注热水开发潍北高凝油藏

潍北低渗高凝油藏的原油含蜡量高达30%左右,其流动性对温度极其敏感.当温度低于析蜡点时,蜡逐渐结晶析出;当温度低于反常点时,原油黏度急剧增加,且储层具有较为严重的水敏效应.油藏在注水开发过程中,存在有机堵塞、水敏堵塞、冷伤害堵塞以及固体颗粒堵塞问题;注热水保持油层温度和压力,可达到储层解堵和提高储层吸水能力的目的,而且注入水温度优化后,还可以节能降耗,降低注水开发成本.     

高凝油井筒温度场计算及流态转变分析

高凝油含蜡量高,凝固点高,在沿井筒向上流动的过程中,当油流温度低于所含蜡的初始结晶温度时,蜡容易析出并聚集,使原油逐渐失去流动性,最终阻塞管线,严重影响开采效果。为解 决这一问题,根据传热学基本原理,建立了适合高凝油井的井筒温度场数学模型,通过实验得到了高凝油的黏温曲线,进而对潍北油田的高凝油井筒温度场及流态转变进行了研究,指出了解决该油田油 井结蜡问题的途径,对实现高凝油的正常生产具有一定的指导意义。     

潍北油田高凝油流变性研究

针对潍北油田高凝油井因原油凝固、井筒结蜡等导致的抽油杆卡死、断脱、油井停产等不能正常生产的现象,通过气相、液相色谱分析了潍北油田4组油样的组成,运用液体流变性测量仪研究了其粘温特征、流变特性,利用原油凝固点测定仪测定了其在不同含水(乳化水)率下的凝固点,进而对4组油样的流变模式进行了分析研究.通过分析实验数据和流变模式发现,4组油样的碳数最大值均出现在C25附近,平均碳数为22左右,其含蜡量高达28.83%～30.06%,胶质含量为4%左右,沥青质含量约为1%,凝固点高达31～39.5 ℃;高凝油对温度十分敏感,其粘温关系呈三折线式;高凝油的凝固点随含水率的增加先增大后减小,在含水率为70%左右出现峰值;在高凝油的凝固点附近剪切时,高凝油的粘度大幅降低,高凝油温度低于凝固点时,4组油样均为非牛顿流体,具有剪切稀释性.采取井筒加热、原油破乳、螺杆泵实时高速剪切等措施,可以有效改善高凝油的开采效果.     

准等熵加载特性对PBXC03炸药起爆的影响规律

为了研究准等熵加载特性对高聚物粘结炸药(PBX)起爆响应特性的影响规律,对具有不同加载压力(8,10,12 GPa)与加载斜率的准等熵加载下PBXC03炸药起爆响应过程进行数值模拟计算。采用准等熵加载下PBXC03炸药起爆响应实验得到1,1.5,2,3,4 mm处炸药背面粒子速度时间曲线,确定了PBXC03炸药的弹粘塑性双球壳塌缩反应速率模型(DZK)参数。利用DZK模型与参数得到了准等熵加载下峰值压力与加载斜率对PBXC03炸药起爆响应特性的影响规律。结果表明,两种加载方式(不同压力与不同斜率)对PBXC03炸药起爆过程均有较大影响,其他条件相同的情况下,加载斜率或峰值压力越大,炸药内的冲击波阵面峰值压力曲线和冲击波迹线增长越快且到爆轰时间越短。     

Investigation of phase modulation and propagation-route effect from unmatched large-scale structures for Doppler reflectometry measurement through 2D full-wave modeling

To interpret the common symmetric peaks caused by the large-scale structure in the complex S(f) spectrum from the heterodyne Doppler reflectometry(DR) measurement in EAST, a 2D circular-shaped O-mode full-wave model based on the finite-difference time-domain method is built. The scattering characteristics and the influences on the DR signal from various scales are investigated. When the structure is located around the cutoff layer, a moving radial or poloidal large-scale structure k_θ■...     

Experimental study of density gradient-driven micro-instabilities and the confinement degradation during H-mode in EAST

A broadband(BB) mode is observed by collective Thomson scattering diagnostics in repeatable shots of EAST and analyzed for the first time. This BB mode usually grows during L–H transitions,featuring a BB quasi-coherent mode with increasing frequency. During H-mode operations, it is characterized by steady-state BB in the high-frequency range( f ～ 200–2000 k Hz), at the electron scale(k_θρ_s= 1–2), mainly driven by the density gradient, and is sensitive to the value of ηein th...     

网络中基于Agent的信息搜索特点及策略规划

基于网络条件下信息搜索的特点，采用搜索策略表示信息收集Agent对主机进行信息查寻的规划和过程，将搜索过程看作是一个三维空间，这个空间由条件、方法、信息源构成；给出了一种基于Agent的信息查找策略，用AgentSpeak(L)描述并实现了规划过程．     

Density Modulation Experiments to Determine Particle Transport Coefficients on HT-7 Tokamak

The particle diffusion coefficient and the convection velocity were studied based on the density modulation using D2 gas puffing on the HT-7 tokamak. The density was measured by a five-channel FIR interferometer. The density modulation amplitude was 10% of the central chord averaged background density and the modulation frequency was 10 Hz in the experiments. The particle diffusion coefficient （D） and the convection velocity （V） were obtained for different background plasmas with the central chord averaged density 〈ne〉 = 1.5×10^19m^-3 and 3.0×10^19 m^-3 respectively. It was observed that the influence of density modulation on the main plasma parameters was very weak. This technology is expected to be useful for the analysis of LHW and IBW heated plasmas on HT-7 tokamak in the near future.     

Modification of Boundary Parameters and Fluctuations by IBW and LHCD in the HT-7 Tokamak

Measurements of boundary parameters and their fluctuations have been performed in ohmic (OH) plasma and Ion Bernstein Wave (IBW) and Lower Hybrid Current Drive (LHCD) enhanced confinement plasma using a pneumatically driven Langmuir probe array on HT-7 toka-maX. In the enhanced confinement plasma~ the gradients of electron density and temperature become higher and a transport barrier comes into being in the vicinity of the limiter. The boundary potential shows a clear modification in the same region. The fluctuation levels are significantly depressed and the coherences between fluctuations are reduced evidently in the enhanced plasma.Meanwhile, we obtained the spectral features and the poloidal phase velocity of fluctuations us-ing a two-point correlation technique and found obvious modifications of the turbulence and the poloidal flow. The results suggest that the improved confinement in the IBW and LHCD enhanced plasma is at least partially due to the modification of the boundary parameters and the suppression of the boundary fluctuations and fluctuation induced fluxes.     

基于Agent的网络信息收集中的“信息度”

文章首先简单描述了一个基于Agent的信息收集系统的模型。然后针对此类基于Agent的网络信息收集系统中存在的效率问题,提出了信息度的概念,用信息度反映历史查询的状态,并作为将来查询的依据,来改善在信息收集过程中的效率问题,减少将来查询的盲目性。