A Cone Penetration Test (CPT) also referred to more informally as a Cone Test, is a way to get at subsurface information without having to directly sample the subsurface.

Many organizations that order drilling services are also using CPT within their operations. CPT testing services are a good support option to monitoring well drilling services, since many of the potential customers and skills overlap.

 

What is Cone Penetration Testing - Cone Penetration Testing (CPT) is the practice of using an ASTM standard hardened cone shape that is directly pushed into the ground to substantial depths. The cone is pushed using steel rods that are able to be connected to each other in 1-meter lengths as the depth increases. Powerful hydraulic cylinders (rams) are used to generate a substantial amount of pulldown force to enable the cone to penetrate  soils, sand, clay and sometimes even soft rock.

In order to keep the surface equipment (truck, track or portable platform) in place and not simply be lifted up by the pulldown force, the vehicles that the CPT equipment are mounted on (or in) are typically quite heavy.  Also, the use of (solid stem auger based) anchor systems to the ground will increase the ability of any vehicle mounted CPT system to push harder and therefore deeper.

There are a couple of different imperative goals to any subsurface investigation. The first one is the nature and sequence of strata or soil sediments and other geological subsurface features. Using CPT for this is called geotechnical testing. In addition, the groundwater conditions can be established during a sounding. CPT can be used to determine: the composition, strength and distribution of subsurface soils. These can range from clay, sand, bedrock, groundwater table, hydrocarbons, contaminants and more.

 

Advantages of CPT - There are many different advantages to Cone Penetration Testing (CPT), including, prompt collection and interpretation of field data – this is also up to three times faster than traditional methods (other than roto-sonic), economical, eliminates drill cuttings, environmentally friendly, enhances operational safety, inclement weather operability and adaptive to many different terrains. These are just a few examples of the advantages to CPT, proving its value for testing.

With the CPT business on the rise in the U.S. and developing nations it takes many skills to be a part of this growing industry. Drilling well technologies and CPT hydraulic rams have many similarities but will still require proper operator training for anyone new to the business. Additionally, you will need training on how to provide accurate, simplified information to your clients.