Exploration & Mining Services

Exploration and Mining

Gregg Drilling can conduct specialized geotechnical drilling and Cone Penetration Testing (CPT) to extract samples and gather data from a site for exploration/mining purposes. These samples can be utilized to determine if and/or what type of mineable mineral deposits exist, to assess whether it would be economical to mine, to assist in the management and evaluation of mine tailings or to determine viability of reclamation of a former mine site. The demand for this type of drilling has grown in recent years as new and less expensive mining techniques have made it feasible to mine previously uneconomical sites and the utilization of former mining sites has gained importance.  Our drilling services require a high level of expertise and technical competence because the samples extracted must be free of contamination and accurately reflect the underlying mineral deposit, geology/hydrology and ground conditions.


Gregg has also worked on various seismic, geotechnical and instrumentation projects, drilling all types of ground conditions in all types of locations. Using the latest drilling equipment and technology combined with a wide range of experience spanning many years, we can lend special expertise to projects around the country. Continual research into new drilling techniques and equipment keeps Gregg at the forefront of the industry. Our rigs can be mounted on rubber or steel tracks, or for drill sites in remote or steep locations, we have compact drilling equipment easily transported via helicopter. Gregg also has access to track-mounted amphibious units for work on tailings and soft semi-liquid surfaces.

Specialized amphibious equipment for soft soils and tailings

Specialized testing including downhole vane shear and fast vane

CPT and Seismic CPT

Geotechnical drilling and sampling

Instrumentation installation (VWPs and inclinometers)

Remote operated un-manned CPT for high-risk environments


Gregg’s vast experience drilling throughout the Western US and exceptional safety rating provides the confidence and trust our clients have learned to value.

Gregg constantly strives to maintain one of the highest safety ratings across California. Recently Gold Shovel Certified, Gregg is constantly improving our safety program and equipment to provide our clients the highest quality service available.

Gregg’s employees have some of the most extensive safety training available and are able to work on refineries, military sites, railroads and confined spaces.


Gregg Drilling offers a number of innovative solutions for mine tailings investigations. With safety as a core value of our business operations, our clients are confident in our abilities to accomplish the work in a safe and reliable manner.
Gregg Drilling has completed investigations at mines across the United States involving:
  • Cone Penetration Testing (tracked, amphibious, limited access and truck-mounted options available)
  • Wireline CPT with rotary drilling (increased depth capability past 100m)
  • Vane shear and fast-vane testing for silty materials
  • Sonic drilling and continuous sampling
  • Rotary drilling and sampling

Project news:

We are excited to announce the completion of a 175m CPT at Pinto Valley in Arizona. This was accomplished by combining a surface push CPT to 100m and then switching to our Raptor-CPT wireline method to complete the push to depth.

Mining Experts

Gregg works closely with our Technical Advisor, Dr. Peter K. Robertson, a world leader in stability evaluation of tailings dams. Gregg has completed CPTs and incremental drilling and CPT to extensive depths at mine sites as well as instrumentation installation.

Interested in learning more about the application of CPT or our drilling capabilities? Contact Kelly Cabal to request a introductory meeting or CPT discussion.

Additional Services