A set of high temperature and high pressure miscible and precipitation experimental device was designed, and a new judgment method of miscible flooding was proposed. By establishing a discrimination diagram of formation type changing with the proportion of injected CO2, it qualitatively judged whether the injected gas and stratum fluid were miscible, and characterized the change law of gum and asphaltene through the method of relative precipitation amount. The experiment shown that the mechanism of CO2 flooding in Donghe 6 reservoir was primary contact miscible; The relative precipitation of asphaltene increased rapidly and then decreased slowly with the increase of injection proportion, while the relative precipitation of gum decreased first and then increased with the increase of injection proportion; After gas injection, the reservoir was exploited by depletion. With the pressure decreasing, saturated hydrocarbons were preferentially recovered, and the asphaltene content of formation crude oil increased rapidly.
Blending hydrogen into natural gas can increase fuel reactivity and the risk of jet fires in case of pipeline leakage though it is an effective delivery method. In this work, horizontal jet fires of hydrogen-blended natural gas at various operating pressures and hydrogen content were investigated experimentally. The flame temperature, lift-off distance, and flame length were measured for the scenarios with 0%-50% hydrogen content (in volume fraction) and 200-800 Pa. Results show that with the increase of hydrogen content, the flame temperature rises while the lift-off distance and flame length decrease. The flame length is slightly affected when the hydrogen content is less than 10% and a maximum reduction in flame length is 13.7% as the blended hydrogen content increases to 50%. Further theoretical analysis suggested the dimensionless correlations of the temperature distribution along the jet axis, lift-off distance, and flame length with different hydrogen content, respectively. The research results may provide reference for the risk assessment of hydrogen-blended natural gas pipelines. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
为了高效开发边际油气田和深水油气田,水下增压已成为全球海上油气田开发的重要技术手段之一.陆丰22-1 油田属于二次开发,具有含水率高、井口压力低等特点,为充分利用油田的剩余开采储量和提高油田的商业价值,采用全水下生产系统开发模式,利用水下增压泵将井口流体增压后输送至平台进行处理.应用多相流动态模拟OLGA软件建立了陆丰22-1 油田从水下井口至平台的流体输送模型.首先针对单海管工况和双海管运行工况进行了模拟分析,结果表明陆丰22-1 油田双海管运行时水下增压泵均在最佳运行区域内,且流体温度高于原油凝点;而单海管运行输量<300 m 3/h时,水下增压泵工作点处于最佳运行区域外;然后通过调节水下增压泵转速对双海管在线清管进行了动态模拟,结果表明在平台用200 m 3/h的生产水推动清管球对第一条海管清管时,需将水下井口的流量限产至420 m3/h,待清管球通过第一条海管后在平台停止注入生产水,同时水下井口恢复至正常产量,双海管在线清管总时间约11.4 h.研究结果对深水油气田应用水下增压泵解决流动安全问题具有指导意义.
在压缩机组运行过程中,针对多个监测信号量发生微小故障作用下的隐含特征对机组运行的影响,提出了基于图卷积神经网络(Graph Convolutional Neural Network,GCNN)的压缩机组风险预警模型.将时序的压缩机组运行数据转化为基于时间点的信号网络,依据改进的密度峰值聚类(An Improved Density Peak Fast Search Algorithm,AIDP)算法对机组运行数据进行故障粗分类,获得标签样本;再通过GCNN训练标签数据的隐含特征,实现机组风险预警;在真实数据集中进行预警分析.实验结果表明,所提出的模型极大增强了压缩机组风险预警的识别能力,为保证整个压缩机组的安全平稳运行提供了理论与实践依据.
为提高工程技术人员对大型液化石油气(Liquefied Petroleum Gas,LPG)覆土式子弹罐应用前景的认识,提升大型LPG覆土式子弹罐设计与建造能力,对比了覆土式子弹罐与地上球罐差异以及执行标准适用条件,同时结合 EEMUA PUBLICATION 190:2000 Guide for the design,construction and use of mounded horizontal cylindrical vessels for pressurised storage of LPG at ambient temperatures讨论了子弹罐沙床、覆土及罐体的详细设计要求,探讨了可行的建造、无损检测以及热处理方案.结果表明,大型LPG覆土式子弹罐较地上球罐具有安全性高、安全距离小、土地利用率高等优势,推荐的设计要求及建造方案可以指导同类项目建设.
