Reelwell Drilling Method
RDM employs revolutionary technology that utilizes accurate pressure management and superior well control through the use of closed loop fluid circulation. RDM pushes the limits of what was previously thought possible by the wider drilling industry.
Using a Dual Drill String, with a separate inner pipe for the return fluid from the well, RDM provides excellent hole cleaning, enabling drilling beyond the conventional limitations and increasing the overall efficiency of drilling operations.
Accessing reservoirs previously considered to be extremely
challenging or impossible to access.
RDM in action
In 2018, together with OMV and Halliburton, Reelwell demonstrated the RDM system and completed the largest drilling project in 20 years at Ullrigg, at the NORCE Research Centre in Stavanger.
The project was set up to demonstrate the potential for the RDM technology and to effectively drill the shallow Wisting field reservoirs whilst minimizing risk.
As future wells in the Wisting field in the Barents Sea are only about 250 m below the seabed, the demo consisted of drilling at a very high dog leg build up rate to penetrate the shallow reservoir and circulate at a low flow rate. The low flat rate was essential to reduce the equivalent circulating density downhole: avoiding formation damage and to get the most production from the Wisting field.
Common drilling methods may not be applicable because they create too high pressures downhole, but RDM provides a solution. Dag Helge Breivik, drilling manager OMV Norway, told Teknisk Ukeblad, "This technology makes it possible to drill with a significantly lower fluid flow and with lower mechanically transmitted forces than conventional drilling."
"This technology makes it possible to drill with a significantly lower fluid flow and with lower mechanically transmitted forces than conventional drilling."
Pushing the limits of ERD
Extended Reach Drilling (ERD) is directional drilling of very long horizontal wells enabling access to larger areas from one surface drilling location.
This approach maximizes productivity and drainage capability as well as supports production from remote locations to avoid environmental damage or hazards.
By removing the drill cuttings from the wellbore just above the BHA, and transporting them back to the surface via the inner string, the RDM provides superior hole cleaning.
In addition, accurate pressure control enables drilling within a narrow pressure window by avoiding dynamic pressure gradients in the open hole section and the maintaining pressure margins at long horizontal reach.
“With RDM, the current challenges in ERD are overcome."
Improving downhole pressure control
Managed Gradient Drilling (MGD) differs from conventional Managed Pressure Drilling (MPD) by the near static downhole pressure gradient.
MGD enables increased casing setting depth for wells with narrow pressure margins, lost circulation- and hole cleaning challenges.
Finally, RDM’s unique, patented, Heavy Over Light solutions significantly reduces the torque and drag of the drill string to maintain drill string buoyancy.
RDM avoids troublesome cuttings accumulations in the well through its superior hole cleaning capability, even at low flow. By transporting the cuttings rapidly to the surface, it provides improved capability for formation evaluation, and contamination of the mud as mixing and grinding of cuttings is avoided.
The risk of an unstable hole is addressed by the near static gradient in the well annulus, which improves stability and avoids washouts. Since the near static gradient is determined by fluid in well annulus, it provides a constant bottom hole pressure during pump start / stop, important for narrow pressure windows or long sections.
RDM can reduce the fluid loss in depleted formations by a constant pressure gradient and low flow.