MANER – INTERSECTION TECHNOLOGY
Crossing of the mighty Maner River in India is a part of prestigious Mallavaram Bilwara pipeline project being undertaken by GSPC India Transco Limited (GITL) for the installation of an 18 in (457 mm) diameter pipe from the state of Telangana to Rajasthan state. The main contract was signed between GITL and Kalpataru Power Transmission Limited (KPTL) after due diligence and based on past performance. KPTL on approval from GITL awarded the crossing works job to Trenchless Engineering Services Pvt. Ltd. (TESPL) which was to install the pipeline using HDD methodology.
Detailed geotechnical investigations were carried out and it was found that there were two transition zones to rock, one at 300 m along the bore route and the other at 2,000 m. The rock zones totalled some 400 meters maximum length, while the remainder of the strata along the bore path comprised largely soft soil with a mixture of gravel and sand. The intersect zone for the bores was selected to be located between 1,950 m to 2,000 m along the bore route, just after exiting the rock layer and entering in the softer ground zone. This also meant a good guidance coil could be installed to ensure accuracy for the intersect operation. The guidance system used for the pilot bores was a Paratrack 2.
Subsequent to the installation of the main 18 in (457mm) diameter pipeline a second 6⅝ in (165 mm) diameter pipeline was also to be installed parallel to the main pipeline. The overall length of the respective bore was 2,532.05 m for the 18 in (457 mm) bore and 2,532.27 m for the 6⅝ in (165 mm) diameter bore. Reaming of the respective bore was to 28 in (710 mm) for the 18 in (457 m) diameter bore and 10 in (254 mm) for the 6⅝ in (165 mm) diameter bore.
Given the need for the intersect at ‘mid’ bore, the pilot bore length for the 18 in (457 mm) installation from the rig side was 1,989.20 m, whilst the rig side pilot bore for the 6⅝ in (165 mm) installation was 1,961.31 m. From the pipe side the 18 in (457 mm) installation pilot bore was 546.13 m whilst the 6⅝ in (165 m) installation was 573.87 m. The bores ran at maximum depths of 20.11 m and 19.69 m respectively. The bores were completed using 400 t and 100 t capacity HDD rigs
INTERSECT METHOD
Drilling using the bigger rig was started from one side of the river and once the pilot bore length reached 1,500 m, drilling commenced from the pipe side rig. The boring head assembly had to be changed twice. Initially starting with a jetting head, this was changed to a down-hole motor for boring in the rock layer. It was changed back to a Jetting assembly once clear of the rock. Casing pipe was installed on both sides of the river to contain any frac-outs and drilling fluid returns were processed in an environmentally-friendly way.
After approval of the intersect coordinates and pilot hole from the project owner and TPI, the reaming procedures were carried out. The 18 in (457 mm) pilot hole was opened to a diameter of 28 in (710 mm) and for the 65⁄8 in (165 mm) diameter OFC conduit the ream to a diameter of 10 in (254 mm). The pipe was pulled immediately after the pilot hole was completed. The tooling used for Hole opening operations was fabricated in-house and designed to operate for the complete length of the crossing without having to ‘trip’ it out for the changing of cutters.
Both intersection operations were completed ‘like clockwork’. While the first intersection for 18 in (457 mm) diameter pipe was achieved at 1,989 m into the bore, the second 65⁄8 in (165 mm) pipe intersection was achieved at 1,961 m. It was a defining moment for ‘TEAM TRENCHLESS’ to have successfully executed two such intersections one after another without the use of intersection tools such as Passive Ranging or Rotating Magnets. The intersections were carried out on basis of absolute accuracy provided by the company’s steering engineers and drill crews. This operation is claimed to be the first in India to be completed using in-house design engineering and application capabilities. The total time for the project from start to finish was just 41⁄2 months.
TESPL
Trenchless Engineering Services (P) Ltd (TESPL) is the largest Trenchless Service provider company in India and lays claim to over 2 decades of experience in the field.
As an Industry Leader in Construction Engineering, TESPL currently undertakes projects that span diverse industry segments such as Oil and Gas, Water and Sewer, Power and Telecommunications.
TESPL’s aim ceaselessly pursues a vision to build a better infrastructure through best engineering practices, innovation and dedication on the impact for the nation and the progress of its people. A few of National and International Clients served by TESPL include OPAL India Ltd, Indian Oil Corporation Limited, Oil India Limited, ONGC Ltd. Gujarat State Petronet Ltd, Lanco Infrastructure Ltd, I&LFS in India, INGL of Israel, PetroBangla, Titas Gas Ltd., Gas Transmission Co Ltd of Bangladesh, Fernas – Turkey, Mears Inc. USA, Enikkom Construction, Zakhem in Nigeria, SNC Lavellin in Madagascar, Cherrington Inc. USA and China Petroleum Corporation in Taiwan.
TESPL brings to bear a wealth of engineering and construction expertise to develop infrastructure aimed at further propelling the Indian nation forward, into the 21st century and beyond setting new records and completing challenging projects.
To provide a complete range of services to its clients, TESPL has a qualified taskforce and over 20 Horizontal Drilling Rigs ranging from 30 tons to 500 Tons capacity. Besides HDD, the company also owns and operates Laser Guided Tunnel Boring Machines, Auger Boring Machines for installing casing pipes under roads and railways, Pipe Ramming, Pipe Jacking and Box Pushing systems for Railways and claims to provide a range of ‘Total Trenchless Solutions’.
TESPL is directly employs 400 experts, engineers, skilled and unskilled manpower under the chairmanship of managing director Vipin Gupta who stated: “We are proud of our accomplishments in the Trenchless Industry and in Horizontal Directional Drilling. We are determined to continuously expand our business through latest techniques, high quality services with a complete safe working environment as we are committed for our customer service and support to make sure our client’s success without stress.”