Continuous Circulation
The Non-Stop Driller (NSD) is a sub-based system which enables the continuous circulation of drill fluids down the drill string while making or breaking drill pipe connections. The system has been designed to reduce the cost of drilling by improving drilling efficiency, operational safety, hole condition and reducing non-productive time.


The NSD System is easily integrated into the rig to facilitate:
  • Managing bottom hole pressure
  • Managing ECD
  • Improving hole cleaning and reducing wiper trips
  • Eliminating connection gas
  • Reducing mud conditioning time
  • Improving wellbore stability
  • Reducing temperature of BHA components for HPHT
  • Preventing stuck pipe and lost BHA’s


Non-Stop Driller System has been proven to reduce Non-Productive Time (NPT) by mitigating
  • Stuck pipe incidents and lost BHA’s
  • Extended wellbore conditioning and nuisance gas circulation
  • Casing running problems related to hole condition
  • Excessive bottom hole temperatures and bottom hole Assembly (BHA) heat soak damage
  • Time required to re-establish two-phase circulation for foam/air
  • Cementing and zonal isolation as an FOSV for running/rotating liners to TD and cementing
Underbalanced Drilling (UBD) and Managed Pressure Drilling (MPD) applications
  • Provides seamless integration to UBD/MPD operations, offering unprecedented bottom hole pressure control on connections
  • Improves operational safety by eliminating surface pressure increases during connections
  • Eliminates post-connection stabilization time during multiphase drilling on air, foam and two-phase wells
All NSD units are designed to be shipped in standard CSC shipping containers.
Both ISO corner blocks and offshore specification certification certified lifting pad eyes are provided on all container units.


Over 4500 connections
105 sections drilled over 5 continents
Over 730 days of rig time saved

Murphy Malaysia Kikeh Spar

[14 wells, 28 sections]

Client identified problems with depleted reservoir zones resulting in drilling fluid losses. Relatively unconsolidated and poorly sorted sands present in the field geology. Drilling window narrow due to pore pressure/fracture pressure gradient uncertainties. Client predicted borehole instability, differential sticking, high background gas probability. Managed Pressure Drilling with Continuous Circulation System used to drill with lighter muds (WBM and OBM) and control the ECD/BHP accurately within the drilling window to avoid losses and NPT. Compact footprint of equipment meant this was easily achievable in a limited space environment offshore.

  • Minimised Drilling problems with NSD continuous circulation and MPD ASBP.
  • Prevented stuck pipe by allowing uninterrupted transport of cuttings.
  • Minimize BHP surging on stop start circulation due to gel strength.
  • Reduced ECD variations in narrow formation pressure margin wells.
  • Prevented Wellbore Ballooning and wellbore instability by maintaining CBHP.
  • Zero well control incidents or significant mud losses occurred during drilling or MPC.
  • No differential sticking in depleted sands or stuck pipe occurred during drilling.
  • Able to determine the drilling boundaries with dynamic FITs / LOTs.
  • NSD assist in hole cleaning of high angle wellbores by keeping cuttings in suspension.
  • Prevent settling of cuttings on the low side of the hole.
  • Prevent sliding of cuttings at hole angles < 45deg.

OilSearch PNG

[22 wells, 22 Sections]

Client observed multiple lost BHA’s whilst drilling surface and intermediate sections leading to multiple side tracks. Losses observed up to and including total losses. Foam drilling technologies were identified and utilized however time spent adding surfactants and breaking down the foam before making a connection added 2-3 days to drilling each section. Heli-rig operating in the PNG Highlands so equipment footprint and personnel numbers required to be small and light. Continuous Circulation system was used to eliminate stuck pipe and lost BHA’s through maintaining foam drilling over each connection.

  • Minimised Drilling problems with NSD continuous circulation and eliminated NPT related to breaking down foam over each connection.
  • Eliminated lost BHA’s in top-hole sections and prevented stuck pipe by allowing uninterrupted transport of cuttings with total losses.
  • Small NSD Crew of 2 people to rig up run and maintain the system in a remote location.
  • Heli portable NSD equipment footprint easily transportable between rig sites.
  • Maintained strict zero discharge environmental policy for PNG.
Other international case histories available on request



Case History of using Continuous Circulation with Air/Foam - Improving Operational Efficiencies
- 10 Years of Drilling Optimization

October 2019, IADC Wells Technology 2019 Conference & Exhibition, Kuala Lumpur, Malaysia
Chris Schmikl, Oil Search Limited, Scott Petrie and Rick Doll, Adrilltech
For more information, please contact


Adrilltech featured by The OGM


Adrilltech has been featured by The OGM portal with an article written by our Technical Services Manager, Scott Petrie, describing how to reduce risk while implementing a new technology. Read the full piece here

Adrilltech featured by JPT


Adrilltech has been featured by Journal of Petroleum Technology in the August issue with an article exploring how the Non-Stop Driller continuous circulation system has reduced connection times in harsh-environment projects. Read the full piece here

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Continuous-Circulation Technique Drills Narrow-Margin Deepwater Wells


Ultradeepwater wells are commonly characterized by their narrow margins between pore and fracture gradients. In these wells, even a small variation in pressure profile may lead to severe operational issues. Read the full article from JPT describing the Continuous-Circulation Technique in Deepwater Wells:

MPD and continuous circulation technology overcome deepwater challenges


Wells drilled offshore Sabah, East Malaysia, using conventional open wellbore technology, have experienced well control events and significant NPT. Problems encountered included kicks, stuck pipe, and lost mud circulation. Read the full article from World Oil explaining how MPD and Non-Stop Driller Continuous-Circulation technology was used to overcome Deepwater challenges:


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