【作者】 李小兵；

【导师】 刘炯天；

【作者基本信息】 中国矿业大学 ， 化学工艺， 2011， 博士

【摘要】 油田采出水处理是矿场油田开发利用和环境保护面临的重要课题,是油田开采必不可少的生产环节。随着三次采油技术的广泛应用,油田采出污水产出量大,水质复杂且难处理问题突出,现有技术已经无法满足油田正常生产的要求。因此,迫切需要开发与三次采油技术配套的采出水处理技术,开发无药剂添加、不产生含聚油泥、操作简单、能耗低的物理除油工艺及设备。旋流–静态微泡浮选分离是将常规旋流器和常规泡沫柱分离结合起来,集旋流分离、气浮与聚结分离于一体的高效分离方法。旋流–静态微泡浮选柱在煤炭分选、有色金属选矿、铁矿提质降杂、油水分离等领域得到了广泛应用。本论文从基于微泡浮选的旋流分离强化除油、聚结分离强化除油等方面开展研究,对于油水分离用浮选柱的开发和工业应用提供理论指导。主要研究内容包括以下几个方面:研究了基于微泡浮选的旋流分离强化除油机理。分析了旋流器中油滴的受力情况,描述了浮选柱内置旋流器油水旋流分离过程。研究了起泡剂浓度,给料速度,循环压力,充气速率等操作参数对脱油率的影响规律。建立了旋流分离脱油率的数学模型。采用PIV粒子成像测速仪测试了浮选柱内置旋流器速度场分布。研究了基于微泡浮选多元聚结强化除油机理。深入分析基于浮选柱内旋流段、管流段和气浮段的流体行为和油滴聚结、破碎过程,提出了旋流–静态微泡浮选柱中旋流聚结(90o碰撞聚结)、管流聚结(0o碰撞聚结)、层流聚结(180o碰撞聚结)机制。考察了充气速率、温度、给料速度、循环压力以及粘度等操作条件对旋流聚结效果的影响规律,充气速率、温度、给料速度以及粘度等操作参数对层流聚结效果的影响规律,充气速率、循环压力、粘度、管段长度、管段直径以及含油浓度等操作参数对管流聚结效果的影响规律。建立了旋流聚结、层流聚结和管流聚结的数学模型。明确了旋流聚结、管流聚结与层流聚结过程能有效处理粒径范围。利用流体力学软件Fluent对浮选柱内的两相流场进行数值模拟,获得了浮选柱旋流段、管流段和气浮段三部分经过旋流聚结、管流聚结和层流聚结后油相的浓度场分布和油滴粒径分布云图。模拟结果和试验结果相吻合。研究了基于射流的气含率调控强化除油机理。分析了喷嘴口径、充气速率、起泡剂用量、循环压力四个参数对气含率的影响规律。确定了适合于油水分离的气含率不应低于10%最佳范围。建立了基于操作参数影响预测气含率的数学模型,以及基于BP神经网络和基于GRNN神经网络的气含率预测模型。通过静态实验,研究了吸附时间、投放煤种、煤粉颗粒粒径、含油污水pH值、含油浓度等因素对原油在煤粉颗粒表面的吸附规律。实验结果表明,随着吸附时间的延长,石油类物质在煤粉颗粒表面吸附量先增加而后趋于平衡;同一粒级下无烟煤对石油类物质的吸附量大于贫(瘦)煤及褐煤,同一煤种下细粒级吸附量大于粗粒级的吸附量;石油类物质在无烟煤表面吸附量随pH值增加缓慢减少,pH值对吸附量的影响不大。石油类物质在+0.046mm粒级煤粉表面吸附符合Freundlich等温吸附规律,在-0.046mm粒径煤粉表面吸附符合Langmuir吸附等温规律。吸附过程符合二级吸附动力学模型,吸附形式为物理吸附与化学吸附共存的吸附过程,物理吸附为主,化学吸附为辅。认识到聚合物驱采出水处理过程实质是两种生产(采油生产、采出水处理)、两种循环(水循环、聚合物循环)的采出水循环体系,应进行进行适度处理,既要使出水达到回注要求,同时使聚合物最大限度的保留。在此原则下,以旋流–静态微泡浮选柱为主要分离设备,利用煤的天然吸附性,以煤粉作为吸附剂,选择性吸附采油污水中原油,保留聚合物,开发了聚合物驱采油污水浮选柱选择性吸附气浮工艺。结合浮选柱多元聚结作用和充填材料聚结作用,开发浮选柱聚结气浮工艺,配套开发油煤基吸附料资源化回收利用技术。通过浮选柱聚结气浮–载体选择性吸附气浮工艺集成,在胜利油田孤六联建设了2000m3/d“浮选柱聚结气浮–选择性吸附气浮”工业系统。工业试验结果表明,该技术具有工艺独特、指标先进、无底泥产生等特点。针对含油浓度1000 mg/L~2000mg/L、悬浮物120mg/L左右的进水,处理后出水含油浓度为23.39 mg/L,总脱油率为97.70%。同时,每处理1m3水可减少污泥排放量1.87Kg,污泥量减少,既简化了整体处理工艺,又降低了处理成本。该论文有图143幅,表15个,参考文献139篇。更多还原

【Abstract】 The treatment of oilfield produced water, which plays an essential role in the production process, is an important research project for the development and utilization of the oilfield and also for the environmental protection. Therefore, treatment technology of oilfield produced water assorting with the tertiary oil recovery technology, is in urgent need. Besides, physical separation processes and equipments with no added chemicals, no production of poly clay, a simple operation and low energy consumption are also in great demand. The Cyclone-static micro-bubble flotation separation, which combines the conventional Hydrocyclone with conventional flotation column, is a high efficient separation equipment, integrating cyclone separation, flotation and coalescing separation. In this dissertation, researches are carried out in the areas of cyclonic separation and coalescing separation by flotation column to enhance oil removing, which provide theoretical guidance to the development and industrial application of flotation column in oilywater separation. The major research includes the following aspects:Study concerning the mechanism of cyclonic separation strengthening oil removing by flotation column is conducted. The forces of the droplets in the cyclone are analyzed and the oilywater separation process in the flotation column built-in cyclone is depicted. The operating parameters, such as frother concentration, feed capacity, circulating pressure and inflation rate influencing the oil removal rate are studied. Mathematical model of cyclonic oil removal rate is established. The velocity field of the flotation column built-in cyclone is tested by particle image velocimetry (PIV).Study on the mechanism of multiple coalescence enhancing oil removing by flotation column is conducted. Based on the deep analysis of the inner cyclonic section and pipe flow section, the behavior of the air flotation fluid and the process of oil coalescence and comminuting, the mechanisms of swirl coalescence (collision coalescence of 90o), pipe flow coalescence (collision coalescence of 0o) and laminar coalescence(collision coalescence of 180o) in the cyclone-static microbubble flotation column are proposed. Several operating conditions are taken into consideration, such as the effect of inflation rate, temperature, feed capacity, circulating pressure and viscosity on the swirl coalescence, the effect of inflation rate, temperature, feed capacity and viscosity on the laminar flow coalescence and the effect of inflation rate, circulating pressure, viscosity, pipe length, pipe diameter and oil concentration on the pipe flow coalescence. Mathematical models of swirl, laminar flow and pipe flow coalescence are established. Particle size range, which can be effectively dealt with during the process of swirl, laminar flow and pipe flow coalescence, is clarified.Oil concentration distributions and droplet size distribution nephograms of the swirl, pipe flow and air flotation sections, being processed by swirl, pipe flow and laminar flow coalescence, is obtained, after the numerical simulation of two-phase field in the flotation column using the fluid dynamics software (Fluent). Simulation results and experimental results match well.Study on the mechanism of jet-based gas holdup control enhancing de-oiling is conducted. The law that the four parameters, namely, nozzle diameter, aeration rate, frother dosage affecting the gas holdup is analyzed. The optimal gas holdup for oil-water separation, no less than 10%, is decided. Two models are established, that is, the mathematical model for predicting the gas holdup which is based on the influence of operating parameters and the gas holdup model based on the BP neural network and GRNN neural network.The law of different factors, such as adsorption time, coal rank, coal particle size, pH value and concentration of oily wastewater, affecting the oil substances adsorbing in the surface of coal particles, is researched through the static experiment. The law of oil substances in the surface of +0.046mm anthracite and -0.046mm anthracite can be fitted by Freundlich adsorption isotherm and Langmuir adsorption isotherm respectively. Pseudo-second-order kinetic model fits the process of adsorption, the form of which is the coexistence of the physical and chemical adsorption, the former being the major and the latter being a supplement.Oil recovery wastewater from polymer flooding, essentially being a produced water circulation system which includes two kinds of productions (oil production and produced water processing) and two kinds of circulations (water and polymer circulations), needs appropriate treatment, the purpose of which is to make the effluent meet the requirement of reinjection and to retain the maximum polymer at the same time. The flotation column selective adsorption flotation process of polymer flooding produced water is developed, with the cyclone-static micro-bubble flotation column as the main separation equipment, and by means of natural adsorption of coal, with coal fine being the adsorbent, crude oil being selectively adsorbed and polymer retained. Considering the effect of multiple coalescence and stuffing coalescence, coalescence floatation process of flotation column is developed, and the recycling technology of coal-oil-based adsorption material resource is developed as well. After the integration of the coalescence flotation and the carrier selective adsorption process, a 2000m3/d industrial system named coalescence flotation-selective adsorption process is constructed in Shengli oilfield Gudao No.6 joint station. The industrial test shows that this technology is featured by unique process, advanced equipment, excellent indexes and sediment-free production, for the inefluent of oil and suspended matter concentration being 1000mg/L~2000mg/L and 120mg/L respectively, a effluent of oil concentration of 23.39 mg/L and the total oil removal ratio of 97.70% were obtained. Meanwhile, every 1m3 water treatment can reduce 1.87Kg sludge emission.更多还原