Geoprobe® 8150LS Makes Deep Wells a Breeze for GFA International

The 8150LS sonic drill rig quickly proved itself to GFA International, Inc., while drilling in complex conditions. 

“By adding the Geoprobe® 8150LS sonic rig to our fleet, GFA offers our clients a complete range of preferred drilling and sampling methods,” said Tom Ortner, GFA’s Executive Vice President.  “We are now able to offer our clients faster drilling rates and better samples at greater depths and in a wider variety of geological conditions than ever before.”

GFA International, Inc., is a Florida based Engineering and Geological consulting organization that provides Environmental, Geotechnical, Construction Materials Testing and Inspections services. 

GFA was recently retained by AECOM to perform a round of deep wells at the Miami Beach Marina and South Pointe Marina in Miami Beach, FL.  

One very important stipulation governing the project was that the Miami Beach Marina site needed to be completed in one week.  

This included one 2 in. monitoring well installed to depths of 40-ft. below ground surface, one 2 in. monitoring well installed to a depth of 100 ft. below ground surface, and one 2 in. monitoring well installed to a depth of 250 ft. below ground surface and back plugged to 190 ft. with 10 in. screen.  

Gamma logging of the 250 ft. well also had to be performed. 

Thanks to the addition of the 8150LS, GFA was able to complete the job on time.  

The South Pointe Marina followed with one 2 in. monitoring well installed to depths of 40 ft. below ground surface and one 2 in. monitoring well installed to a depth of 190 ft. below ground surface.  

GFA completed these wells in just three days using the Geoprobe® Sonic Weighted Wireline technique. 

In addition, GFA was selected by the City of Hollywood, FL, to install four deep salinity observation monitoring wells to 220 ft. in depth in various locations throughout the city. 

The 2 in. wells will be used for monitoring of salt water intrusion along the coast of Florida and aid the USGS and city managers in managing the delicate water resources of the City of Hollywood.

In order to meet the timelines and provide near continuous soil sampling for the project, a geologist-approved rotary sonic drilling technique was selected.  
Project specifications required discriminate interval water sampling of the boring to determine the conductivity and water quality to design the screen interval of the well.  

To accomplish this, GFA used an inflatable packer system designed specifically for the sonic tooling to seal off the water column and pull water samples from specific depth intervals as required by the project geologist.