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聚合物低剪切井下配注器的研制及应用 被引量:10
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作者 马宏伟 单晶 +2 位作者 申秀丽 张宏禄 袁云 《石油机械》 北大核心 2005年第8期33-34,3,共2页
为了解决聚合物井下低剪切配注问题,研制了新型聚合物配注器。该配注器阻流段采用同心双环形连续扩缩管结构,对聚合物限流阻力大、剪切率低,当流量在25~170m3/d范围时,可产生压降1.5~3.6MPa,剪切降解率小于6%;配注器出口通道设计有低... 为了解决聚合物井下低剪切配注问题,研制了新型聚合物配注器。该配注器阻流段采用同心双环形连续扩缩管结构,对聚合物限流阻力大、剪切率低,当流量在25~170m3/d范围时,可产生压降1.5~3.6MPa,剪切降解率小于6%;配注器出口通道设计有低剪切洗井滑阀,具有反洗关闭、正注增阻的双重功能,可以避免地层返吐物堵塞水嘴,并实现反洗井,提高分注适应性,延长分注工艺有效期。现场应用42井次114套次,工艺成功率95%,取得了良好的应用效果。 展开更多
关键词 聚合物 井下低剪切 配注问题 结构设计 适应性 工艺
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Joint subcarrier and power allocation with threshold in cooperative multiuser networks 被引量:1
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作者 Tang Mingwei Wang Xiaoxiang 《High Technology Letters》 EI CAS 2011年第4期360-365,共6页
In this paper, we investigate a resource allocation issue in OFDMA-based decode-and-forward cooperative multiuser networks and propose joint subcarrier and power allocation schemes. The optimal solution of this combin... In this paper, we investigate a resource allocation issue in OFDMA-based decode-and-forward cooperative multiuser networks and propose joint subcarrier and power allocation schemes. The optimal solution of this combinable allocation shows high computational complexity, so we allocate subcarriers and power separately. At firstly, we distribute subcarriers to relays and users under the assumption of equal power distribution. Here, we propose an equal capacity increment (ECI) allocation strategy to achieve tradeoff between total throughput and fairness. To further improve the system performance, we introduce threshold into ECI strategy, named ECI strategy with threshold (ECI-T), where subcarriers with bad performance are prevented from transmitting. Subsequently, a water-filling method is adopted to distribute the power to cooperative links in order to fully utilize the limited power. Simulation results show that system performance of the proposed schemes is significantly enhanced compared with an existing resource allocation scheme. Besides, the resource allocation schemes with the water- filling method notably outperform schemes with equal power allocation. 展开更多
关键词 cooperative communication orthogonal ~equency division multiplexing access (OFDMA) resource allocation THRESHOLD
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