Analysis of Maximum Liquid Carrying Capacity Based on Conventional Tubing Plunger Gas Lift

China’s unconventional gas fields have a large number of low-productivity and low-efficiency wells, many of whichare located in remote and environmentally harsh mountainous areas. To address the long-term stable productionof these gas wells, plunger-lift technology plays an important role. In order to fully understand and accurately graspthe drainage and gas production mechanisms of plunger-lift, a mechanical model of plunger-liquid column uplift inthe plunger-lift process was established, focusing on conventional plunger-lift systems and representative wellboreconfigurations in the Linxing region. The operating casing pressure of the plunger-lift process and the calculationmethod for the maximum daily fluid production rate based on the work regime with the highest fluid recovery ratewere determined. For the first time, the critical flow rate method was proposed as a constraint for the maximumliquid-carrying capacity of the plunger-lift, and liquid-carrying capacity charts for conventional plunger-lift withdifferent casing sizes were developed. The results showed that for 23/8 casing plunger-lift, with a well depth ofshallower than 808 m, the maximum drainage rate was 33 m3/d;for 27/8 casing plunger-lift, with a well depth ofshallower than 742 m, the maximum drainage rate was 50.15 m3/d;for 31/2 casing plunger-lift, with a well depthof shallower than 560 m, the maximum drainage rate was 75.14 m3/d. This research provides a foundation for thescientific selection of plunger-lift technology and serves as a decision-making reference for developing reasonableplunger-lift work regimes.

智能柱塞及机器人井下排水采气研究进展

气井进入生产后期,携液能力弱,产能大幅降低,柱塞气举技术的发展对提高采收率具有重要意义。在技术日益进步的背景下,智能柱塞气举和井下智能机器人排水采气技术在油田得到了应用,调研了国内外的生产研究现状,对比了3种工艺原理,研究了工艺的基本模型及其优化情况,对工艺的适用性与效果进行了评价。指出传统柱塞气举技术存在的不足,以及对新智能系统技术的展望。

等截面双作用柱塞泵的仿真与试验研究

【目的】为提升水肥一体化机施肥泵的机械效率,设计了一种等截面双作用柱塞泵,通过仿真分析和对比试验结合的方法验证了新式柱塞泵的稳定性与精准性。【方法】运用Fluent软件对柱塞泵模型内部流道进行仿真,验证了设备结构的合理性。开展柱塞泵与文丘里施肥泵的对比试验,测试进排水肥可溶性离子浓度(EC值)和泵的机械效率,分析等截面双作用柱塞泵应用于水肥一体化机组的实际工作性能。【结果】进排水肥溶液EC值平均值方差仅约为48.5,同文丘里施肥器试验数据的平均值方差814.8相比,极限值波动减少约54%。【结论】试验工况范围内,等截面双作用柱塞泵对比文丘里施肥泵的最大机械效率提升点出现在0.30 MPa时,约提升56%。研究为提升水肥一体化机工作效率,增强水肥一体化机市场适应性提供理论和试验参考。

大型柱塞泵约束阻尼基座隔振性能研究

为了缓解多台柱塞泵协同作业时注聚平台甲板振动响应过大的问题,本文基于阻尼剪切变形耗能原理提出了一种新型约束阻尼减振基座。利用Abaqus软件建立了柱塞泵-约束阻尼基座-注聚平台振动响应分析模型,探究了约束阻尼基座的阻尼材料损耗因子、阻尼层厚度和拓展层层数对其隔振特性的影响规律。研究表明,随着阻尼材料损耗因子、阻尼层厚度、拓展层层数的增加,约束阻尼基座的隔振性能将逐步增强,当阻尼材料损耗因子为1.0、阻尼层厚度为20 mm且拓展层数为3时,约束阻尼隔振基座的减振效果达到最优,其隔振量高达75.25 dB,可显著降低注聚平台的振动响应。

伺服电机驱动变量柱塞泵试验台研发

针对伺服电机驱动变量柱塞泵的控制研究,对相关试验平台进行设计,根据控制方案对液压系统和电气系统硬件进行了搭建;利用PLC编程软件,开发了用于控制输出的程序以及用于部分传感器数据采集的程序。同时,在LabVIEW平台上编写了包括控制逻辑、PID控制算法以及数据采集的程序,形成了适用于试验平台的上位机用户界面。通过OPC通信协议实现了PLC与LabVIEW之间的数据交互,确保了控制系统的完整性和协同工作能力。

316L柱塞泵泵头开裂失效分析

柱塞泵是油田注水开发过程中影响注水效率的重要设备。某油田的316L柱塞泵在服役过程中发生了泵头开裂失效,为了确定其失效原因,对该柱塞泵泵头材料的化学成分、金相组织、力学性能及开裂断口形貌进行了试验分析,并对其泵头的应力分布情况进行了有限元模拟分析。结果表明,316L柱塞泵泵头材料的化学成分、金相组织和拉伸试验结果均符合ASTM A473-01标准的要求。该柱塞泵泵头为疲劳开裂失效,其疲劳裂纹起源于内孔表面。柱塞泵泵头疲劳裂纹源区存在较大的结构应力及机加工刀痕缺陷是导致316L柱塞泵泵头开裂失效的主要原因。建议改进柱塞泵泵头的结构设计,降低结构应力,并消除机械加工刀痕缺陷。

Microstructure and properties of ductile iron bars for plunger pump prepared by horizontal continuous casting process

Ductile iron bars(DIBs) with a diameter of 145 mm, used for plunger pump production, were made by the horizontal continuous casting(HCC). The microstructure of the samples cut at three locations with different distances away from the surface(~20 mm from the surface, half of the radius and the center of the HCCDIBs)were investigated. The mechanical properties were measured by tensile and torsion tests. Results show that after the spheroidization of graphite, the iron matrix incorporates the nodules of Format I, Size 8 close to the surface, Format I, Size 7 at the half of the radius from the surface, and Format II, Size 6 in the centre of the bar,according to the ASTM A247 standard. The content of pearlite in the matrix changes from 55%(~20 mm from the surface) to 70%(half of the radius) and 80%(the center of the HCCDIBs). The strengths in tension are 552, 607 and 486 MPa with the elongations of 12.5%, 10.5% and 5.8% in samples cut at these three locations from the surface to the centre, respectively. The strength in torsion is equal to 558, 551 and 471 MPa at corresponding torsion angles of 418°, 384° and 144° respectively to the same distance from the bar surface. Fracture in tension is manifested via crack propagation through the interface between graphite nodules and matrix(Mode I), while in torsion the fracture is caused by the shear of graphite nodules(Mode II). It is shown that the transition between two fracture modes is also dependent on the size of graphite nodule. Typically, fracture Mode I was observed for nodules of smaller diameter(less than 22.7 μm) and fracture Mode II was seen for nodules of greater diameter(more than 24.8 μm).

Fluid characteristic of multiphase fluid in annular space between pump barrel and plunger

The pump performance parameters,such as pump pressure,plunger friction and pump valve resistance,are fundamental parameters of optimal design of pump efficiency and sucker rod pumping system (SRPS).In this paper,considering the characteristic of geometrical nonlinear and rheology property of multiphase fluid,the pump performance parameters are studied.Firstly,a dynamics model of annular fluid flow is built.In the detail,a partial differential equation of annular fluid is established and a computing model of fluid pressure gradient is built.Secondly,the simulation models of plunger friction and hydraulic resistance of pump valve are built.Finally,a novel simulation method of fluid pressure in annular space is proposed with software ANSYS.In order to check up the correction of models proposed in this paper,the comparison curves of experiment and simulation results are given.Based on above model,the whole simulation model of plunger pump is simulated with Visual Basic 6.0.The results show that the fluid friction of pump plunger and instantaneous resistance of pump valve are nonlinear.The impact factors of pump performance parameters are analyzed,and their characteristic curves are given,which can help to optimize the pump motion parameters and pump structural.

Study on a Gas Plunger Lift Model for Shale Gas Wells and Its Effective Application

The problem of efficient gas lift for gas well annulus packers that rely on their own energy plungers is considered.The complex related gas-liquid problem is addressed in the frame of model where the gas inflow dynamics and liquid inflow dynamics of the considered shale gas wells are weakly coupled.On this basis,and with the aiding support of indoor simulation experimental data,a new gas plunger lift design taking into account liquid leakage is obtained.Finally,a dedicated software relying on this approach is developed and used to verify the reliability of the model by means of field examples.

A Dynamic Plunger Lift Model for Shale Gas Wells

At present,the optimization of the plunger mechanism is shale gas wells is mostly based on empirical methods,which lack a relevant rationale and often are not able to deal with the quick variations experienced by the production parameters of shale gas wells in comparison to conventional gas wells.In order to mitigate this issue,in the present work,a model is proposed to loosely couple the dynamics of gas inflow into shale gas wells with the dynamics of the liquid inflow.Starting from the flow law that accounts for the four stages of movement of the plunger,a dynamic model of the plunger lift based on the real wellbore trajectory is introduced.The model is then tested against 5 example wells,and it is shown that the accuracy level is higher than 90%.The well‘switch’,optimized on the basis of simulations based on such a model,is tested through on-site experiments.It is shown that,compared with the original switch configuration,the average production of the sample well can be increased by about 15%.

柱塞气举排水采气研究现状及展望

气井积液是大部分天然气井在开发中后期存在的主要问题,排水采气工艺是排出井底积液并恢复和提高气井产量的关键技术之一。柱塞气举是一种可以高效排出井底积液的间歇生产工艺,该工艺具有结构简单、成本低等优点,适用于低产井和高气液比井,是目前我国最主要的排水采气技术之一。为此,系统地从柱塞类型及应用场景、柱塞气举速度模型、工作制度优化及故障诊断、新型柱塞气举工艺4个方面进行研究综述,分析了不同模型的优缺点,并总结了8种新型柱塞的特点和应用场景,进而针对目前气井生产效率低和井底积液难排出的情况,展望了柱塞气举工艺的技术发展方向。研究结果表明:(1)相比于国外,中国柱塞气举工艺应用广泛,发展较为成熟,新型柱塞气举工艺的发展进一步扩大了其应用范围。(2)速度模型可精确模拟柱塞在井筒中的运动状态;工作制度优化逐步向智能化发展。(3)目前仍存在柱塞气举工艺智能化程度低和无法适应复杂油气井生产的问题。结论认为,柱塞气举工艺下一步发展应聚焦4个方向:智能化技术的应用、适应复杂井条件下的技术开发、结合其他采气工艺的复合应用、基于气藏—井筒—地面一体化的井群制度优化。该研究成果对进一步推动国内柱塞气举相关研究与应用,具有较好的参考作用,并可以为柱塞气举未来发展方向提供指导。

基于预吸排油结构的柱塞泵配流盘优化

配流盘过渡区域的结构对于柱塞泵的脉动抑制以及减振降噪起着至关重要的作用。基于配流盘吸空抑制原理,对配流盘过渡区进行结构优化。首先计算为了平衡节流面积变化速率和柱塞腔运动速率所需增加的节流面积,并对配流盘过渡区结构进行优化。然后通过PumpLinx对轴向柱塞泵压力、流量脉动以及空化进行了仿真分析与验证。结果表明,优化后的配流盘过渡区结构可以有效降低压力、流量脉动,缓解空化发生。

高含水致密凝析气藏稳产技术应用——以四川盆地安岳气田须家河组气藏为例

四川盆地安岳气田上三叠统须家河组二段气藏为低孔、低渗、有水、中含凝析油、弹性气驱、高压岩性圈闭的砂岩气藏,气藏底水能量充足。针对气井生产过程中受地层水水侵和反凝析污染影响造成稳产难度较大的情况,结合储层及气井产液特征,开展有水凝析气井稳产技术应用实践,分析并总结应用实践经验和成果,选取了应用效果较好的注气吞吐、电潜泵排水、车载压缩机气举、柱塞气举排液和自动化开关井5种稳产技术。结果表明:①针对储层反凝析液伤害,形成单井注气吞吐技术应用选井原则;②针对气藏水体赋存特征和水侵模式特征,调整气藏排水采气对策思路,采用电潜泵排水技术和车载压缩机气举技术;③针对地层压力低、举升能量不足,优化油、气、水三相流动条件下的柱塞气举排液技术;④针对低压间歇生产井采用自动化开关井技术,增加生产效率,降低人工成本。对5种主要稳产技术的应用情况进行了分析评价,认为一系列稳产技术的应用有助于安岳气田须二段气藏稳定生产,为类似高含水致密凝析气藏的稳产提供了借鉴和参考。

基于C-DCGAN的铁路道岔转辙机柱塞泵故障诊断方法

针对铁路道岔转辙机设备状态监测数据不完备、非平衡和局部缺失等问题,提出基于改进生成式对抗网络(GAN)的转辙机柱塞泵故障诊断方法。首先,构建条件深度卷积生成式对抗网络(C-DCGAN)模型,利用一维卷积层处理柱塞泵振动信号的时域和频域特征,通过博弈对抗机制优化生成器和判别器,提高模型的泛化能力和故障特征提取能力;其次,引入双时间尺度更新规则(TTUR)来解决判别器正则化过程中的缓慢学习问题,提升模型训练的稳定性;最后,采用实测数据进行案例分析,验证所提方法的有效性。结果表明:在4种不同工况下,生成样本的JSD值分别为0.190,0.235,0.240和0.185;在正常样本与故障样本比例分别为100∶1,50∶1,20∶1和10∶1时,故障分类精度依次达到91.24%,94.13%,94.96%和96.08%。该方法在样本生成方面具有更好的性能,尤其在处理数据不平衡问题时,可达到较高的故障分类精度,为铁路安全运行提供有力保障。

考虑表面粗糙度与空化效应的组合密封润滑分析

为了研究表面粗糙度及空化效应对压裂泵柱塞密封副密封性能的影响,基于稳态Reynolds方程,建立了粗糙峰和空化效应影响下组合密封的弹流润滑数值模型.在数值模拟基础上,采用有限体积法求解稳态Reynolds方程,研究了密封副在表面粗糙度影响下的油膜厚度、油膜压力、油膜流速分布规律,以及不同的往复速度和滑环表面粗糙度对密封性能的影响.结果表明,外行程流体动压效应微弱,油膜在空气侧附近会出现空化现象;较高的往复速度有利于减小泄漏量及摩擦阻力;滑环表面粗糙度从0.8μm增加到1.8μm时,净泄漏量与外行程摩擦力分别升高了180.4%和11.17%.因此,在工作过程中应设置较高的往复速度和使用较低粗糙度的滑环以提高密封性能.

火星探测器进入过程防热层温度测量方法

火星探测器进入过程中的防热层烧蚀温度是防热结构设计和气动热环境辨识的关键参数之一。为了满足防热层温度在轨测量的需求,提出采用柱塞式结构大底分层测温探头和U形结构背罩测温探头,与电缆和多通道温度变换器共同组成温度传感器进行在轨测温的方法。设计内容包括测温探头热电偶元件选取、结构形式和安装方式,以及信号集中放大变换和自动冷端补偿等。开展全量程标定和风洞专项试验验证,证明所设计的温度传感器可以实现1300℃以下烧蚀温度变化全过程测量,测量精度达到0.28%。该温度传感器已在我国首次火星探测任务“天问一号”探测器的着陆巡视器上成功应用,可为进/再入航天器烧蚀温度在轨测量的实施提供借鉴和参考。

考虑柱塞倾斜的航空柱塞泵柱塞副润滑特性研究

柱塞泵在高速高压下运行时,柱塞和缸体之间常常存在一定倾角,使得柱塞副出现摩擦磨损或柱塞卡滞现象,严重影响其服役寿命。为研究柱塞倾斜对柱塞副润滑及泄漏特性的影响,引入压力流和剪切流影响因子修正间隙流动的雷诺控制方程,建立考虑柱塞偏斜下的油膜厚度方程,采用有限元方法分析柱塞副的润滑及泄漏特性,得到以下结论:柱塞倾角对柱塞副的润滑特性影响极大,柱塞倾斜时的最大油膜压力明显增大,最小油膜厚度明显减小;倾角为0.00015°时,柱塞副内的润滑状态由弹流润滑向混合润滑转变,倾角为0.00025°时最大油膜压力约为无倾斜时的14倍;柱塞倾角对柱塞副的泄漏特性影响不大,随柱塞副的两端压力差增大,单个柱塞副的泄漏比大部分呈近似线性增大的趋势,当接触长度较小时,泄漏量大且变化曲线的斜率较陡;当单边间隙增加到一定值时,泄漏比显著增大。研究结果为航空柱塞泵柱塞副的精确理论设计及核心旋转组件的失稳问题研究提供参考。

喷油器柱塞副动态泄漏及特性

为了研究高压共轨喷油器柱塞副的动态泄漏特性,建立了柱塞副间隙燃油流动的数学模型,通过有限差分法对数学模型进行数值计算,研究了不同轨压下柱塞副燃油的平均动态泄漏率的变化趋势,与试验值进行对比,验证该数学模型的有效性,并分析了轨压、进口燃油温度、柱塞最大升程和喷射脉宽四种因素对柱塞副动态泄漏量的影响及在不同柱塞速度下,油膜压力、厚度和温度参数的变化趋势。结果表明,在一个喷油循环内,动态泄漏率的变化曲线与控制腔油压变化曲线相似,平均动态泄漏率随着喷油器的轨压、入口燃油温度和柱塞最大升程的增加而增加,但随着喷射脉宽的增加而减小;随着柱塞速度由正速度到负速度的过程,油膜的厚度逐渐变薄,油膜的温度整体上升,油膜的压力变小。

基于键合图理论的斜盘多柱塞泵建模与仿真

为了研究9个柱塞组合而成的斜盘式轴向柱塞泵的性能特征,应用键合图理论,通过AMESim仿真平台建立模型,研究斜盘倾角和配流盘窗口前端的减振槽对柱塞泵流量脉动的影响,分析扩展模型中斜盘所受的力矩。结果表明:柱塞泵斜盘倾角越大,输出的流量越多,流量脉动幅度越大;配流盘窗口的减振槽形状和大小越合理,流量脉动越小;用AMESim仿真平台中的接收和发射元件可以扩展模型,获得斜盘所受的力矩曲线。

水压泵柱塞密封性能实验装置的设计

为解决油水分离式柱塞泵的柱塞与缸套的密封可靠性及选型设计问题,研制了模拟水压柱塞泵实际运行工况的柱塞密封性能实验装置及其加载系统,并对实验装置进行了动平衡设计。在建立实验装置加载系统的仿真模型后,通过仿真对比确定了合理的加载方式。该实验装置的加载实验和稳定性实验表明,实验装置运行稳定可靠,且容积效率在合理范围内。