AMC’s SRU™ facilitated the early completion of a civil construction project.

AMC’s client, DM Civil, experienced delays and loss of productivity as a result of highly dispersive clays overloading their system. Large pumps on equipment in the system exacerbated dispersion of clays in the fluid and significant time was lost dumping fluid and cuttings.

Challenge

DM Civil had experienced a decline in their mud properties at the Sewerage Expansion project in Armadale, Western Australia. The project consisted of several Micro Tunnelling shots up to 176 metres at 860mm in diameter, drilled with two metre pipe lengths. Once a new mud system was introduced, the initial two pipes would progress well with good mud properties. During the third and fourth pipes, they would decline significantly with increased viscosity, mud weight, sand content and reduced rate of penetration. Other issues, including the need to evacuate the lines to reduce pressure in the circuit, resulted in substantial downtime.

When the drilling fluid reached a viscosity of 40 seconds, the mud properties worsened significantly as the program progressed. The mud system quickly became inoperable and progress of the project came to an immediate halt.

Results


  • Initial 176m shot completed in record time, 9 days ahead of engineering schedule
  • No further drilling fluid systems were required to be dumped once AMC Equipment was paired with AMC drilling fluid systems
  • Rate of penetration remained high and unimpeded without mud property issues for duration of the shot
  • SRU™ removed between 50 – 100kg‘s highly dispersive clay every 2m product length cut

Solutions

AMC’s experienced equipment specialists and fluid engineers identified the SRU™ would address issues caused by existing equipment, including dispersion caused by large pump rates and minimal de-silting capabilities. Additionally they engineered the system to be run autonomously, adding two Aqua-Plus submersible pumps to transfer fluid from the shaker storage system to the SRU™ and returned once fluid was processed.

The new operational system only required a crew member to remove a wheelbarrow full of cuttings every 15 minutes and and for a member to clean the centrifuge and shaker screens at the end of each shift.

Once the AMC SRU™ was in place, the micro tunnel project progressed well with a consistent level of viscosity and optimal mud weight and sand content levels. No further dumping of fluid was required for the remaining 144m of the project.
The SRU™ is very easy to use and is continuing to pull clay from the system even though the formation has become predominately sandy in nature. We will be keeping the unit for future planned bores.

Drill Rig Operator

Mud Properties Summary
Before SRU™ After SRU™/Dilution + 2.5kg/L AMC CLAY DOCTOR™
Viscosity 36 seconds 40 seconds 31 seconds 32 seconds 32 seconds
SG 1.08 1.1+ 1.02 1.04 1.05
600 16 19 8 10
300 4 6 1 4
PV 12 13 7 6
YP 8 7 6 2
Sand content 2.0% 3.0+% Trace 0.2% 0.25%
Filtrate 10ml 10ml 12ml
Cake 10mm 11mm 2mm

Project Outcome

AMC’s SRU™ facilitated the early completion of the micro tunnelling project with productivity improvements reducing the project by four to seven days, while a further five days saving was gained by eliminating the need to dispose of up to 137,500L of fluid along with treating the same amount of fresh make up fluid in replacement. The AMC SRU™ significantly improved the efficiency of the operations including;

  • No further fluid disposal following the SRU™ setup on-site
  • Significantly reduced disposal costs
  • Closed loop system reduced time spent managing and mixing fluids, allowing personnel to focus on completing the drilling program
  • Improved productivity, resulting in a saving of 4 days for the life of the project
  • Initial 176m shot was completed 9 days ahead of engineering schedule
  • Consistency changes in the clay spoil from the SRU™ improved crews understanding of the formation and torque readings as a result
  • Rate of penetration remained high and unimpeded without mud property issues for duration of the shot
  • SRU™ removed between 50 – 100kg‘s highly dispersive clay every 2m product length cut.
The use of the AMC’s SRU™ was praised highly by the DM Civil crew and will be kept on hire for future use in other planned projects for the company.

For more details on this successful project, contact amc@imdexlimited.com

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AMC’s SRU™ facilitated the early completion of the micro tunnelling project, reducing the project by four to seven days, while a further five days saving was gained by eliminating the need to dispose of up to 137,500L of fluid.