Title Forecasting the oil temperatures along the proposed China-Russia crude oil pipeline using quasi 3-D transient heat conduction model
Author Li Guoyu; Sheng Yu; Jin Huijun; Ma Wei; Qi Jilin; Wen Zhi; Zhang Bo; Mu Yanhu; Bi Guiquan
Author Affil Li Guoyu, Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China
Source China-Russia crude oil pipeline in permafrost regions in northeastern China, edited by Jin Huijun, G. Gay and M.C. Brewer. Cold Regions Science and Technology, 64(3), p.235-242, . Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165-232X
Publication Date Dec. 2010
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309511
Index Terms climatic change; design; foundations; frost heave; global change; global warming; permafrost; pipelines; gas pipelines; forecasting; settlement (structural); soil mechanics; strains; stresses; temperature; thawing; thaw depth; thermal regime; China; Asia; China-Russian oil pipeline; climate change; depth; Far East; frost heaving; ground-surface temperature; heat flow; mitigation; natural hazards; petroleum; prediction; seasonal variations; settlement; strain; stress; three-dimensional models; transient phenomena
Abstract The China-Russia Crude Oil Pipeline (CRCOP) faces significant challenges due to differential frost heaving and thaw settlement resulting from significant variations of oil temperatures along the pipeline. Oil temperature distribution along the pipeline during the long-term operation period is a very important factor in pipeline foundation design under future climate warming and various frozen soil conditions. It is important for the assessment and prediction of differential frost heave and thaw settlement of the pipeline foundations soils, forecasting the development of the seasonal and inter-annual frozen and thawed cylinders around the operating pipeline, stress-strain analysis of the pipeline, and mitigation of subsequent frost hazards. A quasi three-dimensional computational model was developed to predict the oil temperature along the pipeline. It was verified by analytic solutions of the minimum oil temperatures along the route provided by the Daqing Oilfield Engineering (DOE) Co. The oil temperatures were predicted and analyzed for two proposed annual oil flow rates of 15 million tons (0.3 mbpd) and 30 million tons (0.6 mbpd) with and without mitigative measures (only pipe insulation was considered here) during the operation period. Also, the inter-annual variations of oil temperature at key typical locations were investigated to understand the impact of climate warming. The results indicated that the maximum oil temperature cools southwards, but the minimum oil temperature warms southwards (with the inlet oil temperatures from -6 to +10C). However, the average annual oil temperature decreases southwards in the northern part of the pipeline, then it starts to slowly increase. The amplitudes of oil temperature change will decrease southwards. Oil temperatures will slightly increase with elapsing time due to the imposed boundary conditions of climate warming. The oil temperatures with a lower flow rate vary more significantly than that with a higher flow rate because the oil temperature with a low flow rate is more affected by the thermal regime of the surrounding soils and the external environments. Insulation around the pipeline tends to reduce the oil temperature variations along the pipeline during pipeline operation period. Therefore, pipe insulation can effectively reduce the development of frozen and thawed cylinders in the permafrost zone. The phase change of water in soils around the pipeline has a distinct influence on the oil temperature during the freeze-thaw transition periods. The oil temperature tends to be equal to the ambient ground temperature around the pipeline with southward distance and with elapsing operation time. The pipeline oil temperature is controlled by the incoming oil temperature and the surrounding ground temperature before the equalization. It would be mainly controlled by the ground temperature around the pipeline afterwards.
URL http://hdl.handle.net/10.1016/j.coldregions.2009.08.003
Publication Type journal article
Record ID 65006596