Installation of 12'' +3'' NB, bundle pulling x 1800 meters under Ganga at Kanpur by Horizontal Directional Drilling.
The main line was laid in the year 2000-01 between Lucknow and Kanpur to take multi products to feed Lucknow. The line passed through Ganga, which at that time was 1300 meters wide and was installed by HDD. Unfortunately, when Ganga changed course in 2008, the main line was exposed and what was the then exit point of the HDD came in the mid-Ganga stream. Eventually the line got snapped in the month of September and fuel supply to Lucknow was disrupted. When attempts to repair the line by conventional method failed, IOCL floated TENDER on nomination basis.
After a very rapid and brief bidding process, Trenchless Engineering Services Pvt. Ltd., a specialist contractor based out of Delhi was selected. A 320 ton rig was selected for the job and mobilized to site in the month of January. While the mobilization process was on, it was decided to carry out additional soil investigations to better understand the geology. The soil was 90% sand and silt with pockets of cemented sand and gravel at a few locations in the profile. Design and Drawings were submitted and got approved by IOCL and pilot hole started on 12th February, 2009. Since the crossing was long and working on fast track project, anticipating problems in pushing the pipe in sand and gravel, another rig was mobilized on the pipeside to help intersect the line to complete the pilot hole. Also, Mud engineering was planned and amongst running polymers to stabilize the hole, two 40 cu.mtr mud mixing and recycling tank were mobilized to prevent “break” in drilling due to mud mixing. 265 meters of casing was also pushed to take care of the radius and to reduce load on the drill pipe. Amongst a few drilling problems like wireline leakage and a major failure of the Hydraulic Pump, the punch out was completed on 18th March. This was achieved without the need to intersect, although the 30 ton rig had drilled a hole of 400 meters from the pipeside. The punch out was picture perfect as it knocked a pre-installed Flag at the 1800 meter mark, resulting in a remark by IOCL’s EIC, Mr. S.P. Pandey, that this was the most accurate drill he had seen or heard in his career for such a long crossing.
Immediately after the punch out, casing was removed and 18 inch ream commenced followed by 24 inch reaming. Highlight of the crossing was that all throughout the drilling/reaming process the returns at the opposite end were maintained. On a borelenght of 1800 meters, returns were received till approx 1650 meters on the pilot hole and likewise on each of the reaming pass, indicating that the condition of the hole was excellent. Swab pass was skipped and the pre-welded line, passing through 3 roads and culverts, pre-placed on over 100 rollers was committed to the pull.
Pulling went on smoothly, with the gage never moving over 22 tons throughout the crossing, the pulling was completed on April 4, 2009 at 8:30 p.m., witnessed by IOCL personnel on site.
Special thanks to Mr. U,K, Pal , GM-IOCL for showing faith in TESPL.
TESPL is proud to have done this crossing with 100% Indian work force, right from Grass root Roughnecks to Mud Specialists, Guidance Specialists and Directional Drillers.