May 2021 Vol. 76 No.5
Features
Warrior’s New Tool Sets Pipe Extraction Record
For some time, pipe or pipeline removal and extraction has become a common occurrence. Either because of pipe failure or environmental changes, pipe extraction is more prevalent today.
Extraction or removal is expensive, and the possibility of incomplete removal is always present. Paying attention to this problem, Warrior Field Services (WFS), Lufkin, Texas, set out to improve the pipe extraction process.
WFS has developed a pipe extraction tool that can safely remove pipe sections installed traditionally or using horizontal directional drill (HDD). This patent-pending process is non-destructive, does not require excavation or dredging, and requires no divers or barge work in maritime conditions. That means it’s safer for workers, and protects the environment and surrounding infrastructure, as well.
Extraction process
On Oct. 5, 2020, a contractor for a major pipeline company drilled 3,300 feet of 12-inch, 0.375 wall pipe under a residential area at a depth of almost 200 feet. This drill was part of a multi-mile new pipeline project to transfer ethane.
Upon completion in late January, the entire system was pressured up for a final hydrotest. During this test, the pressure inexplicitly dropped. After looking for leaks, the test was restarted and failed again. Soon it was determined that a leak was present somewhere in the 3,300-foot HDD section.
The original installer of the HDD section was remobilized to extract the pipe, but the effort failed. The pipeline company’s engineering team determined that only 500,000 pounds of force could be generated during the extraction, which clearly wasn’t enough. With the cause of the leak undetermined, the idea of using a pneumatic hammer to assist in the extraction was rejected. Engineering did not want to take a chance of damaging the pipe in the extraction efforts, since they were not able to determine the exact cause of failure.
In early February 2021, the owner inquired about WFS’ process of non-destructive pipe extraction and gave the Luftkin company the opportunity to apply it to the HDD section. As soon as WFS mobilized, it advanced the extraction tool downhole 900 feet on the east side of the HDD drill, and then removed the tool to clean the hole of cuttings.
During this time, the massive winter storm hit Texas, causing widespread power and water outages. Because of this unprecedented weather, all parties involved determined the working conditions were unsafe and, therefore, suspended the project for three days.
Curveball
After resuming work, WFS began resending the extraction tool downhole. After only 500 feet, the tool encountered resistance and forward progress halted. While trying to determine why the advance was stopped short of the 900 feet that had been obtained only a few days earlier, WFS discovered a major problem had since occurred.
When the work was paused, the pipeline contractor installed a pull-head on the HDD pipe for WFS’s extraction efforts. Unfortunately, a set of line-up clamps were inadvertently left on the pipe. During the winter storm, the bell hole at the east side had filled with melted snow and rain, which hid the line-up clamps from view.
In turn, when WFS began the readvancement downhole, the line-up clamps were carried 500-feet downhole until they lodged in the formation. This obviously halted all extraction efforts from the east side. With this downhole obstruction, WFS was unsure about the ability to proceed.
Plan B
The line-up clamps had to be removed from the hole. Drilling a new hole and abandoning the current path and pipe was impossible due to ROW constraints. After some discussions, WFS removed its extraction tool from the east side and installed it on the west side.
As it began advancing the tool, WFS stopped at various times to bottom up the hole and clean the cuttings out. At 2,800-feet downhole from the west, the driller reported that he had hit the line-up clamps. WFS then slowly advanced its tool toward the east, and pushed the clamps back and off the pipe, saving the hole.
After the extraction tool was advanced the entire 3,300-foot length of the HDD bore, WFS connected the pipe to the drilling rig on the west side. According to the original driller’s log, the HDD was installed at a maximum pullback of 140,000 pounds five months earlier. Since pipe had been in the ground for so long, it was uncertain what force would be required to move this section.
To everyone’s surprise, at only 75,000 pounds of force, the pipe started to move. At this point, WFS moved the HDD rig out of the way, and turned the pipe over to the pipeline contractor. The contractor hooked a dozer to the pipe, and 10 minutes later, the entire HDD pipe section was once again above ground.
CCI Inspection was hired to oversee the HDD inspection on this project. After the pipe was removed, CCI informed WFS that its efforts had resulted in setting a world record for pipe extraction. No other pipe or HDD section of this length or depth has ever been removed without the use of excavation, destructive methods or a pneumatic hammer. WFS removed the section without these – and entirely intact.
FOR MORE INFORMATION:
Warrior Field Services, (936) 632-5552, warriorfsllc.com
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