New Tool Allows Minimizes Impacts From Air Hammers

By Jeff Griffin, Senior Editor | September 2011, Vol. 66 No. 9

Sharewell LP has introduced a new internal shock-absorbing tool that permits the use of an air hammer with a wireline steering tool for horizontal directional drilling projects.

The HST (hydraulic shock tool) is available for rent by Sharewell customers using the company’s MGS wireline steering tool, said Steve Cornwall, Sharewell vice president, HDD services.

“In today’s aggressive drilling environments, downhole sensors and other electronics are subjected to destructive Z-axis shocks and vibrations,” Cornwall said. “The cumulative abuse and wear inflicted by air hammers on downhole electronics has been unsustainable. Such abuse is greatly reduced by the HST.”

Cornwall said the tool replaces the non-magnetic extension bar often used on HDD wireline projects and works similar to a motor vehicle’s shock absorber, hydraulically reducing shock that could impact the steering tool. He said to Sharewell’s knowledge, the HST is unique to the market place.

“HST components,” Cornwall continued, “are manufactured to an exacting standard of the highest quality, low magnetic signature material in order to ride within the non-magnetic drill collar.”

Field tests
He said the HST tools have been used successfully in the oilfield for more than eight years. Sharewell's MWD (measurements while drilling) Division started using it on oilfield jobs more than a year ago.

“During that time,” said Cornwall, “the HDD division entered into discussions with Thru-Tubing Rentals, the designer and manufacturer of the HST system. We thought it would have an application in the HDD industry in mud motor wireline jobs and possibly with air hammer jobs. The test results proved successful far beyond our expectations.

Therefore, Sharewell has agreed to an exclusive, long-term contract for the HDD industry with Thru-Tubing Rentals.”

A recent project in Pennsylvania illustrates the capabilities of the HST system. Directed Technologies Drilling, Port Orchard, WA, had a challenging project to make a 1,100-foot line shot under Black Moshannon Creek in central Pennsylvania to install a 6 5/8-inch, steel-reinforced HDPE gas line. The creek is a high-quality trout stream and is surrounded by wetlands. The environmentally-sensitive area dictated the use of directional drilling, and hard limestone required the use of an air hammer. Because of the 60-foot required depth, wireline steering was used. The specified route of the pilot bore had an exit point 120 feet above the entry level and included a 54-degree right-hand turn.

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