利用能量耗散率计算管流的平均剪切率

含蜡原油的流变性与其所经历的剪切历史有关.以往用截面平均剪切率或湍流时的管壁剪切率衡量流体管流的剪切历史,有不当之处.根据能量耗散率与剪切率的关系,提出了按流体的体积平均能量耗散率计算流体平均剪切率的方法,即可根据流体的密度、平均流速、管道直径、流动的摩擦因子或摩阻压降以及流变参数计算牛顿流体和幂律流体管流的平均剪切率.对于湍流,按本方法计算的平均剪切率能合理地度量流体的平均剪切历史.在原油管道正常运行的雷诺数范围内,按截面平均方法计算的湍流剪切率比按体积平均能量耗散率计算的结果约偏低20%～40%.     

原油管输经济运行温度的计算

从影响加热输送管道输油成本的动力费和燃料费出发，提出了经济运行温度的概念，探讨了原油管道加热输送条件下经济运行温度的计算方法，首先数学模型；分析各参数的选取和影响因素以及各公式的选用；给出计算公式，方法和求解步骤。选择了最小能耗费用作为目标函数求解最经济的运行温度；同时还可以利用不同公式，参数和方法而确定不同气温条件下输送不同物性的油品和不同输油量的经济运行温度，达到节约能源的目的。     

原油管输经济运行温度的计算

从影响加热输送管道输油成本的动力费和燃料费出发,提出了经济运行温度的概念,探讨了原油管道加热输送条件下经济运行温度的计算方法。首先建立数学模型;分析各参数的选取和影响因素以及各公式的选用,给出计算公式、方法和求解步骤。选择了最小能耗费用作为目标函数求解最经济的运行温度;同时还可以利用不同公式、参数和方法而确定不同气温条件下输送不同物性的油品和不同输油量的经济运行温度,达到节约能源的目的。     

非牛顿管流摩阻计算方法的比较

介绍非牛顿层流的假塑性幂律体、宾厄姆塑性体和屈服假塑性体的管流可用同一表达形式的范宁摩阻系数公式计算摩阻损失。对常用的非牛顿湍流摩阻系数公式及用管流特性系数反算的表观粘度为参数按牛顿湍流公式的计算结果进行分析。对非牛顿管流摩阻计算提出建议。     

长距离管输添加降凝剂含蜡原油模拟试验

通过在试验环道及仪器上进行的长距离管输添加降凝剂含蜡原油模拟试验，研究多次过泵剪切及管流剪切对加剂原油低温流动性的影响，分析环道试验所测管流粘度与旋转粘度计测量结果的对比关系。     

原油外输考虑摩擦生热时管线初始温度计算的新方法

本文通过分析建立了油田原油外输考虑摩擦生热时求解管线初始温度的数学模型,并首次采用弦截法取代以往使用的试算法,从而提高了运算效率和计算精度,并在此基础上编制了一整套程序系统.     

原油输送管道结蜡厚度的计算方法

已知:管道沿程水力摩阻 h(m),平均输油温度下的体积流量 qv(m~3/s),管道的计算长度 L(m),平均输油温度下的原油运动粘度 v(m~2/s),管道内壁结蜡后的绝对粗糙度 e(m),管道结蜡前的实际内径 d。(m)。求:管道结蜡后的平均内径 d(m),管     

管流液体的有效剪切速率

管流液体的有效剪切速率应是宏观表征摩擦特性的参数,层流和紊流光滑区管流有效剪切速率数值上等于管壁剪切速率。通过分析管内流体受力与沿程摩阻之间的关系,对牛顿流体和假塑性流体,给出了稳定流动条件下不同流态时管流有效剪切速率的一般计算公式,可用于计算工业管道中的有效剪切强度。     

计算原油管路摩阻的一种新方法

分析幂律流体圆管层流流动特点，提出可用有效管流表现粘度及牛顿流体摩阻计算公式计算幂律流体的层流和紊流摩阻损失。针对热油管道工况特点，提出通过用旋转粘度计模拟测定管输原油流变性来计算摩阻的方法。     

剪切作用对加剂原油低温流动性影响的研究

加剂输送技术是目前主要的含蜡原油节能输送技术，原油管输过程中受到的剪切作用主要包括过泵加压时受到的高速剪切和管流剪切，在安装了减压阀的大落差段还包括减压阀的高速剪切，在原油析蜡高峰区的温度范围内，这些剪切作用都可能对加剂原油的低温流动性产生影响，这一影响的大小与原油的组成，剪切的温度，强度及时间等因素有关。概述了过泵高速剪切和管流低速剪切对加剂原油低温流动性的影响规律，剪切影响机理和剪切作用的描述方法等的研究现状及进展。     

直叶涡轮搅拌槽中流场的数值模拟

以PY型直叶涡轮搅拌槽为原型建立数值模拟模型 ,通过计算机流体动力学方法对其流场进行分析研究。数值模拟结果和激光多普勒测速实验数据吻合较好。对实际操作条件下高粘度流体在搅拌槽中的流场模拟表明 ,搅拌叶轮位置、转速以及物料性质等因素对流场的分布影响较大     

压力容器火灾工况安全泄放质量流量的动态研究

以某气田段塞流捕集器为例,使用HYSYS动态模拟建立了压力容器包含关断逻辑的全动态生产模型,使用该模型对不同初始压力和液位下段塞流捕集器火灾工况的泄放过程进行了分析和研究。结果表明,初始条件对段塞流捕集器的最大安全泄放质量流量有明显影响,在计算最大安全泄放质量流量时,应充分考虑初始条件的影响,为安全阀的计算和选型提供正确的基础参数。     

Flow characteristics of xanthan solutions and their crude oil emulsions in terms of thixotropic behavior

The thixotropic characteristics of xanthan solutions and their emulsions with crude oil were investigated experimentally. Understanding these characteristics are required for the crude oil displacement mechanism by polymer solution during the enhanced oil recovery phase. RS100 rheometer with a cone and plate device was employed for this examination using controlled-rate mode. Two crude oil concentrations of 25% and 75% by volume were examined. A wide range of xanthan gum concentration of 500–10⁴ ppm was covered. This study results that the aqueous solutions of xanthan gums showed thixotropic behavior. The high concentrations of xanthan solutions provide higher hysteresis loop than the solutions of lower concentrations. The existence of crude oil within the xanthan emulsions considerably elevates the thixotropic rheograms profile.     

注聚合物速度对提高原油采收率的影响

通过对孤岛油田注聚合物先导区,孤岛油田注聚合物扩大区,孤东油田注聚合物扩大区注聚合物驱油效果的研究,认为聚合物溶液粘度受剪 切速度的影响,在地层中的滞留情况与现场注入速度有关,年平均注聚速度高的区块见效早,早期采收率提高幅度高,但最终采收率低于年平均注入速度低的区块,因此,应根据各区块地质特点适当控制注入速度,以减少由于剪切,滞留待地聚合物粘度造成的影响,达到提高原渍采收率的目的,该三个区块注聚驱获得的成功经验为胜利油区其它同类油田开展聚合物驱油提供了重要依据。     

Prediction of Viscosity Variation for Waxy Crude Oils Beneficiated by Pour Point Depressants During Pipelining

Pour-point-depressant (PPD) beneficiation is an emerging technology for facilitating pipelining of waxy crude oils. However, it was found both in lab studies and field tests that the viscosities of PPD-beneficiated waxy crude oils may increase as a result of pump shear or pipe flow shear during pipelining, called the shear effect. Current method for understanding this viscosity variation is to measure the viscosities by experimental simulation, which is quite time- and effort-consuming for long-distance pipelines. A new method for predicting the viscosity variation during pipelining is presented in this article based on a mathematical model for predicting viscosity of PPD-beneficiated waxy crude oils at certain temperature after shear and a model for predicting non-Newtonian viscosity of waxy crude oils as a function of temperature and precipitated wax. As verification, viscosity variations of five PPD-beneficiated waxy crude oils during pipelining are predicted by using the presented method and compared with the measured data from experimental simulations. The predicted viscosities are in good agreement with the measured data, with an average absolute deviation of 14.1% for all 52 data points. Comparisons between the measured or predicted viscosities during pipelining and viscosities obtained from the fast cooling experiment of PPD effectiveness evaluation demonstrate that the evaluation of PPD effectiveness for practical application should take the shear effect into consideration. The presented method provides a new way to evaluate the PPD's effectiveness in pipelining application quickly and effectively.     

The Variation of the Gel Point of Daqing Crude Oil with Pipelining History

Abstract

Daqing crude oil is a typical waxy crude oil with a wax content of 26.6 wt% and a gel point of 32°C. In order to conduct the safety analysis of pipeline operation, the variation of gel point of Daqing crude oil with thermal and shear history was studied through pipelining simulation experiments. The experiments were performed under different annual throughputs and shear rates of pipeline flow. The results suggest that the change of shear action has little effect on the gel point of crude oil. As the final dynamic cooling temperature is increased, the change of gel point experiences two stages, staying constant at first and then decreasing. Through 13 groups of pipelining simulation experiments, the effects of heating temperature ranging from 45°C to 65°C on gel point of Daqing crude oil were studied. It has been indicated that the gel point increases as the heating temperature is increased under the same final dynamic cooling temperature. The relation equation was constructed to be used to predict the gel point under certain heating temperatures and final dynamic cooling temperature. The average absolute deviation of 52 predicted values of gel point is 0.58°C.     

歧离率在油气藏勘探中的应用研究

利用有限元数值模拟方法，构建了油气藏理论模型。采用井中供电地表测量的井地二极装置形式进行了正演模拟计算。当地下存在油气藏时，分别在油气藏上、下方供电，求出参数歧离率，利用该参数，可增强微弱的油气藏异常，提高油气藏的分辨能力；如果油气藏上方有地层的干扰，参数歧离率可以消除或大大减弱地层的影响。最后，通过水槽模拟实验证明了该方法的有效性。     

Experimental investigation of the rheological behavior of algerian crude oils from the quagmires

In this work, the rheological behavior for three types of crude oil coming from different quagmires namely Amassak, Tamendjelt and Tin Fouye of the TFT sector (Tin Fouye Tabankort/South Algeria) has been experimentally investigated. A controlled stress rheometer (AR 2000, TA Instrument) was used throughout this investigation. The experimental measurements in terms of flow and dynamic tests were carried out at different temperatures during the shear rate over the range of 0–700?s^?1 and frequency range of 0.1–10?rad/s. The obtained results show that the viscosity and shear stress of the crude oils decreases about 53.30%, 58.80%, and 59% respectively, when the temperature increased from 10 to 20?°C. The yield stress required to flow of crude oils also decreased to 37.06%, 89.78%, and 77.53% respectively. The dynamic analysis of the crude oils by identifying of the storage modulus (G′) and the loss modulus (G″) has indicated that the rheological properties of crude oils were significantly temperature-dependent.     

同步荧光光谱多点函数拟合确定原油样品浓度技术

目前油田使用的定量荧光录井中存在二维发射光谱单一峰值浓度的定量测量范围小、多次稀释增大了人为误差和浪费的问题.利用同步扫描荧光光谱技术,在10^-4g/L至10g/L浓度范围内获取胜利油田原油样品在不同浓度下波长差为40nm的正己烷萃取液的同步光谱,发现不同的浓度下同步光谱不仅表现为峰高变化,峰位也有显著变化.选取了最具代表性的7个峰值,将光谱数据在非线性范围内进行多峰值的最小二乘法浓度响应函数拟合,多点同时定量,所得误差小于5%,重复率和准确率较高.图1表2参9     

针对SZ36-1油田稠油的柴油基洗井液的制备及性能评价

以渤海SZ36—1稠油油田的油污为研究对象,研究并确定了柴油基洗井液体系最佳配方：0^#柴油与渤海海水体积比为50：50,主乳化剂HCA—X加量3．0％,助乳化剂HAS加量0．25％,稳定剂HTC加量1．0％,NaCl加量1．0％。对该洗井液的各项性能评价表明,相对0^#柴油来说,柴油基洗井液具有洗井成本低、时间短、清洗能力强等优点,并且具有良好的配伍性和储层保护性能,泵送性和沉降稳定性也完全满足现场洗井施工要求。