NEW CASTLE, OKLAHOMA WATER IMPROVEMENT PROJECT
The city of Newcastle Oklahoma undertook a major water improvement project to accommodate the growing demands on the aging municipal water system. The plans called for a 24” HDPE pipeline to be installed under the Canadian River and connected from the Oklahoma City system to the Newcastle municipal water system thereby increasing the volume of water for the growing population.
The river crossing presented some serious design challenges and concerns over the very sandy soil conditions and the annual flooding of the river. Chisholm Services was chosen to install the pipeline utilizing the Horizontal Directional Drilling method as a solution to the many construction challenges and addressing the many environmental concerns of crossing a major river. The water in the river, trees along the shore and private property all benefited from the utilization of directional drilling on this project.
The project called for the pipeline to cross the river at a depth sufficient to place the line below the “Red Rock Layer” about 60 ft below the surface. This was to protect the line from erosion of the constantly shifting sands of the river. The line was to continue well up the river banks to more stable ground where connections to the water system could be made. This layer of rock proved to be very hard and challenging to bore through, but it eventually gave way to the powerful American Auger 1.1 million pound drilling rig and a persistent crew.
After the pilot hole was drilled the process of reaming out the bore to the required diameter of 36 inches began. During the reaming process, great care must be taken not to collapse the bore. This is where the experience of Daniel Benefield and his crew becomes very evident. Carefully monitoring the pullback force, rig torque and drilling fluid pressures are critical to a successful bore.
When the bore is complete, it is necessary to pull back the pipeline into the bore as soon as possible. This becomes an all night process with a pipeline of this length. The pipe is filled with water during this process to add ballast to the line so it does not float and create pressure on top of the bore. This process adds many thousands of pounds to the already heavy pipe. The pullback force required to pull the pipeline into place was over 200,000 pounds. This is a critical time in the process and the crews of Chisholm Services performed at the highest levels of expertise.