June 29, 2011The winter of 2010/2011 is particularly cold all over China. The nationwide apparent gas consumption hits a high of 33.3 billion cu m in the first quarter of 2011, increment of 20.8 percent compared with last year.
Many energy companies have, henceforth, sped up the construction work of gas pipelines. From January to March 2011 alone, there were six Herrenknecht horizontal directional drilling (HDD) rigs deployed for the installation of 8.1 km of gas pipelines.
The construction of the second pipeline of West-East Gas project is in full swing. The second line starts from Khorgas in Xinjiang, southwards to Guangzhou and eastwards to Shanghai. With a combined length of all lines more than 7,000 km, the 2nd Line brings the natural gas from Central Asia to China’s most developed economic zones – the Pearl River Delta and the Yangtze River delta. In first quarter 2011, there are 3 Herrenknecht HDD rigs installing the pipeline.
Herrenknecht H-032 HDD rig had also successfully tackled the difficulties posed in the Xi-Jiang River Crossing project. H-032 started its drill across Xi River of length approxinately 1,600 m and diameter 508 mm on April 30, 2010. After careful consideration in construction period and expenses, project owner, Foshan Natural Gas High-Pressure Pipeline Co., Ltd., decided to work with construction company, Henan Puyang Zhengtong Pipeline Engineering Co., Ltd., which owns the Herrenknecht HK250T HDD rig.
The geological conditions of the Xi River Crossing are complex with gravel strata distributed on both sides of riverbank. The pipeline was installed through 22 strata and 15 different geological soils including rounded gravel, pebble, gravelly sand, as well as cavities. H-032 must carry out a pilot drill to meet the other borehole in the middle. Besides reaming, H-032 must also tackle problems such as different-diameters steel casing pipe installation and gravel extraction. The construction team accomplished their mission after eight months on Jan. 18, 2011. The deepest point of crossing is 43 m under the river bed. Along the boring alignment, the length of steel casing installation reached in total more than 200 m, creating a record length of steel casing installation in China.