层水的水质测定、结垢趋势预测和静、动态配伍性实验以及注入水与储层原油的配伍性实验,明确了HH油田注入水与C8、C9储层流体配伍性。结果表明,HH油田注入水与C8、C9地层水不配伍,存在碳酸钙垢趋势,且随着注入水比例的增加、温度的升高,碳酸钙结垢越严重,注入水与地层水比例为9∶1时结垢指标SI值为2.354,SAI值为2.873,结垢程度严重;注入水与地层原油之间配伍性良好。该研究结果对HH油田注水水质指标标准制定、注水开发方案制定及水质处理等研究提供了依据。     

水平井解释处理技术及在新疆某井的应用

介绍了水平井处理技术及其测井资料解释方法,并给出了应用实例。该处理技术是把水平井测井资料转换为井眼轨迹信息和储层特性参数信息,最终绘制出各种图件和图表。以便测井分析家和地质分析家进行地层对比,更好更准确地评价油气层,而且还为水平井今后测试、采油等工作提供了重要参考资料。     

Mathematical model of formation of carbon dioxide hydrate upon injection of carbon dioxide into a methane hydrate stratum

A mathematical model of formation of carbon dioxide gas hydrate upon injection of warm carbon dioxide into a natural stratum saturated with methane and methane hydrate has been presented. The case when methane hydrate decomposes into gas and water on two frontal boundaries and the subsequent formation of carbon dioxide hydrate from carbon dioxide and water has been discussed. The regions where this mode is implemented depending on stratum permeability have been studied based on the pressure–temperature plane of the gas being injected into the stratum.     

降低二氧化氯在油井钢管腐蚀速率方面的研究

对二氧化氯的理化性质进行了小结,研究了二氧化氯作为解堵剂降低油井N80钢管在不同温度下的腐蚀速率,从而达到调整配方、降低二氧化氯腐蚀速率的目的。     

Influence of ethanol as bore fluid component on the morphological structure and performance of PES hollow fiber membrane for oil in water separation

The relationships among varying bore fluid compositions containing ethanol/water were studied. The ethanol composition was varied in the ratio of 0%, 25%, 50%, 75% and 100%. The membrane dope solutions were prepared from 17.25 wt% polyethersulfone (PES), 0.75 wt% polyethylene glycol (PEG), 3 wt% silicon dioxide sol and 78.25 wt% of 1-methyl-2-pyrrolidone (NMP) via dry-jet spinning process. The membranes’ morphology as a result of varying ethanol ratio in the bore fluid composition was characterized and their effects on crude oil/water emulsion separation were evaluated. Results show that the membrane pore size and porosity decreased with increasing ethanol content in the bore fluid mixture, whereas the inner wall thickness of fibers increased. Furthermore, an increase in ethanol concentration also resulted in a slight increase in water contact angle. The use of 100/0 of ethanol/water resulted in UF membranes with the lowest performance. On the other hand, bore fluid mixture containing 25/75 ethanol/water produced membrane with the best performance for crude oil/water separation. Overall, the use of bore fluid mixture containing 25/75 ethanol/water mixture was found to be a powerful way to tune the morphological properties and performance of HF membrane.     

A油田油井结蜡机理及清防蜡对策研究

针对A油田油井全井段结蜡的特殊性,从影响结蜡的主要因素入手,分析了原油组分、原油含蜡量,蜡样成分;同时考虑压力与气油比对析蜡温度的影响,采用高温高压釜与石蜡沉积激光检测仪分析了不同压力、不同气油比下析蜡点,掌握了A油田全井段结蜡的主要原因,得出了原油析出蜡主要以微晶蜡为主,而且熔点较高,不宜采用热洗方法清蜡。针对这一点,现场开展了防蜡防垢降粘增油器、声波防蜡器、空化防蜡器三种防蜡工艺对比试验;室内评价了长庆油田目前在用的五种清蜡剂对A油田的适应性。优选出适合A油田的防蜡工具和化学清蜡剂,对该油田清防蜡工作的开展有一定的技术指导意义。