Russia pushes ahead with new pipelines

The start of the construction of an oil export pipeline from Eastern Siberia to the Pacific Ocean marks an important new phase in Russia's policy of diversifying its exports away from Europe. Sales to the former Comecon nations of Eastern Europe have been eroded over the last decade-and-a-half since the countries there have tried to import crude oil from the North Sea and elsewhere, following the collapse of the Soviet economic bloc with its barter system of trade in oil and major commodities. Recently, Western Europeans have expressed concerns about the share of Russian supplies in their energy balances, particularly since the argument between Russia and Ukraine over gas supplies at the beginning of 2006 ( see 'Gas and Power', February 2006 ). Since then, the European Commission has been warning of the danger of the European Union's becoming over-reliant on Russian energy.     

Filling pipelines with liquid cryogenic agent

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 4, pp. 19–21, April, 1989.     

新型密封钢圈在注汽活动管线连接中的应用

在活动管线连接中采用新研制的密封钢圈,可减少密封钢圈直接与管线卡箍接触造成的密封工作面损伤,从而增强密封性能,有效降低管线漏失现象的发生,确保注汽质量。     

Pigging simulation for horizontal gas-condensate pipelines with low-liquid loading

Liquid condensation in natural gas transmission pipelines commonly occurs due to the thermodynamic and hydrodynamic imperatives. Condensation subjects the gas pipeline to two phase transport, which dramatically affects their delivery ability and operational modality and the associated peripheral facilities. It is therefore imperative for the pigging simulation in gas-condensate flowlines to be taken into consideration in their design. Periodic pigging helps keep the pipeline free of liquid, reducing the overall pressure drop, and thereby increasing the pipeline flow efficiency. A new simplified pigging model has been developed for predicting the pigging operation in gas-condensate horizontal pipelines with low liquid-loading, which couples the phase behavior model with the hydro-thermodynamic model. The comparison of the calculating results with those of the two-phase transient computational code OLGA (with a dynamic, one-dimensional, extended two-fluid model), indicates the new pigging model has a good precision and high speed in calculation. The model also contains the capability of pig-tracking and slug-length-increasing model, which can be suitable for engineering design.     

A new hydrate deposition prediction model considering hydrate shedding and decomposition in horizontal gas-dominated pipelines

Hydrate formation and blockage in gas-dominated pipelines has always been an important issue in research of pipeline flow assurance. In this work, a novel hydrate deposition prediction model considering hydrate shedding and decomposition for gas-dominated pipeline is proposed and solved by the finite difference method and iterative technique. Finally, the model has been applied in the existing gas-dominated pipeline experiments. The results show that: (a) the predicted results are in good agreement with the experimental data. (b) when the maximum degree of pipeline blockage reaches the blockage limit, the hydrate layer will shear off, and the layer that has been sheared tends to fall off twice. (c) when the pressure is the same, the higher the negative subcooling (N-subcooling), the faster the hydrate decomposition rate, and when the N-subcooling is similar to the subcooling, the decomposition with the same hydrate volume is faster than the formation. (d) increasing the hydrate shedding amount or increasing the hydrate decomposition rate can be used to deal with hydrate deposition and blockage accidents in natural gas pipelines.     

含轴向缺陷管道的爆破压力计算方法研究

对含轴向缺陷管道的爆破压力做了研究,将几种国际上流行的计算管道爆破压力公式中的流变应力以及鼓胀系数进行重新组合,并将计算结果与试验数据进行比较,得出流变应力是影响爆破压力的主要因素,并且得出在相同的鼓胀系数下,采用BS7910中的流变应力计算结果更接近试验数值。在用NG-18方程评价或计算管道的爆破压力时,采用修正后的ASME B31G准则中的鼓胀系数和BS7910中的流变应力是一种比较理想的结合。     

Predicting corrosion remaining life of underground pipelines with a mechanically-based probabilistic model

A methodology is presented for predicting corrosion remaining life of underground pipelines with a mechanically-based probabilistic model by taking effect of randomness into account in pipeline corrosion. Monte Carlo simulation technique is employed to calculate the remaining life and its cumulative distribution function (CDF). The sensitivity analysis is performed to identify the most important parameters that affect pipeline failure. The results show that the corrosion defect depth and radial corrosion rate are the key factors influencing pipeline failure probability and remaining life. The pipeline remaining life can be prolonged greatly by reducing mean value of corrosion defect depth and radial corrosion rate. CDF is more appropriate to characterize the pipeline failure probability compared to probability density function (PDF) and reliability index.     

Oil Deals to Widen Trade Deficit with Russia

The US$150 billion oil deal between China and Russiawill expand bilateral trade and China‘s huge trade deficitwith Russia, according to Chinese experts. China‘s exportsto Russia may have increased rapidly in recent years but thenation is expected to see its trade deficit with Russia widenfor the foreseeable future.