Rigonomics: Steering Tools Continue To Lead HDD Revolution

By Jeff Griffin, Senior Editor | September 2010 Vol. 65 No. 9
A Horizontal Technologies probe is readied.

John English, president of Horizontal Technology Inc., believes misinformation about available steering tools is a by-product of the rapid growth of the HDD industry.

“In order to compare steering systems and select the right one for a job, it is necessary to ask questions,” he said. “Any magnetic steering system is comprised of four components: the steering tool, guidance software, secondary verification system and the guidance technician, who will set up and operate the first three.”

Owners and contractors must select the equipment best suited for each project.

Growth driver
English said the growth of HDD is directly related to the development of a secondary (tracking) verification system.

“The advent of surface tracking allowed HDD to move into more congested areas where the vast majority of construction takes place,” said English. “This is accomplished by creating a precise magnetic field on the surface and using the algorithms of the steering software to locate the steering tool’s position below the artificial magnetic field. The more precise the surface set up and the higher the intensity of the field the more accurate the readings. The most accurate system requires the use of a DC current through a surface wire precisely placed along each side of the drill path. Whichever steering tool or software system is used, the DC surface tracking system is the most flexible and accurate.”

English emphasized that perhaps the most important component of a magnetic steering tool system is its operator.

“There is no alternative for training and experience,” he said.

Jim Cloud Jr., president of Slimdril International, said gyroscopic guidance tool systems (GST) are an option to magnetometer wireline systems. GST systems use highly-accurate gyroscopic sensors to establish measurements relative to the earth’s true north and are not affected by natural or man-made magnetic anomalies,

“Gyro systems have been in use for many years, but most applications have been to locate existing pipelines,” said Cloud. “Slimdril introduced the HDD gyro steering tool to the United States and currently is the only company in the industry offering this technology.”

Cloud said an important benefit of GST steering equipment is the stability of sensors during drilling and rotating, providing highly-accurate (plus or minus 0.04 degrees) measurements relative to the earth’s true north and are unaffected by magnetic anomalies.

“I believe,” said Cloud, “we will see HDD projects that were not feasible or possible prior to recent steering tool advances.”