集输管道中含水易凝原油加入流动改进剂后的流动特性

发布时间：2018-04-22 00:35

本文选题：含水易凝原油 + 流变实验　；参考：《东北石油大学》2015年博士论文

【摘要】：对高凝、高黏和高含蜡原油,其常规集油工艺是耗能较高的伴热工艺。为了节能降耗,可以在集输管道中添加流动改进剂,以改善流动特性和降低集输温度。本文给出了含水易凝原油在圆管中流动特性和流变特性测量的相关理论,通过油田地面集输管道流动和流变特性测试实验,利用优选的流动改进剂和加剂浓度,进行了管道中含水易凝原油加入流动改进剂后的流动特性研究,并将研究成果应用于大庆油田现场实验。首先给出了含水易凝原油在圆管中的流动特性分析和流变特性测量的相关理论,得到了油水混合物在圆管中层流和紊流两种流动状态下流动特性规律,并给出了室内细竹道流动和旋转圆筒黏度计测得含水易凝原油流变参数的方法。根据上述含水易凝原油流变测量相关理论对大庆油田易凝原油和含水易凝原油的流变性进行了实验研究。用流变仪测量了易凝原油和含水易凝原油的屈服应力特性、黏滞特性和触变特性,得到温度、剪切速率和含水率对其屈服值和表观黏度的影响规律。根据加入流动改进剂后大庆油天含水易凝原油的乳状液转相点、油珠聚并温度、凝油黏壁量、流动改进剂的破乳性能和凝油黏壁温度等指标,评价DODE系列流动改进剂的性能,该流动改进剂可以明显降低集油温度。为研究加入流动改进剂后含水易凝原油的流动特性和优选加剂浓度,进行了加DODE流动改进剂大庆油田含水易凝原油的室内流动实验,实验管道采用三种直径的圆管,实验介质为含水率30%～90%的大庆油田含水易凝原油,在流动改进剂不同加入浓度和实验温度条件下进行流动特性实验。依据细管道流动特性实验测得流变特性的相关理论,应用罗宾诺维奇—莫纳(Robinowitsch-Mooney)方程,利用管道流动实验参数确定加DODE流动改进剂含水易凝原油的流变性。结果表明,加流动改进剂的含水易凝原油为幂律流体,其流性指数小于1,属于剪切稀化流体。进行加流动改进剂含水易凝原油停输再启动的室内实验,给出了大庆油田含水易凝原油集输管道停输再启动过程中启动压力梯度与流动改进剂加入量、冷凝时间、原油含水率和管道直径的相关规律。实验结果表明,添加流动改进剂可以明显降低启动压力梯度。在大庆油田10个采油厂,37座转油站上进行了加入DODE流动改进剂现场实验,实验总油井数为2331口。实验结果表明,集输管道中含水易凝原油加入流动改进剂明显改善流动特性,降低油井掺水温度和回油温度,应用期间集油系统的平均输送吨油耗气量大幅度下降,节能降耗效果明显。
[Abstract]:For high coagulability, high viscosity and high waxy crude oil, the conventional oil gathering process is a heat tracing process with high energy consumption. In order to save energy and reduce consumption, the flow improver can be added to the gathering pipeline to improve the flow characteristics and reduce the gathering temperature. In this paper, the theory of measuring the flow and rheological characteristics of water-containing and easily condensed crude oil in circular pipes is presented. Through the experiments of flow and rheological characteristics of oil field surface gathering and transportation pipeline, the optimal flow improver and concentration of additive are used. The flow characteristics of easily coagulable crude oil with water cut in pipeline were studied after adding flow improver, and the results were applied to the field experiment of Yu Daqing oilfield. Firstly, the flow characteristic analysis and rheological characteristics measurement of water-soluble crude oil in circular pipe are presented. The flow characteristics of oil-water mixture in laminar flow and turbulent flow in circular pipe are obtained. The rheological parameters of porous crude oil with water content and easy to coagulate are obtained by measuring the flow of fine bamboo channel and the viscosity of rotating cylinder. Based on the rheological measurement theory, rheological properties of easily condensable crude oil and water-cut crude oil in Daqing oilfield are studied experimentally. The yield stress, viscosity and thixotropic properties of easily coagulable crude oil and water-bearing crude oil were measured by rheometer. The effects of temperature, shear rate and water content on yield value and apparent viscosity were obtained. The properties of DODE series flow improvers were evaluated according to the emulsion phase transition point of Daqing oil with water cut and easily coagulable crude oil after the addition of flow improver, the aggregation temperature of oil beads, the amount of condensed oil viscosity wall, the demulsification performance of flow improver and the viscosity wall temperature of condensing oil. The flow improver can obviously reduce the temperature of oil collector. In order to study the flow characteristics and concentration of water-soluble easily coagulant crude oil after adding flow improver, the laboratory flow experiment of water-cut easily coagulable crude oil in Daqing oilfield with DODE flow improver was carried out. The experimental medium is 30% water cut and 90% water cut crude oil in Daqing Oilfield. The flow characteristics of the crude oil are tested under the conditions of different concentration of flow improver and experimental temperature. Based on the theory of rheological properties measured by the flow characteristics experiment of fine pipes, the rheological properties of crude oil with DODE flow improver were determined by using Robinowitsch-Mooneyy equation and the experimental parameters of pipeline flow. The results show that the water-bearing crude oil with flow improver is a power law fluid, and its flowability index is less than 1, which is a shear-thinning fluid. The laboratory experiment of stopping and restarting of crude oil with water cut and easy coagulant with flow improver was carried out, and the starting pressure gradient, the amount of flow improver and the time of condensing during the shutdown and restarting process of gathering and transporting pipeline of water cut and easy coagulable crude oil in Daqing Oilfield were given. Correlation between water cut of crude oil and diameter of pipeline. The experimental results show that the starting pressure gradient can be significantly reduced by adding flow improver. The field experiment of adding DODE flow improver to 37 transfer stations in 10 oil production plants of Daqing Oilfield was carried out. The total number of oil wells was 2331. The experimental results show that the addition of water-containing and easily condensable crude oil to flow improver can obviously improve the flow characteristics and reduce the water and return temperature of oil wells. During the application, the average gas consumption of the oil gathering system per ton of oil is greatly reduced. The effect of saving energy and reducing consumption is obvious.
【学位授予单位】：东北石油大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TE832

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