A pressure drop model of post-fracturing shut-in considering the effect of fracturing-fluid imbibition and oil replacement

Since the production regime of shut-in after fracturing is generally adopted for wells in shale oil reservoir,a shut-in pressure drop model coupling wellbore-fracture network-reservoir oil-water two-phase flow has been proposed.The model takes into account the effects of wellbore afterflow,fracture network channeling,and matrix imbibition and oil exchange after stop of pumping.The simulated log-log curve of pressure-drop derivative by the model presents W-shape,reflecting the oil-water displacement law between wellbore,fracture network and matrix,and is divided into eight main control flow stages according to the soaking time.In the initial stage of pressure drop,the afterflow dominates;in the early stage,the pressure drop is controlled by the cross-flow and leakoff of the fracture system,and the fractures close gradually;in the middle stage of pressure drop,matrix imbibition and oil exchange take dominance,and the fracturing fluid loss basically balances with oil replaced from matrix;the late stage of pressure drop is the reservoir boundary control stage,and the leakoff rate of fracturing-fluid and oil exchange rate decrease synchronously till zero.Finally,the fracture network parameters such as half-length of main fracture,main fracture conductivity and secondary fracture density were inversed by fitting the pressure drop data of five wells in Jimsar shale oil reservoir,and the water imbibition volume of matrix and the oil replacement volume in fracture were calculated by this model.The study results provide a theoretical basis for comprehensively evaluating the fracturing effect of shale oil hori-zontal wells and understanding the oil-water exchange law of shale reservoir after fracturing.

Study of main factors influencing unsteady-state temperature drop in oil tank storage under dynamic thermal environment coupling

With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.

Movement of a millimeter-sized oil drop pushed by optical force

We show experimentally that when an unfocused continuous wave（CW） laser beam is obliquely incident onto the surface of a millimeter-sized mineral oil drop on sucrose solution, it will exert a pushing force on the oil drop, making it move forwards along the surface of the sucrose solution. However, after a period of time, the oil drop stops moving. This can be explained as the phenomenon caused by the change of Abraham momentum, the optical gradient force, and friction together.

The Essential Oil Content and Composition of Selected Salvia Species, Sage Teas, and Sage Drops

Sage is popular for its manifold applications and has always been used in herbalism. The Salvia genus encompasses up to 900 species, but only a few of them have been investigated. Hence, the objective was to investigate the essential oil content as well as the terpene composition of a number of Saliva species. In this context, S. officinalis var. Extrakta, S. officinalis ＂Aurea＂ and S. patens were investigated for the first time. To some extent, it was also possible to associate the terpene distribution of the investigated commercial sage teas and drops with the processed sage oil. Furthermore, an ultrasonic extraction with ethyl acetate seems to be an efficient quick-method for extracting the essential oil.

DROPS在石油钻机设计中的应用

介绍了DROPS落物防坠方案设计理念,然后通过把DROPS理念引入到石油钻机的设计中,从设计源头最大限度地保护人员的操作安全,从而减少钻井风险,降低钻井安全事故的发生。同时DROPS理念的引入也契合了石油钻井行业HSE的要求,提高了产品的市场竞争力。

Experimental Study on Heavy Oil Drag Reduction in Horizontal Pipelines by Water Annular Conveying

Transportation of heavy oil by the so-called water-ring technique is a very promising method by which pressure drop and pollution can be significantly reduced.Dedicated experiments have been carried out by changing the phase’s density,viscosity,velocity and interfacial tension to systematically analyze the characteristics of the water ring.On the basis of such experimental data,a mathematical model for pressure drop prediction has been introduced.This research shows that as long as the density of oil and water remains the same,a concentric water ring can effectively be formed.In such conditions,the oil-water viscosity difference has little effect on the shape of water ring,and it only affects the pressure drop.The greater the viscosity of heavy oil,the smaller the pressure drop of the oil-water ring transportation system.The influence of phases’interfacial tension on the characteristics and pressure drop of the heavy oil-water ring can be considered negligible.The pressure drop prediction model introduced on the basis of the Buckingham’s principle provides values in good agreement(95%)with the experimental data.

CFD analysis of Al_(2)O_(3)-syltherm oil nanofluid on parabolic trough solar

In this paper,in order to improve the performance of a linear parabolic collector,the thermal effects of using Al_(2)O_(3)-syltherm oil nanofluid with different concentrations and new flange-shaped turbulators are investigated.The simulation was performed by ANSYS-FLUENT-18.2 commercial software using Realizable k-εtwo-equation turbulence model.In accordance with the results,it was realized that increasing the volume fraction of nanoparticles(to 5%)and number of turbulators causes the heat transfer coefficient(h)of the fluid to elevate and ultimately the uniform temperature is created in the absorber.For instance,at a flow rate of 4.5kg/s and an inlet temperature of 350 K,the value of h increases by about 8.5%by changing the number of turbulators from 10 to 15 sets.On the other hand,the results indicate that by changing the arrangement of the turbulators,the heat transfer efficiency of the collector can be increased by 5%for 350 K,3.5%for 450 K and 1%for 550 K inlet temperature.

Flow Characteristics of Crude Oil with High Water Fraction during Non-heating Gathering and Transportation

In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields.

Experimental investigation of oil particles filtration on carbon nanotubes composite filter

Due to the lipophilicity of carbon nanotubes (CNTs),the carbon nanotubes composite filter for removing oil particles in cooking fumes is synthesized. The composite filter was fabricated by the chemical vapor deposition (CVD) method. The filtration characteristics of the resultant filter and the influence of the parameters were investigated. The results show that the filtration efficiency of the CNT filter during the saturation period is 99.92%, which satisfies the high efficiency particulate air (HEPA) standard. Pressure drop increases linearly before saturation and the pressure drop at the saturation stage is only two times that of the initial stage, which is far less than that of conventional glass fiber filters. The efficiency increases by enhancing filtration velocity. Pressure drops in the composite filter at the equilibrium stage are equal under different aerosol concentrations. The increase in concentration can improve the efficiency of composite filters. Therefore, the CNT filter is suitable for decreasing oil particle pollution due to its lower increase ratio of pressure drop and higher efficiency.

基于停泵压降数据的页岩气井单段裂缝参数反演——以长宁N209井区页岩气井为例

水平井多级分段多簇压裂是页岩气藏有效开发的关键技术,准确评价缝网参数是开展压裂效果评估、压裂工艺优化和压后产能预测等工作的重要前提.传统页岩气井压裂裂缝参数表征主要采用裂缝扩展模拟与现场监测等手段,对压裂施工停泵压降曲线的信息挖掘与利用不足.采用数字滤波方法消除停泵压降数据的水锤波动,利用分形裂缝表征页岩气井压裂缝网,结合数值试井分析实现了单段裂缝参数反演,建立了一套基于停泵压降数据的缝网参数反演工作流程.该成果在长宁公司N209井区压裂井成功应用,并对裂缝参数评价结果与一体化压裂模拟和产气剖面测试等反演结果进行了验证.结果表明,基于停泵阶段压降数据的单段裂缝参数反演结果显著提升了参数解释精度,有助于揭示页岩气井段间产气能力差异的原因;气井产能与裂缝总长和裂缝表面积的相关性明显高于利用广域电磁法确定的压裂改造体积,其中,早期日产气量与总缝长相关性最高;预计最终回收率与裂缝表面积相关性最高;缝网总长与单簇压裂液规模强线性相关,反映了长宁区块页岩气井压裂工艺2.0的技术先进性.获取页岩气井单段裂缝参数可为产能主控因素分析和压裂效果评价提供更加有效的分析指标.

Hydrolysis of Olive Oil with Immobilized Lipase in a Tapered Column Reactor

Lipase was immobilized in ion exchange resin and then used in the hydrolysis of olive oil to produce fatty acids and glycerol. The time course of hydrolysis of olive oil was investigated in a stirred tank reactor using both of the free and immobilized lipases to find the yield of activity of immobilized enzyme. Continuous hydrolysis of olive oil was also carried out in a tapered column reactor and a cylindrical column reactor with a bottom ID of 10 mm at different upward flow rates. It can be known from experimental results that the degree of hydrolysis of olive oil in the tapered column reactor is moderately better than that in the cylindrical column reactor, the pressure drop in the tapered column reactor is much smaller than that in the cylindrical column reactor.

基于停泵压降曲线的压裂窜扰效果定量评价--以吉木萨尔页岩油平台井为例

针对目前缺乏压裂窜扰效果定量评价方法的难题,创新提出一套基于停泵压降曲线的压裂窜扰效果诊断分析方法。结合井组拉链式压裂工艺,提出了4种典型窜扰模式下的停泵压降曲线,用以诊断压裂窜扰类型。选取吉木萨尔页岩油A平台6个典型压裂窜扰段开展实例应用,通过与微地震监测结果对比,验证了方法的有效性。在此基础上,利用压降试井解释方法对吉木萨尔“新井组内部压窜”和“新老井间压窜”两种典型的停泵压降曲线开展拟合分析,反演解释缝网参数。解释结果表明,新井组内部压窜使主次裂缝的改造效果均受到影响,具体影响效果因窜扰类型的不同而存在差异;新老井间压窜主要影响主裂缝的改造效果,导致缝网由“长宽”向“短窄”转变,有效体积降低28%,整体改造效果变差。

基于机器视觉密立根油滴实验的教学探索与实践

密立根油滴实验是大学物理实验中的重要课程。实验中学生通过宏观的力学研究微观世界的量子性,能够培养学生的动手能力自主学习能力、对已有知识的综合运用能力、组织协调能力。然而教学中存在实验样本少、实验流程长、“试错”选择性筛选结果等问题。本文通过分析教学成果,探讨了教学过程中存在的缺陷,并提出对教学设备进行改进的方案:使用机器视觉来改进密立根油滴实验的流程,实时图像处理和自动化数据收集,学生可以更专注于实验的理论和结果分析,而不是繁琐的操作过程。这样的系统还可以使实验结果更易于分享和讨论,增加互动性,从而提高学生的学习积极性和吸收效果。不仅可以提高教学质量,还可以激发学生的兴趣,培养他们的科学素养和创新能力。这是教育技术发展的一个重要方向,值得探索和实施。

烷基化工艺泄漏油气混合物气液分离及回收特性的实验研究

烷基化工艺为重点监管危险工艺,其泄漏后的危险物料极易引发火灾、爆炸等二次事故。对泄漏的气、液多相态混合物料进行分离、回收对于降低事故危险,预防事故升级具有重要意义。设计了新型的套筒式气液分离器,并研究了不同物性的浅液层和纯液体泄漏物在不同风机频率、充液高度下的回收量、分离效率,还对气液分离关键组件进行性能分析和优化。结果表明,浅液层与纯液体泄漏回收量随黏度的增加而下降,最大降低55%和20%,最大回收量分别为25 kg/min和98.5 kg/min。对于难挥发液体,分离效率接近100%,对于中高黏度液体,总体效率均超过80%。优化后的向上旋液气液分离器对高黏度的液体回收量提升了约20%,压降降低约10%。

苍耳子油滴剂对变应性鼻炎小鼠行为学症状及血清IL-5水平的影响

目的观察中医验方苍耳子油滴剂对变应性鼻炎(AR)小鼠行为学症状和血清白细胞介素-5(IL-5)水平的影响。方法将SPF级BALB/c雄性小鼠32只,随机分为正常组、模型组、对照组、实验组,每组8只。除正常组外,其余三组采用卵清蛋白致敏法建立变应性鼻炎小鼠模型。造模成功后,实验组用苍耳子油滴剂滴鼻,对照组用盐酸西替利嗪滴剂滴鼻,其余两组用生理盐水滴鼻,疗程9 d。治疗结束后,对小鼠鼻部行为学症状进行评分,ELISA法检测血清炎症细胞因子IL-5水平。结果与模型组比较,对照组小鼠行为学评分略升高(P<0.05),实验组小鼠行为学评分降低(P<0.05),对照组、实验组小鼠血清IL-5水平均降低(P<0.01);与对照组比较,实验组小鼠行为学评分降低(P<0.05),血清IL-5水平亦降低(P>0.05)。结论苍耳子油滴剂可以改善变应性鼻炎小鼠的鼻部行为学症状,并降低其血清IL-5水平。

Millikan油滴仿真实验设计

密里根油滴实验运用电学和力学原理,分析油滴在电场和重力作用的下的运动轨迹进而算出油滴的电荷,也有为了测量分数电荷以此方法为基础进行了相关研究拓展实验。通过研究Millikan油滴实验目的、原理,运用计算科技发展而产生的仿真实验平台,把这个近代物理实验用仿真步骤方法做一遍,使得学生对电荷测量及仿真实验教学有了全面的了解,仿真实验教学增加学生学习物理实验兴趣。

延迟焦化粗汽油做顶循油的改造与模拟分析

焦化装置在大量掺炼重污油时,会产生分馏塔塔顶压缩机压降上升,顶循环量下降,导致塔顶温度无法控制。通过技术改造,利用顶循泵打汽油的流程来控制分馏塔顶温,但是汽油干点偏低。通过Aspen hysys软件模拟粗汽油回流代替顶循,发现维持相同的汽油干点需要控制更高的分馏塔塔顶温度,从而解决汽油干点偏低的问题。

爱尔卡因滴眼液-苯酚-薄荷油制剂应用于鼓膜表面麻醉中的效果观察

目的观察爱尔卡因滴眼液-苯酚-薄荷油制剂在鼓膜表面麻醉中的效果。方法210例(248耳)行鼓膜部手术患者,随机分为A组(124耳)、B组(68耳)、C组(56耳)。以大小适中的棉片,随机分别浸透爱尔卡因滴眼液-苯酚-薄荷油制剂(A组)、鲍南氏液(B组)和爱尔卡因滴眼液(C组)置于鼓膜表面麻醉,约20 min后取出棉片,进行鼓膜穿孔边缘处理加鼓室冲洗、鼓膜切开加置管、鼓膜周边小肉芽剔除,鼓膜表面病变处理(含烧灼)等耳科门诊手术,并评估三组麻醉剂的麻醉效果、在各类手术中的麻醉效果及术后随访结果。结果A组(124耳)经爱尔卡因滴眼液-苯酚-薄荷油制剂鼓膜表面麻醉效果的良好率为67.7%,总有效率为93.5%,术中未发现眩晕、耳鸣、恶心、呕吐等并发症,术后追踪至少2周亦未发现任何耳道或中耳的并发症;B组(68耳)经鲍南氏液鼓膜表面麻醉效果的良好率为50.0%,总有效率为79.4%,但大部分患者在放置棉片后数分钟内耳道有不同程度的刺痛感;C组(56耳)经爱尔卡因滴眼液鼓膜表面麻醉总有效率的良好率为32.1%,总有效率为60.7%,有10耳(17.9%)须改用其他麻醉方法。A组与B组鼓膜表面麻醉总有效率比较,无显著差异(χ^(2)=3.522,P>0.05)。A组与C组鼓膜表面麻醉总有效率比较,差异显著(χ^(2)=29.945,P<0.01)。A组在穿孔边缘、鼓室冲洗,鼓膜切开、吸引或(和)置管,鼓膜周边小肉芽剔除,鼓膜表面病变处理(含电离子或射频烧灼)手术中麻醉总有效率优于B、C组,差异显著(P<0.05)。术后回访的大多数患耳的气导纯音听阈均值[(0.5 kHz+1 kHz+2 kHz)/3(dBHL)]均有所降低,但鲍南氏液麻醉者中有11耳(16.2%)的骨导听阈提高10~25 dBHL。经爱尔卡因滴眼液-苯酚-薄荷油制剂麻醉的124耳患者中未出现明显的全身性副作用和不良反应。结论将爱尔卡因滴眼液-苯酚-薄荷油制剂用于鼓膜表面麻醉,效果比鲍南氏液稍好,较单纯用爱尔卡因滴眼液优越,同时具有安全、速效、效果确实、制备使用方便、无毒副作用、不易成瘾、价格低廉等优点。

叉车双油箱强制温降消泡液压系统的性能分析与改进

介绍了一种叉车双液压油箱结构,且此结构在强制温降消泡功能液压系统得到应用。此系统采用2个独立且串联的独特液压油箱结构,油箱之间通过管路串联组合而成,系统采用增长液压系统油路气泡挥发通道和增加液压油有效整机散热面积,经过样机液压系统热平衡数据测试,证实此强制温降消泡液压系统达到了降低液压系统油温的效果。

耳穴压豆联合苍耳子炒麻油滴鼻治疗儿童过敏性鼻炎临床观察

目的探讨耳穴压豆联合苍耳子炒麻油滴鼻治疗儿童过敏性鼻炎(AR)的临床疗效。方法采用随机数字表法将2020年7月—2022年6月赣州市南康区第一人民医院门诊收治的120例AR患儿分为耳穴压豆组、中药组和综合组,各40例。综合组采用基础治疗+耳穴压豆+苍耳子炒麻油滴鼻治疗,中药组采用基础治疗+苍耳子炒麻油滴鼻治疗,耳穴压豆组采用基础治疗+耳穴压豆治疗,3组均治疗8周。对比3组临床疗效、症状评分、体征评分、免疫球蛋白E(IgE)水平、嗜酸性粒细胞(Eos)和不良反应。结果与中药组、耳穴压豆组比较,综合组治疗总有效率较高,症状、体征评分及IgE、Eos水平较其余2组低(均P<0.05)。结论儿童AR应用耳穴压豆联合苍耳子炒麻油滴鼻治疗效果较佳,可显著改善临床症状,降低IgE、Eos水平,值得推广。