低压气井泡沫排水适应性分析

在川西气田,泡沫排水工艺由于设计施工简单,井况要求不高,投资成本小且效果显著等特点被广泛应用,并取得了良好的排水效果。但随着泡沫排水采气工艺的推广应用,人们发现即使在泡排剂选择合理、加注工艺正确的情况下,还是有些气井不能达到很好的排液效果,分析认为这其中最主要的原因是泡沫排水采气的时机选择不对。为了选择出正确的泡沫排水采气时机,本文以气井最小携液流速理论为基础,选用改进后的特纳携液模型,对泡沫排水采气应用时机的初点和末点时机进行了研究,选择出最佳的泡排时机,避免时机不对盲目采用泡沫排水而造成的不必要的浪费。     

高含硫气井泡沫排水采气技术研究

为探索泡沫排水采气技术在普光气田高含硫气井中的效果,优选XHG-10E耐温抗硫泡排剂进行了室内评价分析、加注工艺配套和现场试验。室内评价结果表明:该泡排剂与普光气田地层水具有较好的配伍性,耐温、抗盐、耐酸碱、耐硫化氢及携液性能较好;配套加注工艺进行现场试验,取得了较好的排液效果,表明普光高含硫气井泡沫排液适用于固体泡排剂加注泡排。     

泡排工艺技术的灵活应用

气田进入高采出程度期间,探索出的新的排水采气工艺,在同一口产水气井采用两种或两种以止的排水措施维持气井生产的一种采气工艺技术,就属于复合排水采气技术.泡沫排水采气工艺具有设备简单、施工容易、投资少、见效快,在各种助排工艺中应用效果最好等优点,针对特殊单井复合式的泡沫排水技术,使泡排技术得到了灵活应用,取得了较好的效果.本文主要阐述了泡排技术的灵活多样性,用泡排辅以其它工艺启动气源诱喷,建立连续生产制度.     

苏里格气田往复式压缩机组频发故障原因分析

通过理论计算、计算机模拟仿真、现场故障分析得出,由于苏里格气田普遍采用泡沫排水采气工艺而无消泡设备,泡排剂进入了分离器,造成分离器分离效果变差,大量液体和固体杂质进入了天然气压缩机,造成压缩机负荷加重发生液击、气阀失效、活塞杆磨损等故障。     

苏里格气田气井泡排工艺优化

泡沫排水采气作为气田排水采气的重要措施之一,一直得到广泛的应用,但通常使用泡排剂只考虑泡排剂与气井积液是否匹配,携液效率是否达标,通常现场使用效果较差。本文通过室内实验、现场实验结合生产曲线、液面高度等数据,对泡排剂、泡排方式、时机、周期等进行了优化,提高了苏里格合作区块的泡沫排水采气效果。     

吉林油田起泡剂室内评价与应用

泡沫排水采气工艺是维护气田日常生产的一项关键技术,它具有方便、快洁、投资小见效快、操作简单等优点,本文结合泡沫排水采气工艺技术在吉林油田HS气田应用的大量现场试验资料,对已应用的泡排药剂进行室内评价,消除了使用起泡剂可能产生的负面影响,节约生产成本,有利于天然气的生产。     

大牛地气田水平井泡沫排水技术优化研究

泡沫排液采气工艺是对付自喷能力不足,气流速度低于临界流速气井较有效的排水方法,其设备简单、操作简便,一般适合于有一定自喷能力、产液量低于100m^3／d、井深小于3500m的产水气井。该工艺在大牛地气田已运用多年,其应用的井数在逐年增多,且通过新泡排制度的摸索施行其成功率也在逐年提高。然而过去的泡排工艺大都针对直井,随大牛地气田近年来水平井数量的逐渐增加,有必要同时对水平井的泡沫排液采气工艺也进行评价和优化设计,完善大牛地气田泡排工艺技术。     

耐高温泡排剂的研制与应用

气田在开发过程中,随着生产时间的延长、气井边底水的推进,导致气井产水量上升。泡沫排水是最简单有效的排水采气方法。但是常规泡排剂不能满足徐深气田高温高压的特点,因此,我们进行了高温泡排剂的研制与应用,实践证明,该泡排剂能够保证高温高压气井的连续排液,保证气井的正常生产。     

分体式柱塞工艺在大牛地气田D1-74井的应用

大牛地气田随着生产时间的增加,气井压力逐渐下降,气井排液越来越困难,普通泡排工艺受泡沫密度、含有凝析油等因素影响,使得一些积液减产气井生产困难。针对以上原因,第一采气厂引进了分体式柱塞气举排水采气工艺,采气一队D1-74气井于2012年12月开始分体式柱塞工艺实验,通过实验已经取得了一些成果,有助于分体式柱塞工艺在大牛地气田的推广和应用。     

气田排液采气配套技术研究与应用探讨

随着气田的开发,压力的下降,气井积液对气田产量会产生很大影响。排液采气是气田开发中的重要手段,是采气工艺研究和提高天然气采收率的主要内容和关键所在。本文分析了现阶段不同的的排液采气配套技术如泡沫排水采气、气举排水采气、机抽排水采气等技术在实际采气中的运用情况,对其研究和使用具有借鉴意义。     

采用压力传感技术测量鼓泡床中流体力学参数

引　言鼓泡床以其良好的传热、传质、相间充分接触和高效的可连续操作特性在许多领域得到了广泛应用 .在过去的 4 0多年里 ,人们采用许多测量方法(光导纤维、多普勒测速仪、电导法、压力传感技术 )对鼓泡床中的各种流动行为进行了大量研究 ,由于床层内流动的复杂性以及各测量手段间的差别 ,得出的结论不尽相同[1] ,而且工业反应多数在高温、高压、非透明体系下进行 ,这限制了许多测量技术的应用 .压力传感技术以其适用范围广、所需仪器便宜、耐用、测量结果准确的特点在鼓泡床流体力学参数测量中得到了广泛应用床层塌落法是压力传感技术在鼓泡床流体力学参数测量中的一个重要应用 .Sriram和Mann[2 ] 较早地将其应用于测量鼓泡床中的气含率 ;Fan等[3] 也曾利用此方法测量鼓泡床内的固含率 .前人大都采用压力传感技术测量床层内的平均相含率 ,而采用此方法测量大小气泡分数和气泡上升速度的报道很少 .本文根据前人在此方面的研究成果并结合本实验的特点进行了这方面的研究1　实验装置本实验结合工业对二甲苯氧化反应器的特点设计并建立了其流体力学冷模实验装置 ,如图 1所示 .鼓泡床高 6 6m ,内径 0 3m .在鼓泡床一侧自...     

基于气泡群相间作用力模型的加压鼓泡塔流体力学模拟

目前,多数文献报道了冷态加压湍动鼓泡塔内流动特征,并且通过实验数据回归相关经验关联式。然而,此类关联式适用范围有限,难以直接外推到工业鼓泡塔反应器条件。因此,在FLUENT平台上建立了基于气泡群相间作用力的、动态二维加压鼓泡塔计算流体力学模型。通过数值模拟考察了操作压力为0.5~2.0 MPa,表观气速为0.20~0.31 m·s^-1,内径0.3 m鼓泡塔内流场特性参数分布,并且与冷态实验数据进行比较。结果表明,采用修正后的气泡群曳力模型、径向力平衡模型以及壁面润滑力模型描述气泡群相间作用力,能够较为准确地反映平均气含率和气含率径向分布随操作压力和表观气速变化的规律。     

气液鼓泡床泡罩式气体分布器流场的CFD模拟

采用ANSYS FLUENT商用CFD软件对气液鼓泡床内泡罩式气体分布器单体进行了数值模拟。以Ug=12.34m/s的入口速度对计算模型进行单相三维稳态模拟。研究了泡罩内径、泡罩齿片和入口管开孔分别对塔内不均度和泡罩式气体分布器的压降影响规律。研究表明,随着泡罩内径的增加,塔内不均度和分布器压降减小;泡罩齿片加宽,齿片对气体的阻力增加;齿片间距增加,齿片对气体的阻力减小;入口管开孔数对塔内不均度没有任何影响。开孔数很少时,开孔数量的增加使分布器的压降减小,然而开孔数增加到一定数量时,开孔数对分布器的压降影响甚微。对泡罩式气体分布器进行了结构优化。     

分布器对鼓泡塔中气泡直径分布的影响

采用电导探针测定了冷态鼓泡塔中不同气速下的气泡直径及气含率的轴向分布,考察了分布板对鼓泡塔操作性能的影响.结果表明:随着开孔率的减小,从均匀鼓泡区到过渡区的转变提前;在均匀鼓泡区,开孔率对气泡直径影响较小;在过渡区,开孔率大的分布器形成的稳定气泡直径较小、气含率较大;分布板开孔直径越大,形成的初始气泡直径越大,但对轴向气泡直径分布的影响仅限于分布器区.包含分布器影响的气泡直径经验关联式为d/D=140.2Bo-0.5Ga-0.12Fr0.099(h/D)-0.15T-0.34(0.5 cm/s＜ug＜7 cm/s).     

Nonlinear response of an ideal gas bubble to ambient pressure change in a quiescent fluid

This paper is concerned with the small-amplitude oscillations of a bubble composed of an ideal gas in response to anabrupt change in the ambient pressure field. Specifically, we consider the bubble response to a pressure pulse and a pressure step in an otherwise quiescent fluid. The method of analysis employed in the present study is a standard two-timing expansion to eliminate a secular behavior encountered in the asymptotic expansion. In the impulse response the secularity is self-induced due solely to the nonlinearity of the problem whereas the secularity in the step response arises from the change in the equilibrium bubble volume caused by the ambient pressure change. The two-timing solution for each response shows that the secularity modifies the natural frequency of the radial oscillation. Further, the critical intensity of either the pressure pulse or the pressure step for existence of the steady-state bubble radius is determined from the frequency modulated solution and the stability of the bubble response is also discussed in terms of the bubble compressibility and heat transfer across the interface.     

相国寺气田末期开采高低压分输效果分析

相国寺气田是个老气田,井口压力低下,末期开采需进一步降低井口回压,采用高低压分输技术能够提高气田、气井采收率。本文分析该技术在相国寺气田末期开采中应用效果,得出该技术在不上增压机节约投资成本的条件下起重要作用。     

十六烷/超临界CO2混合体系气泡成核的分子动力学模拟

研究了十六烷/超临界二氧化碳（CO2）混合体系的气泡成核过程。采用全原子分子动力学方法,选择等温-等压系统,使体系的粒子数、压力（P）和温度（T）保持不变,采用exp-6力场描述原子间的相互作用,采用距离判别法识别气泡核,根据气泡成核过程的分子位形跟踪气泡的形成过程。结果表明,降低十六烷/超临界CO2混合体系的P,首先形成了低密度的气泡核,然后CO2分子不断地进入气相,直至系统内部形成含有大量气相分子的气泡。     

Numerical simulation of bubble growth in a limited amount of liquid

In this study, we examined the growth of a spherical bubble in a limited amount of liquid by using a finite‐element‐based numerical simulation method. The bubble growth was assumed to be controlled by both momentum and mass transfer. A truncated power‐law constitutive equation was used to describe the rheology of the melt. The gas inside the bubble followed the ideal gas law. The gas concentration at the bubble surface obeyed Henry's law. A computer code was programmed to solve the equations with the Galerkin method. A backward Euler scheme was used to discretize time. Grids were remeshed after each incremental time step to ensure the accuracy of the numerical results. The bubble growth process was simulated with the code. The numerical results, such as the instantaneous bubble size, gas pressure inside the bubble, and gas concentration profile in the liquid, were predicted. The influences of the liquid volume, initial gas pressure, temperature, and rheology of the melt on bubble growth were also studied. The results of the bubble growth simulation in this study were in satisfactory agreement with others' work. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

High-frequency formation of bubble with short length in a capillary embedded step T-junction microdevice

The performances of slug flow gas–liquid reactors are mostly determined by slug length, especially for the high gas–liquid flow rate ratio condition. This work is the first time to report the short bubble generated with high frequency in a capillary embedded step T-junction microdevice. The aspect ratio of bubble could be around 0.5 with a frequency higher than 750 s⁻¹ when the gas–liquid flow rate ratio is even higher than 5. The specific surface area of the generated gas–liquid microdispersion system is larger than 10,400 m²/m³. The short bubble formation process includes two periods, and its formation mechanism is mainly because of the relatively higher pressure drop in the step T-junction, which provides a much higher breakup force for the squeezing flow. Finally, two models are developed to predict the bubble frequency and volume. This work provides a highly promising dispersion technology for the gas–liquid process intensification in microreactors.     

Generation of Two‐Phase Air‐Water Flow with Fine Microbubbles

Aiming at the development of a low‐cost technology for multipurpose water and surface treatment in the chemical industry and beyond, using microbubbles, a novel scheme of liquid‐gas interaction within a specially designed bubble generator was tested. Its efficiency for the production of microbubbles with a size distribution in the micron range is confirmed. The basic element of the device is a vortex chamber with water supply through tangential ducts, while the gas (air) is introduced in a highly turbulent swirling flow of water in radial direction through the orifice in the gas supply duct, located on the chamber axis. Bubble diameters, bubble velocities in the pipe flow and effect of the output pressure on the bubble size distribution were studied.