稠油聚驱中聚合物溶液的最优浓度与最优段塞尺寸

聚合物驱是在实际中应用最多的化学驱方法,但一般不建议将其用于开采稠油。稠油除了常规注水开采外,大多使用热采的方法开采,但对于深度较深和厚度较薄的稠油油藏,热采方法的驱油效果也不理想。而聚合物驱对此条件不敏感,且近年来水平井的大量应用与油价的高涨,这使采用高浓度大段塞聚合物溶液的稠油聚驱成为可能。该文采用数值方法模拟了四分之一五点法井网的稠油聚驱过程,比较了不同聚合物溶液浓度与段塞尺寸下稠油聚驱的采收率,结果表明:聚合物浓度与段塞尺寸分别存在最优值,即当浓度或段塞尺寸低于最优值时,采收率随浓度或段塞尺寸的增大而显著增加;而当浓度或段塞尺寸高于最优值时,采收率的增加不明显。在此基础上研究了原油黏度、渗透率变异系数、聚合物溶液注入时机以及注入速度对最优浓度和最优段塞尺寸的影响。     

混凝土圆柱体试件和立方体试件抗压强度关系的分析

世界各国混凝土抗压强度的试验标准各不相同,同样的混凝土,得出的抗压强度试验值不同。在国际技术交流中,为保持使用数据的一致性,必须研究混凝土圆柱体试件与立方体试件所测得的抗压强度值的关系。本文介绍了混凝土圆柱体试件与立方体试件的强度比的影响因素、转换系数与转换公式,供同行遇到类似问题时参考。     

汛限水位动态控制的条件及最适应时间分析

以降雨预报条件下如何实施水库汛限水位的动态控制为研究对象。利用汛限水位动态控制条件及最适宜时间分析,得出汛限水位动态控制值。     

送电线路承力塔基础预偏值的计算

文章根据送电线路转角塔及终端塔基础的预偏要求进行了分析和计算,得出了在不同条件下基础预偏值的计算方法。     

RTK测量技术中的坐标转换方法研究

介绍了全球卫星定位系统（GNSS）在测绘工作中的应用发展历程,讲述了采用RTK技术获取的WGS84坐标转换到地方坐标的方法,结合工程数据进行了坐标转换研究,得出了三参数、四参数及七参数坐标转换方法的应用范围及使用条件。     

黄河水质COD监测与评价问题研究

通过研究原状水样COD值与含沙量的关系,推导出水样COD值与泥沙有机质含量间的转换关系式。经实验验证,原水样的COD值与其中悬浮泥沙的有机质含量定量相关,在一定条件下,泥沙COD值与有机质含量可以通过关系式互相换算。在此基础上对黄河原状水样评价结果的合理性进行了分析,得出“水相未受污染时,评价结果不能合理反映水质客观情况;水相受污染时,评价结果难以区分污染影响”的结论。另外,还对黄河COD澄清水监测与评价方案的合理性进行了分析,认为黄河水质COD监测与评价采用原状水和澄清水同时进行的方案为最优,建议在水中含沙量不大于200mg/L时监测评价原状水,大于200mg／L时监测评价原状水和澄清水。     

立管系统泡状流和段塞流的流动特性研究

立管系统作为最基本的结构单元,目前已被广泛应用于海洋工程各领域中。而伴随着现场采出液复杂的气液混合状态,对于立管系统中的气液两相流动问题,越来越引起学术界和工程界的广泛关注。该文分别针对立管系统中最常见的两种流型:泡状流和段塞流进行了研究。在绘制流型图的基础上,针对上述两种流型的转捩边界进行了划分。其中,对于泡状流中发生的速度滑移现象进行了定量化描述,并采用漂移流模型进行了简要分析。另一方面,给出了段塞速度、段塞频率、以及段塞长度等特征参量,随表观流速增大的变化趋势。此外,对于压差信号的功率谱密度分析,可能将对在线流型识别产生积极影响。     

卧底管-悬链线立管严重段塞流数值模拟

POT深海油气田投产前优选并构建了卧底管-悬链线立管集输系统,严重段塞流的预防及影响因素分析至关重要。该文基于卧底管-悬链线立管结构参数及生产参数设计,应用OLGA软件对管线内的流动进行数值模拟,计算分析产量和气液比等生产参数对流型的影响,预测严重段塞流并描绘严重段塞流的流型特征,监测不同产量及气液比情况下立管内最大液塞长度及立管底部最大压力波动值。计算结果表明,卧底管-悬链线立管结构参数设计合理,设计的生产参数范围内不会产生严重段塞流,而在低产量情况下严重段塞流特征规律明显。计算分析产量及气液比与流型的关系,绘制了严重段塞流流型区间预测图。计算得出立管内最大液塞长度及立管底部最大压力波动值,着重分析节流法在抑制严重段塞流中的效果,得到节流阀开度为0.2的POT深海油气田最优化结果,为严重段塞流的预防提供依据。     

基于SE-DEA-IAHP方法的贵州省岩溶地区水资源可持续利用效率评价

贵州省位于我国西南喀斯特地区的中心,地貌类型以山地为主,河谷深切,水资源开发利用难度大,提高水资源利用效率对于贵州省的可持续发展具有重要意义。基于水资源利用、社会经济、生态环境等3个一级指标构建水资源评价指标体系。在此基础上,以次级指标为松弛变量,利用超效率DEA模型（SE-DEA）计算一级指标超效率值;采用区间层次分析法（IAHP）计算一级指标权重向量。基于SE-DEA和IAHP方法建立水资源综合评价模型SE-DEA-IAHP,得出水资源利用总效率值。结果表明：贵州省水资源利用效率值较低,2015-2019年总效率值在1附近动态变化;从一级指标来看,社会经济指标的IAHP权重值最大,但水资源转换效率并不高,说明贵州省经济的高速发展也带来了一定程度的水资源浪费;考虑到贵州省特殊的岩溶地质条件,增加相应的经济管理投入、优化产业水量配置结构和提高用水技术手段是贵州省水资源可持续发展的关键。     

微尺度流动界面现象及其流动边界条件分析

水平微尺度毛管中低Reynolds数流体流动出现许多另人费解的现象,如流动前缘并未出现Poiseuille速度剖面,而似一种“段塞式”流动,固/液界面看似不符合无滑移边界条件. 该文针对这些易引起困惑的问题,利用可视化微管流动实验及岩石孔隙仿真光刻模型流动实验,考察了润湿性对微尺度毛管中流体流动的影响,探讨了微尺度毛管中表面流动现象产生的实质.结果表明,在微尺度流动中观察到的小分子液体“段塞流动现象”,以及看似壁面滑移流动等现象,其实质是液/固壁面仍为无滑移边界,三相接触点以尤如运动的“坦克的链轨”发展方式,沿壁面发展,从而产生“段塞式”流动.虽然仍在低速层流的条件下,但由于界面张力的作用,接近动界面处流动质点的运动已不再保持一维直线运动.     

EXPERIMENTAL AND NUMERICAL INVESTIGATIONS ON HORIZONTAL OIL-GAS FLOW

Experiments were carried out to investigate the characteristics of oil-gas flow in a horizontal pipe on a large scale (with the inner diameter D = 125 mm). With the experimental data, the flow patterns were presented. Through the analyses for the flow regime transition, it was found that there was a critical superficial velocity of liquid phase for the flow regime transiting from stratified flow to slug flow. The slug flow could not occur until the superficial velocity of liquid phase was higher than the critical velocity. For the flow pattern transiting from stratified to slug flow, the transmitting velocity of gas phase decreases with the augmentation of superficial velocity of liquid phase. On the basis of the experiments, numerical simulations of different flow patterns and their transitions were performed with the use of the Volume Of Fluid (VOF) technique. The results of the computations are shown to match well with the measured data in the experiments.     

水平管道油-气-水三相段塞流动持液率模型研究

油-气-水三相段塞流型持液率预测往往先将油水两相看作混合均匀的单相，再利用气液两相方法进行计算。这种方法适用于油水混合均匀的段塞流型。但在低气液相流速下，油-气-水三相段塞流型中有时油水是分离的，此时如果使用上述方法，可能导致比较大的误差。研究建立了分离假塞流型（油基和水基）的平均持液率计算新模型。统计分析发现新建模型与实验数据吻合很好。在实验的基础上，将油-气-水三相段塞流型划分为油基／分离／段塞流、油基／分散／段塞流、水基份离／段塞流、水基份散／段塞流四种。研究四种流型表明，在其他条件不变的情况下，对于气液两相流动和分散／段塞流型，持液率随着液相折算速度或液相黏度的增加而增加，随着气相折算速度的增加而减少。但对油基／分离／段塞流和水基／分离／段塞流，持液率则随着气相折算速度的增加，先上升后下降。     

A MODEL FOR LIQUID SLUG LENGTH DISTRIBUTION IN VERTICAL GAS-LIQUID SLUG FLOW

The slug length and the trailing Taylor bubble velocity in an upward vertical slug flow were measured by using the optical probes and the EKTAPRO 1000 high speed motion analyzer. The correlation between the trailing bubble velocity and the length of liquid slug ahead of that bubble is derived from the experimental data. Based on this correlation as well as the bubble overtaking mechanism, a model for the slug length distribution at any designated locations along the pipe is proposed. The predicted results are in agreement with the experimental data.     

INFLUENCE OF SURFACTANT ON TWO-PHASE FLOW REGIME AND PRESSURE DROP IN UPWARD INCLINED PIPES

The influence of a surfactant on the two-phase flow regime and the pressure drop in upward inclined pipes is investigated for various gas/liquid flow rates.The air/water and air/100 ppm sodium dodecyl sulphate aqueous solution are used as the working fluids.The influence of the surfactant on the two-phase flow regime in upward inclined pipes is investigated using the electrical tomographic technique.For 0o,2.5o and 5o pipe inclinations,the surfactant has obvious effect on the transition from the stratified wavy flow to the annular flow,and the range of the stratified smooth flow regime is also extended to higher gas velocities.For 10o pipe inclination,no stratified flow regime is observed in the air/water flow.In the air/surfactant solution system,however,the stratified flow regime can be found in the range of and.For all inclination angles,the changes of the pressure gradient characteristics are accompanied with the flow pattern transitions.Adding surfactant in a two-phase flow would reduce the pressure gradient significantly in the slug flow and annular flow regimes.In the annular flow regime,the pressure gradient gradually becomes free of the influence of the upward inclined angle,and is only dependent on the property of the two-phase flow.     

水跃对水平管弹状流压力降的影响

本文对气、液两相分别应用一维形式的质量守恒方程和动量守恒方程。假设各流动物理量在水跃面上具有第一类间断点,推导出水平管弹状流中水跃压降的表达式。对以水和空气为流动介质,内径为２５．８ｍ,５１,２ｍｍ和３００ｍｍ的三种管道,在液相表观流速为１．１１ｍ／ｓ,气相表观流速为２￣１０ｍ／ｓ的范围内,计算出了水跃压降的大小随Ｌｏｃｋｈｒｔ－Ｍａｒｔｉｎｅｌｌｉ参数的变化关系,分析了水跃压降对水平管弹状流摩擦     

INFLUENCE OF INCLINATION ANGLE ON THE MOTION OF TAYLOR BUBBLES IN UPWARD SLUG FLOW

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＳｌｕｇｆｌｏｗｉｓｏｎｅｏｆｔｈｅｍｏｓｔｃｏｍｐｌｉｃａｔｅｄｆｌｏｗｐａｔｔｅｒｎｓａｎｄｏｃｃｕｒｓｏｖｅｒａｗｉｄｅｒａｎｇｅｏｆｇａｓａｎｄｌｉｑｕｉｄｆｌｏｗｒａｔｅｓｉｎｓｍａｌｌａｎｄｍｅｄｉｕｍｓｉｚｅｔｕｂｅｓ .Ｉｔｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｌａｒｇｅｂｕｌｌｅｔ ｓｈａｐｅｂｕｂｂｌｅｓ (ｒｅ ｆｅｒｒｅｄｔｏａｓｔｈｅＴａｙｌｏｒｂｕｂｂｌｅｓ) ,ａｌｍｏｓｔｆｉｌｌｉｎｇｔｈｅｔｕｂｅ ,ｗｈｉｃｈａｒｅｓｅｐａｒａｔｅｄｂｙｌｉｑｕｉ…     

低速非达西双渗油藏DST段塞流测试渗流模型及应用

本文在分析了实际低速非达西双渗油藏DST段塞流测试非自喷井渗流规律的基础上，导出了其有效井径数学模型，利用Laplace变换及特殊物理方程理论，导出了该模型的拉氏空间解析解，利用Stehfest数值算法进行数值反演，得出了实空间解，并绘制了无因次样板曲线。结果表明：启动压力梯度、层问储容比、地层系数比的变化对段塞流试井解释结果有较大的影响。当窜流系数比较大时，在晚期段曲线几乎相交于同一条曲线；但是当窜流系数比较小时，层间储容比、地层系数之比对于压力曲线的后期段有较大的影响，曲线后期段上翘。采用本模型绘制的样板曲线，能较大程度上提高拟合精度，可有效运用于现场DST段塞流试井分析。     

A PHYSICAL MODEL FOR PREDICTING THE PRESSURE DROP OF GAS-LIQUID SLUG FLOW IN HORIZONTAL PIPES

A comprehensive treatment of all sources of pressure drop within intermittent gas-liquid flow is presented. A slug unit is divided into three parts and the pressure gradient of each part is calculated separately. In the mixing zone the momentum theory is employed and the mixing process between the film and slug is simulated by a two-dimensional wall jet entering a large reservoir to calculate the mixing length. The boundary layer theory is utilized to calculate the pressure drop for the slug body and the momentum equation of the film zone is integrated to calculate the pressure drop for the film zone. The pressure drop predicted in present model is in good agreement with all the measurements.     

EFFECT OF SURFACTANT ON TWO-PHASE FLOW PATTERNS OF WATER-GAS IN CAPILLARY TUBES

Flow patterns of liquid-gas two-phase flow were experimentally investigated. The experiments were carried out in both vertical and horizontal capillary tubes having inner diameters of 1.60 mm. The working liquid was the mixture of water and Sodium Dodecyl Benzoyl Sulfate (SDBS). The working gas was Nitrogen. For the water/SDBS mixture-gas flow in the vertical capillary tube, flow-pattern transitions occurred at lower flow velocities than those for the water-gas flow in the same tube. For the water/SDBS mixture-gas flow in the horizontal capillary tube, surface tension had little effect on the bubbly-intermittent transition and had only slight effect on the plug-slug and slug-annular transitions. However, surface tension had significant effect on the wavy stratified flow regime. The wavy stratified flow regime of water/SDBS mixture-gas flow expanded compared with that of water-gas.