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深水气井测试求产阶段管柱内天然气水合物防治方法 被引量:20
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作者 李相方 刘文远 +4 位作者 刘书杰 胡瑾秋 南宇峰 田甜 周云健 《天然气工业》 EI CAS CSCD 北大核心 2019年第7期63-72,共10页
深水气井测试求产过程中,预防与控制天然气水合物(以下简称水合物)堵塞对于保障测试安全至关重要。为此,通过分析不同测试条件下的井筒温压场分布,应用水合物生成—沉积及分解计算方法,评价了不同测试制度下全测试过程中管柱内水合物的... 深水气井测试求产过程中,预防与控制天然气水合物(以下简称水合物)堵塞对于保障测试安全至关重要。为此,通过分析不同测试条件下的井筒温压场分布,应用水合物生成—沉积及分解计算方法,评价了不同测试制度下全测试过程中管柱内水合物的沉积与堵塞程度的变化;在此基础上,提出了基于水合物防治的深水气井测试求产方法。研究结果表明:①深水气井测试过程中井筒内常形成水合物堵塞风险最大的环雾状流型,测试过程中采取防止水合物堵塞措施比防止水合物生成更加合理;②常规四点测试方法要求设置流温较低的低产气量测点,但高压、低温的井筒环境容易导致水合物生成、沉积,测试持续时间过长会增加测试管柱的堵塞风险;③所提出的适合于深水气井测试的混序测试制度在不改变测试产气量与时长的前提下,通过调整测点顺序形成的井筒温度变化使水合物沉积层分解,降低了测试过程中测试管柱的最大堵塞程度;④对于无出砂、无应力敏感、无反凝析且不产水的深水气井推荐使用三点或二点测试法,相对于四点测试法,前者能有效降低测试管柱内的水合物沉积、堵塞风险,同时又能在保证产能方程准确性的前提下缩短测试时间、降低测试成本。结论认为,该研究成果可以为深水气井的现场测试施工提供帮助。 展开更多
关键词 深水气井 测试求产 天然气水合物 防治方法 混序测试 堵塞程度 流动保障
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Moving object detection method based on complementary multi resolution background models 被引量:2
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作者 屠礼芬 仲思东 彭祺 《Journal of Central South University》 SCIE EI CAS 2014年第6期2306-2314,共9页
A novel moving object detection method was proposed in order to adapt the difficulties caused by intermittent object motion,thermal and dynamic background sequences.Two groups of complementary Gaussian mixture models ... A novel moving object detection method was proposed in order to adapt the difficulties caused by intermittent object motion,thermal and dynamic background sequences.Two groups of complementary Gaussian mixture models were used.The ghost and real static object could be classified by comparing the similarity of the edge images further.In each group,the multi resolution Gaussian mixture models were used and dual thresholds were applied in every resolution in order to get a complete object mask without much noise.The computational color model was also used to depress illustration variations and light shadows.The proposed method was verified by the public test sequences provided by the IEEE Change Detection Workshop and compared with three state-of-the-art methods.Experimental results demonstrate that the proposed method is better than others for all of the evaluation parameters in intermittent object motion sequences.Four and two in the seven evaluation parameters are better than the others in thermal and dynamic background sequences,respectively.The proposed method shows a relatively good performance,especially for the intermittent object motion sequences. 展开更多
关键词 moving object detection complementary Gaussian mixture models intermittent object motion thermal and dynamic background
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Evaluation of reclaimed asphalt pavement binder stiffness without extraction and recovery 被引量:1
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作者 马涛 黄晓明 U.B.Hussain 《Journal of Central South University》 SCIE EI CAS 2011年第4期1316-1320,共5页
A new testing procedure to estimate the low-temperature stiffness of the reclaimed asphalt pavement (RAP) binder was developed. In the testing procedure, the SuperpaveTM Bending Beam Rheometer (BBR) with special m... A new testing procedure to estimate the low-temperature stiffness of the reclaimed asphalt pavement (RAP) binder was developed. In the testing procedure, the SuperpaveTM Bending Beam Rheometer (BBR) with special modifications and binder blending charts by Asphalt Institute were utilized. Modifications involved the development of a new kind of sample mold and different testing parameters were made to BBR testing procedure to capture the theological properties of bitumen mortars produced by mixing fresh binder with fine RAP materials or RAP aggregate. The stiffness relationship between binder and bitumen mortar was established based on the BBR test results. The blended binder stiffness in bitumen RAP mortar was estimated from the RAP mortar stiffness based on the binder-mortar relationship. And finally, the RAP binder stiffness was estimated from the blended binder and fresh binder stiffness based on the blending charts by Asphalt Institute. The results indicate that the new procedure can capture the rheological properties of bitumen mortar and can be used to estimate the low temperature stiffness of RAP binder without binder extraction and/or any chemical treatments. 展开更多
关键词 aged binder reclaimed asphalt pavement MORTAR STIFFNESS Bending Beam Rheometer blending chart
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Thermal Performance Study of Three Models of Solar Air Heater Made of Concrete
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作者 Messaouda Anis Kerkeni Chakib 《Journal of Environmental Science and Engineering(B)》 2013年第9期559-564,共6页
An experimental study was conducted on three models of solar collectors having an absorber made of concrete designed and built in the TPL (Thermal Process Laboratory). A sequence of tests was performed on these mode... An experimental study was conducted on three models of solar collectors having an absorber made of concrete designed and built in the TPL (Thermal Process Laboratory). A sequence of tests was performed on these models for the two air circulation models (forced and natural) in order to compare their thermal performance. The results are presented in terms of useful energy, stored energy and thermal efficiency of each model. 展开更多
关键词 Solar energy heat transfer natural convection forced convection solar collector made of concrete.
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