The International Information Center for Geotechnical Engineers

The are several factors that need to be taken into account in order to optimize the quality of an undisturbed soil sample.

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According to United States Geological Survey (USGS), Wolfcamp Shale and overlying Bone Spring Formation in the Delaware Basin part of Texas and New Mexico's Permian Basin province contain a vast quantity of continuous oil and natural gas resources.

The Dyck Memorial Bridge, constructed in the Rural Municipality of Clayton approximately 300km east of Saskatoon, collapsed just six hours after its opening.

A series of earthquakes between 2008 and 2010 in the Raton Basin - along the southern Colorado and northern New Mexico border – was likely due to fluids pumped underground during oil and gas wastewater disposal, according to a new study by the University of Colorado Boulder.

According to the U.S. Geological Survey annual forecast on natural and human–induced seismic risk, Oklahoma and Kansas may experience serious ground shaking during 2017 due to the drilling activity of the oil and gas industry.

Thursday, 15 September 2016 07:41

Sonic Drilling

Sonic drilling is a soil penetration technique that strongly reduces friction on the drill string and drill bit due to liquefaction, inertia effects and a temporary reduction of porosity of the soil. The combination makes penetrating a large range of soils easy for Gregg's sonic rigs and tooling.

Why Sonic Drilling?

When drilling with a sonic drill head, the entire drill string is brought to a vibration frequency of up to 150 Hz. This causes a very thin layer of soil particles directly surrounding the drill string and bit to loose structure. Instead of a stiff mass, the soil behaves like a fluid powder or paste. This fluidization, or liquefaction, dramatically reduces friction.

In addition to the liquefaction the soil simply is not able to stick to the drill string, because it is moving up and down some 150 times per second. The vibrations of the drill bit cause the soil to loose structure, changing it to a higher density with a lower porosity. The soil then opens up for the drill string to advance. When you retrieve the drill string after drilling, the suction and some vibration will cause the soil to regain much of its old lower density, and water will be able to flow freely again. Therefore through liquefaction and inertia effects, you are able to collect very long and continuous samples. Due to the vertical high-frequency movement the drill string stays extremely straight, with a diversion of no more than a few centimetres over the full length of the bore hole.

In alluvial material, vertical vibrations are generally enough to drive down a drill string for many meters without the injection of any water or air. When you are drilling in hard formations, liquefaction cannot take place. In such cases you can combine vibration with rotation, and use rock drill bits to cut the material.

Learn more about Sonic Drilling here