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Poland’s First Direct Pipe ® Pipeline Crossing Adapted from Information by Herrenknecht AG Poland reacted to the increasing local demand for gas by constructiing more connections to the north- south pipeline. Part of this network expansion is the Czeszów-Wierzchowice Gas Pipeline Project in the southwestern part of the country. For the first time, main contractor PGNiG Technologies S.A. and drilling contractor PPI Chrobok S.A. opted for the innovative Direct Pipe ® technology from Herrenknecht. This method combines the advantages of microtunnelling and horizontal directional drilling (HDD) technology. In a single step, the required borehole is created and the prefabricated pipe is simultaneously installed without a trench. Prior to this project, only HDD technology was used for crossing rivers or roads during pipeline projects in Poland. The HDD method has proved its worth for large numbers of boreholes, but it can reach technical and economic limitations in certain conditions. The sandy, sticky clay of the pipeline crossings in Wierzchowice and Czeszów presented the drilling crew with just such project conditions. Another issue was the two alignments, with lengths of approximately 2300 and 1500 feet, run along existing gas lines, so uncontrolled deviations during the drilling process had to be avoided at all costs. To solve these technical issues, the Direct Pipe technology was chosen. From the launch pit, the soil is excavated using a slurry-supported Herrenknecht Microtunnelling Machine (AVN). It pumps the excavated material through a slurry circuit inside the prefabricated pipeline, to a separation plant located aboveground. The pipeline, which is laid out on the surface on rollers and welded to the end of the microtunnelling machine, is pushed into the borehole at the same time as excavation takes place. The necessary thrust force is provided by the Herrenknecht Pipe Thruster. It pushes the microtunnelling machine forward together with the pipeline. The push force is transferred to the pipeline through the Pipe Thruster’s clamping unit and then to the machine’s cutterhead. During excavation, the tunnel face can be controlled consistently and safely using slurry-supported tunneling technology. With the Direct Pipe method, the footprint of the equipment at the launch and reception points is small. Therefore, the technology can be implemented even in densely populated residential areas. It is no longer necessary to construct deep shafts, and the microtunnelling machine is recovered in segments of approximately 10 feet in length after excavation is finished. In the final step, the supply and discharge lines are removed from the pipeline. The crossing is complete, and the pipeline has been installed in one single step. Thanks to the gyrocompass navigation system, which allows for an exact steering of the tunnel boring machine, the drilling crew for the Czeszów-Wierzchowice Gas Pipeline Project precisely installed the two pipelines. In doing so, they safely crossed beneath an ecologically sensitive fish pond. The sticky ground which tends to cause blockages was not a barrier for the Direct Pipe method. Even at very high levels of friction resistance, the thrust provided by the Pipe Thruster in the launch shaft was more than enough. Despite the small overcut of only a few centimeters, no damages were detected at the coating after the pipe laying. Overall, a very positive conclusion was drawn after successful completion of the project. Roland Kośka, planning and mon- itoring manager for client GAZ-SYSTEM said, "As a combination of HDD and microtunnelling, Direct Pipe overcomes their respective limitations which, to a large extent, are no longer obstacles to pipeline construction. This will also allow us to pursue new projects in the future and complete them economically, quick- ly, and with minimal impact on the local infrastructure and environment." Editor’s Note: In between our print issues, the WWDR Team prepares an electronic newslet- ter called E-News Flash . Based on readership, this was the most popular E-News Flash article of the month. Get in on the action and subscribe today at: www.worldwidedrillingresource.com The last of two breakthroughs using the Direct Pipe method in Poland. This is an amazing opportunity to network with the best in our industry, and receive the latest education and information to keep you at the top of your business. Get All The Details & Register at www.UtahGroundWater.org January 10 th , 11 th , and 12 th , 2018 at the CasaBlanca Resort & Casino 8 DECEMBER 2017 WorldWide Drilling Resource ®