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Pressure Grout your DI Logged Borehole During Tool Retraction

The Direct Image® (DI) Grout Sub (222346) will attach to any 2.25 in. DI tool string and allow you to easily pressure grout your borehole from bottom up.


DI Pressure Grout Sub Overview


When mapping through high-level contamination or penetrating confining units, contaminants can move down the borehole spreading the plume if they are not properly sealed. Being able to grout your DI logged borehole immediately after logging ensures that the actual borehole gets completely sealed, eliminates vertical transport of contaminants, and avoids grout bridging. Using the DI grout sub will save project time and money by eliminating the need to re-drill borehole solely to grout which may even require additional rigs to complete. Geoprobe® has successfully post-log grouted numerous DI logged boreholes utilizing both bentonite and neat cement grouts including in areas where pressurized natural gas zones over 100 ft. deep would have blown out the hole if the DI tools needed to be removed to redrive grouting tools. By immediately grouting with the inline grout sub blow outs were avoided and time was saved.

The DI Grout Sub is inserted above the connection tube on any 2.25 in. Direct Image® tool string. The Grout Sub utilizes a separate grout line eliminating much of mess and cleanup usually associated with grouting. Its three-winged design creates pathways for the grout to flow down and around the probe on retraction so you can be assured grout flows to the bottom of the hole.


Pressure grout with the 2.25in Grout Sub


  • The 2.25in grout sub is placed above the DI connection tube and below the HPT-GWS water seal drive head.
  • The designated grout line is threaded through all 2.25in rods along with the specific DI trunkline.
  • The grout tube is fixed with band clamps to the grout tube end assembly which is placed through the hex grout seal and is positioned between the grout sub and the HPT-GWS water seal drive head.
  • The operator will attach the designated grout line to a GP300 or GP350 grout machine at the surface.
  • Prior to Direct Image log the grout line is charged with water removing all air from the line.
  • A rubber plug is pressed into the grout port and held in place with a stainless steel tab.
  • The Direct Image log can now be advanced as outlined in the specific tool SOP.
  • Once the log is complete and has reached the targeted depth the probe is retracted approximately 1 ft. to bend back the stainless steel tab.
  • Water is then pumped to dislodge the grout plug (using a pressure gauge on the grout pump hydraulic line makes it is easy to determine when this happens). The rubber plug and stainless steel tab are expendable components for each boring. 
  • Grout can now be added to the pump and pumped down hole through the grout line.
  • Make sure to initially pump enough grout to fill fill the grout line and have it exit the grout injection port.
  • Now the rods can be slowly retracted injecting grout as the rods are being retracted and shut off during rod removal.

Features & Options


When mapping through high-level contamination or penetrating confining units, contaminants can move down the borehole spreading the plume if they are not properly sealed. Being able to grout your DI logged borehole immediately after logging ensures that the actual borehole gets completely sealed, eliminates vertical transport of contaminants, and avoids grout bridging. Using the DI grout sub will save project time and money by eliminating the need to re-drill borehole solely to grout which may even require additional rigs to complete. Geoprobe® has successfully post-log grouted numerous DI logged boreholes utilizing both bentonite and neat cement grouts including in areas where pressurized natural gas zones over 100 ft. deep would have blown out the hole if the DI tools needed to be removed to redrive grouting tools. By immediately grouting with the inline grout sub blow outs were avoided and time was saved.

The DI Grout Sub is inserted above the connection tube on any 2.25 in. Direct Image® tool string. The Grout Sub utilizes a separate grout line eliminating much of mess and cleanup usually associated with grouting. Its three-winged design creates pathways for the grout to flow down and around the probe on retraction so you can be assured grout flows to the bottom of the hole.

  • The 2.25in grout sub is placed above the DI connection tube and below the HPT-GWS water seal drive head.
  • The designated grout line is threaded through all 2.25in rods along with the specific DI trunkline.
  • The grout tube is fixed with band clamps to the grout tube end assembly which is placed through the hex grout seal and is positioned between the grout sub and the HPT-GWS water seal drive head.
  • The operator will attach the designated grout line to a GP300 or GP350 grout machine at the surface.
  • Prior to Direct Image log the grout line is charged with water removing all air from the line.
  • A rubber plug is pressed into the grout port and held in place with a stainless steel tab.
  • The Direct Image log can now be advanced as outlined in the specific tool SOP.
  • Once the log is complete and has reached the targeted depth the probe is retracted approximately 1 ft. to bend back the stainless steel tab.
  • Water is then pumped to dislodge the grout plug (using a pressure gauge on the grout pump hydraulic line makes it is easy to determine when this happens). The rubber plug and stainless steel tab are expendable components for each boring. 
  • Grout can now be added to the pump and pumped down hole through the grout line.
  • Make sure to initially pump enough grout to fill fill the grout line and have it exit the grout injection port.
  • Now the rods can be slowly retracted injecting grout as the rods are being retracted and shut off during rod removal.

Depend on Team Geoprobe®

Since 1987, Geoprobe® has manufactured innovative drilling rigs and tooling - engineered for efficiency and safety - simplifying drillers’ jobs and empowering their companies to succeed as productive and profitable leaders in the industry. When you partner with Geoprobe® you receive:

Customer-inspired Innovation

Engineering and building industry-leading drilling rigs, tooling, and techniques for the technical driller based on your needs to work safer and more efficiently.

Exceptional Value

Ensuring drilling rigs and tooling are created in conjunction – with consistent quality – to collect the highest-quality information with the most accurate result to get you to, into, and through the job efficiently.

Superior Service

Equipping you to do your best job and keeping you in the field via one-on-one expert sales and service technicians manning live support phone lines, shipping necessary parts same-day.